Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: Andy M on June 12, 2019, 11:52:29 pm

Title: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on June 12, 2019, 11:52:29 pm
Hi, I am hoping to build a mini version of Rorqual, I built the full size model many years ago, with a merco 61 in it. Sadly it and the plan are long gone so I want to draw up my mini sized plan as close to original proportions as possible. I have a fairly decent side view so could manage with either bulkhead drawings or a decent top view or both if possible. Many thanks in advance, Andy.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: chas on June 13, 2019, 12:31:01 am
Hi Andy, if you pm me your email address I think I have just what you need.
Chas

Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: DaveM on June 13, 2019, 09:30:49 am
Would this do? I've traced it full-size in CorelDraw and also have a PDF copy of that tracing - that's if Chas doesn't have what you need anyway.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: chas on June 13, 2019, 09:36:48 am
Hi Dave, almost the same thing as I was going to send, saves me a little job.
Chas

Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on June 13, 2019, 03:43:00 pm
Hi , thats perfect, and very quick, thanks very much. Do you have the rest of the text by any chance? Not critical that I have it, but would be interesting read. I built mine from the plan without seeing this article. I will try and look out photos of mine to put on here. Thanks again, Andy.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: DaveM on June 13, 2019, 04:00:40 pm
PM sent.
DM
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on June 13, 2019, 05:47:18 pm
Hi DM, PM sent. AM. Lol.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: DaveM on June 13, 2019, 05:52:42 pm
AM
JPG, CDR and PDF sent.
OK?
DM
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on June 13, 2019, 06:55:02 pm
Amazing, thanks very much. When I built mine, I had no idea that they hadnt built the model before releasing the plan. Turned out to be very good, even with a heavy merco 61 in it. Wasnt through choice, it was only marine motor I had.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on June 13, 2019, 10:22:15 pm
Here are some old pics of my rorqual. The photo of me holding it up is to drain water out after it sank in 6 feet of water.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on July 26, 2019, 01:01:52 pm
Hi, here is my mini rorqual build, 15 1/4 inches long, couple of small changes to suit this size of model, mostly to front end of hatch/top at the front.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on August 23, 2019, 03:31:58 pm
I thought I should update on progress of rorqual. Several coats of paint later, I dont know whether to leave it 'leftover' yellow or do a different scheme. Tons of room inside for radio and motor, just have to decide what is going in it. I have several options,  I will report further as it progresses.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on September 17, 2019, 03:16:33 am
I haven't done anything to rorqual for a while, I have been busy with rtr models recently, with impressive results. I have been using my Toyabi T03, two of my friends have one of these each as well. Amazing value for money. I describe these in more detail in my post, 23cm cabin cruiser.
I have also been using my Heng Long Atlantic Yacht, also good value for the money and ripe for upgrading if desired. The boat as it comes out the box is good, decent battery life from provided 2000mah pack, a 4400 li ion (18650 cells) pack ran for ages.
Rorqual project will get some attention soon, at least the paint will be well hardened for a final sand and coat of paint. I hope to get some pics of progress soon.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on May 04, 2020, 04:56:07 pm
I took Rorqual for a test float, partly to spur me on to get radio gear installed and also just to see it in the water for the first time. It is an amazing shape, very unusual, but it works.
 Being made from balsa, it is very light and should go well once I get the radio and motor, etc in and finally finish it.
 
