Gearboxes (and motors)

[Broder Incertus]

Greetings,

Again contemplating what to build next, one idea is some sort of paddle tug (say something dieselpunk-ish inspired by modern Russian paddlers, e.g., http://img-fotki.yandex.ru/get/5107/vladimi-shulae.5/0_52e95_7b7090ce_orig and http://www.riverfleet.ru/fleet/list.php?SECTION_ID=3156), more or less Graupner Glasgow sized using Graupner paddle wheels (or something similar). But the motor+gearbox I've used before seems to be discontinued (the Pile-Mot used in the Glasgow), so what to use instead? Are there any suitable quality gearboxes available? Preferable something you can use with the motor of your choice, and for independently driven paddle wheels. Tank hardware?

tia/tm

[TailUK]

Look on Ebay for replacement Heng Long gearboxes.  I've bought several for various jobs and for the price the quality is excellent.  A pair of gearboxes with motors for less than 12.00GBP, bargain!

[Broder Incertus]

Isn't the diameter of the output axis of the Heng Long (tank) gearboxes on the largish side (8 mm or so)? Making the use of off the shelf timing belt pulleys harder?

[TailUK]

That's true but the output speed is around what you need for paddlers so you could mount the wheel directly to the gearbox or drill out the belt drive wheel to fit the Heng Long shaft which is 8 mm.  The advantage of the gear box is the torque.  To directly drive the wheel you need a fairly high torque motor.  The Heng Long motors are 6V 340 can motors and the torque is gained through the gear train but with large power requirements.  By using both boxes you can achieve "tank steering" quite easily and they look pretty cool when they're fitted.

[Broder Incertus]

Haven't really got the proper tools to trill out anything that size, and I'd guess the Graupner paddles wouldn't take kindly to that kind of treatment (but I could be wrong: happens most days). How easy is it to replace of the original motors? I've standardised on 3s and 4s LiFe batteries, and given the price of those I rather use the ones I have than buy a set of 2s. (A 6V motor on almost 10V would require additional gearing and run rather hot IIRC the bad old days doing nasty things to 6V SPEED 400s in parkflyers)

Perhaps there are some robot kit parts that could be used ... (though most of what I've found is rather lower power stuff – or very high power ...).

Apart from Heng Long tank gearboxes, what else is used? I've think I've seem Bühler motors being mentioned, but which Bühler motor(s) and where do you buy these?

[bill stafford]

have you thought about building your own paddler g/boxes ??
you can get tooth belt sets in MXL pitch at reasonable $$ approx. 50mm CtoC , or graupner gear sets in 3:1 ratio
mount these in a Alum. channel , slot the motor mount holes to allow adjustment of gear mesh or tension t/belts , mount the second set to form a Vee of 90 degrees between the 2 gear sets , then a HTD t/belt set of 3:1, from this mounted in the bottom of the hull, up to the paddle drive shaft , this gets your motors down low in the hull.
i have build a similar set up to this for a aussie paddler drive , not yet in the model .
 regards bill s

[Broder Incertus]

I have thought about it and dismissed the thought (the gearing I did for my one and only steam powered paddler is strictly DIY using timing belts – not working well; the gearing for my twin prop tug is also OD using timing belts – working very well).

I have found a geared motor intended for robots that seems to fit the bill at a reasonable price (about the price of two timing pulleys from HPC) and it's even sold locally.

[bill stafford]

its not that hard to build your own g/box , if you use t/belts , they need to be adjustable tensioned .
first reduction , simply slot the motor mount to allow a small movement (5mm?) of the motor , can be done w files
the first and second shaft need to be supported on the other side of the motor by a second alum. plate , this can be done w 3mm brass all thread bolts inside 6 mm brass spacers/columns
second reduction has the Centre to C distance , just slightly shorter than required too tension belt (-2mm?), to allow you to just squeeze the belt on , you then fit a flat pulley on a adjustable arm , to final tension belt , on its back side , last reduction is from g.box to paddle shaft ,using HTD t/belts
inside g/box use MXL belts , you tune the set up w different motors+speed control
jaycar in Australia make a 550motor+spur gear box ,in a ratio that is too slow , so we over drive the t/belt ratio to get paddle wheel revs ,1:2 say
aiming at 300-350 rpm
regards bill s

[Broder Incertus]

P'haps not that hard, but I'd need to build two 3-stage (or 4-stage) GBs to fit in a fairly small space, and I'd need four (or six) more pulleys than using an off-the-shelf GB, at about £10 per pulley: one of the Pololu 37D geared motors ought (!) to work, and they're less than £20. And good ol' KISS, with emphasis on the last S :-).

