I painted the original body for my RC10 day-glo orange, like they used to use for street maintenance in the mid 80’s.  It’s showing its age, with scratched paint all over the place, and cracks where it is most often stressed.  Also, it’s ugly.

It turns out that Team Associated still sells bodies for the original RC10.  Two different varieties, even.  So, when I ordered steering parts (that didn’t work) in August, I also ordered a new Viper body.

I already thought this buggy reminded me of the Viper Mk II from Battlestar Galactica. So, why not use a Viper-inspired paint job?

RC10 gold pan, new Viper body

I masked the windows and applied masking tape for stripes in the approximate locations of the red stripes on the Viper Mk II, and sprayed the rest white.  After removing the tape I sprayed red with another layer of white behind it.

I finished it with hand painted netting on the windows.

I learned a bit about masking: you need to be very careful about getting the edges of the mask to touch the car, or they don’t work.  Unfortunately the white overspray on the red portions don’t work that well as battle damage, yet, because the rest of the body looks so pristine.

I hope to get some decals printed with BSG viper logos.  I think that would add a lot to the look.

Flashback to late August:

After replacing the wheels on my RC10 gold pan buggy, it didn’t handle very well.  Considering the fact that the front wheels rubbed on the front a-arm at full steering travel, that should not have been surprising.  But I wanted to try reducing the steering travel to avoid rubbing, and see if that helped.

Unfortunately this didn’t work.  The steering linkage was plagued with problems.  The car had a wider turning radius in one direction than the other, the servo struggled, and there was a lot of play in the linkage.

After looking at the steering linkage enough times, I realized it pretty much sucked.  Plastic bell cranks ran directly on threaded screws for pivots without bearings; the servo saver was sloppy; and it had a bent wire linkage to the servo instead of a ball and socket linkage.

After doing some research at rc10talk.com, I learned that replacing the steering linkage with one that used bearings was common.  Most of the bell cranks that were used Back In The Day are no longer available.  However, Traxxas makes a bell crank set that’s a perfect fit.  Sweet!  Okay, well not perfect, but close enough.

As outlined here, you need to make shims to fit between the inside of a 3/16 bearing, and the 8-32 screw used as a pivot on the RC10.  I used some of the #8 washer/spacers used on the rear wheels, to ensure that the bearings spun freely instead of rubbing on the chassis.  Once you do this, the rest is easy: install the bell cranks and turnbuckles, and you’re good to go with identical steering geometry to the original.

This helped a lot: steering was faster and more responsive, and with the better turnbuckle linkage I could tune it a lot more finely than it was before.  Unfortunately there still just wasn’t enough travel, so I was still stuck.

I wanted to get new front hubs with more caster.  The original car has 25° for the shock travel angle, but the hubs push caster back to 10°.  I wanted to try 25° of caster, so I bought some RC10B4 caster blocks and hub carriers and associated gubbins.  Unfortunately I got the wrong king pins, and couldn’t assemble it.

Flashforward to late September:

RC10 with Traxxas bell cranks and wide track arms

I sat around not doing anything with the RC10 for a long time, but then I needed to order a replacement part for my Losi XXX-SCB.  So, I added my missing king pin (and screws) onto the order.  A-Main hobbies also carried some original RC10 swept-back front A arms, the “wide track” version in black; so I added those to the order as well.

Oh, I should also really replace all the transmission bushings with bearings, so let’s just throw those onto the order as well…

So on Tuesday night and Wednesday, I put it all the new parts on and rebuilt the shocks with heavier oil.  Here’s the result.

I had to remove the front anti-roll bar, because there is no mounting point for it on the wide track A-arms.  I calculated appropriate turnbuckle lengths to maintain the original geometry by extrapolating based on the increased A-arm length, but I expected to have to tweak them after driving it a bit.  Now, at extreme steering angles, the inside of the plastic hub is the first part to hit the A-arm; but at that point, you have plenty of turning going on, so it’s not a problem.

The shocks have never been completely disassembled and rebuilt, and they’re showing some wear inside.  It’s not ideal, but I’m going to live with them for now.  I completely cleaned the transmission parts using Simple Green in an ultrasonic cleaner, removed the bushings, and reassembled everything with the bearings.  Once every 30 years isn’t too often, is it?

On Wednesday night, I brought the car to the track and tried it out.  It worked a lot better than I expected: handling was great without me having to tweak anything at all.  I ran it through 2 battery packs, as much as I ran the Losi-SCB last night.  Apparently I’ve already bent one of the camber links, though; I guess I need Real Turnbuckles instead of threaded rod.

There was one problematic incident: I popped an E-clip on the transmission, and it blew the “bearing adapter”out the left side of the car. That’s weird.  There seems to be more slop on this shaft than it had with the bushings.  I used a new E-clip there, and it was fine for the rest of the night.  Consulting the assembly instructions didn’t show me any parts I was missing, so maybe the bearings aren’t the same dimension as the bushings they replaced.

