Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: rado-steve on April 13, 2012, 11:19:04 pm
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Hi All,
just got one of these boats as a bit of a toy:
http://www.red5.co.uk/remote-control-toys/the-dash-high-speed-rc-boat.aspx
Problem is, its just not quick, the video on the website and subsequent ones I've seen on youtube show it to zip along quite rapidly.......mine just seem to produce a huge rooster tail, its faster on 1/2 throttle then on full <:(
Anyone else got one or heard of any issues??
To me it looks like the prop is a surface drive????? and 30mm in Diameter, that seems pretty large for a boat thats only 350mm long!
(http://i6.photobucket.com/albums/y230/beeftech/013730cb.jpg)
(http://i6.photobucket.com/albums/y230/beeftech/e4d420e1.jpg)
I've had it in the bath and at rest the prop is fully submerged, but as soon as you apply power it seems to bring it out of the water, is it meant to do this?? If i hold the back end deeper in the water you can really feel the prop bite and the boat pulls hard {:-{ Or could I maybe put some weights in the rear to lower the prop further into the water?
Would changing the prop to a smaller one help?? It seems a weird thread too, it looks like M2.5????....can only find M2 & M4 on the net...do they even make props in M2.5?
Sorry for all the questions on a 1st post, its just quite a cool little boat, just maybe wondering if mines Duff >:-o
Any help much appreciated
Cheers
Steve
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the prop is fine, its a surface peircing drive. When the boat gets up 2 full speed on a plane only one blade of the prop is in the water, this is how they work. Due the fact that only half the prop is in the water and any one time surface props are larger in diameter to their fully submerged counterparts. Ive not seen this boat before have you got a link to some footage of one running?
actually just found some:
http://www.youtube.com/watch?v=XNkaR7SF8uw
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the prop is fine, its a surface peircing drive. When the boat gets up 2 full speed on a plane only one blade of the prop is in the water, this is how they work. Due the fact that only half the prop is in the water and any one time surface props are larger in diameter to their fully submerged counterparts. Ive not seen this boat before have you got a link to some footage of one running?
actually just found some:
http://www.youtube.com/watch?v=XNkaR7SF8uw
Yeah....mine ain't anyway near as fast as that, its quicker at 1/2 throttle then full >:-o
It just seems to pull harder when its full submerged..
I'll try and get some video of mine running, see what you think!
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if you look at the reviews at the bottom of the page youl will find your not the only one disapointed with the speed of your boat:
http://www.red5.co.uk/remote-control-toys/the-dash-high-speed-rc-boat.aspx
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if you look at the reviews at the bottom of the page youl will find your not the only one disapointed with the speed of your boat:
http://www.red5.co.uk/remote-control-toys/the-dash-high-speed-rc-boat.aspx
Yeah I'd seen that, thats my comment on the website BTW (Yellow car), I'd seen someone else had complained :(
Do you think a smaller prop would help, as it does pull so much harder fully submerged........
Also M2.5????? Bit of a weird thread isn't it?
Cheers
Steve
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The push/pull force of the boat it what is called by the tug lads bollard pull. Its measured in grams or tons whatever and basically measured by fixing a scale to somewhere solid tying a boat to it and giving it some welly. Fast boats with surface peircing props have very little bollard pull but lots of top end speed. Same way a ducati wont pull a plough like a tractor can. The propeller will produce more bollard pull fully submerged, but at speed a submerged prop will cause excessive drag and slow the boat down. have a look at this too show their operation, read the bottom bit:
http://www.originalpropshop.com.au/resources.php
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The push/pull force of the boat it what is called by the tug lads bollard pull. Its measured in grams or tons whatever and basically measured by fixing a scale to somewhere solid tying a boat to it and giving it some welly. Fast boats with surface peircing props have very little bollard pull but lots of top end speed. Same way a ducati wont pull a plough like a tractor can. The propeller will produce more bollard pull fully submerged, but at speed a submerged prop will cause excessive drag and slow the boat down. have a look at this too show their operation, read the bottom bit:
http://www.originalpropshop.com.au/resources.php
Cheers for that....
I'll post some pics of mine running, when at full throttle the revs rise buy no increase in forward momentum...
