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Picked up a Hirobo Invader off of Craigslist yesterday, and am pretty excited to rip into this thing and revive. The body looks like hell, but internals so far look pretty good. I've yet to open the gear boxes, but at least in the case of the rear with the clear plastic case walls, the gears look to be in solid shape.




The rubber is pretty shot, and unfortunately, they are heavily glued to stock wheels, which have also seen better days. So my first order of business here is to try and replace the axles with something that will accept a wider array of wheels. Hex adapters seem the way to go, but dropping the ones from my Kyosho Lazer ZX on the stock Invader axles leaves a couple cm of space between the back of the hex adapter and the carrier hubs/bearings. I don't necessarily mind spanning this space with nylon washers, but would like to have a tighter fit if possible.



From left to right are Tamiya, Kyosho Lazer, and the Invader axles. Tamiya are the right length, but the cup rubs on the inside of the carrier (a real bummer, as I'd love to mount some gold rims on this!). The Kyosho cups fit just fine and spin freely, however the taper is too far out on the axle and creates an even greater gap between the hex and carrier hubs. The cups are also a bit longer, which is perhaps too snug a fit with the stock dog bones.



Any Invader owners out there who've found a good fitting axle to replace the stock? Lots of info on the Zerda, but I've only found a couple posts about Invader mods, and the one that mentions hex adapters does not give specific info.

Thanks in advance!

I know this doesn't help much but BITD there was a two bearing upgrade kit that replaced the one big bearing with an insert that accepted two standard bearings and I think then used kyosho axles , good luck finding a set of those though , I think your best bet is a spacer of some kind .
It's worth mentioning that other than the colour of the plastic the hubs and axles are the same for the Rock n city/veyga ,zerda and alien invader so any upgrade or mod used on any of them would work , the Rock n versions had a two piece front hub but the bearing and axles were still the same .

Get a longer axle (hpi). Cut the cup off. Grind a flat at the end. Slide an outdrive cup over the axle and lock it with the setscrew.

These are from an academy str-4.
Don't bring your wheel too close though, or it will rubb against the screws that hold the bearing.

Dadio wrote: ↑Mon Dec 24, 2018 4:11 am axles are the same for the Rock n city/veyga ,zerda and alien invader so any upgrade or mod used on any of them would work

That's helpful to know! I was wondering what parts are interchangeable, and good to know at least those are. The extra arms that came with this are labeled Alien Mid, so I figure there must be others stuff that's plug and play.

Mr. ED wrote: ↑Mon Dec 24, 2018 5:44 am Get a longer axle (hpi). Cut the cup off. Grind a flat at the end. Slide an outdrive cup over the axle and lock it with the setscrew.

Good call, and will be my plan B! I found a design on Shapeways for 12mm Marui hex adapters that will hopefully just slide right on. And if the taper isn't right, they should be very easy to modify since they're plastic. Looking forward to their arrival.

A taper fit for a plastic hex is only going to work on the shelf , a 3d printed taper fit hex will be even less structurally sound so it really depends on if you want to drive it or not .

Dadio wrote: ↑Mon Dec 24, 2018 4:20 pm A taper fit for a plastic hex is only going to work on the shelf , a 3d printed taper fit hex will be even less structurally sound so it really depends on if you want to drive it or not .

Curious, less structurally sound in what way? Plastic hex adapters seem to be fairly common. The set of 4 via Shapeways are only $5, so if it doesn't work out, no big deal and I'll rig something more substantial up. The only thing I can think of that would "give" is if the taper winds up wearing out it could start to slip. But of course, here I am pouring over info on Marui Samurai conversions to see if there's another alternative someone else has already tried out

Like Dadio wrote, tapered fit plastic hex is not going to work for driving.
The plastic is too flexible and will most likely crack when pressure, to obtain sufficient amount of friction against the axle, is applied by the M4 nut holding the wheel.
Yes plastic Hex´s are common but only as crosspin mounted.

MR ED´s suggestion is an easy fix - I would go for that.

Mr. ED wrote: ↑Mon Dec 24, 2018 5:44 am Get a longer axle (hpi). Cut the cup off. Grind a flat at the end. Slide an outdrive cup over the axle and lock it with the setscrew.

Yup this sounds good if you want to drive it or just make up the spacer tubes .

A lot of 12mm hex adapters or spacers have a small flange at rear to stop the adapter hitting the outer part of bearing. Use a tapered file to allow adapter to ride further onto zerda tapered axle. The hex piece in your pic is a lot thinner than pieces on eBay for about 4quid. You won't be able to use non slip bar but can have pretty much the same fit as zerda round spacer. I put a pic in the HIROBO ZERDA. FROM WRECK TO RUNNER thread.

Use these on your stock axles:

https://www.gpmparts.com/team-losi-mini-8ight-alloy-hex-adapter-4pcs-set-gpm-m8010-p-90061544.html

Use screw for hex adaptor to lock onto axle. A sturdy fit and allows you to use 2.2 inch rims with easy.

I've used them and they are ideal for light running or racing. I'm sure you could use this mod for other Hirobo buggies too