Cheap NO SLOP hex mod using stock 17mm adapters

[pavmentsurfer]

There was a thread about this idea a while ago but I haven't yet seen anyone actually do it. My ERBE had some slop in the hexs so I figured since I had a spare set I might as well try cutting them down and seeing if it works. Heres what I did.

I cut the threads off the stock 17mm adapters leaving only the hex. I used a battery powered sawzall and the cut was actually pretty good. Pretty clean. Heres a pic of a newish set of hexs on the left and my cut hexs on the right:


The next step is to use some sort of cone file (or in my case a cone bit on a dremel) to clean up the cut end of the axle hole. If there are ANY burrs the hexs wont slide back over the stock axles. I learned this the hard way:


Then, of course, re-install the hex using the stock screw pin. Nothing special about this except the threaded end of the adapter is missing:


Lastly, install your wheels (with this mod you can use standard 17mm wheels OR traxxas style 17mm wheels) using the nut from the HPI 17mm hex set:


The results of this mod is nearly ZERO slop. After the install is done any looseness in the adapters is gone and the wheel is tight on the axle. Total cost, about $10 for the HPI 17mm hexs and nuts but you could probably get JUST the nuts for less if you look around online. Total time for mod, about 20 minutes with some good power tools.

There are lots of other options out there. But since anyone wanting these type of results likely already has a worn out set of stock 17mm adapters you might as well try it. You have nothing to loose.

[M n M]

Cool Idea Pave!

[Mark94]

Interesting... What causes the slop and does it take time for new hexs to wear or is their slop right when they are new?

I think I have the slop and was thinking of buying new hexs but if they will be just as bad, might give this a shot.

[87 GN]

Good idea if you are using Traxxas wheels. If not just use the HPI hubs. If you cut the hub down keep the hub face flat, or it will make the wheel wooble, even more. Not possible for most, but if you know somebody with a lathe, it will keep the face flat. The other thing I don't like about the Traxxas hubs is the pin. I have had to dremel the head of the pin off because of a stripped head, ruining a hub.

[pavmentsurfer]

The problem with the HPI hexs is they don't fit correctly. You need to use spacers, which isnt ideal. When I cut these ones down the face of the hex is more than flat enough to keep the wheel flat and tight and I didnt spend a whole lot of time trying to get them perfect. I think if a person had a hand metal saw they could do a WAY better job than me using the power saw. I have the HPI hubs and tried them before I did this and was not happy with the amount of looseness in between the hex and the carrier bearing. I tried to throw some spacers in it but it just felt all wrong.

The stock adapters wear after a pretty short amount of time. They don't wobble when new but it only took about 10 runs for mine to get loose. They are tight as a drum now.

[87 GN]

you have a good point about the spacers, if Traxxas would sell the MW 6x10x2. This washer is a spacer for the Summit Rocker Arm Post #5354. as a set. prob solved.
http://traxxas.com/forums/showthread...=1#post5065568
& post 120

[pavmentsurfer]

I did see that. Its funny you can't just buy the washer really. One TINY part is all you need. Hehe. I bought 2 sets of HPI hexs and nuts and planned to use them on my summit and ERBE but I think ill just use the nuts now. If the pins become a problem ill report on it here for sure. So far theyre tight. Im only running 4S though.... nothing crazy.

[M n M]

The problem with the HPI hexs is they don't fit correctly. You need to use spacers, which isnt ideal.

Yep this is true. I have a washer between my carrier and HPI hex nut.

[BL-Bob]

Cool Idea Pave!

Not his idea M n M like he mentioned above. It was Ducati777 who first envisioned the mod.

[pavmentsurfer]

^^ This is true... but I may be the first to actually do it. If not, I'm cool with that. Just glad i could clear up the fact that it works. Im going to do it to my summit as well in the next day or so. My ONLY concern at the moment, and it would be no different with any 17mm hex conversion, is weather or not the nuts will stay tight. I think they should. But you never know. My 17mm nuts didnt ever come loose. But time will tell.

[BL-Bob]

Okay cool. Oh no another reason for the chop shops to raise the price of hpi 17mm hex sets. They should stay tight the nuts are knurled against the wheel.

