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Taking an old Bullet model out of mothballs

Posted: Mon Nov 13, 2023 7:09 pm
by SupraGuy
So I found a box in my garage. An old Traxxas Bullet model that's been stored and not run for a very long time. I can't find the transmitter for the radio, and who knows if the battery can even be charged any more...
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I have an.8.4V battery that is good and an ESC for a brushed motor as well as a radio unit. They were intended for use with another project, but I am thinking of going another direction with that.

Anyway...

Care and feeding of a geriatric car? Will the nylon parts get brittle? Can they be revived? The wheels seem to still move smoothly at least.

Is the speed control usable as it sits? I don't mind getting rid of the resistor pack, speed control and servo for the ESC, in fact it simplifies a lot.

The body is ... kinda rough. I'm missing one clip,, and the mounts are iffy.

I held on to the original box. It's full of other stuff, a Tamya chassis from the late 70s (F1 style car that had no suspension at all, but it sure moved. No body for it tho.) And a Futaba FX10 chassis that was pretty broken. I thought that the radio was supposed to be in there...

Not sure if it's worth anything in current condition. eBay seems to have some for more than I'd expect it to cost, or parts thst also seem high priced.

Some parts (body roll cage) seem to be in demand. I was thinking of making a replacement body, since this one is pretty rough, and though replacement bodies seem to be available, they're costlier than I'd like to spend.

I was thinking that I could 3D print/vacuum form an alternate body. As such, I would not mind parting the roll cage, if anyone is interested, since it seems to be an "in demand" part.

For that matter, given it's apparent eBay value, I could probably send out the whole car, with box. (Assembled car does not fit in the box :( )

Re: Taking an old Bullet model out of mothballs

Posted: Mon Nov 13, 2023 7:28 pm
by juicedcoupe
Before you plug an esc into that old Airtronics receiver, don't forget that they are wired different.

Re: Taking an old Bullet model out of mothballs

Posted: Mon Nov 13, 2023 7:46 pm
by jwscab
Yeah the Traxxas white nylon definitely ages poorly, if you plan to restore it and run it it is worth boiling the parts or at least soaking in water for day or so.

The gear case/arm mounts is not pure nylon so DO NOT boil that part. It is also quite fragile.

The body is super fragile, and as you found the cage is very hard to find.

Re: Taking an old Bullet model out of mothballs

Posted: Mon Nov 13, 2023 8:17 pm
by RC10th
That bullet box is impressive

Re: Taking an old Bullet model out of mothballs

Posted: Mon Nov 13, 2023 10:13 pm
by SupraGuy
juicedcoupe wrote: Mon Nov 13, 2023 7:28 pm Before you plug an esc into that old Airtronics receiver, don't forget that they are wired different.
Well, considering that I do not have the transmitter for that receiver, I would be swapping the receiver out with the speed controller. I believe that the receiver I have is compatable with the ESC.
jwscab wrote: Mon Nov 13, 2023 7:46 pm Yeah the Traxxas white nylon definitely ages poorly, if you plan to restore it and run it it is worth boiling the parts or at least soaking in water for day or so.

The gear case/arm mounts is not pure nylon so DO NOT boil that part. It is also quite fragile.

The body is super fragile, and as you found the cage is very hard to find.
Yeah, the body is pretty badly cracked. I will take my calipers to stuff and see if I can model a replacement body that I can vacuum form. I may need a larger vacuum former though, the one that I have is 8" by 10".

As to boiling the parts, is that the way to restore them? I thought nylon was hygroscopic and moisture was a problem... Well, that means I wouldn't have thought of it, so I'll look it up.

For restoration, I have a CNC machine, 3D printer, vacuum former, and other tools to make parts. I could probably cut new aluminum flat parts, but bending them would be dicey. It's probably way easier to measure/model parts that aren't broken, so parts that are likely to break should probably be measured up.

The costs of replacement parts seems awfully high, so if anything breaks, that I can't produce with what I've got, it may be more to the point to buy a new model... Maybe I'll copy the body, and put this one on a shelf.

Re: Taking an old Bullet model out of mothballs

Posted: Mon Nov 13, 2023 10:58 pm
by jwscab
If you can make a new body, that's pretty great!!!

For sure if you run it hard enough you will break stuff. If your plan is that, you are probably better off cleaning it up for shelf duty

Re: Taking an old Bullet model out of mothballs

Posted: Tue Nov 14, 2023 2:52 am
by Dadio
Nylon needs a water content to remain supple , if you 3d print as I do you then you'll be used to drying it to print for better results but after printing you should also rehydrate it if you need the part to be supple , old nylon usually dries out and becomes brittle , in order to rehydrate it you need to soak the parts for 6-8 hours in hot not boiling water , boiling is no quicker and may warp the parts or in cold water for 24 hours , I usually do it cold for 24 hours as it's easier .
Personally I would not part the roll cage from the car as you'll devalue the car , I'd model it up in CAD and print one that's disposable .
If your driving it the a modern radio 2.4gig and ESC will give you way more range and better control than the old school crystal units of the past and a cheap modern ESC will make it nicer to drive .
Obviously be mindful if your driving it that parts are scarce , for this reason a few of us have started CAD modeling our favourite cars and 3d printing either the easily broken parts or whole cars , if you print a whole car you can "drive it like it's the 80s" as all parts are expendable and replaceable .
Welcome to the forum .

Re: Taking an old Bullet model out of mothballs

Posted: Tue Nov 14, 2023 5:15 am
by juicedcoupe
SupraGuy wrote: Mon Nov 13, 2023 10:13 pm
juicedcoupe wrote: Mon Nov 13, 2023 7:28 pm Before you plug an esc into that old Airtronics receiver, don't forget that they are wired different.
Well, considering that I do not have the transmitter for that receiver, I would be swapping the receiver out with the speed controller. I believe that the receiver I have is compatable with the ESC.
In that case, don't forget that those servos are wired in the old Airtronics pinout. Using them in a standard format (Futaba/JR/Hitec type) receiver will definitely fry the servo and possibly the receiver.

Re-pin it to the correct format or just change it (standard servos are cheap).

Re: Taking an old Bullet model out of mothballs

Posted: Sat Nov 25, 2023 10:20 pm
by SupraGuy
juicedcoupe wrote: Mon Nov 13, 2023 7:28 pm In that case, don't forget that those servos are wired in the old Airtronics pinout. Using them in a standard format (Futaba/JR/Hitec type) receiver will definitely fry the servo and possibly the receiver.

Re-pin it to the correct format or just change it (standard servos are cheap).
Thanks! I may have made a big mistake there without warnings.

I was thinking of just buying a new model instead, but I think I'll revive this one a while to see if I get back into it.

Re: Taking an old Bullet model out of mothballs

Posted: Sun Nov 26, 2023 5:52 am
by Dadio
SupraGuy wrote: Sat Nov 25, 2023 10:20 pm
juicedcoupe wrote: Mon Nov 13, 2023 7:28 pm In that case, don't forget that those servos are wired in the old Airtronics pinout. Using them in a standard format (Futaba/JR/Hitec type) receiver will definitely fry the servo and possibly the receiver.

Re-pin it to the correct format or just change it (standard servos are cheap).
Thanks! I may have made a big mistake there without warnings.

I was thinking of just buying a new model instead, but I think I'll revive this one a while to see if I get back into it.
Buying a modern car is a bit of an eye opener , brushless motors and lipo battery's make em fly and it's less of a case of how fast can I make it but more can I control it at that speed ! It's a very different world now in RC cars but owning and running a piece of 80's history has a very different feel .