Model Boat Mayhem - Forum

Dry Dock / Shipyard: Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: Mad_Mike on April 09, 2013, 01:33:52 AM

Title: Fast electric deep vee monohull build
Post by: Mad_Mike on April 09, 2013, 01:33:52 AM
I have recently acquired some plans for a deep vee monohull from an on-line friend in the US who runs the website
http://www.building-model-boats.com/ (http://www.building-model-boats.com/)
I approached him with a request to slightly change some allready available plans but in the end it was decided that the best option and a win win outcome for both of us would be to start again. I get a free plan and he gets some new material to retail on his model boat plans website.
Here goes:
I started by getting the plans printed whole on a1 sheets of paper, as you can imagine this saved a lot of time and alignment problems rummaging through a jigsaw of a4 printouts. The template shapes were roughly cut out of the paper and stuck down and backed to piece of thin card. Experience has taught me to use Prittstick to do this as pva glue makes the templates crinkle and shrivel during drying.
 
 
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 09, 2013, 01:42:10 AM
I cut the shapes out and drew round them on 1.5mm birch ply. I try to waste as little space as possibly when positioning the templates, especially for smaller parts as they can fit into the gaps amongst the larger sections. So far i have cut out the chine shelf, this part will have the bulkheads and formers fixed to it. Ill update after i made some more progress.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 08:34:28 AM
For some reason ive gone threw neary a dozen blades building this boat, ive never had this issue before. Ive changed my cutting board and its harder than my last one, i think its that. Anyway these are all the parts for the frame cut out.
Title: Re: Fast electric deep vee monohull build
Post by: Tug-Kenny on April 12, 2013, 10:13:11 AM

Have you tried the modeller's cutting mat ?


Ken

Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 12, 2013, 12:29:01 PM
Looks good Mike what size is she,whats the plan as regards powerplant etc.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 09:56:54 PM
Looks good Mike what size is she,whats the plan as regards powerplant etc.
Mart
she is 700mm bow to transom. Im planning on using a 2700 kv 3650 inrunner on 4s. Props im not sure. I have a 4mm stinger and im thinking of using 40mm props but ideally i would like to use an octura x440. I can buy the prop but i do not have the expertise or equipment to balance and sharpen it. Prestwich use to but no longer do this service. Until i can find a ready made one im stuck with plastic gear.
Have you tried the modeller's cutting mat ?


Ken
no i havent got one. Im using the side of a wardrboe to save the dining room table but my older one was the back of the wardrobe which was a bit freindlier in my knives.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 10:04:13 PM
The progress of my thread is misleading as the progress on my boat is far beyond what is written. I tried to upload earlier several times but i was getting issues.
After the peices were cut the first sections were glued togeather. The deck stringers were first fixed along the length and reinforced and joints with blocks. In any build ive done these first fixing are allways tricky and need a bit verbal persuasion. Shouting and swearing at it helped enormously, plus a little bit of epoxy. A right mess but wont be seen so who cares.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 10:11:08 PM
The forward deck stringer and bulkheads were fitted next. All joints and angles are reinforced with a block.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 10:21:09 PM
My original intention was to use a solid propshaft for the surface peircing. I have used these before and had success with them, they are cheaper than flex shafts and eaiser to maintain, there downside is they can be quite noisy, even if the couplings are perfectly aligned a slight bit of off balance on the prop and the the sound can be defening. With this original intention i requested that the access hatch on the boat be massive to allow the motor to be postioned way forward and for easy maintenance access. Since im now using a shorter flex drive ive downsized the hatch to increase rigidity. The front and rear edges of the hatch have been edged with 2 batons whihc are screwed from the sides through the deck stringers.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 10:30:28 PM
The last picture of the batons shows the screws slightly out, this is because one of the screws i had started to split the wood. Its only a temporary fix until the glues have fully gone off, the deck on top will further reinforce these batons.
I next started on the chine sides. The plans have the side, top and bottom skins allready pre shaped, it is a simple case of copying them to the ply and cutting them out. The use of the chine shelf and deck stringers keeps the frame and formers rigid and square during construction. As a result the pre shaped chines fit almostly perfectly, laser cutted parts would fit like a jig saw puzzle. Upon fixing they are also reinforced with block along the seems. I went belt and braces at the corners with some epoxy. 
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 10:33:38 PM
The bottoms were then cut out after the edges off the hull were smartened up a bit, they are also preshaped on the plan. They were also attached. Lots of tape was used to hold it down while it dried.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 12, 2013, 11:21:48 PM
The second bottom skin was fixed and the edges were smartened up. I reinforced the inside seams between the chines and bottom with 2 blocks running along the inside of the hull. The deck went on next, the boat by this stages wasnt quite exact to plan and the pre shaped template was slightly to small. I simply laid the hull deck down on the ply and drew around it, using the original template, i roughly marked out the hole for the access hatch. Once the glue had gone off, the central section of the bulkheads were then cut out. The edges of the hatch still need trimming flush. I reinforced the joint between the two skins in the bottom of the hull. I laid a strip of ply long the length of the seam and fixed it with epoxy. The first application of epoxy didnt go off properly and had to be scraped off and some new reapplied. This has left that joint a little untidy, but with the motor and propshaft going down the centre aswell im hoping it wont be too noticeable.
 
