Machine Robo / Gobots Machine Robo / Gobots Regular Gobots

Service: Gobot Tank (MR-02)

So, as per my previous post, I’ve been reacquainted some of my old Gobots I had as kid, and this is another retro toy that has a lot of very cool qualities, that still work pretty well today. The only issue with Tank here was his arms (and his missing guns but I’m sure they’re in a box somewhere!). The joints there have become a bit loose and don’t stick in place as well as they used to. Solution – Liquid Plastic! Learned this from some googling about repairing Gobots/Machine Robo, and came across some very good YouTube videos by Mr Bobot.

Liquid Plastic is something I had never heard of before, but is perfect for this problem. It essentially works by hardening a liquid into solid plastic via ultra violet light, so where you need to build up the layer of plastic (to replace what has been worn away) this is perfect – and non-damaging to the existing plastic. It’s a terrible glue, mainly because if you try to bond 2 things together the ultra violet can’t get into the place where the two surfaces are actually joining together. But in this case that’s perfect – we don’t want (or need) a glue, just something to build the volume of plastic back a bit.

The liquid plastic I used was 5-Second fix, a cheap brand but seems to work fine, a more expensive version is Bondic, for for what needs to be done here not sure it’s worth the extra cost for same outcome.

MR-02 – Tank – Back

So, with this goal I took old Tank apart, pretty easy – one screw! There are other screws on the legs but they were fine so didn’t take him totally to bits. I could see quite easily where the problem was on the joint as the plastic was lighter with wear right where the arms were held by the body. What I found is that it is only a tiny bit of plastic that needs to be worn away for these joints to become loose, it is quite dense plastic and doesn’t wear easily, but enough rotations of those arms will do it eventually as it is just friction that is holding them in place. So a very small amount of liquid plastic, hardened, is all that was needed, then a squeeze together with the diecast body while rotating the arms just to carve into it and get the body to press together tightly again.

Gobot Tank – MR-02 – Disassembled

Now Tank is as good as new! All up probably a 10 minute job at most.

Like I said before these old Machine Robo/Gobots are well worth preserving, they have a unique and interesting design and great fun to muck around with. I’ve got young kids who have some current Transformers and they love seeing and playing with these old Gobots of mine, I’m not precious about my old toys and are happy to fix them up to be played with again. I’m going to track down some of others, beat up ones I’ll share with the kids, others I’ll keep for myself 🙂

Maintenance Tonka Clutch Popper

Maintenance: Fix slipping wheels

One issue I’ve come across with a very beat up Clutch Popper, which is pretty easy to fix is where one (or both) of the rear wheels slips around the axle, therefore not driving the motor. This can happen on very well used/beat up models, and they’ve effectively been written off as no longer working. It’s an easy one to spot, if you turn one of the tires and the opposite tire doesn’t also turn, then that tire is no longer fixed to the axle. Solution – glue it back on! This is another one you could get kids to do (with help), but they need to be a bit older as for a couple of the steps (particularly the gluing) you need to be careful what you’re doing and where you’re getting that glue – i.e. don’t get a 5 year old to give this fix a try on your dining room table:p

So first you’ve got to get the tire off, and even though it’s turning on the axle it still may take some force to lever it off. Easiest to put it in a vice, and with a large screwdriver between the wheel and the chassis, lever the wheel off a bit at a time until it pops off.

Then you just need to glue it back on, but not any old glue for this one. You’ll really need to use an epoxy type (2 part) glue to make sure these wheels stay stuck on for good! Mix the epoxy according to the instructions, just need a very small amount, then apply a little to the axle (use a nail or something like that as an applicator), and put a little into the hole in wheel where the axle will go. Push together until the wheel is fully on, if any extra epoxy has bunched up on the axle near the chassis, then carefully scrape that away – you don’t want to epoxy the wheel to the base!:) Let it sit for a good 8 hours to fully cure/harden (even if it says it cures in 30 minutes or something like that), and it should be good to go.

I had/have one like this, very beat up, but once the wheels were fixed back on (both of them slipped around the axle) it turned out to be one of the best!


Maintenance: Sanding rear tires/ Regrip

With one of these old Clutch Poppers, there’s a good chance the rear tires have become quite shiny. This means they will not grip as well to a surface, therefore not travel as well/fast or spin out if going too fast on a shiny surface. There may also be some rubbish embedded in there that it would good to sand out/even out. They are made of pretty hard wearing rubber, and a light sanding can bring them back to full grip.

So take a small piece of sandpaper (120 grit or so) and just hold the rear tire and sand it lightly to rough the surface, slowly moving the tire around around doing a bit at a time until it is all even. Do the same to the other tire. Then as an optional extra you can tape a piece of sandpaper to a bench, spin up the tires to full speed and then slowly lower them onto the paper evenly a few times.

