Soloratov

My Feedback: (1)

Well, in my quest to design my own 1/4 scale truck, everything has gone very easily, however, I have hit a giant wall with the differential issue. I don't have the cash to dish out and buy something from FG or another manufacturer, and it's getting really hard to find anything that will work. The thing is, I don't need a gearbox, no ratios of any kind, this is taken care of already in another system, all i need is the diff itself.
I am greatly against a straight shaft, and I just don't know where to turn. I need something that will fit a wheelbase of about 24-26 inches and can take the power from a 50cc motor. (limited slip would be my dream, but, eh whatever)

If you have any ideas, please let me know where I can find the items. Thanks.

funshawstud

bottom line
you need to design and hand machine the parts or purchase them
anything else will be cheesy at best , I have designed allot of complicated technical machines and if you want it right you buy the parts and design around them or design the parts and make them yourself.
Odds are slim you will go to a junk yard and find a perfect little diff in a washing machine or somthing ! and if you did it would not last after all the hard work of getting it together.
Just build what you can now , save up and buy a proper 1/5th scale diff man. End the suffering and save yourself the pain !!!!
Mike

Soloratov

My Feedback: (1)

Thanks, I was planning on just designing the diff if I had to, I have access to all the gears I need, it's just the housing I am worried about, that and the carriage for the bevel gears, but, I'll work it out. Thanks.

jimbo1890

Just an idea
what about something from a ride on mower??

mbba2002

My Feedback: (10)

To buy gears that will hold up to your motor will be more expensive than using FG parts. My limited slip diffs are for on road use only. After that all my off road trucks use solid axles. My limited slip is for 6"-7" light weight tires max and for bigger heavier tires I use solid axles.
Weight is the biggest thing to overcome. The lighter the better on drive line parts. A 2 wd off road truck should weight 35-45 lbs. max. Monster truck 4x4 should weight 55-65 lbs max with all options and a 3-4 hp Zenoah motor.

funshawstud

I must say those diffs are impresive.
Nice machining work mbbaj2001.

Soloratov

My Feedback: (1)

I'm looking at having an approximate wieght around 50lbs. I was going with a solid axle in back, but was worried about the turning ability. The truck overall is 48" long, 23-26" wide (with tires). Kinda big, and have 10" dia. tires. If I can use a diff to improve the handling i will. What would be the cost if I wanted to get one of those beauties from you, if they would work?

mbba2002

My Feedback: (10)

Your best solution is to find speed reducer gear boxes with a 6:1 or 7:1 ratio with large tires. My MT 1/5 truck has 12" tires with 4 wheel steering weight 55#.
My 1/4 off road truck has 9" tires weight 36#.
1/4 scale rear ends parts are expensive and hard to find.
all my parts work for 1/4 scale.

VAPER-ACE

HI . MY 1/4 SCALE DRAGSTER IS 64'' LONG.I WAS THINKING OF USING THE REAR WHEELS FROM A RIDING MOWER.THERE 5'' WIDE/12'' DIA. I,M USING A 33cc CHAINSAW ENGINE
WITH CHAIN DRIVE.
ANY IDEAS WILL BE HELPFULL.

Mike@Accurate

I'm just about done with my scratch-built buggy. It has a 27" WB & 11" tires. I've used a poor-man's limited slip on the Go-Karts I've made for the kids. Mount the RR with a solid hub, maybe keyed to the shaft. Mount the LR with a solid hub made of UHMW or something. No key. I put a good shaft collar on the inside (drilled set-screws) and thread the outside. Use a washer on both sides of the hub. I use a nylon insert nut and tighten the wheel untill it is hard to turn. By turning while you tighten, you get a feeling for the "break away" torque. Make it as tight as you can, and still steer. I shoot a little dry moly on the axle the first time I put it together. This has worked really well on my kid's Go-Kart. It will move with the RR off of the ground. The only diff/axles I've seen were for bigger Go-Karts and had 3/4 or 1" axles. The center was too big (Dia) for a little off-road buggy.
BTW, my kids' karts were built for them when they were each 4-5. The first (Tom is 13 now) was 25cc Homelite powered (16:1 XL timing-veebelt-#35 chain reduction/8" tires/belt tensioner clutch) and made of wood. The second (Steve's 9 now) is 72cc 4-stroke Kawasaki (generator engine) and was made with machine tools & stuff I now own. It is steel-tube and has disc brake/chain jack-shaft 16:1/centrifugal clutch/13" tires. Good luck, MIKE