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on April 13, 2013, 09:31:57 PM
Hi Mike,

Your build is coming along nicely!

Regarding your propulsion plans; with 2700Kv on 4S you'll have close to 40.000 rpm unloaded, a 40 mm prop will be on the edge, as I can tell from experience, unless the pitch is lower than 1,4.

Also, as you'll no doubt know, your runs will be extremely short, as a plastic prop, even the Graupner K-series, will shed it's blades within feet as soon as the boat jumps a small wave when running full throttle...

I couldn't run anything bigger than a 31 mm metalprop on my 25" stepped hull with a 3660 2700Kv motor on 4S, I fried an ESC on the first testrun with a 40 mm Graupner prop, because I couldn't get beyond half throttle without flipping the boat... (violently).

As the boat had a floodchamber, I kept trying to get the boat to run full throttle, only to flip is again and again, until the ESC decided it had had enough.

As your boat doesn't seem to have a floodchamber (yet), you won't fry the ESC, as either, you'll have flipped the boat after a few feet, or the prop will be bladeless...

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 13, 2013, 09:54:56 PM
you would have thought so but the motor and graupner 40mm prop are from my catamaran and ive allready had it running. Ive just shelved the cat because the strut angle needs messing about with and i dont know enough about cats or there planing characteristics to make the right adjustments.  Intially i had a 2000kv outrunner on 5s with the cat, 40mm graupner it went well but it had overheating issues. So i swapped for this 2700kv inrunner on 4s same prop, it went slower not sure why {:-{ , despite the fact it had a higher unloaded rpm. This is the motor:
http://www.giantshark.co.uk/bl3650-2700kv-watercooled-inrunner-motor-p-404993.html (http://www.giantshark.co.uk/bl3650-2700kv-watercooled-inrunner-motor-p-404993.html)
I understand these hulls better than cats so i can make better adjustments. What throws me is that a 2845 3600kv motor on 3s will turn a 37.5k series no problem and barely get warm, so i would have thought that a 3650 2700kv motor would easy spin a 40mm prop, i just cant fathom why it went slower.
This boat wont have a flood chamber as is not incoperated into the design. Although i think with some rethinking it could be on the plan for the future. 
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 13, 2013, 11:04:53 PM
Looking good Mike,as regards props i can get nice cnc alloy props in dif sizes ive just installed these two on a build im doing using twin 4074 1050 kv motors on 6s,these are 42 mm, probs on the small side but i also have a few bigger ones to try.If you need any let me know and ill get you a price from my suppliers.
Been installing a carbon sub frame inside to put all the parts on came out great,made the carbon plate myself.
Mart
 
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 14, 2013, 01:13:04 AM
some pretty meaty motors in there. What esc's are those?
Ill likely chase you up on that offer of propellers at a later date, see how funds are. thanks  :-))
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 14, 2013, 09:18:28 AM
Yea i had these left over so thought id use them ,im a  dealer of the new sss motors from China i just didnt have any this size smallest i had was 4092 versions and im saving those for a bigger hull probably a cat.Also going to be starting a 58 Apache with the big 5694 versions soon  :} .
These esc are only cheap HK ones,they should work as a friends used them in his Apache on 6s with good results so ill try them,any problems ill change them for something better, t 180,s  maybe when i get more in.
No worries about the props ill email you a list of what props i can get and prices if you wish, props come really sharp and balanced.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on April 14, 2013, 11:24:54 AM
Intially i had a 2000kv outrunner on 5s with the cat, 40mm graupner it went well but it had overheating issues. So i swapped for this 2700kv inrunner on 4s same prop, it went slower not sure why {:-{ , despite the fact it had a higher unloaded rpm. This is the motor:
http://www.giantshark.co.uk/bl3650-2700kv-watercooled-inrunner-motor-p-404993.html (http://www.giantshark.co.uk/bl3650-2700kv-watercooled-inrunner-motor-p-404993.html)
Hi Mike,

A lot depends on the setup being spot on, but I suspect the multipole outrunner has more torque over the two pole in runner, causing it to bog down under load.

