HBX Devastator = Sumo XL

[penneyma79]

Originally Posted by Sparks1337

Yeh good idea I was starting to think along those lines, I just wasn't sure how strong the joint would be.

Can't hurt to try though. I'll have to see what brass tube I've got lying around The spare axles from Banggood are only £5 each so I've ordered a couple of sets

For now it has gone back together with a ball bearing behind the pinion and a 0.5mm shim on the driveshaft side to remove slop. I added bearings in the hubs and another shim to keep the diff gear steady. Axles run with much less slop now.

I also took the opportunity to shorten the links down to their minimum length. This meant I had to move the shock tops back one hole to regain some movement. It is now 135mm wheelbase - 9mm less than out of the box which should give the drive shafts a bit of a break.

This might be a stretch, and I did NOT search threads yet- Has anyone tried casting their own gears and/or axles from resin of some sort? I know a lot of resins alone prob wont hold up long, but there are some that might. Axles I assume could be made composite by casting the ends right onto a hollow tube, could be a way to lengthen drive shafts too, would have to find a way to add mechanical adhesion between resin and whatever you use as a tube. JB weld is super strong, I'm curious with a decent pour, meaning no air bubbles, if all teeth would show up and not tear off under stress.
I am considering trying a ring and pinion in a lesser quality rc that is rebuild able to test this theory. By pressing ring into modeling clay, which is pretty hard when its cold, you should get good enough detail to accomplish a good one part mold. thoughts?

[spoo76]

I've thought about it. I used to work with very high quality poly urethane. I don't think it would be quite as strong as a stock gear only because of the small size of the gear itself, but it should be strong enough for normal crawling on lighter rigs IMO. It may or may not hold up very long to heavy brass builds,getting bound up,speed. Though it should be Ok for slow crawling on lighter rigs and you could always cast more and change them often. There are things you can do to tweak it as well. One thing for sure is finding a suitable material to cast. The stuff I used to use had some great properties that would make it ideal,but it was very very expensive and could only be imported from another country. Its a little bit of a drive now,but I've thought about visiting my old job to see a friend that worked in the department with me. I had hopes of getting a tiny bit to sample.

[penneyma79]

I may get some refuse samples from my father, who in the auto body industry uses probably ten different urethanes, glues and other materials which usually have a bit of scrap at the end. At least I could check the material strength that way. If I find something I think may work, I can have a coworker sell some to me at our cost and try making some parts...Having some ideas about making extra axle housings and things of that nature...

[spoo76]

Haha great minds think alike. It seems in this hobby if you wait long enough someone will do all the hard work for you lol.

[johnnyh66]

Thanks for the write up and heads up!
I just ordered 1 and a few spare parts/lipo's.
I hope to take this little rig backpacking through the mountains next year.
I was going to build a lightweight MRC but when you are carrying 50lbs on you back for a week... every once counts!

[penneyma79]

Sounds like a great deal of fun! Do you have a specific area in mind for this trek?

[johnnyh66]

Hiking to Gannett Peak in Wind River Range, WY... we go entire days without seeing other people.

[Brake Weight]

Originally Posted by johnnyh66

... we go entire days without seeing other people.

Best part...and the beautiful scenery, too.

[Sparks1337]

oof that looks amazing. I'm suitably jealous

Okay so for the removal of any doubt, this thing is definitely using different internals in the axles, with no possibility of changing the bushes or adding the extra bearings.

I decided to keep this truck as a crawler and picked up a set of proper redcat axles for my go-fast project:



You can see the redcat axle comes apart easily while the HBX is definitely a single piece. Also the HBX is much fatter at the point where the outer bearings should fit.

This is probably fine at crawler speeds and it shouldn't break any time soon, but I didn't fancy putting 3s through those bushings. Shame they chose this as a place to cheap out on.

I also found the axle casing is slightly different - the outer caps that the steering knuckles pivot on are made from a slightly thinner plastic, and the tiny mounting screws are slightly shorter. The end hole is also a larger dia to get over the dogbones.

Again not really an issue unless you're thinking of mixing and matching with redcat parts but worth a mention.

[penneyma79]

So, redcat bearings wont help. Dang. Vaca location=wow!!

[Sparks1337]

No they won't, not for the axles.

