Delrin Ring-n-Pinion for PTI axles.

[K_B]

So there was some discussion over at one18th about Delrin gears for the PTI. I figured I'd start a thread here for those who might be interested, since one18th is T.U.

Mine showed up direct from GPM over the weekend. I'll be posting up my results shortly, but I still wanna do some experimenting with the stock gears. After tearing down the axle the other night, I'm semi-confident that I can solve the gear stripping problem with shims rather than spend $20 bucks on 4 plastic gears that I THINK will most likely do the same thing.

I'd be interested in hearing from anyone who might already be using the delrin gears to see if that will actually work or if the teeth snap off just like the stockers.

Better yet, if anyone knows of a manufacturer that makes METAL/ALLOY diff gears for the TC3/4. Definitely post up

[overlimit]

Finally, I've been waiting to hear from you or maxxitout on these.

Anyways, I've tried running a Traxxas teflon washer 6x8x0.5mm, p/n 1985 between my pinion and the bearing and it hasn't helped one bit at all. I really really hope these delrin gears work although I do hope someone steps up and offers a metal gear set for the goliath.
I'm getting tired of replacing these gears after every run (which is about 1/3 of a fully charged pack).

On a sidenote,
I'm kinda p.o.'ed at GPM right now. I just got an email from them this morning stating they're gonna ship my order tomorrow. I kinda thought they would have been arriving at my door within the next few days as it was Sept. 26 when I ordered them and they said they were in stock.

[K_B]

Well, that's not very re-assuring. I re-shimmed my front pinion but it too, didn't help any. But that was also with a ring gear that already had the teeth worn out. I'm gonna try it with my last set of new stock gears and see what happens. Interestingly enough, my rear diff hasn't had any problems. And I can't remember for sure, but I don't think it's shimmed either. I'm using the steel spool for the NTC3 which came with a black gear. But I was told that the black gear is the same material as the other gears, but so far, it's held up fine.

Hopefully maxxitout gets on here because he should have gotten his already.

[speedsport22]

Am I the only one that has never striped these gears? I run the steel spool in the front and the rear. 55t lathe motor, 7 cells and all. I to would like to see metal gears though.

[K_B]

I thought I was the only one that never stripped 'em... until mine stripped, of course. I don't have the same bad luck as overlimit though. Mine last for quite some time, usually months before they go bad.

So you have the steel spool up front as well, eh? And no strippage? WTF is up with the steel spool? Mine hasn't stripped either. Did your spool come with a black ring gear?

[Mechanicalbob]

I have been looking for a steel ring gear but have had no luck in finding one yet. But I have a gear company that I have delt with in the past and am looking into a gear set they have that could work. Here is the link to the gears I am looking at. http://www.qtcgears.com/RFQ/BevelGears.htm


Steve

[K_B]

Good find. I don't know anything about hardness but I assume since they list the hardness, these things would not be much fun to try and cut. Those spiral cut gears would be awesome. Those would NEVER slip. But they're probably twice the price of the standard bevel gear.

[JasonInAugusta]

Have any of you guys tried the stock gears on the Irrgang spools?

[K_B]

My front spool is IRS. And the teeth snapped off. The gear itself seems identical to the stock gear.

[overlimit]

Yeah, I have the Irrang spools front and rear. They don't hold up any better. It is the exact same gear as a stock PTI gear with the exception of a larger center bore. From what I understand the larger hole is from a Nitro TC3 and the smaller from an electric.

As far as the black gear/white gear thing goes I was told by friend that used to disribute Associated and race a TC3 that the white gears were the newer ones and they were supposed to hold up better than the blacks.
I think I kinda believe that, the black set I put in the rear seemed a lot harder than the white ones and they didn't hold up as long.

[maxxitout]

Hey there! Well I got the front Delrin gears in and so far so good. I have not driven much due to work load but I do believe the ppl with spools will need to drill out the center hole to fit :-( I am running modified/locked ball diffs and the new ring gear center hole diameter was made for this set-up. The pinion needed to be shimmed a bit like we talked about. All went inside the case fine. I did add a dab of clear diff lube for good measure. Now if only I can find time to do the rear and get it out to punish it for being a big cool looking paper weight...j/k!