When the outrunner is used without a watercooled mount, heatbuild up can be an issue.
I have all my outrunners on a watercooled mount and when I prop them right, nothing overheats.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 14, 2013, 11:24:39 PM
the motor i had was in it was a venom v500 2000kv outrunner, here is one though this isnt where i purchased it:
http://www.rchobbyexplosion.com/Venom_V500_Marine_Brushless_Outrunner_2000Kv_p/ven1366.htm (http://www.rchobbyexplosion.com/Venom_V500_Marine_Brushless_Outrunner_2000Kv_p/ven1366.htm)
I ran it on 4s at first and the temps were fine but a bit slow, upping to 5s and i got the speed but the overheating problems came aswell. Various sources claim that the motor can run on 5s, whereas some such as the one above say 4s. The outrunner has a fan on the end which draws air through the motor, i used a water cooled motor mount and even modified the motor to allow the air to flow through the can easier. Even with all this it still got hot.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 15, 2013, 01:36:24 AM
ive made some progress on the hatch. I designed my hatch so that it sits on a rubber seal. When the hatch lid in on it will press against this seal to keep the water out. The seal will be mounted around the inner edge of the hatch on a rebate and then the lid will be held down with rc car body clips through posts.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 15, 2013, 02:14:24 AM
I think ive made a mistake and mounted my offset propshaft on the wrong side. Ive just read here that it should be on the right. I thought the offset prevent the torque roll it seems that is just recorrects the turning right affects off the torque roll by making the boat steer left.
http://www.fastelectrics.net/prop_effects.php (http://www.fastelectrics.net/prop_effects.php)
Also i think the propshaft is too high now ive moved it over. what do you people think. its 4mm higher from the bottom off the hull.
I shouldve just put it in the centre,
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 15, 2013, 08:23:29 AM
Hi Mike yes wrong side,main reason we put them on the right is to correct prop walk,when the props spinning it makes the transom want to walk left which makes the boat veer right,having the prop slightly over on the right counter acts that a little.Best thing to overcome prop walk is to have a nice sharp balanced prop.If i were you id move it over to the right,just cover the hole you have with some thin ply on the inside and fill the outer with some body filler then redrill your hole to the other side.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 15, 2013, 08:57:04 AM
pants better get the sandpaper out. :((
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on April 15, 2013, 10:46:47 AM
Hi Mike,

If you don't fancy moving the strut to the right, there's always the option to go clockwise...
Downside to that would be the purchase of a counter rotating flexshaft and having a lot less choice in props.

I'd move the strut.

I wouldn't rely too much om foam to keep the hatch watertight, specially when you motorize sufficiently to enable a flip at high speed...
The only way I managed to get a foam edge to really seal the hull was by pressing it down with six screws.

If you paint the deck with something that will stand up to tape, you can always tape it shut.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 15, 2013, 12:09:27 PM
Yea ill second what Jan said about the hatch id stick with tape forgive the Pun lol.If you dont want to move the stinger you could spin the prop the oposite way like he said ,what size flex are you using as i do have some 3/16 reverse ones here should you decide to go that route.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on April 15, 2013, 02:29:00 PM
Hi Mike,

Should you do for a reversed set up, keep in mind that cornering left will be much smoother than right, due to the propwalk in the other direction.
If you're going to run with buddies with 'normal' propwalk, you'll be at a disadvantage when the track is counterclockwise...

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 16, 2013, 01:52:33 AM
I have moved the stinger now and repositioned it centrally. Im not racing anyone so course direction isnt an issue. Im using a 4mm flex shaft. If need to change props to imperial sizes ill use a prop adapter. The seal isnt foam, its a window and door rubber 'P' seal that has a sticky back to it.
http://www.astrodraft.com/astro_glazing_seals.html (http://www.astrodraft.com/astro_glazing_seals.html)
I compress the seal down with the hatch lid, then pins hold it down and in place, it worked very well on the cat and im confident about it on this hull too. I dont mind hatch tape but it pulls the paint off my other boats and its awkward on a windy day to cut from the roll. If i should have problems with it ill revert back to tape :-))
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 16, 2013, 09:16:47 AM
A good tape ive used before was 3m magic tape it doesnt bring off the paint or leave residue.I used it on my radio boxe lids for a while before i got screw down lids never had it come off even in a 60 mph summersault and 4 back flips lol.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on April 16, 2013, 11:18:26 AM
I have moved the stinger now and repositioned it centrally. I'm not racing anyone so course direction isn't an issue.
Hi Mike,

You'll experience the wisdom of that decision as soon as the boatspeed approaches 40 mph.

As you'll have to steer left continuously to run straight, the rudderblade will start to act as a lever when the speed goes up, pushing the left side into the water while lifting the right rear.
Expect some violent flips and (depending on the speed) severe handling issues.

You can effectively skip the first word of the topic title, or add 'looking' between the first and second word.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 16, 2013, 11:47:59 PM
Hi Mike,

You'll experience the wisdom of that decision as soon as the boatspeed approaches 40 mph.

As you'll have to steer left continuously to run straight, the rudderblade will start to act as a lever when the speed goes up, pushing the left side into the water while lifting the right rear.
Expect some violent flips and (depending on the speed) severe handling issues.

You can effectively skip the first word of the topic title, or add 'looking' between the first and second word.

Regards, Jan.
I am aware and expect there maybe issues with my boat and set up. I decided on going centrally with my stinger as it is the lowest point in the hull, the lowest point being if I'm not mistaken the optimum position to keep the stinger parrel to the waterline for most effective operation. If i had offset the stinger the dead rise angle would have resulted in the stinger being raised on the transom as a consequence. I'm not sure of the effects that this raising will do to the surface drive operation and therefore played it safe by going with something i personally know works with a reasonably positive outcome.

Are there not others with pro effective centrally mounted stingers or am I an exception and consequently doomed to failure?

