wheel drives

[tom bowen]

hi,has anyone teid useing a chain type drive and how did it work?also if you have where did you get the chain and the gears?i've thought about useing a gog type belt but i can't find any.i just don't like that oring that you have to glue together that dumas gives you with the creole queen,i can just see getting in the middle of the lake and the glue connection breaks.not a good day at the lake.thanks,  tom

[Eddy Matthews]

I've used plastic chain and sprockets from Hobbies of Dereham here in the UK, and I've also used Meccano metal chain and sprockets which is easily obtainable on Ebay. Both worked well....

If you want to use a more realistic roller chain, your going to have to pay a considerable amount of money!

[Peter Webster]

Tom,
       I have always used neoprene o-rings on my last three paddlers , the PS Pevensey, PS Capt. Sturt and the PS Phantom although I have never used the "you join them variety" as you said they can come apart and usually in the middle of the lake. I also put a few spares on the axle and check them before each session for wear. So far so good. I suppose I'm inviting disaster after saying that.
Peter Webster

[derekwarner_decoy]

Hi PD's.....Tom... you should never have to   glue an O-ring unless that is the only method of installation....if it was the case, MODIFY the installation as the glue used is that CRYNOCRY-alot stuff   :sob   and would only good for gluing your thumb & fore finger to the O-ring section  :

O-rings are manufactured in ever increasing sizes [and a number of sections] and measured as the bore X the section so the outer diameter = [bore + twice the section] etc - any roller bearing store will have an extensive range available in ANSI or BS Standards.... both imperial - Nitrile 70 Duro the preferred material for dynamic/rotational applications.... O-rings will stretch, but an increase in tension = an increase in friction

You could also consider manufacturing twin O-ring pulleys = twice the transmitted power - the big killer in small O-ring drives is the need to maintain approx 1/3 circumferential wrap on the diameter of the pulley, so with a reduction ratio... a method of attaining [or exceeding] this 1/3 wrap on the smaller pulley is to use over size/length O-rings & employ a third or 'tensioning' o-ring pulley

You can access "Stock Drive Products" from our Web Links & there you will find stainless steel or and plastic roller chain & pinions down to 0.1475" or 3.75 mm pitch.....  ...as Eddy notes..... certainly not inexpensive

[kiwimodeller]

Tom, I think it depends on how big the boat is and what it is powered by. I am playing around with a large paddler powered by a big single cylinder steam engine. I started with an O Ring drive and found that I got lots of slip, especially when leaving the bank but perhaps I should have tried double O rings as Derek suggested. I then tried a cogged belt and pulleys but found these needed to be so tight that it used all the engine power to turn the belt system and it would stall the engine at anything less than full throttle. I am now putting together a chain drive system using a .325" pitch chain. I found both 1/4" pitch and 5mm pitch chains which were nice and fine but had difficulty finding sprockets in the sizes I needed. I could have had some made but at an exhorbitant price so will try the .325 which I have sprockets for. Ratio also comes in to it, too high geared and the drive will slip more often. 5 to 1 seems to be about the concencus as a starting point. Of course if you are running electric power none of the above will probably apply and you will be fine with one or two O rings so I am sorry to have wasted your time with all this dribble! :twisted: Cheers, Ian.

[tom bowen]

thanks guys i will look to see if i can go a chain type drive or maybe 2 o'rings,ian you did not waste my time i love to here what everybody else does,it gives me a lot of good ideas. thanks,  tom