Schumacher BossCat Comp Rebuild

[dr_gn]

Understood, thanks.

[dr_gn]

BTW I think the main issue with the dampers is corroded rods. I guess we could turn some new ones up on the lathe out of stainless.

A bigger issue might be the rather chewed up/asymmetric plastic ball sockets in the lower ends. Likewise I suppose we could make new ones, maybe part plastic, part aluminium of new ones aren’t available?

[groomi]

Ah, those rear shocks aren't what I thought they were. They're not Schumacher at all - I've no idea what they are, or whether spares are available.

The plastic ball cups are no problem. Just stick with Schumacher items.

[dr_gn]

groomi said:

Ah, those rear shocks aren't what I thought they were. They're not Schumacher at all - I've no idea what they are, or whether spares are available.

The plastic ball cups are no problem. Just stick with Schumacher items.

OK, if we needed 4 decent but not amazing shocks, what would you go for?

Same with the motor/battery/ESC?

I did find some spares online from a couple of places, but none of the part numbers were anything like in the parts list, which seemed odd because they were under a drop-down for the bosscat.

BTW, I requested to join the vintage Schumacher FB group a few days ago (to get more advice), but its not been approved yet.

Cheers!

[generationx]

The fronts look like Kyosho Option House. You can sometimes get pretty decent replicas (long and short) from places like rcMart.

[72twink]

Ignore the Vintage Schumacher group on FB, find the True Vintage Schumacher page and join that - it’s not a dictatorship! Also don’t listen to Groomi - I started Lockdown with one XLS “for old times sake” and now I have 4 CATs, a TopCAT, a Cougar and no money - his boundless knowledge and enthusiasm is bankrupting me! Nice little project that but BossCATs are quite tricky to find bits for.

[dr_gn]

72twink said:

Ignore the Vintage Schumacher group on FB, find the True Vintage Schumacher page and join that - it’s not a dictatorship! Also don’t listen to Groomi - I started Lockdown with one XLS “for old times sake” and now I have 4 CATs, a TopCAT, a Cougar and no money - his boundless knowledge and enthusiasm is bankrupting me! Nice little project that but BossCATs are quite tricky to find bits for.

Cheers for that. By pure luck I found the True Schumacher group and got accepted straight away. Already got a lot of good info.

Yep, restoring/ collecting old stuff can soon get out of hand, but all good fun!

[dr_gn]

Quick question:

What’s a good compatible pinion to get for general use?

Thanks.

[TheBinarySheep]

dr_gn said:

Quick question:

What’s a good compatible pinion to get for general use?

Thanks.

If I'm right, a 48dp pinion is compatible. Then you just need to select the amount of teeth you want depending on whether you want acceleration or top end.

For comparison, my Schumacher Layout is using a 48dp 22t pinion with a 6.5 turn brushless motor.

[groomi]

72twink said:

Ignore the Vintage Schumacher group on FB, find the True Vintage Schumacher page and join that - it’s not a dictatorship! Also don’t listen to Groomi - I started Lockdown with one XLS “for old times sake” and now I have 4 CATs, a TopCAT, a Cougar and no money - his boundless knowledge and enthusiasm is bankrupting me! Nice little project that but BossCATs are quite tricky to find bits for.

[72twink]

dr_gn said:

Quick question:

What’s a good compatible pinion to get for general use?

Thanks.

48dp if it’s on a factory spur. On page 21 of your BossCAT instructions there’s a gearing chart, I used to race my ProCAT (a year before those instructions were written) on a 14 Double with SCEs and it was plenty fast enough - it’s a bit too long ago to remember the pinion though!

[dr_gn]

Pretty much stripped to component parts now:



A few bent bits, a few things that need turning up on the lathe, and some minor standard parts to be bought, but nothing that can’t be sorted:







One of the layshaft pulleys will also need some work with a modelling chisel and a file:



Ordered a body from Penguin yesterday, arrived today:



Also got new belts, and a bearing set on order. An FB group member is sending me a couple of front suspension parts. The rear diff was missing a bush, and had allowed the diff to tilt and rub against the transmission side plates - unbelievable crack-handedness:



Fastener sets are out of stock, but when I get those, the rebuild can start. Undecided about the JC Racing wheels, they are pretty grubby even after paint stripping, plus the rim strakes have been butchered, so I’m not sure if the tyres would stay on anyway. The way this thing has been treated makes me wince.

[dr_gn]

I asked this question on FB but didn’t get an answer yet:

I appear to have Sport diffs, not Comp.

