Jump to content
MadInventor

Txt-1 Drive Shafts Made From Butter

Recommended Posts

My txt has eaten it's centre drive shaft UJ's for the second time. I've seen some people fit tnx drive shafts, can anyone advise if these are any good long term. I've had a look at the tamiya exploded diagram, and there appear to be different drive shafts for left and right (is this left and right of car, or left and right side of drive shaft (e.g. left side fits gearbox and right side holds axle.) If I need to get the parts, what part numbers do I need to look for?

I'm running 2 22T Kyosho magnetic mayhem motors with 19T pinions on an 8.4V battery and double diff locks. This seems a fairly mild setup comapred to wha tother people are using, but I'm still getting bad wear in the UJs very quickly.

The alternative is to make my own (I'm currently thinking 16mm dia shafts with 3/5mm dia UJpins, all in steel. (I've noticed I'll have to narrow the necks at one end to clear the txt centre gearbox.)

Similar to this

post-34100-1276554650_thumb.jpg

(This is the rear drive shaft I made for my 4x4 lunch box with bits from a slightly worn txt UJ.) All the positive comments I've received about the lunch box has got me making another for the front so that I can run it and do a vid.

If the TNX drive shafts are hard wearing and a reasonable price, I'll probably go for that rather than make my own because of the time involved, but if they're not going to do the job then I'd rather make my own and save getting something else which is not going to last. Any advice would be good.

Thanks

Share this post


Link to post
Share on other sites
My txt has eaten it's centre drive shaft UJ's for the second time. I've seen some people fit tnx drive shafts, can anyone advise if these are any good long term. I've had a look at the tamiya exploded diagram, and there appear to be different drive shafts for left and right (is this left and right of car, or left and right side of drive shaft (e.g. left side fits gearbox and right side holds axle.) If I need to get the parts, what part numbers do I need to look for?

I'm running 2 22T Kyosho magnetic mayhem motors with 19T pinions on an 8.4V battery and double diff locks. This seems a fairly mild setup comapred to wha tother people are using, but I'm still getting bad wear in the UJs very quickly.

The alternative is to make my own (I'm currently thinking 16mm dia shafts with 3/5mm dia UJpins, all in steel. (I've noticed I'll have to narrow the necks at one end to clear the txt centre gearbox.)

Similar to this

post-34100-1276554650_thumb.jpg

(This is the rear drive shaft I made for my 4x4 lunch box with bits from a slightly worn txt UJ.) All the positive comments I've received about the lunch box has got me making another for the front so that I can run it and do a vid.

If the TNX drive shafts are hard wearing and a reasonable price, I'll probably go for that rather than make my own because of the time involved, but if they're not going to do the job then I'd rather make my own and save getting something else which is not going to last. Any advice would be good.

Thanks

Most people use Revo shafts. I went that route as well. The only problem I had with the Revo shafts was that the joints that go to the transmission need to be pretty tight and the set screws just thread into plastic ends. Mine stripped out pretty quick under my twin Titan 550 14.4 volt setup. I solved the issue by swapping the TXT metal joint ends onto the Revo shafts and all is happy again.

Share this post


Link to post
Share on other sites

Don't you get the same problem with the original txt ends wearing against the steel pin like this. (Sorry for the duff photo, it's the best camera can do)

post-34100-1276578967_thumb.jpg

I would have thought that using the original txt ends you'll still get the same prob as you've strengthened the rest of the drive shaft, but the brass txt yoke is stilll a weak point ????

If I'm doing this to mine on a 8.4V battery in maybe 7-8 runs, is having the diffs locked causing the problem (I use my car mainly for hill climbing, and have run it either on short rough grass or sand dunes). I have noticed that it's mainly the rear end drive shaft that wears.

