All the Lazers

[HS-YZ250]

So, in another post I mentioned I got a little crazy and bought all the Kyosho Lazers:

A Lazer ZX-R Mk2 from Pakistan
A Lazer ZX-R from eBay
And a Lazer ZX from Facebook

I got them in that order and did so because they were in increasingly better condition: the Pakistani Lazer was a gritty, bent, basket case, but the first I had seen for a reasonable amount (WELL under $800), the Facebook ZX looks and feels like a racer that someone maintained. The eBay ZX-R is in between, but was also pretty inexpensive. I'm probably going to let that one go once I refresh the hardware and rebuild the diffs. Not sure I'll hold onto both of the others, but we'll see.

So my current focus has been the Pakistani Lazer. I started by cutting down 3mm stainless steel dowels to replace bent rear hinge pins, upgrading the universals and dogbones to CV joints (had to track down the elusive LA231 ZX-5 universal for the front), refreshing bearings, and upgrading the rear hubs to the 3D printed parts that NeoVintage recommended for improving the handling. Then I spent weeks obsessively replacing almost all of the JIS cross head fasteners with new hex drive fasteners for no real reason than I just didn't want to drag out my JIS drivers all the time. Also a couple of critical ones were rounded, since people usually use Phillips on them. I got lucky with the M2.6 fasteners and found that Axial sells some to replace those. Also threw some Optima ReRe front knuckles on for looks with new bearings in the hubs, and spent a small fortune with Lunsford on turnbuckles for all three buggies. Finally, I rebuilt the diffs, where I made some...interesting...discoveries about the maintenance habits of the previous owner. This buggy was definitely bashed, bandaged, bashed, glued, and bashed some more. I used new diff rings, ceramic balls, and yokomo diff grease which might be a little too thick. Also managed to find front and rear Optima ReRe springs because the originals were mangled somehow. Shocks got new o-rings and Associated 40wt oil, which might be a little too heavy. I also dropped the money on the Javelin ReRe plastic shock hardware because the black parts were out of stock. Hoping to end up with a really tight suspension.

My big concern at the moment is I replaced the belts with new Tough Racing belts, but ended up with a front belt that's as loose as the one I replaced. Both the eBay ZX-R (pictured behind it) and the Facebook Lazer are pretty taut. This is my first time messing with a Lazer, so I'm not familiar with their quirks. Does the ZX-R Mk2 use a shorter belt, or something? I saw a couple of belt tensioner kits on Shapeways. Any have experience with these?

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[EvolutionRevolution]

My big concern at the moment is I replaced the belts with new Tough Racing belts, but ended up with a front belt that's as loose as the one I replaced. Both the eBay ZX-R (pictured behind it) and the Facebook Lazer are pretty taut. This is my first time messing with a Lazer, so I'm not familiar with their quirks. Does the ZX-R Mk2 use a shorter belt, or something? I saw a couple of belt tensioner kits on Shapeways. Any have experience with these?
IMG_20220913_090801746.jpg

To my knowledge, the belt is the same length. Is your chassis straight (flat)? That can cause that problem, AFAIK.

Also, you're still missing the Lazer ZX Sport (kelron chassis) and Lazer Alpha (fragile as heck plastic parts + fragile as heck plastic tub + all plastic parts with slightly different designs than real Lazer ZX).

[HS-YZ250]

To my knowledge, the belt is the same length. Is your chassis straight (flat)? That can cause that problem, AFAIK.

I'll have to take a look when I get a chance, though I just put it all back together. I had noticed the front arms had some space to move fore and aft between the braces. I thought that might be because of the "custom" brass front brace, but considering how bent up a lot of it was, I wouldn't doubt it got driven headlong into a few objects and that brass piece replaced a destroyed one.

Also, you're still missing the Lazer ZX Sport (kelron chassis) and Lazer Alpha (fragile as heck plastic parts + fragile as heck plastic tub + all plastic parts with slightly different designs than real Lazer ZX).

No more Lazers! Lol!

[scoobyrs25]

ZX-5.....ZX-6.....ZX-7......

[HS-YZ250]

So, I swapped the Top Plate for the eBay ZX-R to the Pakistan ZX-R Mk2 and found the latter is actually about 1/8 in longer if you bolt one end together, even though the eBay ZX-R's belt is taut?

In this image i have the eBay ZX-R's top plate (w/velcro) mounted onto the Pakistan ZX-R MK-2 with the latter's top plate on top with a single screw though both. Not sure what's going on that the Pakistan ZX-R
s belt is so loose.

Any chance the front bulkheads are different between the Mk1 and Mk2?

[HS-YZ250]

I'm scratching my head a bit, here. I went to put the original top plate back on and noticed that if I screwed in just the ends, the belt's tension was better. Then I noticed the steering posts and center support didn't line up with the holes in the top plate. I could push them over and get the screws in, but then the belt went slack again.

Next I removed all the screws from the steering, support, and the three at the motor support. When I did, the plate stood up off the motor support about 1/8 in, and the belt got a bit tighter.

I pulled out the center support and left the steering post screws out, the plate would fully sit down on both ends.

I'm wondering if this is the right top plate and/or if the center support is deformed from a crash.

[HS-YZ250]

Ah! Starting to see a picture, here. This is the rear brace for the front suspension. I thought that the buggy might have been driven hard into an un-yielding object because it had a hand-made front brace. Wondering if this and maybe another center support are bent and hosing the belt tension. Wonder if the front diff housing is messed up, also.