Now the thing with doing this, as well as the other two steps (axles and lube), is that if the motor is still in proper working order, the car may well go very fast if it gets revved up to max speed, and that’s where you’ll see whether you need to address any of the next maintenance steps. This one is one of the main fixes/hacks that will help it stay straight(ish) going very fast on a smooth surface, the other is weight which I’ll do another post about.


Maintenance: Lube around the motor

The next main thing you’re going to want to, after cleaning the axles, is is to get some lube around those axles and potentially (read ‘A bit about the motor’ here, and blog post here) into the motor. You don’t want anything too sticky or oily, I’ve found CRC 556, Noxy, Power Lube with PTFE, or Multilube Gel the best, this is because you don’t want anything that’s just going to attract more dirt (you want something that will repel it – these ones all do that more or less). Also it is difficult to get to the innards of this motor (unless you drill out the rivet), so you need something very fine that can penetrate through a small crack (again CRC). Once you sprayed a little around the axles – using a straw nozzle attachment, spray a little along the top (again with the straw nozzle), and a little around the flywheel axle joints. Then give it a good rev up a push the clutch flap (that button normally presses) to get the lube moving into the motor and parts.

Any type of lube that you can spray on as a liquid then evaporates into a gel or tacky film-like grease (but does not attract dust), is pretty good for the outside of this motor around the gear rods and flywheel, as this type resists fling off at high speed and will likely last longer. Also probably pays to check that whatever you choose is ok for plastics, there are some nylon gears in there, and even though nylon is pretty stable with most lubes probably good idea to go with something that is non destructive on plastics. Synthetic lube that has penetration capability and is long lasting would be a good choice. Once you’ve got everything moving pretty quick, you may need to look into some of the other maintenance points related to counter-balancing and grip on smooth surfaces.


Maintenance: Cleaning axles, motor (outside)

This is usually the first thing you’ll want to do, and often the main issue that will be stopping the car from functioning properly. After years of abuse a fair bit of gunk can build up where the wheel axle meets the body of the car and the motor. Once you’ve got the body off, and dust cover removed, you’re going to need a very fine screwdriver or tweezers. You’re going to use this to scrape out all the gunk from around the axles, bit by bit until it’s all gone. Don’t think about using water and some kind of brush for this – water and this motor aren’t great together, probably not the end of the world, but you don’t want to get water in there, and you don’t want to blow any of this dust and gunk into there either, so just pick and scrape it away. The front wheels don’t normally have any problem, but check those out while you’re at it.

As far as the motor itself goes, you’ll want to try and clean that down as much as possible without taking it out if you don’t need to. So easiest way to do that is with some cotton buds sprayed with CRC (WD40 will also be ok for that) then just wipe away at it, all around until it’s as clean as you can get it.


Maintenance: Disassembly

Removing the main body from the base

There are two main methods for the common Clutch Popper Chevy models. For both you’ll need a number 10 size star type Allen key or screwdriver. The Chevelle type (bonnet/hood screw) has standard Phillips head screw. You don’t want to do this procedure too many times, as each time you unscrew/re-screw you will be wearing down the thread channel in the plastic. Also – do not overtighten when screwing back into the base/turbo piece, just get it so it is firm and tight but stop there. If you do stuff up the turbo piece or thread channel of the base, it is fixable with a thin layer of epoxy on the inside, that once hardened you can carve a new thread channel into, however this is a bit of a pain in the butt so best avoided!

Chevy Monza & Vega (Red & Blue)

These two both have a ‘turbo’ block piece on the top of the front bonnet/hood, the screw on the underside in the front of the base screws into this block. Unscrew this screw (I find it easiest with an allen key star type), then lift the top off, the two tabs at the back will slip forward out of the base.

There is a plastic dust cover over the motor, remove this for maintenance but it is important not to lose and put put it back on before reassembling. That plastic cover does a very good job keeping dust and crap from getting sucked into the internal gears, which over time would clog it up, slow it down, and be much more difficult to fix.

Follow the listed maintenance steps described here, as with all of the models you’ll want to give everything a good clean while you have the body and parts separate so that you reduce the number of times it gets taken apart.

Chevy Chevelle (Yellow)

This one (and models of this type) has screw (Phillips head) going the other direction, and is in the top of the front bonnet/hood, under the decal, going down into the base. You’ll need to lift the decal to get at it so this one’s a bit more annoying and intrusive. If the car is already pretty beat up (good chance) then it doesn’t really matter that much and you could just lose the bonnet decal (can look really good – see here), if you’re not a fan of that then you’ll just need to be careful.

Once you’ve got that screw out it’s the same as above for the other Chevy types.

Follow the listed maintenance steps as per the other models, as with all of these you’ll want to give everything a good clean while you have the body and parts separate so that you reduce the number of times it gets taken apart.