Share this post


Link to post
Share on other sites

Thanks for the feedback guys. In the end I went for the REVO drive shafts, as they were considerably cheaper than getting all the tamiya bits for making up the TNX drive shafts. I did have to make several modifications in order to fit them however:

1. Cut off factory seals and shorten outer casing of slider by about 30mm.

2. Shafts at the axle end fitted perfectly, just slide on and add the retaining pin.

3. Rear shaft fitted to centre gearbox without modification to the gear casing or shaft, but I did need to file a small amount off the lower gearbox heatsink in order for it to clear the drive shaft, as well as make the flats on the centre gearbox drive shaft slightly longer so that the retaining pin would fit properly.

4. For the front drive shaft I had to increase the length of the flats on the centre drive shaft (only about 1mm), but I did have to turn a small amount off the yoke for it to clear the gearbox.

5. I also fitted some rubber boots to the lower UJ joints to keeep the dust out of them.

UJ fitting to centre gearbox, note the turned down yoke on the front UJ.

img33435_26062010232014_1.jpg

HUCO UJ rubber boots, perfect fit for the revo shafts

img33435_26062010232014_2.jpg

The first time I tried them out, they worked very well but the car only lasted about 3 minutes. Whilst making a turn the car lifted on two wheels, so I turned into it to prevent the roll and the front wheel dug in and lifted the whole car up onto the one front wheel, at which point the front wheel parted company with the car :blink: . When I investiagted, the centre of the stub axle carrier had been ripped out. I've never had this happen before, but I guess it's a lot of weight to put on one wheel, especially with the front diff locked.

To try and improve on locking the front diff, I'm in the process of making my own 1 way roller unit for it. I've machined the centre out of the main diff gear, and attached the 2 sides of a TT01 one way to each side (Making sure that the rollers are going in the right direction ;) ). I've also had to make my own drive shafts as the standard ones are splined on the end and won't grip the one way bearings. The drive shafts are nearly finished, only problem is that I have to get the ball bit on the end machined on, I tried to shape it with a file while spinnning it in the lathe , but the axle binds when steering is operated, so I've got to get a ball turned on the end with a CNC. Otherwise it's good to go :D . I just hope the TT01 one way bearings are up to taking the torque......

Home made drive shafts and TXT-1 one way unit. Drive shafts use pins punched out of DF02 dogbone shafts.

img33435_26062010232014_3.jpg

Close up of left hand side one way roller fitted to txt gear

img33435_26062010232014_4.jpg

Share this post


Link to post
Share on other sites

I use Traxxas Revo Driveshafts for mine as well after the same happened to me. I am running twin HPI 550 motors at 14.4V so there is a fair amount of torque going through them. I haven't had any more problems with them and if I do its a quick and cheap fix. I am having more problems with the rear gearbox poppings its top mounts :blink:

I used the HPI drive shaft grub screws as they are the right length for the shafts when they go into the centre drive shaft and they just tap straight in.

Share this post


Link to post
Share on other sites
Thats a neat mod ;)

It'll be interesting to see how it copes with the torque of the txt-1's transmission, hopefully it holds up :D

Yes, I'm wondering about that myself. I'm only going to use an 8.4 battery with the magnetic mayhems (22T motors) running 19T pinions. The major worry is the 2mm bolts holding the 2 halfs together as the original gear is only 1mm thick metal between the one way roller halves. If it works good but can't take the power I might try to get an engineering shop to make me a heavy duty one from a solid block of ally, with the one way bearings pressed into it. Got the finished drive shafts back today, so hopefully next week should be able to put it in the car and see what it drives like.

Share this post


Link to post
Share on other sites

Well, I've been out and thoroughly bashed the one way rollers in the front of the TXT-1, and I think I can safely say it's up to the job. I've been runnning the TXT on an 8.4V battery with 2 LRP 19Turn motors on 14T pinions and have had no problems at all with the transmission. Nice tight cornering now with on 2WS at the front, and it still flys up hills even with an unlocked diff in the back. Only disadvante is that if you do get stuck you've only got 2wd to back out, but being able to do tidy handbrake turns and being able to apply hard braking to the rear wheels going down a steep slope without flipping the truck over more than makes up for it. :(

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...