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when the boat is going full tilt and the prop starts too surface drive, the props rotational speed increases dramatically because there is less load on it. Usually such behaviour your describing would possibly call for either the increase in diameter or pitch of the propeller. Its hard to say what would be suitable because its one of those trial and error things. Changing the propeller design changes the affects and load on the motor. A wrong propeller can overwork the motor, cause a massive increase in current and heat through the electricals of the boat and basically fry it. just need to get some idea of whats in the boat:
1) what battery voltage does it run at? and what is the mah?
2) does the boat have a digitally proportional radio in it?
what i mean by that is, is it a hard right hard left steering on it with all stop all go speed controlling or can you accuartly adjust the steering to a desired postion and control the motor speed accordingly?
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when the boat is going full tilt and the prop starts too surface drive, the props rotational speed increases dramatically because there is less load on it. Usually such behaviour your describing would possibly call for either the increase in diameter or pitch of the propeller. Its hard to say what would be suitable because its one of those trial and error things. Changing the propeller design changes the affects and load on the motor. A wrong propeller can overwork the motor, cause a massive increase in current and heat through the electricals of the boat and basically fry it. just need to get some idea of whats in the boat:
1) what battery voltage does it run at? and what is the mah?
2) does the boat have a digitally proportional radio in it?
what i mean by that is, is it a hard right hard left steering on it with all stop all go speed controlling or can you accuartly adjust the steering to a desired postion and control the motor speed accordingly?
It comes with fully proportional controls which I was quite imprssed buy, the battery is 7.2V 650mah. No idea what the speedo/rx combo is rated at though, can be that high! the motor is a 370 type.
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is the propeller dog drive or screw on. the nut on the end suggests a dog drive. im having a browse for the props that would possibly fit, as you say m2.5 is an odd size
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people are allways asking aboat how to speed up their boats usually those nqd things, but it MAYBE possible with your boat because it has an esc in it.
If you take this advice on your head be it, as doing this may fry your boat, may do nothing or may go like stink
IF your prop shaft has the dog drive you might be able to fit one of these larger spare props on from the nqd range:
http://www.ebay.co.uk/itm/110575171817?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2648
there is 2 in the set and one LH one RH, theyre 3mm but with some fine fiddling and a bit of craftsmanship you should be able to get the nut to screw the prop against the male dog teeth.
dont blame me if you see smoke %)
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Hi Steve,
What strikes me as odd is the prop; if I see it correctly it spins clockwise (seen from the rear), while most single prop boats have a counterclockwise spinning prop.
Reason for this is the motor; most brushed motors have a preferred direction in which they run faster than the other way, this is called timing.
Unless the manufacturer has a shipload of clockwise timed motors he needs to shift, my guess is that the motor will spin faster in the other direction.
The problem at hand is the odd size of the shaft, which makes finding a counterclockwise spinning prop very hard to impossible...
Also, the pitch seems to be small, which isn't a bad thing, it'll keep the motor from overheating, but the speeds won't be very high (as you've noticed).
Another thing is the hull; with strakes that have the wrong shape; maybe this works best for such a small hull, but my small boats most definitely have strakes that look 'normal', aka have vertical sides and run perpendicular to the waterline.
Regarding a bigger prop, as Mike already suggested, be careful, specially if the motor doesn't have watercooling, it may overheat very quick.
If you can alter the shaft by converting it to M4 thread, you'll have the entire M4 threaded props of the world at your disposal; most likely in the 2318.XX series you'll find a Ø 29 and 31 mm prop with a slightly higher pitch, which should result in more speed.
Having watched the video a couple of times, it looks as if parts have been speeded up, the actual speed is hard to see due to the erratic driving...
Regards, Jan.
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Hi I think the problem maybe cavitation? I found this video which seems to show the exact problem. http://www.youtube.com/watch?v=DADgUzGGw_U&feature=related He seems to reduce the throttle to get it up on plane and then increases the power. I also baught one with the view to mod it with brushless and water jacket... never done it before so advice would be great...
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do as jan suggested and upgrade the propshaft to 4mm. Display your general wareabouts and people can then suggest some options.
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Thanks... I really am a complete noob. could you give me some advice as to which brushless motor you would recomend for a boat of this size to give more speed? I am going to water cool it. would I need to upgrade the speed controler too? This is just a cheap rtr toy and I am guessing has low quality components.