Still worth getting eight 3x6x2.5 bearings for the C-Hubs and two 3x7x3 for the diff pinions though. Every little helps

The only way I could see to try and change those axle bushings was to heat the dogbones and knock the pins out - that way you can slide the bearings on/off. Unfortunately I managed to heat the shaft as well and bent it

No matter as the spare is available on Banggood for £5 and I have two in the post to me. It was worth a go, but requires someone with a bit more talent

[penneyma79]

Originally Posted by Sparks1337

No they won't, not for the axles.

Still worth getting eight 3x6x2.5 bearings for the C-Hubs and two 3x7x3 for the diff pinions though. Every little helps

The only way I could see to try and change those axle bushings was to heat the dogbones and knock the pins out - that way you can slide the bearings on/off. Unfortunately I managed to heat the shaft as well and bent it

No matter as the spare is available on Banggood for £5 and I have two in the post to me. It was worth a go, but requires someone with a bit more talent

You are braver than me! I am so concerned with trashing my original parts I waste 4 times as much time building my own instead of spending a few bucks to buy what I need. But, with two kids, a dog and a wife, Papa hasn't got extra funds for toy truck parts. Heck, got yelled at for buying some extra coffee for work just for myself!!

[Brake Weight]

I've wrestled mine for two days now. I had it reduced to a pile of bolts, spacers, and plates numerous times. Nothing seemed to work out right for me due to the motor setup contacting the driveshaft. I've finally got it built up like I want it and need to address the motor situation some more. Then it hit me...why not rotate the little transmission 90* to put the motor on the high side and clear.

I'll be heading to the LHS tomorrow in search of a bag of stuff to get this one and three others operational. I'll also be looking for some 1/4" or so thick delrin or plastic to make a tranny skid for this HBX.

[penneyma79]

Keep it up BW, sorry,I don't know your real name. Ha ha, anyhow, keep it up,I too have spent a fair bit of time lately thinking through my own build, so I don't have to rebuild it a fifty first time. And this is my test rig. Good thinking on rotating motor! Been wanting to see another build like yours! :-)

Sent from My Galaxy using the Force

[Sparks1337]

Brake Weight I had some of the same issues with the motor - I found I could only shorten the links a little bit before it started getting in the way.

Might help to swap it for a losi unit as it has a shorter can. Pinion would probably need swapping to be compatible with the reduction box tho, and I'm not sure how easily it will come off.

Another easy option would be Fungi's losi/sumo adapter skid plate which clocks the tranny like you have said. Trouble is its designed to work with a losi chassis so the width is wrong for the HBX :/

[Brake Weight]

I'd hate to swap it out. If I were to start swapping everything out of should've just gotten a Losi in the first place. This was about $50 cheaper than a new Trail Trekker and has a decent rear steer setup and TX. I'm still looking around for something to use for a skid.

[Sparks1337]

I decided the bushings in these axles weren't up to it for the go-fast FOFF project. I've not given up on that idea, but it needs proper sumo axles with the extra bearings, so it's on the backburner for a while.

This is now going in a different, slower direction, I'm starting a separate thread for it:
HBX 1/20 Toyota FJ70 Cruiser

[Stiggolas]

Hi, new here and just taken delivery of one of these crawlers. It's badged as an FTX Ibex here in the UK. So far my 7 year old has managed to break a driveshaft by pushing the truck along the floor....managed to drill and pin the UJ to get it going again and now ordered a fresh pair of shafts. This is my first crawler having raced 1/10 buggies in my youth and I have to say I love it! Speed ain't everything. I would like to buy another for the boy, maybe give him the FTX and buy a Losi....we'll see. Anywhoo thanks for the thread

[Sparks1337]

Welcome aboard Stiggolas

I noticed it is now in the UK as the Ibex - a few months ago uk ebay sellers were selling it as a HBX lol.

When you come to fit the replacement shafts, remove all the links and wind the ends in a few full turns - you'll lose a few mm of wheelbase but it reduces pressure on the shafts

[Sparks1337]

... just re-read your post. Hats off for pinning the uj - I bet that required some patience!

Still worth shortening the links though imho - provided you keep an eye on the pinion angle when re-installing it'll help save your shafts.