Overall, I am now very happy with the way this car handles, indoors at least.  Unfortunately, whenever you pick the lowest hanging fruit, there’s always another one: it’s really slow, especially during acceleration. So now I’m thinking I might need to look into a “stock” (17.5 turn) brushless motor setup for it, to replace the brushed system it has now.  But I’m going to start by going to the J&C Hobbies flea market scheduled for next Sunday to see if I can find anything fun there.

Frank broke a part on his equally vintage Kyosho Optima on Wednesday night.  Don’t replace it! It’s a slippery slope, and a totally inefficient way to get a running buggy.  At this point it’s almost as easy  for me to list the parts I haven’t replaced, than those I have.  But several modifications ago I decided to “embrace the project” since it really is at least as fun as driving the resulting car.

After getting my RC10 back in service, it became apparent that I would need new tires some day.  The rear tires had very little tread or traction left, and the ground clearance was barely sufficient to run it on short grass.

Unfortunately, the original RC10 wheels are a small obsolete size, and modern tires aren’t available to fit them. My options seemed to be:

• find vintage wheels and tires on ebay or other sources
• buy JC Racing wheels that use standard buggy tires but allegedly fit on the original RC10
• rebuild the rear end to fit modern buggy wheels

The JC Racing wheels look really nice, but they take a long time to ship from the UK, they’re expensive, and I’d need to salvage the wheels every time I replaced the tires since they cost so much.  Also, there isn’t nearly as much challenge involved in slapping new wheels on the car as there is with rebuilding the entire rear end.

There are many threads on various RC forums regarding the various ways you can adapt your gold pan RC10 to run modern 1/10 scale buggy wheels.  Unfortunately they tend to skimp on the details and expect you to figure stuff out yourself.  Truthfully, there are so many minor differences in early RC10 buggies that this might be the best bet.  But hopefully the story of what I did will help others who have the same problem.

I’ll deal with the front and rear wheels separately, because the front is much easier than the rear.

Front Wheels

Currently, RC10B4 wheels are still available, and they fit just fine on my original 3/16″ axles.  I started with DE Racing “Borrego” wheels for the B4 buggy, with 3/16″x3/8″ bearings to fit them.  I bought JConcepts Barcode front tires.

DE Racing Borrego front wheel, and original RC10 wheel

Overall, this setup mostly works, but it isn’t perfect.  The larger diameter wheel fits just fine, but the wheels are also wider. This causes the tire to rub on the front A-arm at full steering. This can be adjusted with servo travel on the transmitter, but it must increase your turning radius somewhat.

The Barcode tires were completely useless on grass, I may as well have been driving slicks.  Since my options were either to drive them for a few days and buy replacements, or save them for indoor driving and buy replacements, I opted to save the bar codes and buy even more wheels and tires.

I got Associated B4 wheels all around, hoping they might work slightly better than the DE Racing wheels.  For the front, I got Pro-Line 4 rib tires, a modern version of the original tires on the car.  Overall these worked very similarly to the bar codes: they’re a bit too wide, but otherwise they work fine.  They also don’t have great traction on the grass, but they have a heck of a lot more tread.

Rear Wheels

When I say “rear wheels” here, I really mean the entire rear end of the car.

There are two basic problems with using the original RC10 with newer wheels.  First, the old RC10 axle is weird. Instead of being a constant diameter 3/16″ axle as in the front, it has a fat section near the center of the car, tapering down to a narrower part where the wheel mounts.  The taper keeps the wheel from rubbing on the hub, but modern setups use a thick conical washer for this instead.  The second problem is the wheel offset: the old hubs don’t stick out as far, so modern wheels end up rubbing on the rear arms.

The basic solution to both of these problems is to replace the original hubs and axles with RC10B4 hubs and axles.  Unfortunately since you’re changing the hub location, this has a bit of a cascading effect and requires replacing quite a few parts.  For reference, I’ve found it useful to refer to the RC10B4 manual pdf (Google it if the link ends up broken), to find modern part numbers for the required replacement parts.

I opted to stick with the RC10B4 pin drive on the rear wheels for now, but it should be easy to use hex drive wheels with a hex adapter if the B4 wheels become unavailable.

I’ll try to detail everything I ended up actually using, without any of the extra parts I didn’t use; but I may forget something.  Most of these parts are shown on page 10 of the manual referenced above.

• Associated 9584 rear hub carrier
• (4) 3/16″ x 3/8″ bearings
• Associated 9670 rear axle RTR
• Associated 7368 3/16″ axle shims
• (2) Associated 9671 B4 RTR dogbone
• Associated 7377 axle spacers
• Associated 7369 universal roll pins
• Associated 5407 O-rings
• Associated 9608/9608B wheel spacer
• 4/40 threaded rod, for longer camber links
• 8/32 wheel locknuts

RC10 gold pan with RC10B4 rear hubs

The assembly is mostly straightforward.  Remove the old wheels, hub carriers, and camber links.  Save the ball link parts for use with the new hub carriers and camber links, and reassemble the hubs as shown in the manual above.