Thanks
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I do not own this boat so i cannt really give good advice but i will where i can. Ill have a look around see what can be done.
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brushless motors need a brushless speed controller which this boat does not have. you have to plug the brushless speed controller into the receiver. If on your boat their is no option to plug the speed controller in and the standard speed controller is built into the circuit of the receiver then your entire radio is useless. You need to open it up without damaging anything and see. Also i might add that the standard batteries that come with your boat will be useless for brushless and you will need to upgrade to lithium polymer with a balance charger to boot. This convertion could cost you in excess of 100 pounds to complete.
It may not be necessary to go brushless which i beleive may be possible. I think the motor has the boot but the prop is the weak link. If you were to keep the standard motor. do you have the skills and tools to:
a) reverse the wires on the motor so that it spins the other way
b) possibly use the same standard coupling and drill a hole in the propshaft end to take the slightly fatter 4mm prop shaft
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Hi Mike, thanks for the reply. I have a good friend who is an electrician and is really good at making stuff, so he can help me with the project. I am disabled and have poor dexterity. Have a look at the Joysway Magic Vee, the hull is virtually identical, but different manufacturer. I noticed the prop shaft is slightly longer and has off-set rudder. Also it is water cooled and is faster. http://www.youtube.com/watch?v=9Uf9zqzjlQo Do you think that making the prop shaft longer would give it more bite in the water?
Thanks again for your help...
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Just another question.... Do you think water cooling is good idea? At the moment there is a cooling rotor fan on the prop shaft. This obviousely takes some power from the motor.
Thanks
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judging by the photographs at the top of this page i thought this boat did have an offset rudder. your boat is larger too, the specs say that the joysway is 27cm where the dash is 32cm. as a general rule of thumb for surface peircing propellers the back of the prop needs to be between 11% and 13% the length of hull away from the transom. I have no idea what ive just written so to put into english for both us measure the hull pointy end of the bow to the flat end of the stern. Dont include the prop, rudder and the other gubbins in that measurement. for eg:
32cm or 320mm
12% of 320mm is 38.4mm
therefor the back of the prop needs to 38mm away for the transom. The transom is the back panel of hull if you didnt know.
you will need to measure it on your boat.
an offset rudder would help a lot as inline one on surface peircing prop interferes with the propwash and causes unstabilty in turns and a prop thats in the right place would defintaly help.
water cooling is a good idea if it is necessary. Its better than fan cooling as like you said a fan draws power.
I think the motor should be allright but needs to spin the other way so that the new prop wont unscrew itself. But an jan mentioned earlier that brushed motors spin faster one way than they do the other. lets just hope that when the direction of the motor on your boat is reversed its going the faster direction. Like i said you will need your mate to unsolder the wires on the motor and swap em over. But as of the minute its hard to say whats needed at this point until we know
a) if the props in the right place
b) the length of the standard propshaft. that includes 2 measurements, the tube and the innershaft
you will need a ruler.
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Hi Mike, Thanks for all your help.
The hull is 29cm long, The distance from the transom to the end of the nut on the end of the prop is 2.5cm. To the end of the actual prop is 2.2cm. By my calculations the distance should be 3.19cm - 3.77cm going by the rule of thumb. I believe the nut on the end of the prop is a 4mm nut. How do I measure the prop shaft?
Thanks
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something doesnt seem right in the calculations. Its the distance between the end of the prop and the prop. its only 3mm, that sound like the nut width. A picture here shows which bit needs to be the 11 to 13 percent length of the hull.
(http://s17.postimage.org/6ms83oomj/distance_to_back_of_prop.jpg) (http://postimage.org/image/6ms83oomj/)
so far as we can tell then the prop is too close the transom as standard no doubt the reason its doesnt drive properly!
It was mentioned earlier in the thread that the propshafts diameter was 2.5mm. When nuts and bolts are measured the size go by the bolt diameter on most outer part of the thread. For example an 6mm bolt with have a 10mm nut. BUT the bolt is called an m6 bolt and the nut is called an M6 nut. M is the thread type.