As regards to the title of my thread. I'm not looking to build a racing boat nor compete in tournaments. Ill be satisfied with speeds up to 40mph, excess of that will be a bonus. The goal of this project is purely for entertainment and the opinionated negative judgment on its performances will remain irrelevant to that cause.
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 17, 2013, 07:56:39 AM
Mounting the stinger as low as possible is not allways the best position on all monos .Having it set a little higher has two benefits one been it makes it easier for your motor to spool up the prop but to me the biggest advantage is it settles the transom a little deeper and allows the boat to run smoother rather than skipping arround especially in the turns.Im more used to running larger boats and this is def the case with those take my Apaches for instance the stinger is usually set so its arround 5/16 -1/2" up from the vee .To me personally having it as low as possible will in itself cause some handling issues.I def think offsetting the prop especially on smaller hulls is the way to go.
Mart
Heres an Apache a friends building this shows how high we put them and the offset
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 17, 2013, 08:29:48 AM
ok ill offset the prop to right. I have removed the prop tube without causing too much damage to the hull.
So how much offset from centre do i need? 3mm?
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 17, 2013, 09:20:27 AM
ok ill offset the prop to right. I have removed the prop tube without causing too much damage to the hull.
So how much offset from centre do i need? 3mm?
Further research has lead to me this thread and another of jans posts.  Ill position it 4-5mm to right.
http://www.rcgroups.com/forums/showthread.php?t=1656789 (http://www.rcgroups.com/forums/showthread.php?t=1656789)
I better do as im told  :((
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 17, 2013, 09:27:36 AM
Hi Mike please dont think were telling you what to do im sure Jan is the same as me and is just trying to offer you advice based on our own experiences and what we have learned over the years  :} .
You wont regret offsetting the drive,also what i personally like to do is make the hole into a slot up and down this allows me the option of been able to raise or lower the drive a little if need be by also slotting the bolt holes  a tad, it also allows easier adjustment of the stinger,just seal the hole with silicone to seal it as well as the bolt holes for the stinger.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on April 17, 2013, 04:59:53 PM
Hi Mike,

As Mart said, we're only offering advice based on our own experience, we're not telling you what to do...

But, as we've made a lot of the setup mistakes ourselves (at least I know I did) and know what devastating effect these can have on the running attitude, we like to keep you from repeating them.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 17, 2013, 11:48:31 PM
I know you are both helping i was only joking about doing as i am told. I suppose i was a bit irritated about having to pull the propshaft out again after reparing the damage caused the first time round.  I was preparing to the take risks of the possible outcome in order to get out of moving the stinger again, plus i felt  a little insulted and rebellious towards Jans advice after his comment on my thread title, a clearly petty reaction on my behalf. At the end of the day it would be foolish of me not to take the experienced advice both of you have offered and for that i am grateful.
I have moved it 4.5mm right and reinstalled the flex tube. Althogh a good idea I wont be cutting a slot as the hull being wood if i cut anymore holes in this transom it'll lose its integrity around the stinger mounting plate.
thanks :-))
 
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on April 18, 2013, 09:32:08 PM
Ive deviated a away from the hardware a bit and did the hatch. It made from bread and buttered balsa then wittled and sanded to shape, it still needs some work but you get the idea.
 
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on April 19, 2013, 08:27:05 AM
Nice will you be covering with some lite cloth and epoxy?.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 04, 2013, 09:25:07 PM
Ive now got a job so my build time has significantly decreased, therefore the build rate will be a bit slow. In the pictures shows the motor mount and the holes drilled for the bolts and steering push rod. I have also added spray rails, epoxy grp'd the hull and painted the underside in grey primer. I started on the top too but i ran out  :embarrassed:
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on May 04, 2013, 10:26:01 PM
Hi Mike,

On the pictures it looks as if the brass tube for the flex shaft is curved upward, is that the case or does it look that way in the picture?

Did you use glasscloth and epoxy resin for the bottom?
If not, you should have, as paint alone isn't going to cut it in boats this size...

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 05, 2013, 07:45:37 AM
the brass tube has a smooth S bend in it along the its entire length. It aligns with both the stinger and the motor spindle dead straight.
Yes the hull is glassclothed and epoxied on the bottom. This was my first try at glassing my boats, although not the first time glassing. I usually use dope and tissue and i think i prefer that to glassing.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 24, 2013, 01:17:37 AM
Sorry its taken such a long time to update this thread. Painting allways gives me grief whatever boat i do and this one is no exception. Besides theres not a lot you can say about painting is there? It just takes a while and with me working now even longer than it use to. I have gone with matt black and green. I did some colour schemes on microsoft paint and its not quite come out the way i visioned it. The bottom is white just it case it flips over. Its probably not the most sensible colour to use matt black but i dont sail to far away from the bank and i dont do it at night time so im not too worried. Im not a good painter so dont judge me too harshly  :embarrassed:
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 24, 2013, 01:25:14 AM
Hardware installed. Im not sure at the minute how i will arange the batteries. It will either be 2 packs of 2 cell lipos or a singular 4 cell lipo. I have provisions for both by moving the esc to the front. The total displacement of the boat is a little higher than i thought it would be at 1.9kg. Bath test show that it sits quite low which looks good, but i fear will cause issues when the boat climbs onto the plain with the bow going up and the weight shifting to the stern. I do not think there will be any issues at full speed as long as i dont dally about. But at this stage its only a theory.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 24, 2013, 01:28:30 AM
Im using green plastic cheapo props at the minute so i can test for most suitable propellers. The one on currently is a 42mm 1.4 pitch. Im fairly confident but i would like a metal prop. The rudder blade is not aligned with the prop. I hope i dont have to change it.
 