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on February 08, 2021, 11:16:20 pm
After searching everywhere possible, I couldnt find the inner propshaft for this boat, so I ordered another one, they only had longer ones so it was cut down a bit.
  My homemade shaft coupling requires a strip of 11mm wide insulation tape to be wound onto the propshaft to take it to the right diameter. The motor and gearbox are from a Wltoys v262 quadcopter. I wanted to try this setup first, just as a matter of interest. They drive 8 inch props on the quadcopters, my Rorqual prop is 30mm, shouldnt strain it, I hope.
  Radio and motor are hotglued in place, in case the motor doesnt cope and I have to swap it for something else. Hotglue is far stronger than required but the components can be eased off if required.
 Radio gear is 9g steering servo, 20a brushed esc, 27mhz 2ch radio, (vintage) . Lol
 Bath tests indicate it should go fairly fast, takes off from a standing start pretty quick. Doesnt sit very low in the water, so still quite light. Finally finished, apart from maybe some paint, but I quite like the all yellow scheme.
 I might add a couple of little magnets to hold the lid (or superstructure) on.
 No idea when I will get to test it in open water, just been snowing here so not looking promising.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 22, 2021, 05:52:02 pm
I have now tested Rorqual, shown next to my Starlet yacht. The 27mhz radio was glitching really badly, I might try different tx or rx as I have a few old sets.
Anyway, radio issues asside, the test showed that the rudder was very good but the small quadcopter motor and gearbox is not as powerful as I had hoped. Still moves it about but not in keeping with the racy looks of the Rorqual. Once I get the radio issue sorted, I will give it another go with the quad motor setup, in case I wasnt getting full throttle. I have a few bigger motors I can try if it turns out the quad motor setup is actually too low powered.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 22, 2021, 10:12:06 pm
It turned out to be the sanwa transmitter that caused the major glitching problem. Swapping to an acoms transmitter cured the problem, so next venture down the river will be for a decent test. I am quite sure the model is underpowered with the quadcopter setup, but I will verify this next time I get it floating.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on March 23, 2021, 09:25:35 am
Fit a small bruishless outrunner. Makes all the difference.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 23, 2021, 12:14:36 pm
I did think about brushless, but I only have aircraft motors and speed controls, so no reverse. As I use my boats in the local river, it is pretty essential to have reverse. I will see what I can come up with though.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on March 23, 2021, 01:06:05 pm
Just use blheil-s or blheli32 esc's, they can be configured to work in reverse, and they're cheap and small.

e.g. https://www.ebay.co.uk/itm/HAKRC-BLHeli-32-Bit-35A-2-5S-ESC-Built-in-LED-Support-Dshot1200-Multishot-for-RC-/264970532842
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 23, 2021, 05:30:18 pm
Hi, having spent all of my modelling budget on bits for my electric bike, I really have to make do with what I have already. I do have a brushless esc, but it was making the motor kind of stutter and get warm pretty quick, so I figured there was a problem and set it aside. I will do more testing and see if I can get it working properly. My latest projects are being built from what I have in stock, its good to use up some of my odd shaped scraps.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 25, 2021, 11:07:17 pm
I discovered that the problem with my brushless motor and esc was because I tested them on the glitchy radio gear in the Rorqual, now I have changed to a different transmitter, they seem to be working fine, just need to come up with a propshaft coupling of a suitable size, I have one suited for the brushless motor shaft, but the other end is for a 4mm plain shaft, over 2mm bigger than the shaft in the Rorqual. I need to find something with the right inside and outside diameter to make a bush for the grubscrew to nip onto.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 26, 2021, 11:00:23 am
I drilled a 1.7mm hole up the centre of a 4mm brass rod to make an adaptor for my coupling, the brass rod was held in a vice, I managed it but also managed to break the drill and followed through into my pinkie nail. I didnt think it had gone through the nail, then it started oozing blood, then getting more painful. Not my worst injury but pretty sore.
 Anyway, I managed to make my tiny adaptor, not sure if the coupling grub screw will nip it onto the propshaft or if it will have to be soldered onto the propshaft. I would rather it wasnt soldered on, then I can move the coupler between different boats.
There doesnt appear to be any 1.7mm propshaft to 3.2mm motor couplings out there. Anyone know of a source?
I have broken the drill so I cant make another adaptor at the moment, dont really fancy risking another hole in my finger anyway.
  It was a bit of luck that I managed to get the hole running up the centre of the adaptor anyway while drilling it by eye.
 Hopefully the one I have made will work and be able to be moved to different boats.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 26, 2021, 02:12:16 pm
I found another drill to make more adaptor sleeves. For accuracy and to avoid any more finger damage, this time I dug my home made lathe out and made another 4 of them for my other propshafts as I had to solder the first one onto the propshaft to stop it just spinning as the grubscrew on the coupling wasnt nipping the adaptor piece onto the shaft. This was definately what I should have done first time, I managed to avoid any injuries using the lathe.
 I kind of forget that I have it, it is behind a pile of stuff in my shed and doesnt get used much, last job I did on it was alloy wheels for my race cars.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 27, 2021, 08:42:34 pm
After a test of the Rorqual with a non glitchy radio setup, I found that it is definately underpowered, the quadcopter motor and gearbox would probably be fine for a cabin cruiser type model, but Rorqual has a speedy look to it, so it is definately getting a brushless motor. I also found that my non glitchy set of 27mhz radio gear isnt as non glitchy as I thought, probably because the receiver aerial was coiled up in the boat. I have decided I will use 2.4ghz radio instead as the comparatively short aerials are easier to fit in, and I have never had glitches with the 2.4ghz set. This should transform the Rorqual into a fast little boat. I will be running the brushless on 3 cells.
 Pic shows one of my adapters soldered on the shaft, ready for motor fitting. I only have one coupling so it will need to be removed from my Edita motor cruiser (yacht?)  I have made a 1/8 liteply motor mount but it wont be glued in till I fit the motor and run it at low speed to fine tune the alignment.
 I was hoping to get more done on the boats today but I had my first covid jab this morning and its knocked the wind out of my sails a bit.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 28, 2021, 09:20:24 pm
It was quite tight getting the motor in on its mounting plate and the coupling joined before I glued the plate in position. I will still be able to remove the motor easily, hopefully. The rest of the radio was fitted, then a test, not on water yet but still showed me what I needed to know...
 Finally think I have a suitable setup for this little boat. Its a screamer, I actually thought it was going to explode at one point. I was making sure the prop was facing well away from my face, hands etc...
 I have brushless planes, but this will be my first brushless boat. I am expecting it to be fast, judging by the test. Cant wait to try it, I might even try it in the bath for a idea of how much water it can shift.
 I have my 2.4ghz radio in it, so the radio link should be solid for its next river outing.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 28, 2021, 09:21:19 pm
Short video here