What we need to do is change the too short standard propshaft for a longer one which also has the m4 screw fitting on the end. You need to get the entire length of the old propshaft, you then need to work out how much longer the new one needs to be for the prop to be in the right place. More maths
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Hi Mike,
The actual measurement from the transom to the prop is 18mm (just the exposed prop shaft). Far shorter than it should be. I may have to find a way to increase the distance between the rudder and the transom to accommodate the longer prop shaft.
Thanks Mike. I'll try to get more info to you soon. I really appreciate your help.
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ideally the the rudder on these types of boats should not be in line with the prop but offset to one side of the propeller. The rudder should actually be along side the prop to counteract whats called prop walk google it :-)).
if the standard rudder can be unscrewed maybe it can be moved.
If you have use of camera that would help an awful lot theres seems to be very little about this boat on the web and im only going by theory at the minute. You have to bare in mind that what your doing is experimenting and it might not work
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have you tried this boat on the water yet the performance doesnt seem that bad {:-{
http://www.youtube.com/watch?v=DzHSrxjlOGI
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my brother has one of thoase and it goas exactly like in the vid above me thinks yove got a friday special :((
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Hi Mike, I have not had it in the water yet because I bought it as a project boat. But I wil try to take it out this weekend and let you know how it goes. I also baught it to learn on...
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I got to be honest with you for learning this is a not a good way to go about it. When it comes to modifying boats especially fast ones one of the key skills you need is experience. It requires experimentation based on what you allready know and without prior knowledge your shooting in the dark. I and others can help a bit but its difficult to help much sat at a keyboard and what we suggest might not work and then you've wasted your money.
If you want to modify this boat then i suggest you keep it to one side for now and start at the basics on a traditional propulsion system on another boat. Sometimes just getting a normal propeller to work on a slowboat is challenging enough let alone going all out surface drive stuff. If your adamant on going this route then ill try to help where i can :-))
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Hello all 1st post,
bought this as a fun boat for my little Herbert after fun boat mark 1 was retired, ripped out the 40 MHz block Rx/esc and fitted a £6 orange 2.4 ghz Rx ,micro marine 10 brushed esc and another 7.2v 650 mah nimh (£5) for extended fun in between ice cream breaks at maldon promenade boat pond which is also salt water for those who are not familiar.
Pros:
very rapid especially when it gets on the plane which was much improved time wise with the mtroniks esc compared with the original and a higher speed/smoother throttle response, makes boating pond feel quite small due to pace compared with old boat
very watertight seal between top and hull (neoprene strip or similar) which keep electrics and inside dry, beneficial in salt water
roomy enough for basic upgrades - esc/Rx/bigger battery - but standard motor (speed 400?) is cheap to replace and seems quick and torquey enough for application
cons
at this price tag cannot think of too much other than limitations for upgrades due to prop direction/diameter
(http://s7.postimage.org/vnldh9wev/2012_06_27_20_26_02_935.jpg) (http://postimage.org/image/vnldh9wev/)
aerial mast (plus tinsel :}) now purely for sighting purposes after 2.4ghz rx fitted - handy on boat this small
(http://s13.postimage.org/mkexne2k3/2012_06_27_20_26_08_364.jpg) (http://postimage.org/image/mkexne2k3/)
marine viper allegedly water tight out of the box but balloon wraps give Rx and on/off switch some moisture protection
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I took the boat out yesterday, and once it is up on plane it is quite fast, but getting it there is not so easy. It takes a long time to get on plane and when turning drops out of plane very easily. You end up wasting battery power at full throttle going slowly. There is clearly enough power, but maybe the prop shaft needs to be longer? Also it was getting water in the hull from somewhere. I shall have to find out where and plug the leak.
P.S. Mike, thanks for the advice. I will start on another easier project, but would like to tinker a little on this too :-) Thanks for your support
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if you havent got a blatant crack in the hull then water usually comes up either the prop shaft or threw a badly fitting deck lid. On the larger scale ones we tend use whats called hatch tape. Well suppliers say hatch tape but i bought some a while back for 3 quid and it said cellotape on the inside of the real. Bog standard electrician tape does the job. Its not unusual for surface drives boats to be a bit slow from standing start, with the props not being fully submerged they dont grip to well. They work affectivly when the momentum is up and they get on a plane.