Can I fit flanged bearings to the plastic tri lobe washer carriers, or do I need to ‘stick’ (ha ha) with the plastic in brass bushes?

Reason I ask is because one of the bushes is missing and needs making or buying, and it would be cheap enough to buy bearings and be done with it.



The bearings are A532 above. Mine have the brass/plastic bushes instead.

I’ve got the RC bearings set already, but they’re not included.

Cheers.

[dr_gn]

^^^ I think I've answered my own question ^^^

I assembled the plastic bush and brass housing, and measured the overall i/d, o/d and width, and the dimensions match the specified bearings, so I'll replace with bearings and hope for the best.

[dr_gn]

Cleaned up some of the plastic parts with a file/razor blade:



and sprayed them with a light coat of satin black. Sometimes there’s no way you can get all the ingrained dirt off, and/or any discolouration from scuffs etc, and a bit of paint covers a multitude of sins…



Some of the parts look like brand new now.

Also measured up for a 3300 NimH saddle pack, and ordered from Overlander:



And got some 4mm silver steel to turn some new turnbuckles and a layshaft. I need to get a 4BA left hand die for the turnbuckles. A couple of shock spring retainers also need making from aluminium.

The wheels were screwed - the tyre retaining strakes had been cut off, they were scuffed to death and one of the rear drive spigots was rounded off. In the end we ordered a new set from JC Racing for £11, and a set of tyres for the the same amount.

Despite it being a bit of an engineering project, and economics not being the main consideration, so far, including the battery, we (I) have spent £190 on new and used parts…and that’s with using an existing motor and electronics from the Tamiya Mad Bull. Ah well at least the knackered chassis was free.

[dr_gn]

Most of the remaining bits arrived today. Now it’s a case of repairing any oversized screw holes, and machining whatever else we need. Then, once everything’s ready, build it up as per the instructions.

[Ash_]

Is this an engineering project for himself or for part of his school course? If so, is he documenting what he's found, problems he's had and how he plans to rectify etc?

[dr_gn]

Ash_ said:

Is this an engineering project for himself or for part of his school course? If so, is he documenting what he's found, problems he's had and how he plans to rectify etc?

Just for himself. He’s in year 9 and doing engineering. Said he wanted an engineering g project he could do on his own “in the garage with the radio on”. He’s also drawn up a replica light saber that he wants to make out of aluminium on the lathe, so I got him some bar stock yesterday. Progress is slow because he’s revising for end of year exams. Although it’s very tempting to do it myself, I’ve resisted so far.

[Ash_]

dr_gn said:

Ash_ said:

Is this an engineering project for himself or for part of his school course? If so, is he documenting what he's found, problems he's had and how he plans to rectify etc?

Just for himself. He’s in year 9 and doing engineering. Said he wanted an engineering g project he could do on his own “in the garage with the radio on”. He’s also drawn up a replica light saber that he wants to make out of aluminium on the lathe, so I got him some bar stock yesterday. Progress is slow because he’s revising for end of year exams. Although it’s very tempting to do it myself, I’ve resisted so far.

Good on him, I hope he learns loads from the experience, and with the lightsabre, that's very cool, and I'm sure Dad wants one too....

[dr_gn]

Ash_ said:

dr_gn said:

Ash_ said:

Is this an engineering project for himself or for part of his school course? If so, is he documenting what he's found, problems he's had and how he plans to rectify etc?

Just for himself. He’s in year 9 and doing engineering. Said he wanted an engineering g project he could do on his own “in the garage with the radio on”. He’s also drawn up a replica light saber that he wants to make out of aluminium on the lathe, so I got him some bar stock yesterday. Progress is slow because he’s revising for end of year exams. Although it’s very tempting to do it myself, I’ve resisted so far.

Good on him, I hope he learns loads from the experience, and with the lightsabre, that's very cool, and I'm sure Dad wants one too....

The test light sabre bits and pieces we made did look pretty good to be fair…

Anyway, had a couple of spare hours today, so we made the replacement track rods to replace the missing one.

Cut the 4mm rod to approximate length:



Bit of turning:



Bit of trigonometry, lots of figuring out, some trial, some error…







Some threading - a left-had tap from EBay, that’s a first for both of us…





Then drilling the through hole:



And finally put a ring to mark the left hand thread. After all that, and a final polish…success:



Almost identical to the original, would be far easier to buy one for a few quid, but we learned a lot and spent some garage time together.