4x4mm steel u-joint - RC-Monster Forums

DrKnow65 · **4x4mm steel u-joint -** 11.29.2010, 10:40 AM

Hey guys, need a little help locating a steel ujoint that I can use to create a custom front driveshaft for my current hyper7 conversion.

I'm relocating the CD farther back on the chassis and want to section togeather a pair of 4mm (shaft) driveshafts with a ujoint and carrier bearing, but can't for the life of me locate a 4x4mm steel ujoint (or cvd if it exists).

Any body have any ideas? For reference the traxxas Villian XL uses a plastic version of what I'm looking for... http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXGBH2

Arct1k · 11.29.2010, 12:00 PM

http://www3.towerhobbies.com/cgi-bin...&I=LXJG59&P=ML ??

DrKnow65 · 11.29.2010, 04:17 PM

Arc1k, that might work if I could press one of the pins out and combine both metal yokes... Think it's possible?

simplechamp · 04:43 PM

I would say with a vice, hammer, pin punch, etc. it might be possible

Did you ever consider using center dogbones and drivecups instead of a universal joint? You should be able to easily find the right length dogbone, and for the center drives it should be fine as long as the angles aren't too steep on your new relocated CD location. Gotta have CVD/universal in the front, and probably should in the rear, but in the center a dogbone is fine IMO.

DrKnow65 · 11.29.2010, 08:42 PM

Simplechamp, the front dogbone would be roughly 6 inches long, and while I'm sure I could have one made, I'm afraid the first time it slams down the vertical force would bend the shaft. So I figured the individual 3 inch lengths of a two piece shaft supported in the center by a carrier bearing and flexing with the chassis at the ujoint would be a good solution.

I did consider doing two full dogbones both joining at a cup-carrier-cup rig, it just seemed bulky and troublesome to coordinate cleanly.

I realy thought there would be something maybe boat related readily available...

DrKnow65 · 11.29.2010, 08:47 PM

Basically I'm putting the CD right at the rear differential, motor coming off the front of the CD and ending up right on the center of gravity in the buggy.

Hope that helps clarify a little :-)

simplechamp · 11.29.2010, 09:33 PM

So you are basically trying to do a setup like the Hyper 9e? That uses a single large dogbone in the center, and seems to be working fine in that application. Heck, maybe a Hyper 9e dogbone would fit what you want to do?

Finnster · 11.29.2010, 09:43 PM

I think a single bone would be fine. However, you can always do a slider also. The cen genesis has a large slider and hardware for 8mm shafts and diff outputs. Cheap and plentiful as well.

DrKnow65 · 11:15 PM

Thanks finnster, I'll look into it.

Found this http://www.offshoreelectrics.com/pro...?prod=cen-bj17 it may work if I can drill the 1/8th inch end out to 4mm...

Missed your post simplechamp, I'll look at the 9e (completely unaware) :-)

DrKnow65 · 11.30.2010, 12:34 AM

Wow, looks like the 9e is set up very similar to where I'm heading with the H7. Think I'll send out a few PM's and see if I can find the exact length.

simplechamp · 11.30.2010, 01:16 AM

http://www.rc-monster.com/forum/showthread.php?t=20223

Forum member Marvin's thread about his Hyper 9e. He says the center shaft is about 20cm, which is just short of 8" so it may be too long. Even so, you could probably find a dogbone of the correct length from some other vehicle.

I would say the dogbone is the way to go, since it seems to work well for the similarly setup Hyper 9e. There will be some play with it sitting in the drivecups so that when the chassis flexes the dogbone will have some space to move and not get bent. Use small pieces of fuel tubing in the cups to keep the dogbone centered, and being rubber they will compress/flex when needed.