glow plug engines

This topic is empty.

Viewing 14 posts - 1 through 14 (of 14 total)

Author

Posts
28 January 2009 at 20:12 #18185
John Edward
Participant
@johnedward60693
is it me not looking in the rite place or is there no gearboxes so my large model can go forward then in reverse if needed and stop to let bigger models by
Advert

28 January 2009 at 20:12 #5026
John Edward
Participant
@johnedward60693
29 January 2009 at 06:58 #18189
ashley needham
Participant
@ashleyneedham69188
John, I am not an I/C man myself, but I think I am right in saying that there are no gearboxes for i/c boats….you just go jolly fast one way only!! If you want variable speed and reverse, go electric. Ashley
29 January 2009 at 07:01 #18190
Paul T
Participant
@pault84577
Hello John

Ashley is correct…..if you want a gear box for a glow engine then you would have to make it yourself……try using a reversing kitchen type rudder.

Paul
30 January 2009 at 11:59 #18214
John Edward
Participant
@johnedward60693
thanks for the help boys but electric power does not give the same performance even when using 4 motors.

i will however post a set of plans once i have got it working
30 January 2009 at 13:23 #18217
Paul T
Participant
@pault84577
Hi John

What size and type of engine are you using?

Paul (the petrol head)
8 February 2009 at 17:24 #18368
John Edward
Participant
@johnedward60693
hi paul sorry it took so long 2 get back 2 you long days at work

the engine is a supersport 21 marine

why do u ask ???
8 February 2009 at 17:58 #18371
Paul T
Participant
@pault84577
Hi John

The reason for the question is that years ago I came across a marine gearbox for an IC engine that fitted onto a 3.5cc unit, I dont know if it was a standard model or if it been adapted from a standard unit.

The gearbox worked just like a full size marine gearbox (a bit like an autu box on a car) and was worked by a single servo.

You could try talking to Prestwich Models http://www.prestwich.ndirect.co.uk/fsrv/gearbox.htm

or try building your own gearbox from robotic parts. http://www.ema-models.com/products/04255-multi-ratio-gearbox.html

but I am not sure that nylon gears could withstand your engine.

Paul
9 February 2009 at 08:07 #18378
ashley needham
Participant
@ashleyneedham69188
Hi, I think that making a forward/reverse gearbox of the simple one shaft sliding cog type would be easy enough, the trick is the clutch, without which any gearchanging is doomed to stripped teeth and failiure…Thinking about it,a centrifugal clutch is the way to go…might be buildable on a small scale, but your enging would have to reliably idle, or at least slow down a lot sufficient to disengage the clutch, perhaps a larger that usual flywheel could be used, even using this as part of the mechanism??? the fat controllers liking for strimmer engines with built in clutches becomes apparrent!!! Ashley
10 February 2009 at 18:18 #18401
John Edward
Participant
@johnedward60693
hi paul i once saw a gear box in a verry impresive 1/25th scale model of an articulated lorry using a twin cilender desel !!!!!
28 March 2009 at 22:56 #19792
Andy Nightingale
Participant
@andynightingale93292
It’s easy on model cars, just about all out of the box cars do, but it would be damn near impossible on a marine engine. Not only would it probably do untold amounts of damage to the engine, if you did manage to get it to go backwards, due to the design of most powerboats, and the fact you’re using a very high powered engine, the back of the boat would dive in and fill it with water.
28 March 2009 at 23:13 #19793
John Edward
Participant
@johnedward60693
with the introduction of a cog between the gear box and shaft should work and if eny moter can lower a model boat that is a meter long and sits 25 cm out of the watter under it would be good for a laf
29 March 2009 at 08:14 #19795
Paul T
Participant
@pault84577
Hi Andy

Good point about the boat flooding from the transom and I agree that the type of engines that I like to use would drag the boat under the water if used at full speed in reverse.

That is the problem with RC car gears as far as model boat are concerned as they are designed to work at high speed.

With a marine engine you need a gear box similar to a full size boat or an automatic car where the gearing for reverse is slow i.e. geared down.

Paul

Andy and John would you do us the kindness of filling in your profiles as we would like to know a little bit more about the people we are talking to.

Edited By The Fat Controller on 29/03/2009 08:17:49
9 January 2011 at 00:42 #29380
phill d
Participant
@philld
Simple answer for foward and reverse on a model boat is to fit a Jet unit with bucket reversing aid.

This way you can get reverse and it wouldnt damage the engine, also you wont drown the boat by it diving into the water.

The downward thrust in reverse would keep it afloat..

There are a lot of jets nowdays becomming fashionable again.

phill
Author

Posts