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 24, 2013, 01:30:36 AM
Here you can see the rc car body pins holding the deck lid on.
Im not happy with the overall look of the boat, itl do i suppose. Ive got another idea up my sleave and if it works should turn out pretty good i think.
Title: Re: Fast electric deep vee monohull build
Post by: ardarossan on May 24, 2013, 05:28:42 AM
Here you can see the rc car body pins holding the deck lid on.
Im not happy with the overall look of the boat, itl do i suppose. Ive got another idea up my sleave and if it works should turn out pretty good i think.

It's never good to read that someone isn't happy with their model - especially when it's one
they've actually built themselves, and there's nothing essentilly wrong with it.

Thererfore, hoping that you don't mind a couple of thoughts on points you've made: With regards to the Pit-pins, you might like to put a nylon washer underneath each one as they'll quickly scratch the Matt Black paintwork, and also, if you attach a trace to each pin, you won't lose it (otherwise carry a couple of spares taped inside the boat).

The other thing is with regard to the paint colours you've used - Red, White and Green are the colours of both Castrol and also of the Italian flag - With that in mind, I've just had a quick play in 'Paint' that may be of interest. The designs use nothing more than simple straight lines plus a couple of vinyl decals...

Andy

(http://s20.postimg.org/4vzvbzgjx/Fastboata.jpg)

(http://s20.postimg.org/hyvhv96rx/Fastboatb.jpg)
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 24, 2013, 06:07:29 PM
i saw the pictures before i read the post and thought hmm something seems familiar about that boat it looks like mine %% 
I like the castrol one, though i dont think ill be doing it, not at the minute anyway. Painting is a part of this hobby i loathe, I like my boats painted, just hate painting. Sometimes i seriously consider paying someone to do it for me. Id rather spend the money and have some else do a half decent job rather than me do it. I probably should have come on here for inspiration before i started the painting. Ill take into consideration the use of the washers, if the gap between the pin and the lid allow, Its pretty tight. I have a lot of replacement pit-pins (so thats what theyre called) so if i lose one it wont matter they're ten a penny.
Thanks though  :-))
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 26, 2013, 07:31:17 PM
I cant help but find it ironic how when i build a boat on the cheap with notoriously unreliable **** it goes perfect yet when I fork out a bit for some posh gear it all goes TU!! >>:-(
The motor i am using is a bl3650 2700kv motor. Im using Turnigy 4s 3ah lipos through a Turnigy 120a marine esc. Its turning a 2 blade 1.4 42mm prop. I changed down to a 40mm only to find the prop is reversed so i dropped even lower to a 38mm and got cavitation. So back to the 42 it was.
What i cant under stand is why can a 2845 3600kv motor spin a 37.5 graupner k series prop for nearly 15 mins and still be cold yet a 3650 2700kv motor struggles with a 42 and overheats! >>:-( Not too much to cause damage but smoke was coming from the motor. The esc kept on cutting out and going into overheat protection mode. I roughly managed overall about 10 mins of run time but that was with the boat on and off the water. I think constantly id get about 7 mins at a guess. But thats 25 amps continuos and thats well with the capabilities of a 120 amp esc and 68amp motor. The speed was pathetic barely 20mph when it was working. It was planing but not enough to it get to really lift. The prop was surfacing peircing properly so i dont think the overheating was due to the prop being submerged.
So what say you brushless boffins? What am i doing wrong? Is it a case that this is just a bad motor or is the smaller one just exceptionally good? I reckon ill change the motor for something else. I still want to use 4s as thats the only thing i can fit in the boat with a half decent capacity. Im thinking of going for a leopard with a slightly higher kv.
Maybe:
http://www.ebay.co.uk/itm/New-rc-boat-Leopard-4-pole-brushless-2860-2730KV-motor-/230962105793?pt=UK_ToysGames_RadioControlled_JN&hash=item35c66a0dc1 (http://www.ebay.co.uk/itm/New-rc-boat-Leopard-4-pole-brushless-2860-2730KV-motor-/230962105793?pt=UK_ToysGames_RadioControlled_JN&hash=item35c66a0dc1)
with jacket of course
or this:
http://www.hobbyking.com/hobbyking/store/__25091__3660SL_3180kv_Brushless_Inrunner_WaterCooled_.html (http://www.hobbyking.com/hobbyking/store/__25091__3660SL_3180kv_Brushless_Inrunner_WaterCooled_.html)
this:
http://www.ebay.co.uk/itm/E-Express-to-USA-leopard-3660-3060kv-motor-36WCJ-50mm-water-cooling-jacket-/230962105668?pt=UK_ToysGames_RadioControlled_JN&hash=item35c66a0d44 (http://www.ebay.co.uk/itm/E-Express-to-USA-leopard-3660-3060kv-motor-36WCJ-50mm-water-cooling-jacket-/230962105668?pt=UK_ToysGames_RadioControlled_JN&hash=item35c66a0d44)

the kvs are high so ill likely have to go metal props which i was going to anyway.
 