[HS-YZ250]

Ok, I might be on the right track with the front suspension brace. I bolted the top plate to the front diff housing, the steering posts, and the center support, but left out the screws for the rear support and front and rear braces. I also shimmed the top plate between its end and the rear support to keep the chassis from flexing when I push on the belt. Now the belt has good tension. So I'm going to see about replacing the front suspension braces, and maybe the rear support, and see if that holds everything in the right spot. Maybe I can model and 3D Print these before finding NOS or Shapeways parts.

[HS-YZ250]

So, a benefit of having bought all the Lazers is I had a couple of known good parts to reference for modeling and printing. They're in PETG for the time being. I printed the two braces for the front suspensions arms. When I bolted them in place the belt felt more like the other Lazers. I might print the rear support for the top plate as well because I suspect that's deformed slightly, also, because the screw holes don't quite line up. But in the meantime, I left the shims I added for fitment in place to bias the plate forward and reinstalled the screws.

Now I can think about reworking the eBay Lazer, next. Hopefully it'll go a lot faster with all the parts I've bought while working on the Pakistani Lazer.

[HS-YZ250]

I was starting to wonder about how I would power the Lazers when I searched "Le Mans" on the Kyosho website, and now I think I know. Since they won't be racers:

This for the Pakistani Lazer - https://kyoshoamerica.com/newitem/le-mans-240-gold-13-5t-brushless-motor-37034.html

And this for the Marketplace Lazer, which I already have - https://kyoshoamerica.com/37032.html

[HS-YZ250]

Just a quick overview of the eBay Lazer as I start work on it.

I found this Lazer after I received the Pakistan Lazer and started looking for parts on eBay. Being clearly in much better condition, I went for it. Most of this buggy is as you would expect, but there are a few discoveries. First, you'll notice the rear shocks are inverted. It turns out that the shock mounting hardware is a bunch of miscellaneous items, such as undersized screws and bits of rubber. I wonder if it was stored partially disassembled, parts were lost, and then it was thrown together for sale; the seller stated it came form someone else's collection.

The shocks themselves actually feel and look pretty good, better than the Paksitan Lazer. I thought the left front might have been bound up because the suspension didn't move freely, but found some hardware in the front end was rusted, including the outer suspension pivot pin, which I had to press out. Fortunately I had an old pin from out of the Pakistan Lazer when I put Optima ReRe pins in it to see if they would work (perfect fit).

This also came with mis-matched front hubs, one being an original Optima, I gather.

The last obvious thing is a previous owner appears to have converted the batter holders to RC10 body mounts and screws, over-drilling/counter-sinking the chassis. Of course, if there was anything else used to retain the batteries, they weren't included, so I'll have to come up with something. It does appear that this buggy was run with seven cells, despite the optional slot not being trimmed; rub marks are evident on the chassis plate just outside of each slot.

By now I've already replaced a bunch of chassis hardware, the tie rods, and rebuilt the front end. The differential design was quite different than those of the Pakistan Lazer, using a cone washer stack rather than a compression spring. It came out "gritty" despite cleaning and greasing everything. I recall a post saying that Kyosho differentials weren't all that smooth. Is that pretty typical of the cone washer diffs?

I also noticed the Mk2 front universals were slightly longer than these.

Looking forward for a set of CV joints coming in.

[EvolutionRevolution]

For the braces for the suspension arms, Pargu makes them in alloy.

[HS-YZ250]

The clutch on the Pakistan ZXR went back together with a much shorter stack than when I took it apart. I'm sure this has absolutely nothing to do with my messy workspace containing multiple active projects. Anyway, Was trying to figure out what was different, but only have a diagram of a ZXS clutch to reference. Looks like the ZXS has a bearing in the outer pressure plate where the Pakistan ZXR has an aluminum bushing. I found a polished chrome washer, and am wondering if I'm missing a thrust bearing.

Wondering if I can substitute a differential thrust bearing like one of these...

https://www.amainhobbies.com/search?s=thrust+bearing

Or if I can just update the clutch to modern hardware somehow.

[HS-YZ250]

So, I gather I'm working with the LAW-12 "Hyper Clutch", and the diagrams I see partially Here and fully Here suggest I need to go parts hunting. I need to get some measurements when I get home, but I'm hoping I can use this ball bearing and this thrust bearing as surrogates for the missing parts. I'm wondering if that one aluminum spacer was made to replace a lost bearing.

Also, if the ZXS Evo differentials are in any way similar to the ZXR mk2, then I put them back together wrong and I need to move the springs to the opposite sides of the those thrust bearings.

[HS-YZ250]

So, when I was prepping for burn, mentioned in my JRX Pro SE Rebuild thread, I tried to get one of the Lazers working so I could demo older belt drive cars to younger RC enthusiasts. But after two straight days of swapping parts and electronics I had to abandon that idea, finally defeated by expired batteries and mis matched gear pitches. But in the process I may have discovered why the eBay Lazer has RC10 body posts fitted into it when I realized my YZ10's battery holders fit in place with a plastic washer. Since I'm going to have to rebuild saddle packs for any of these cars, I'm debating building a seven cell for this one, though this is the one that would go up for sale first.

Also found the Pakistani Lazer needs a spacer for the motor to be able to get that in right, so I'm looking for something for that as well.