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4WD Gold Tub
Posted: Sun Mar 24, 2013 3:36 pm
by Road Burner
I had a nutty idea to use a nitro DS gearbox and convert one of my runners to 4WD, very similar to the elusive MIP conversion. I used 834-b C-hubs and Yokomo wheel adapters with Tamiya knuckles, axles and carriers. Everything seems to be working except the gear ratio up front is too low and need to find a smaller sprocket. I hope to use the gold tub scraps for a chain guide, etc. And ideas or comments are more than welcome, I'm kinda stuck at this point. Thanks!
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 3:46 pm
by discgolfer72
thats sweet i have been wanting to do the same but i have an old gear box from a hotshot (or somthing like that)
just been trying to figure out how to do it
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 5:59 pm
by losiXXXman
Cool project! I saw this a few days ago on TC. But over there, I mainly just look at pictures.
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 6:11 pm
by GoMachV
Looks very cool, I have had similar ideas but seeing it mocked up and functional gives me even more ideas
Is there a reason you used a gt gearbox besides the fact you had it lying around? What did you do to pin the idler to the new shafts?
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 6:17 pm
by Phin
Looks pretty good so far. How many teeth are on the sprockets?
Going off the idlers with the chain, you've got 2.6 at the front and 2.25 at the rear so I'm thinking you're going to need 13t front and 15t at the rear sprockets to get the ratios as close as you can. Could also opt for overdrive and go 12t/14t and get yourself down to ~2.23 at the front.
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 6:26 pm
by marlo
should pan out to be a very cool build.
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 6:31 pm
by Road Burner
discgolfer72 wrote:thats sweet i have been wanting to do the same but i have an old gear box from a hotshot (or somthing like that)
just been trying to figure out how to do it
I was thinking Tamiya TA gearboxes with shaft drive too, maybe for a future project. I just chose this because I had the parts and everything else just fell together!
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 6:51 pm
by Road Burner
Phin wrote:Looks pretty good so far. How many teeth are on the sprockets?
Going off the idlers with the chain, you've got 2.6 at the front and 2.25 at the rear so I'm thinking you're going to need 13t front and 15t at the rear sprockets to get the ratios as close as you can. Could also opt for overdrive and go 12t/14t and get yourself down to ~2.23 at the front.
Thanks Phin I've got a 12t up front and a 13t in back. Thanks for the ratios, I tried to find them earlier but failed and continued the build knowing this would have to change. Hopefully they don't cost me too much. I wonder if I can make them myself without nice machines?
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 6:55 pm
by Road Burner
losiXXXman wrote:Cool project! I saw this a few days ago on TC. But over there, I mainly just look at pictures.
Thanks. I do a lot of the same there too.
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 7:11 pm
by Road Burner
gomachv wrote:Looks very cool, I have had similar ideas but seeing it mocked up and functional gives me even more ideas
Is there a reason you used a gt gearbox besides the fact you had it lying around? What did you do to pin the idler to the new shafts?
Thank gomachv, I hope you run with them! No other reason for the gearbox. I originally was inspired by an SP-1 gearbox I won from ebay. When I found out it is essentially an SRB gearbox
my gears started turning. I was never going to run the DS again and had already dismantled it to convert to electric. The shafts are the other unspoken problem. I used 3/16" aluminum with steel 3mm screws sandwiched between the pins/screw for sprockets inside the tube. I cut recessed in the idler gears for the pins. I am not a machinist so I would eventually need these made - two identical input/output shafts 3/16" drilled for pins, stepped up to 5mm for the Yokomo sprocket and drilled and tapped for the set screw. Right now I have tape filling the small gap between the shaft and sprocket.
All I can say right now is that I'll run it and see how she holds up!
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 7:35 pm
by Phin
Sprocket should run you about $6-10USD (+shipping) so long as it's not a hard to find pitch.
If you want to take a random shot you could try this 11t Kyosho Mad Force sprocket up front:
http://www.amainhobbies.com/product_info.php/cPath/1_25_1460_1374/products_id/163323/n/Kyosho-11T-Sprocket
Might not be the same pitch though, and you'd have to use a thin sleeve/tube inside the bore since the sprocket is likely made for a metric shaft and the stealth idler shaft is 3/16". If it works you'd be at a 2.2 ratio up front which is pretty good.
Any plans to lower the kick-up angle?
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 7:43 pm
by tiger1
nice work. Would you mind to show some close up photos of the front gearbox and how it is mounted?? Thanks
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 8:28 pm
by Road Burner
Phin wrote:Sprocket should run you about $6-10USD (+shipping) so long as it's not a hard to find pitch.
If you want to take a random shot you could try this 11t Kyosho Mad Force sprocket up front:
http://www.amainhobbies.com/product_info.php/cPath/1_25_1460_1374/products_id/163323/n/Kyosho-11T-Sprocket
Might not be the same pitch though, and you'd have to use a thin sleeve/tube inside the bore since the sprocket is likely made for a metric shaft and the stealth idler shaft is 3/16". If it works you'd be at a 2.2 ratio up front which is pretty good.
Any plans to lower the kick-up angle?
Thank you phin I'll take a look at that but I found a link here for a company that makes these ladder chains and sprockets in many sizes. I have not thought about lowering kickup, do you think I should? If so it's possible by adding spacers to the front support tubes right? Thanks for your input phin!
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 8:50 pm
by Road Burner
tiger1 wrote:nice work. Would you mind to show some close up photos of the front gearbox and how it is mounted?? Thanks
Re: 4WD Gold Tub
Posted: Sun Mar 24, 2013 9:05 pm
by Road Burner