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on May 27, 2013, 12:02:34 PM
Its been a bit quiet regaurding the reply to my post so ive gone with me instincts. I bought a 3660 2700kv leopard with a cooling jacket. Fingers crossed.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 09, 2013, 10:48:15 PM
Martno1fan if you see this ive sent you a pm about propellers cheers mate
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on June 10, 2013, 09:37:31 PM
Hi Mike,

Sorry to hear about your teething problems with your boat.

The motor you're using is a two pole, rather short for the size hull and prone to overheating; on top of that the motor only gets half cooled as there will be air trapped inside the jacket, the outlet needs to be at the highest point!

If the 120A ESC cuts out, you're drawing way too much current, this could be the blunt prop or it's simply too big for this setup.

I think it's safe to say you overheated the magnets, effectively killing the motor, it'll still turn, but have no torque to speak of, draw massive amounts of Amps and run (very) hot...

What settings did your ESC have, you don't want the timing to be off too much, the standard 15 of the T-120 does not agree with all motors, better start low.

I would not go for a 28 mm motor, you'll lack torque, the 3060Kv 3660 Leopard motor is much better, but do make sure it's a four pole motor, giving you the torque you need.

On 3S you'll get close to 30.000 rpm at the prop, which is right in the sweet spot.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 11, 2013, 10:14:29 PM
Hi Mike,

Sorry to hear about your teething problems with your boat.

The motor you're using is a two pole, rather short for the size hull and prone to overheating; on top of that the motor only gets half cooled as there will be air trapped inside the jacket, the outlet needs to be at the highest point!

If the 120A ESC cuts out, you're drawing way too much current, this could be the blunt prop or it's simply too big for this setup.

I think it's safe to say you overheated the magnets, effectively killing the motor, it'll still turn, but have no torque to speak of, draw massive amounts of Amps and run (very) hot...

What settings did your ESC have, you don't want the timing to be off too much, the standard 15 of the T-120 does not agree with all motors, better start low.

I would not go for a 28 mm motor, you'll lack torque, the 3060Kv 3660 Leopard motor is much better, but do make sure it's a four pole motor, giving you the torque you need.

On 3S you'll get close to 30.000 rpm at the prop, which is right in the sweet spot.

Regards, Jan.
Im suprised at the way the motor performed. I have seen good reviews for it yet mine was thoroughly disapointing. I first tried it on my catamaran and allthough it didnt overheat it was pretty slow. It was only a 40mm 1.4 prop on the cat. I put it in the mono with a 42mm thinking it would be fine. What gets me is that 2 years ago i bought a 3600kv tiny 2845 with a seaking 60a esc. On a 37.5k graupner recommended by yourself in runs practically cold on 3s, yet i get a larger motor with a lower kv up the prop size a few mills and that has a fit. 
Your theory on the weekened magnets seems to fit the bill as to what has happened. I did run the motor on 15 degrees, im never too sure what timing to use for my motors.
Anyway ive bought and installed a leopard 3660 2700kv 4 pole running on 4s. The temps are mild to warm but not hot, bearing in mind when i tested it the sun was raging down on the lake, and the boat is matt black. I ran the boat on a octura 1.4 42. The handling was good although i think it runs a little wet. I tested the centre of gravity when i got home and its a bit to far forward at 40%. Theres very little room to move the batteries back either but still it will help. Im going to try some different propellers. Im thinking a 1.4 40 1.6 40 and a 1.6 42. I think if i down the prop size from 42 to 40 ill get the revs up. I dont know yet i havent got them.
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on June 15, 2013, 04:22:43 PM
Hi Mike,

Does the Leopard rev out up to 36000 rpm under load?
The 42mm prop would make that hard I'd guess, better start smaller and see what you can get away with without overstressing the (relative) short canned motor.

Get the COG right before propping up!