https://youtu.be/NYWFrjAMtwA
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on March 29, 2021, 11:03:26 am
Might be a bit overpowered now. Can always knock it down to 2s though. What's the KV of that motor?
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 29, 2021, 11:51:28 am
The motors are 4 pole 2838 4500kv. They were midway down the kv range of the motors on the specification sheet that came with the motors.
 It does sound (really) fast, it is my first brushless boat so no idea what kind of speed that equates to, I hope to do a bath test at some point today, still feeling a bit rough after my covid vaccine on Saturday, so will see how I feel later.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on March 29, 2021, 12:16:51 pm
2s for that kind of kv. 3s is too much IMO, you'll find it overpowered. Even on 2s you're pushing it for a little boat like that.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 29, 2021, 12:36:02 pm
Rorqual weighs around 460g with the 2100mah 3s pack, feels quite a lump.
 Bath test shows waterline at rest. I knew it would sit a bit lower than it did with the geared quadcopter motor and a 2s 500mah pack and its lighter speed controller.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 29, 2021, 12:36:51 pm
Short bath test video here
https://youtu.be/ffqMXdENFPc
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 29, 2021, 12:42:03 pm
No shortage of power now, I was surprised by just how much thrust it has on the 30mm medium pitch prop that came with the propshaft. I can drop to a 2s pack if its too wild.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on March 29, 2021, 01:15:36 pm
I think the thrust is exceeding the weight of the boat, not sure how that goes in boating but for aircraft, it means you can go vertical after you take off like an F15 eagle.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on March 29, 2021, 01:47:06 pm
You'll have a job keeping it upright on 3s. There is a limit for a boats power to weight, and with brushless and Lipo it's easy to overpower things. Was never really an issue in good(bad) old days with brushed motors and nicads.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 01, 2021, 08:28:15 pm
Ok, I underestimated the motor just a bit, I had far too much rudder movement as well, as it was pretty twitchy. I got up to about 1/4 throttle and was in a straight line so I gave it an extra bit, probably about 1/3 throttle and the whole boat rotated round the motor and ended up upside down in the river, socks and shoes off, and wading in to the bouldery freezing water, stubbing my toe but trying to intercept it before it headed off downstream.... I made it past a dead tree in the water and got to it just in time. Filled with water, so gear all needs airlined and dried properly before I test it.
I think 'going to need a bigger boat' applies here! 😁
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 01, 2021, 08:50:56 pm
I have only used brushless motors on planes before, where a smallish motor can drag quite a large plane, but built from depron so they are super light compared to a similar sized, balsa glow plane.
My motors are about 380 brushed size, which is a good bit bigger than the brushless fan motor I have on my 2 metre span camera plane! It weighs about 2 pounds and has 2m wings to stop it torque rolling.
Rorqual's hull is only a matter of ounces, I think the motor just spun the hull around it. Its narrow too.
Far too much power, as warned.
Didnt listen, well I did, but decided to try a shot of a drag boat anyway. 😁😁😁
Its a Little Monster right enough.
If my radio still works, I am going to put it in a bag this time, and have another go on a 2s pack.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on April 01, 2021, 09:01:53 pm
It'll still be too hot IMO at full throttle. A motor around 2000-3000kv depending on whether 3s or 2s is desired, would be ideal. The emax cf2805 re superb motors for this type of boat.  They're my main go to motor for planes and fast electric boats. https://www.4-max.co.uk/emax-cf2805-motor.html