The B4 hub carriers have a narrower hinge pin hole, so open them up with a 1/8″ drill bit.  As long as your hinge pin is loose in the old A-arm, it doesn’t matter if it’s a bit tight in the new hub carrier.

Since the new hubs are offset farther out than the old ones, you need longer dog bones to compensate, or they will fall out when your suspension is fully extended.  Some people have replaced their dog bone linkage with CVD links, but I was not willing to risk getting the wrong part since it cost so much more than the dog bones.

On the original RC10, the rear dog bones are held in place using springs in the hubs with small nylon spacers on the differential side.  In modern cars, O-rings are used at both ends of the linkage. The B4 RTR dog bones are just at the limit of maximum workable length using a reasonable camber angle.  The important part to get these to fit correctly is to remove the nylon washer from the differential side of the link, before replacing it with a rubber O-ring.  When you’re finished, you should be able to bottom out the shocks before the dog bones bind up, but they won’t fall out going over jumps.

The wider hub offset also affects your camber settings.  You need longer camber links in order to maintain the original camber setting.  On my car, I had to increase the distance between the ball link ends to about 0.75″ in order to maintain a good camber setting.  This was enough of a change that I bought a long piece of threaded rod to build new camber links, rather than risking stripping the original plastic ball link ends by using them when they’re too loose.

RC10 with B4 wheels and Traxxas/Pro-Line tires

I started with DE Racing Borrego wheels and Barcodes tires, just like in the front, but these tires don’t have any more traction when you put them on the rear wheels.

For my second attempt, I used Traxxas step pin tires and Associated B4 rear wheels.  These have a lot more traction on the grass than any of the other tires I’ve used on this buggy.  On the grass, the buggy used to oversteer a lot on corners, but now it pushes like crazy.  I like the overall look of the car with these tires.  The combination of pin and rib tires mirrors the car’s original look.

I may want to install a slightly smaller pinion to compensate for the larger wheel size, but otherwise I’m happy with these modifications. I should still be able to use the old wheels, so I can compare the handling to see if it’s any better now.

My original buggy had bushings throughout instead of bearings.  This project replaced almost half of the bushings with bearings, so I now have reduced friction as well as more modern wheels.

As I mentioned before, I had an Associated RC10 remote control buggy as a kid. It was a high quality car at the time, and took the hobby by storm when it was first released.  I wanted to get my car back into service after many years in storage, so here’s what I did.

RC10 gold pan, first release

This is an original “gold pan” model RC10, predating any stamps on the bottom of the chassis.  This dates it at about 1984 when the car was first released.

The first step in getting the car back into service was just to see if it even worked.  This was easier said than done, due to the state of the car’s electronics. The original radio was a wide-band aircraft radio (oops!), using frequencies that are no longer usable, so that had to be thrown out before it was even turned on.  The speed controller was a rheostat, and was mostly broken, so it also needed replacement.

The obsolete NiCd battery was so destroyed my dad didn’t even give it to me.  Unfortunately the original crosswise battery box mounting didn’t leave enough space for modern NiMh batteries.  In retrospect, I think I could’ve found a LiPo battery that would have fit, but instead I decided to remount the battery box lengthwise.

After a few attempts to make an adapter to mount the battery holder without drilling the chassis, I gave up and made a critical decision in the evolution of this car: I was not going to attempt to preserve the original buggy, but instead I would just make it work well using modern parts where necessary.

I’m keeping all the old parts, so it could be returned to close to its original state, but truthfully most of the parts I’m replacing for a reason, not just on a whim. The RC10 was a wicked good car in its day (see what I did there?), but mine was the very first version of the kit.  Changes were made to critical systems early in its life, and even when this car was original, people routinely replaced parts with better alternatives when possible.

So: To heck with it! I drilled and tapped 2 holes in the chassis to mount the battery holder.  Done!  One end of the battery now sticks in where the throttle servo used to be mounted, and the other end is held down by one of the two original battery holders.  A 6-cell NiMH pack fits perfectly, and I could probably run 7 cells if I found a hump pack instead of a long pack.  I haven’t made the switch to LiPo, but I’m sure something would fit here.

For the other parts, I got a Spektrum receiver and a brushed ESC.  I ripped out the throttle servo, speed controller, receiver, and receiver battery pack, and replaced them with the new parts.  The old Futaba servo needed a new connector, so I rewired it.  I also needed new bullet connectors on the motor, to replace the original Tamiya connector. I powered everything up, and… it worked!  Of course it did, why wouldn’t it work after replacing most of the electronics?

In the following weeks a few other problems cropped up.  The steering servo was slow and weak, so I replaced it with the Hitec seen above.  The motor ended up dying a slow death, probably because of worn brushes like my Losi motor (but after 28 years instead of 28 days). I replaced that with an Axial 27 turn motor to keep it at “stock” speed.

In the end, it’s more important for me to get enjoyment out of this buggy than to maintain its original state.  I get more enjoyment out of repairing and improving the buggy than from driving it when it’s in crappy condition.