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 15, 2013, 10:17:42 PM
I can only presume it is. I have no means of measuring the prop speed either static or water born. I havent got the 'ear' for it yet. With the 4214 the motor runs relatively warm. So the motor is worked but not over worked.
I dont know how to adjust the COG, at least not without either adding ballast which isnt ideal or start chopping at stuff which i really dont want to do.
What effects does having the centre of gravity to far foward have?
thanks
Mike
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on June 15, 2013, 10:35:57 PM
Too far forward the boat will struggle to plane which means the motors working harder,too far back the boat will become very flighty,thats why the cog is very important.Cog should be around 30% .
Mart
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 15, 2013, 11:24:40 PM
I had a think about moving the motor to adjust the COG. I thought id experiment to see where the motor would roughly need to go to get the 30% so i put the batteries in as far back as they would go then put laid the motor in loose at the bottom. To get the COG to sit at 30% id have to mount the motor at the stern next to the steering servo!  >>:-(
Itl just have to stay at 40% unless i fit an outboard and ive spent enough money allready.
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on June 16, 2013, 08:06:21 AM
Mike that doesn't sound right to me,i don't understand why you cant get the correct cog how about some pics of the inside to show the position of your gear see if we can help.
Mart
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 16, 2013, 10:22:58 AM
All the parts arnt fitted in at the moment as ive been doing some hull repairs. I had a bit of a tiff with gravity last week and lost. Lesson of the day:
Dont try to find the centre of gravity by balancing the hull on your finger whilst standing on the kitchen floor.  :embarrassed:
Anyway these pics show the battery and motor positions. The batteries on the maiden run were an inch forward then though. The rest of the hardware is not installed, the esc goes forward of the motor which helps the COG even less but that is the only place room for it. The Paint side profile is taken from the original plan. The red circle shows the current COG and the green circle shows the desired point. The blue rectangle is the motor position and the green one is where it needs to be to balance the boat to the correct COG.
I think the COG is off due to the fact that the front of the boat is heavy, the forward section has the chine shelf and frame in it which cannot be removed.
 
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on June 16, 2013, 10:46:16 AM
Hi Mike,

Running with the CoG at 40% is like having taped a brick onto the nose; in time you'll fry everything...

Like Mart said, you'll have to rearrange the components in the hull, your major obstacle is the steering servo.

The picture is of a slightly smaller monohull, where I has issues getting the CoG right.
I ended up with the servo (red) close to the motor:

(http://www.modelbouwforum.nl/forums/members/pompebled-albums-mhz-flash-mono-1-set-up-picture106437-binnenwerk.jpg)

The hull has a floodchamber and is set up as a 3S mono 1, so the receiver sits on the other side of the shaft, but you can see there's room for a second lipo if the receiver was moved under the deck.

Receiver and servo are relative light compared to the motor and batteries, so it's easier to position them where it's convenient without upsetting the CoG.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 16, 2013, 12:08:58 PM
The servo isnt in an ideal position i know. Its the only place i could get it to fit. Theres no room under the deck sides due to the nature of the hull construction, even if there was, the profile is too low to fit the servo between the deck and the bottom.
I wonder if a 2.5kg metal mini servo would do it?
Title: Re: Fast electric deep vee monohull build
Post by: grasshopper on June 16, 2013, 12:41:54 PM
Would it be possible to move the tiller arm on to the other side of the rudder, have a connecting rod running  straight through the hull space to the servo mounted forward of the motor, you could then move the battery packs rearward and closer to the propshaft making the weight lower and more central?
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 16, 2013, 01:21:13 PM
I see what your saying but no. The sides are boxed in by deck formers. You can see them on the first pages off this thread. Theres nothing really i can do about it as the boat sits low at the stern as it is. The water line is only a 1/4 of inch below the deck level. If i put the COG back anymore itl sink  :((
Theres only one thing i can do. And thats remove the construction frame from the front section of the hull. Itl mean having to remove the front deck section and dremeling out the frame.
Which exactly what ill do  %% %%
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 16, 2013, 01:46:56 PM
cant stop now.
Title: Re: Fast electric deep vee monohull build
Post by: grasshopper on June 16, 2013, 09:39:39 PM
You don't hang about do you?


Even if the section under the side decks were in-accessible you could still manage running the control rod along the in board side of the boxed in section.


 As long as the hull is waterproof she only sits low in the water when she's static, after that she should up on the plane..
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 17, 2013, 11:15:39 PM
I dont get enough time these days to do as much as i would like. But generally no i dont hang about, I like to be on I dont see the point in waiting and holding off otherwise things dont happen and what you say you intend to do becomes nothing more than talk.
I waited a few minutes before i stabbed a hole in my boat but in the end it was simply case of ' if your gonna do it, then do it!'
So I did.
Because where the rudder is mounted the throw of the steering arm enters into the boxed off section. If i moved the rudder mount over towards the centre the rudder blade would hit the propeller. I also wouldnt have been able to move the linkage over a hole on the steering arm either without the rod hitting the rudder hinge when turning to starboard.
Anyway im having some success with removing the weight from the front. I dremelled out the frame and reinforced the skin seams. Ive jsut started patching the hole back up. Im afraid i have no pictures at the minute though. Ive managed to take the COG down from 40% to 32.3% Which isnt perfect but definatly better.
Title: Re: Fast electric deep vee monohull build
Post by: martno1fan on June 18, 2013, 01:09:33 PM
You should be ok at 32% mate its certainly a big difference from 40%  :-)) .
Mart
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on June 18, 2013, 08:51:00 PM
And you can always add a wee bit of lead in the rear to get the CoG further back if this should be neccesary...