[K_B]

Originally Posted by overlimit

As far as the black gear/white gear thing goes I was told by friend that used to disribute Associated and race a TC3 that the white gears were the newer ones and they were supposed to hold up better than the blacks.
I think I kinda believe that, the black set I put in the rear seemed a lot harder than the white ones and they didn't hold up as long.

I bounced that same question off Tony Phalen, an AE rep, and he said the exact same thing. But the black gear in my rear axle is holding up fine, so I don't know what's going on. I'm just gonna try to eliminate one variable at a time.

Maxxitout, hurry up and run that thing! I wanna know if those gears make any difference

[overlimit]

all this delrin floating around and no one has punished it yet???? Shame on you guys!
I know... you guys wait until I get mine and we'll see who can strip thiers out first. j/k

[Reflection]

I know it's a different ballgame but it might reassure someone. Behind my BIG outrunner and 8 cells,I was shearing teeth of my maxx spurs every 2 or 3 runs. I went to a delrin spur and have been running it for roughly 20 runs or better and it still looks new.

[K_B]

Well, that's re-assuring at least. Has anyone been sheering teeth of the pinion? Or just the ring gear? So far, I've only sheered teeth of the ring gear, which leads me to believe that mesh may be the culprit.

As I see it in my head, if the pinion is allowed to to slide away from the ring gear, only the shorter, stouter edge of the pinion teeth engage the taller side of the teeth on the ring gear, closer to the top of the teeth. This gives the pinion enough leverage to snap the teeth off the ring gear.

Not sure if that makes sense to anyone else though.

[overlimit]

Thanks Raptor, I'm keeping my fingers crossed.

My gears mainly show wear on the larger side of the pinion, not much near the smaller diameter. I do have one that is showing wear all along the tooth, but I don't recall what the shim situation was.

[maxxitout]

Hello again, Well I finally got both axles all done and did some crawling. Not one issue arose! The Delrin are holding up great. Due to the difficulty in getting the gears I couldn't bring my self to push them to extreme limits but a couple hours of crawling and no problems.

Some items to note while installing:

The pinion will need to be shimmed a tiny bit, but not much! When you test fit make sure the gears spin freely and no 'ratcheting' feel. I added some clear Traxxas diff grease. You may also need to either file the pinion shaft pin a bit or very very slighly notch the back of the pinion so it seats all the way on the shaft.

The ring gear is made for the ball diff type axle so if you have a spool plan on drilling it out to fit, hope it works for those of you. If you have a ball diff (plastic only version!) and want to lock it simply drill a hole through both outdrives and the ring gear while screwed together, then thread a set screw and file flush the end where the bearing seats. I can show a pic if anyone wats to try this.

I'll keep my fingers crossed and drive it some more today. I did get a couple extra sets of gears so maybe I'll push it for this first set and see what snaps! If only they sold them local....

[K_B]

I did some more experimenting with the stock gears this weekend. And I did just like maxxitout did with the shims. I used a TC3/4 shim kit and used 3 shims on both the front and rear pinion shafts. With my alloy spool in the front, there was some side-to-side play so I used one shim between the bearing and the ring gear plate on the spool. I used a body post reamer to enlarge the hole for the ring gear.

I took it out to my usual spots where I'd encounter a stripped R&P. And I beat on it just like I normally do. After a weekend of beatings (approx. 4 hours) I tore it apart and everything seems to be in good shape. But now my drivelines are bent so I have a whole slew of other problems.

As a side note, I encountered a seized CVD. A word of caution about LocTite:

Only apply a little bit to the grub screw that holds the CVD crosspin in place. If you drop a little bit in the hole instead, you're gonna be very frustrated later on. ;)

[overlimit]

I wonder when mine are gonna show up???
If these dont work I may be able to work a little magic on some TLT gears.

[Mechanicalbob]

I was looking around for a gear solution for the PTI/NTC3 diff. What I have found is a steel gear for the Losi Mini LST.


It looks very clost to the PTI/NTC3 ring gear.


I am thinking on ordering one to see.


Steve