About eight quid on ebay.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 01, 2021, 09:54:57 pm
I have something similar in a plane just now, it might be going in a boat for a try.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 01, 2021, 11:33:58 pm
Any hull size recommendations for my motors?
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 02, 2021, 12:22:29 am
I just had a look on ebay to see if there were any boat size recommendations for these motors, found these 2 in jet drives, but it says suitable boat size under 15 inches? My Rorqual is longer than that. Unless the jet drives are really inefficient compared to my propped versions? Confused a bit, but will keep researching.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 02, 2021, 12:23:09 am
Forgot photos😁
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on April 02, 2021, 12:13:08 pm
Probably using tiny props, plus with a jet you get negligible torque effects. Very high revving motors are best suited to surface piercing props. For a submerged mono hull you want lower RPM IMO.

I use the following equation for getting a rough idea of speed prop pitch(mm) x RPM x 0.000022= speed mph. That accounts for a lot of slip, as small model props are very inefficient.

Plugging the numbers in for your boat, assuming a 1.2x pitch on the 30mm prop and 3s-

36 x 49950 x 0.000022=  39.5mph(!!)

Even on 2s the figure equals 26.4mph. You could try a smaller prop if you find the speed too much.



Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 03, 2021, 03:35:52 pm
Jeezo, it was probably doing over 10mph when it flipped at 1/4 to 1/3 throttle.
Obviously too much for my tiny hull. I have already started on a bigger boat build. Lol
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on April 03, 2021, 04:55:01 pm
Well torque roll is a likely factor- the Rorqual looks a fairly narrow hull. Fitting a torque wedge may help a bit along with some strategic positioning of components inside to counter the torque roll and experimenting with smaller diameter/pitch props.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 03, 2021, 08:59:42 pm
I have temporarily decommissioned Rorqual and will be using the motor in a bigger build, a 26 inch long hydro, and I will take your advice and try it on 2s pack to start with.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 06, 2021, 12:13:30 am
Here is Rorqual next to my 'bigger boat', hopefully this hull will handle the power a bit better, I will be going for 7.4v for initial tests.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on April 06, 2021, 11:13:21 am
That hull could probably handle a bit more power, but you certainly won't be overpowered now.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 06, 2021, 12:04:40 pm
Hopefully I will get a longer shot of this one, the Rorqual had about 15 seconds before I flipped it. I still think it will be fast as it is very light for its size.
I kind of like the uncertainty of testing a new model, adds to the excitement. Especially as I have not had any experience of brushless motors in boats, apart from Rorqual, which wasnt very successful. It did give me an idea of how much power they have, so not all bad.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on April 06, 2021, 01:21:54 pm
That Rorqual looks about 15-16" long? If you use the motor I listed earlier, it should be a really fun boat to run.