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 18, 2013, 10:26:44 PM
Progress is coming along slowly but surely. On the underside edge of the hole in the deck i put some small flat peices around the perimeter. Then using a peice of paper and a pencil i placed the paper over the hole and shaded the pencil over it. The outside edge came out as dark ridges in the shading. I drew a heavy live on the dark ridges and cut the paper out as a template. I then transfered the template to the same 1.5mm birch ply i originally made the deck from. The patch fits almost perfectly inside the hole, some trimming was needed in places but the peices i put on the underside makes the top of the deck flush. Some aliphatic resin was used to secure it and some epoxy with a bit of talc in it was used to fill in the gaps. The top has been rubbed down and now almost flush. It will need an another coat of epoxy and paint to seal the wood but with a bit of elbow grease I am confident the hole and the repair will be unoticeable.
Another further addition i could doto the COG possibly is move the esc. As it stands it is still in front of the motor. I could mount it on top of the propshaft with a bit of tweaking however in order to do this and clear the flex coupling i would need to extend the 3 motor/esc wires.
Im thinking though that if i were to extend the wires the additional length would have a higher resistance, affect the back emf readings from the motor to the esc and therefore cause the motor to run badly.
What are peoples oppinion on this?
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on June 19, 2013, 08:48:14 AM
Hi Mike,

Extending the wiring between motor and ESC up to 15 - 20 cm makes no difference in performance, you may want to braidle them to minimize interference.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 19, 2013, 09:24:15 PM
I realised that i can also possibly move the rudder back a bit so that it is inline with the prop. It isnt necessary for prop walk reasons but it wont hurt.
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on June 19, 2013, 09:51:08 PM
Hi Mike,

In fact, positioning the rudderblade next to the prop is a major factor against propwalk, a turnfin is another one, as is offsetting the drive train.

So, in addition to moving the CoG rearward, the running attitude will benefit.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 20, 2013, 11:06:48 PM
Ye I worded that wrong. What i meant was im moving the rudder for other reasons other than prop walk. I know moving the rudder is for countering prop walk, I just dont have any at the minute %%
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 23, 2013, 10:52:51 PM
After cutting all insides out i repatched and painting the hole. Its pretty smooth, itl do for me anyway. Ive also extended the rudder back an inch or so to help with the COG. With all the hardware installed the final COG is about 32.4%. I dont want to add lead because the back is low enough as it is.
Title: Re: Fast electric deep vee monohull build
Post by: pompebled on June 24, 2013, 05:04:46 PM
Hi Mike,

All looks good again, congrats!

Don't be affraid to add lead if required, our boats also lay half submerged when in rest (due to the floodchamber filling), once you hit the throtlle the boat will ride level again.

Regards, Jan.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on June 29, 2013, 02:38:56 PM
Took the boat out again today for another try. After all that pratting about with COG and stuff, its still pretty slow. I dont think im seeing 30 mph out of it. It was actually pretty boring  {:-{
I reckon maybe going up a prop size. perhaps a 43 or a 44mm. Im half tempted to shelve this hull a put this gear into my catamaran.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on September 08, 2013, 06:07:50 PM
Ive sold the both the hull in this thread and the catamaran hull and decided to build another which ive now finished. Took it out twice but then on the 3rd occasion for some unknown reason my boat just burst into life. I couldnt work it out at first, then it dawned on me that the speed controller ive been using has was stuck in recovery mode and faulty. I thought was something was a bit off because the lipos would come in dangerously low, but it hadnt crossed my mind it was because low voltage cut off was stuck on. Ive replaced the esc and sure enough the boat runs as it was intended
Now the other hulls are gone ill never know what they could have been cable of.  >>:-( >>:-(
Title: Re: Fast electric deep vee monohull build
Post by: gazncaz on October 21, 2013, 04:58:53 PM
Did it end up being quite strong?
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on October 22, 2013, 08:30:04 PM
Sorry but did what end up being quite strong? The motor or the hull?
Title: Re: Fast electric deep vee monohull build
Post by: gazncaz on October 23, 2013, 06:40:49 AM
Sorry the motor.
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on October 23, 2013, 07:15:41 PM
yes on the hull i have now (not shown in this thread) it was too strong in fact it produced  so much thrust it flipped the boat over backwards. I replaced the motor with something a little tamer and sold the leopard now for my new found interest in planes.  %)
Title: Re: Fast electric deep vee monohull build
Post by: Netleyned on October 23, 2013, 07:24:00 PM
Be careful Mike.
You can rescue a boat that flips, but flying things
need bin bags for transporting home from the site.

Ned
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on October 23, 2013, 07:42:44 PM
You know beleive it or not im more anxious about my boats flipping than my planes crashing. Accidents happen but the difference is between a plane and a boat is that when things do go TU at least with a plane you can walk over and take something home, boats on the other hand i have walked home with nothing but the TX.  >>:-( 
Title: Re: Fast electric deep vee monohull build
Post by: w3bby on October 24, 2013, 09:07:42 AM
You know beleive it or not im more anxious about my boats flipping than my planes crashing.......... boats on the other hand i have walked home with nothing but the TX.  >>:-( 

Flotation saves a lot of heartache....
Title: Re: Fast electric deep vee monohull build
Post by: Mad_Mike on October 24, 2013, 07:42:28 PM
it didnt sink it just drifted into a small shrub in the middle of the lake.