I think that a propshaft conversion wont hurt. Youl will need to change the direction of the motor too. From what i gather and youl need to confirm this is that the motor spindle is 2mm in diameter, the prop shaft is 3mm. I would suggest that when you convert to the 4mm shaft get rid of the standard coupling completely. There are no cheap couplings either which wil do the job. You will need to use a flex cable coupling 2mm to 4mm, even for solid shafts. Universal Couplings with grub screws for instance the huco range:
(http://s15.postimage.org/tw5zzlm4n/whc1pe2_E_Copy.jpg) (http://postimage.org/image/tw5zzlm4n/)
they are good couplings but are not designed for high prop shaft rpms which you will be using and they shatter beyond 10,000 rpm (if i remember rightly)
Solid type couplings:
(http://s13.postimage.org/n910h2wwz/in_line_coupling_2mm_Copy.jpg) (http://postimage.org/image/n910h2wwz/)
These are good and strong at high rpms but require the propshaft and motor spindle to be aligned perfectly, which is easier said than done.
both of these couplings have grub screws like most to but not all couplings are made well. A problem with these types of couplings is that when you tighten up the grub screw and the internal bore of the coupling is a bit slack the grub screw tightens the prop shaft against one side of inner wall, thus making the coupling tight on the shaft but the coupling slightly off centre. At low rpm applications this is not really a problem but on a 30k rpm surface drive it screams due to the excessive vibrations and ruins your bearings. it is possible to get around this with having couplings with more than one grubscrew in either end so that pressure of each screw on the propshaft counteracts each other. The best type of coupling for surface drive applications is this type:
(http://s11.postimage.org/buue9yjxb/KGr_Hq_EOKjs_E5_Pgpep_Q6_BOVzos_K_k_Q_60_35_Copy.jpg) (http://postimage.org/image/buue9yjxb/)
it is essentially like a drill chuck. It has grub screws at one end and a chuck at the other you tighten with a pair of small spanners. The bore on the grube scew side is usually very tight so it is not normally an issue with eccentricity. You can use this one, BUT you will have to confirm the diameter of motor spindle:
https://astecmodels.co.uk/catalog/product_info.php?cPath=1_43&products_id=668&osCsid=9bf2b57ed103bde0696f649f7f7c6523
the motor spindle usually connects to the large 4mm grubsrew side and the propshaft to the narrower 2mm chuck side. But in your case because your motor spindle will be the smaller counterpart compared to the propshaft you need to use the coupling in reverse so that the smaller chuck side fits on to the motor spindle %%
when changing the coupling the fan will be gone and so you will have to add a water cooling coil to the motor. you will need to measure the diameter of the motor first then look about to find the coil that fits. It would help to also add heat sink paste between the motor and the coil to aid thermal transfer. You will need to extend the shaft like was explained earlier in the thread. you will also need to move the rudder over and fit the water pickup for the cooling. Its probably best to get a new rudder with the water pick built in.I think this might be the right size, it seems right:
http://www.ebay.co.uk/itm/RC-Ship-55mm-Silver-Aluminium-Cooling-Boat-Rudder-HR275-/270757337152?pt=UK_ToysGames_RadioControlled_JN&hash=item3f0a651840
to get your shaft go to this bloke:
http://www.modelboatbits.com/
you need to email him and you and sort out an order. You want a 4mm propshaft, plain on one end with m4 on the other end. Tell him both the length of the propshaft tube required and the length of the inner shaft required too. Id also advise to get a central 3rd bearing too.
any question dont hesitate to ask :-))
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These look like fun! :-)
..... we could start a new race series with these!
http://tinyurl.com/mpl2uaz
http://youtu.be/kwTxZEInTI8
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Be warned!
We had the same idea at our club, 6 of us bought one only to find the (supposedly) 2.4ghz radio systems interfered with each other to such an extent that we couldnt run more than two at a time.
We gave up!
Anyone want to buy one? {-)
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Apart from the crap radio, how did they go?
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I can see it now....
The innaugral MBM Wickstead challenge series
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Topics Merged.
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Well I have bought one and mine seems to run fine, must have a lucky one I guess.