[bill stafford]

good luck , you have some options , and alternative ideas , let us know what works .
i have a 300 rpm motor +g/box from ebay , via china , to test for another paddler drive ,1 per paddle wheel , but on that hull ,. i`m trying concealed props , for full power only ,drive , due too the wind we get at our lake ,just to give me steerage way
will shape 2 1/2 circles in the bottom of the hull, to half conceal props , for any shows , i doubt any-one will pick it up , but i can block cut outs w false plugs.
i like to try different ideas w new models , only for the wind ,i wouldn't bother , model will be fitted w plastic paddle wheel kits from float a boat au
regards bill s 

[derekwarner_decoy]

Hi PD's ....& hullo Bill + Broder  .....yes windage can play havoc with steerage on our OZ paddlers especially the likes of PS Marion..........the skipper of which in a Video compares the windage effect on Marion even on a sheltered Murray river to an ocean going yacht under full sail.....many images of Marion depict her on a 5 ++ degree inclination as she rounds a bend....and is exacerbated by relatively low water velocity from the paddles over the barn door rudders as opposed to propeller flows mounted just in front of the rudders 

In theory.....adding a pair of concealed propeller's should help ....but I am not sure I would recommend them...........do we really want a paddler to turn like a tug boat?

Possibly the lessor of two evils would be an ACTion  manufactured mixer & speed controllers for each paddle motor........to achieve the same or similar result?........I tried it many years ago....however felt the setup was too touchy & very much a tank type drive

Please keep us posted on your progress/s..........Derek

[bill stafford]

gday derek ,
i think i meet you at Renmark , for the anniversary for industry , hello again .
 it is a option to fit a electronic mixer , i used 1 in a tug , but i fitted it separate to the rudder channel , so as i could selectively use it .
what i have done cheaply is put together a 4 micro sw , cam driven motor control , that i can stop or reverse seperate motors , tank steer , normally the 2 motors work together, 99% of the time .
when i need to , mainly due to wind , strong in the south ,i can independently control the 2 motors , to swing the model , to point it away from danger, man made islands , this would be less than 1 % of the time i use the model for , so it hardly justifies spending to much $$.
 the motors i will "hide in ps rodney " will be low power versions ,555, to 50 mm props , which i hope to wire up for ONLY full power use , to increase stearage way .
 as yet i have almost finnished the plan , but have not yet built the model , low spare time , due to job .
food for thought , regards bill s

[derekwarner_decoy]

Hullo Bill...39 years ago I drove thru Mildura on our way to Adelaide...........but never to Renmark......but now I fly....... ........

PS Rodney would be a fine vessel to model....has construction  started? & if so at what scale?......following is an extract of page 125 from Parsons.........

Derek 

[bill stafford]

gday derek ,
 seems i have the wroung bloke , sorry derek, im not good w names , getting old er LOL
my paddlers are built to 1/24 scale , penny is approx. 42 inch+16inch beam , not based on any vessel , rather a collection of photos
almost finnished ps gremma , but its a bit small , still sorting out trim ,have built hull for ranger+fitted paddle wheels , balsa+covered in f/glass .as i intend to build more of brewers paddlers , i will stick to 1/24 scale .
as you know , paddlers can do funny things ,i dont know what it is , but there is a connection to p wheel diam versus speed of hull , it seems to me , the bigger the diam. , the more thrust it will generate , but i dont know why ,also how does no. of floats work in to this ??
ps rodney , plan was generated from a lot of photos taken of Rodney Hobbs model at wentworth , hull was a educated guess , im still tossing around the correct draft , too shallow and it wont carry gear , too deep and it takes too much HP to drive hull, all my models are operational
paddle wheels are off the pevensey , brewers plastic kits , size approx. 1400mm loa+400? beam , hull balsa+f/glass, supers. , may-be 2 mm ply,w planking effect ,or HIPS, but its still in the planning stage , but im collecting parts and have built and painted the p wheels , i do not have a lot of spare time ,bill s

[Harold H. Duncan]

Further to your discussions, have any of you checked out Ivor Bittle's website?

http://www.ivorbittle.co.uk/Articles/Paddle%20wheel/The%20paddle%20wheel%20design%20study%20for%20the%20internet.htm

An engineers solution to the problem

cheers
kiwi