You would think Traxxas would figure a way to stop promoting hpi parts and fix the stock slop.

[Brewers74]

Wonder if the hpi differential will work on the erevo seeing how the stock ones are just plain pathetic

[pavmentsurfer]

So so true. Just curious. Do all 17mm adapters (as in, ones for other vehicles from other brands) suffer from slop after a while. My Ultra GTP2E doesnt appear to have any slop at all... just wondering what theyre doing different than what traxxas is doing.

[muck]

why not cut these so a little of the center still is there for the rim to center on but not so much a nut hits it. That would alleviate the concern over having a flat surface.
I was going to helicoil my old hexes but after being reminded of this idea, Monday's the day LOL

[M n M]

why not cut these so a little of the center still is there for the rim to center on but not so much a nut hits it. That would alleviate the concern over having a flat surface.
I was going to helicoil my old hexes but after being reminded of this idea, Monday's the day LOL

The HPI lock nut he is using in this mod has that raised 17mm portion on the back side of it. So it's not just holding the wheel on its also centering it.

[pavmentsurfer]

I suppose you COULD leave a bit... but like M n M said... the nut does this as well. Which is why I wasn't ever worried about getting the cut perfectly flat in the centre... I can see how it would be a problem if the whole hex was cut on an angle but as long as theyre cut like you see mine the wheel has no choice but to sit flat on the hex. Ill be out this afternoon testing these to see just how well they work.

[muck]

ok, i did this and found the RPM rims are a fuzz too thin. The Nut stop at the end of the threads and is not tight on the rim..... I think it would be fine on a stock rim or something a fuzz thicker...

[randy0050]

where is the slack coming from that you are talking about ? is it between the rim and adapter ? or somewhere else .. i'm no following .. where should i look for the slack ? thxs

[jamann]

It's between the hub and the threaded end of the axle stub. It wears the
?sleeve? Inside the end of the hub creating the slop.They were designed for a drive pin and nut style of hub,the mod does just that


Sent from my iPhone using My fingers

[randy0050]

so the steel axle wears out the middle of the alluminum adaptor ?

[muck]

the threads do. The adapter steps down to drop to the OD size of the threads. But the alum is soft and after a few runs with unbalanced tires, the threads start wearing into the alum adapter. If you pull yours off they may show the grooves from the threads..
There are a few different mods to help fix this.. I wonder if the ofna hexes for the maxx will be any better?

[randy0050]

okay thanks !! i will check out mine, cuz i put mine through the mill

[pavmentsurfer]

I got to test this setup the other day and the nuts stayed perfectly tight. Worked great. Cheap and easy. Ive seen few other pics from people who, instead of using the HPI nut with the flange simply used a washer and a stock traxxas nut for the 14mm hexs. Appears that works just fine also. Especailly if your switching from 14mm hexs as you'd already have the nuts.

[muck]

i may have to find washers and try that next then..

[pavmentsurfer]

Thought this was worth an after Christmas bump.

[Money pit]

How did I not see this??? Are you still running this without any issues? Mine are sitting in the toolbox and this looks like a good way to use them.

[50togo]

Nice mod. I could use that on my maxx. I just put the hpp hubs on my revo

[Jays200]

I just put the HPP hubs on my Summit. They are a quality product, if not a tad too expensive, and do what they say they'll do.

I did have a front wheel fall off though, with the centre locking nut with the o-rings on it still attached to the hub. It hadn't stripped the thread and the only thing I can think of is I must have not pushed the hub on over the pin far enough and the axle spun off the nut.

I don't know why Traxxas don't make a stub axle without the threaded section off the end. Just take it off the production line one step sooner.

[MITCH316]

Did you use loc tite to hold the lock nut in place...I use the HPP hubs and never have had a problem with the lock nut coming loose.

[Jays200]

Yes I did use a small drop of blue Loctite. On rebuild I cleaned the stub with contact cleaner and used substantially more Loctite on the thread.

Would only be a problem on the vehicles right hand side (looking from behind) since there are no left hand threads.

[hottrodd1090]

not sure if i'm allowed to say this but the powers to be will edit it if i'm not but RD Racing makes a sub axle for the stock axles the has no threads on the end.the only problem with that is its for the stock axle and most of us use the summit axles