First thoughts
1. Quite impressive for the money, £35.00 GBP (fleabay)
2. Hatch seal soon came apart at the front, too much 'sticky' is my guess.
3. 'Safety cut off' very effective, wouldn't work with wetted fingers.
4. Thought boat was faulty, so put in bathroom sink to test. Emptied basin in 3 secs!
5. 30 minutes clearing up all the splashed water form above test.
6. Whole boats seems screwed together, including top deck. Excellent!
7. Radio says "27Mhz" but think it covers the whole 27Mhz spectrum.... and probably BBC local radio!
8. Added ' floatation 'to top hatch which will inevitably come off in middle of lake.
9. Will probably also upgrade to 2.4Gig radio, ESC and probably brushless.
On the water.
a. Runs very well on first run but has heavy bias to Port.
b. Rudder trim full Starboard but still pull to Port.
c. 'Vee' kink put in rudder link to set rudder to neutral.
d. Not had another run yet, hopefully this weekend. :-))
will add photos later......
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Photos...
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Photos...
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What sits in the compartment/case holder between the rudder servo & the bridge AFT of the motor?................I see a RED & BLACK wire underneath but no terminal lugs in the case itself for batteries.......
The mounting of all of the components appears to be well designed & very neat............Derek
(http://www.modelboatmayhem.co.uk/forum/index.php?action=dlattach;topic=36557.0;attach=126275;image)
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Hi Derek,
That's just the battery holder in the middle.
The black and red wires are the 'water' / safety sensors, one to the shaft and one to a pin head near the transom.
10. Will try and find some cheap 7.4v Li-po batteries
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Hi Martin,
It's no surprise the boat is biased to port, due to the propwalk of the clockwise turning prop.
As it's a small boat with surface piercing drive, propwalk is a bigger issue than with a larger boat.
The driveline should have built in offset to the left to counteract this phenomenon.
I'm sure it would be doable to alter this, but it's an awful lot of work.
Regards, Jan.
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Probably, but the rudder was offset by about 8o
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Hi Martin,
Than it's a good thing the boat isn't more powerful; when the boat is capable of going faster (by installing a brushless motor) the counter steering to track straight would make the rudderblade act as a lever, lifting the left rear and pushing down the right front.
Keep pushing the throttle and you'll see the boat stumble over it's own awkward running attitude (violently...).
I've tried it with several 50 cm hulls and none of them would run fast without horrendous crashes.
Only offsetting the drivetrain, so the rudder could stay straight, remedies that.
Regards, Jan.
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Hope so! {-)
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Martin just stick a 900 motor in it you know it makes SENSE O0 {-) {-) {-) {-) {-) {-) {-) {-) {-) {-) {-) {-) {-) {-) {-) {-)
Dave
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I have been reading this thread with interest as I bought 2 FT 007s, one for the grandson and one for me, we have had great fun. Based on a few bits I found in my spares box, mainly an ex helli ballraced exposed brushes 370 motor and a 29mm hydro prop I have decided to have a play with mine.
I am curios about the 10 - 13 % rule, is this 10 - 13% of the overall length, prow to transom, or just the waterline length ?
Also, there is hardly any room to offset the drive to counteract propwalk, if required is it OK to keep the shaft in the ventre of the vee and just alter the drive angle to suite ?
Thanks, V.
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Hi Victor,
If the new motor revs significantly higher than the stock motor, you'll suffer more propwalk and have to steer to keep tracking straight, I've explained what the consequence of that will be.
The FT 007 has a driveline, that runs clockwise, seen from the rear, which is opposite to what's custom in the boating world, so chances are that your heli motor and 29 mm hydro prop will rotate counterclockwise (again seen from the rear).
The propwalk will make your boat veer off to the right, counteracting it means offsetting the drive train (motor and propshaft) to the right making the boat unsuitable to run the stock motor and prop again.
The 10 - 13 % is the length of the hull, from the tip to the transom (not including any overhang at the transom if there is any).
The smaller the boat the shorter this distance can be without compromising the running attitude (too much).
If you power the hull beyond the stock setup, you can't cheat too much without running in to trouble...
Behind the transom of the boat a 'dent' forms in the water, as the boat picks up speed; at a certain speed this dent will sit in the spot where the prop is, this causes the prop to lose grip, the revs go up and the speed goes down.