If you want to run 3s for the same performance look for a similar size motor around 1700-2000kv.

The power limit for a boat of that size and type is around 100 watts, perhaps a bit more. the small cd-rom type motors tend to max out around that figure.

The shovelnose should be very quick, but they're hopeless in a small pond, cause they need a wide radius to turn.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 06, 2021, 02:27:28 pm
I really have to go with what I have in my stock of bits at the moment. I will have a small brushless in a plane somewhere, but didnt really want to decommission a plane just for the motor, not just now anyway.
The hydro is an attempt to make use of the motor setup from Rorqual.
As my usual boating area is a river which is fairly narrow, your mention of a wide turning circle isnt really good news. I have other stretches of water I can use it on, so not a disaster.
I appreciate the advice I get, brushless boat motors are a new venture for me, building an appropriate sized hull to match the power of my motor is my main aim, the Rorqual showed just how far of the mark my estimate of the power was. I am fairly confident of a decent boating experience with the hydro, I have 2 power options, 7.4v for initial tests and 11.1v if it needs more.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Subculture on April 06, 2021, 03:48:32 pm
Mono hull or catamaran are best for agility. Hydro's best for outright speed. The fact that hydroplanes have so little hull in the water is the reason for their poor turning circle- they don't have much to grip the water. Don't forget to add a turn fin on one of the sponsons, else it won't turn at all.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 06, 2021, 04:56:50 pm
I will add a fin, my robbe Proppy never had that feature and I remember it turning without any issues, but it was a long time ago, so I might not be remembering it right. Would one on each sponson be ok? To save it pulling to one side?
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on April 06, 2021, 04:57:49 pm
Rorqual is 15 inches long, 4 and 3/4 inches wide and weighs 4.5 ounces with rudder, rudder servo and propshaft fitted.
 Proppy copy is 26 inches by 11.75 inches. Bare weight with no rudder or propshaft fitted but liteply reinforcing pieces fitted is 5.5 ounces. The weight will go up as I will be using a full sized servo and a pretty big rudder (borrowed from my 'four ways' cargo ship) but it should still be very light for its size. It is only one screw to return it to the cargo ship.
 I still have a fair bit to do, but it seems to be going well so far.
Title: Re: Vic Smeed Rorqual bulkhead drawings wanted
Post by: Andy M on December 28, 2021, 09:57:46 pm
This project had been sidelined for some time after the propshaft and coupling proved to be too flimsy for the task.
 I did think about trying to remove the flimsy propshaft and fit a decent one. I was worried it would wreck the boat during removal, so I thought I would try something else first.
 I always wanted a decent outboard, having tried some small cheap ones and even tuning them a bit. Proper model sized outboards are expensive.
 I thought I would try a 3d printed one.
 I have had to modify a few things and add reinforcements where I thought necessary, material is pla, reinforced with superglue, tissue paper, styrene sheet and ice cream tub plastic. I had to make up pipes for the watercooling, the original was fed by a pump, I want mine fed from the propwash.
 I have used a pump for cooling the speed control, the pickup for this is fed down through the empty rudder tube. It exits on left side of transom.
 The boat has had fairly extensive modifications as well, not just adding a transom and motor support, the sponsons, front edge of hull and front underside have had medium hard balsa sheeting added, not exactly tough, but better than bare depron.
 I ended up removing the old propshaft, I took out the plastic bush at the rear and put my soldering iron up the tube, a small amount of constant pressure and after a few minutes it eased away from the ply support quite easily, considering it was well epoxied on.
 I made up a custom battery pack, 7.4v to start with, I am using same motor and prop as the sea rover, which is much heavier, so IF it all holds together, it should be quite quick, with the option still available for 3s pack.
 I am a bit worried, it is printed horizontally so it could crack apart along a layer. I hope my reinforcements keep it together.
 Only one way to find out.........
 I am nearing testing time, but not just yet, few wee jobs to finish off first.