Saturday, June 20, 2020

Kyosho Lazer ZX Rebuilds

Ever since I rebuilt the Kyosho Lazer ZX that I acquired in 1993 (click here to see the start of the restoration that began in 2011), it became more of a shelf queen than runner mostly because of the time and effort I spent on the body. 


It took a fair amount of effort to trim, mask, paint and decal the body and I don't really enjoy the process.  

I wanted to get a second Lazer ZX to have as a runner in order to feel less guilty if I ever flipped or crashed it, but I did not want to have to paint another body.  Luckily a few years ago I found an eBay seller who was selling pre-painted bodies for various RC cars and one of them was the Lazer ZX body in stock colors.  It looked nice enough, certainly good enough for a runner vehicle, so I bought the body and stored it for a while while periodically looking for a used Lazer ZX chassis to pair with it.  

I wasn't looking very hard, really just waiting to see if something came along that looked interesting every once in a while, and then one night a couple years ago I ended up finding a really nice looking chassis.


Honestly, it looked pretty nice and clean.  I bought it, stripped it down and cleaned all of the parts (which didn't need much cleaning), and then built it according to the manual.  It was obvious that it was either hardly run or was someone's "built-it-from-parts" project because everything was in very good to excellent condition and few missing parts.  The tires were rather hard, but I didn't care about that. I fitted the body that I had bought previously, trimming the area around the gear cover, front shocks and drilled holes for the body mounts and antenna.  Lastly, I trimmed and fitted the wing to the rear wing mount.


For this chassis, I used a used Kyosho Le Mans 240SB that I had on hand mated to a Robinson Racing 23T 0.6M pinion and the stock LA-2 spur gear.  Power comes from a 6-cell NiMH pack connected to a Tamiya TEU-105BK ESC.  The receiver is a Futaba R113ip 75Mhz which is controlled by one of my Futaba 3UCP radios.  For steering, I used a Futaba S148 servo which is about as basic as it gets.  I don't race so the driving and steering requirements are not too steep.

The only hop-ups on this chassis are the LAW-1 FRP front and rear shock towers to replace the stock aluminum ones plus the Pro Line Hole Shot tires and JC Racing wheels.

After a few runs with the Kyosho 240SB motor, however, I'm not too impressed with the power or speed.  My original Lazer ZX with the Kyosho Mega 16x2 is much, much more powerful and faster using the same battery, and it's using a 18T pinion on the stock spur vs 23T pinion on the 240SB with same spur.  I think I'm going to swap out the 240SB for something else.  The specs list it as a 19T motor using double 0.65mm wire wound on the rotor.  It was used and has been messed with by the previous owner, so it might not be working as well as it should because it certainly doesn't feel like a 30,000 rpm motor to me.  Even going downhill wide open it's much slower than the 16x2-powered Lazer ZX.

Fast forward to earlier this year and I somehow ended up buying yet another Lazer ZX chassis to restore and run.
This chassis was not nearly in as good condition as the last one.
The front right shock was an Associated shock, not a Kyosho Gold.
The rear shock springs were not for Kyosho Golds and were not the correct diameter to fit the spring holders.
The steering servo mounts were missing.
The front tires were totally cracked and destroyed. (no big deal)
The motor mounting screws were 4-40 instead of M3 thread. (ugh)
The motor (Kinwald stock I think) front bronze bushing was totally worn out.  The rotor rattled side-to-side in the bushing.  Endbell is not removable without bending the tabs on the can.
One of the biggest issues I noticed was that the motor pinion was 48P while the Lazer ZX spur is 0.6M.  Totally different gear pitches that are definitely NOT swappable or even close to being the same pitch.  I really hoped that the previous owner had just mounted the motor to the chassis just before selling to make it look "complete".  Thankfully the spur teeth did not look like someone attempted to run the car with that pinion.  The spur had some wear, but overall looked good enough to keep using.

While rebuilding the chassis, I noticed that 2 of the internal belt rollers were missing, so I had to get a new LA-10 pack to replace the missing parts.  The belts themselves were in excellent condition, so I simply cleaned them with a dry paper towel to remove dirt build-up and used them as-is.  The pulleys were also in perfect condition.

Most of the rest of the parts were in very good condition once they were thoroughly cleaned.  I found a single Kyosho Gold front shock on eBay (amazing luck) and rebuilt all 4 shocks with new shafts, o-rings and fresh oil.

I have ordered a Lazer ZX body, wing and gear cover from Team Bluegroove in Canada plus some Tamiya PS-15 metallic red and PS-1 white spray paint, so I guess I'll be trimming, masking and painting another Lazer ZX body in a few weeks.

Here is how the 3rd Lazer ZX looks now as it sits waiting for a body and wing:


For this third Lazer ZX, I used a Kyosho Le Mans Sports H-240S motor with a Kyosho 20T 0.6M pinion hooked to a Tamiya TEU-105BK ESC.  The receiver is once again the Futaba R113ip 75MHz controlled by a Futaba 3UCP transmitter and steering is a Futaba S148.

I really like the vintage Kyosho 0.6M pinions because they are wider than the modern Robinson Racing 0.6M pinions, so they make contact with the entire width of the LA-2 spur gear teeth. 

Finally, here are all three of my Lazer ZX cars side by side.


All three are great runners and very quiet due to the belt drive.  The only gears are the motor pinion and spur (not counting the gear diffs).  The rear axle is driven by a short belt instead of gears.

I know most people prefer the Lazer ZXR, which is a refined/racing version of the Lazer ZX 4WD design, but I still rather like the ZX-style chassis due to the enclosed belts that keep out dirt.  I know people say that the belt covers prevent any dirt that gets inside from ever leaving and that's true, but with the easy-going on-road driving and mininal off-roading that I do, dirt is not a concern.

Parts are becoming harder and harder to find these days, so restoring one of these chassis is something that will take more time and money than it used to.  There are some alternatives, however, now that 3D printing is more popular than ever.  For example, Shapeways has many parts for Kyosho vehicles, including the Lazer ZX, which can be used if finding the original part is too difficult.