The dent disappears and the prop has grip again and the game starts all over.
On an existing setup you can overcome this by using a larger diameter prop(with a lower pitch if available), but the motor (and ESC, battery and wiring) has to be able to cope with the higher ampdraw without overheating.
The angle of a surface piercing drive has to be as shallow as possible; when the boat sits even keel on a flat surface, the rear bearing has to sit 1-2 mm (more if the hull is larger) above this surface.
Too steep and the prop will be too submerged, drawing way too much amps and pushing the bow down, too high and the prop will loose grip as soon as the boat gets on the plane, as the prop gets lifted out of the water.
A picture to show the angle:
(http://www.modelbouwforum.nl/forums/members/pompebled-albums-arpro-700-ep-picture16278-ashoek.jpg)
Getting the angle right, along with the distance between the prop and the transom, often requires a longer shaft, as simply moving the motor towards the rear compromises the angle.
Regards, Jan.
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Thanks for the info Jan, I realised the situation with the drive length and direction of rotation, as a result I am planning to fabricate a new wire drive to the correct length. I shall also build in some adjustment to allow me to alter the thrust angle to counteract the prop walk. I also want to alter the speed control by switching 2 lipo cells between series and parallel as I don't like ESCs with low voltage brushed motors, OK on scale boats but not if you want to go as fast as possible.
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Hi Victor,
An ESC for a brushed motor is preferable over switching on and off and switching between cells.
This is 'technology' from the '60, damaging to both motor and batteries due to the spikes during the switching.
A cheap forward only ESC (from HK) will do a much better job:
http://www.hobbyking.com/hobbyking/store/__33945__Turnigy_30A_BRUSHED_ESC_EU_warehouse_.html?strSearch=brushed
Regards, Jan.
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OK, as a relatively new member of the boating fraternity, I bought one of these as an addition to my (ahem) Son's R/C Boat collection (first one was the Baloptera Musculus).... and to begin with, all was relatively OK, but after a few months of very sporadic usage, I have two issues - the first is that the boat stubbornly refuses to turn to port with anything less than the turning circle of an aircraft carrier (yet will spin on a sixpence if turned to starboard). I have tried rotating the trim switch in all directions, to no avail.
The second issue is that the connectivity between the boat and the remote control often fails, only to re-engage without any apparent rhyme or reason. Hugely frustrating (for my son of course), and the issue can last from anything between 5 and 30 seconds, each time it occurs (and it occurs regularly at each outing).
Can anyone suggest, in layman's terms, what I might do to remedy the issues?
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Hi Tony,
Mine had a similar issue, turned out that my rudder - servo link was off set, Out of water, check the rudder moves equally left and right, even a few degrees can make a huge difference. You may need to take off and reset the servo arm too.
Check you boat receiver that there is no signs of water ingress...
Martin
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Hi Martin, thanks for the reply.... so, I checked the rudder servo in the sink, it appears to be moving right up to the port/starboard stops, no visual difference in rudder deflection from right to left, although the servo does still try to keep pushing when the control is moved to full starboard steering, although that stops if I trim slightly to port. I have two holes in the rudder connector, and it doesn't appear to make any difference which hole I put the wire connector pole in. I also noticed that the servo tab has 3 holes (vertically), but I didn't experiment there as the wire pole looks securely fitted, and would need unbending to get it out....
Regarding the receiver, there appears no water ingress, indeed, hardly any water gets into the boat after a run, it is quite watertight.
I should also mention that the controller had a completely new battery, so it can be ruled out....
Any further thoughts?
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Oh, and I erred in my initial post, it turns quickly to port and poorly to starboard.....
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Hi there just a thought pos an intermittant servo fault with the rudder, also with the radio cutting out sounds as if your getting co channel interference are you using the standard rc kit that came with the boat, if so change it ASAP as some of the cheaper end rc kit receives on three channels the problem seems to be other boaters using adjacent channel kit hope my input is of help keep on tugging YAAAARG.
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Thanks for that, I am a novice in RC Boating, but I can confirm that the boat has original kit only, and we have tried operating this boat on the water only, doesn't change the fault....
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Try actually measuring the swing from centre to left and centre to right with a compass or ruler...