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.
The Kyosho Rocky shocks are unique in the world of Kyosho, so finding replacement parts such as the shock shafts is impossible. In order to continue to use the original stock cylinder and keep the vintage look, I came up with a way to rebuild the shocks using modern internal pistons and shafts.
First, here is a look at the very unique shaft and piston design from the original Rocky:
From the above picture the shock looks almost normal. It has a black piston and an e-clip to hold the piston at the top of the shaft. But there is a spring under the piston between it and the e-clip. What does that do? Let's look at the parts individually to find out.
The shock shaft has a small piston head built in.
The
piston is hollow with very thin sides that contain notches. The holes
around the center shaft hole allow the shock oil to flow through but
they are partially blocked by the head of the shock shaft when the
piston is pushed against it by the spring at rest.
The spring.
How it works: The spring holds the black piston against the head of the shaft when the shock is at rest. When the shaft is pushed into the cylinder, like when the car hits a bump, the force pushes the shaft into the shock cylinder. The black piston, which is the same diameter as the inner cylinder wall of the shock, wants to stay in place due to the oil in front of it, so it pushes against the spring, compressing it. This action allows oil to flow past the shaft piston head (which is smaller in diameter than the black piston) and flow through the black piston holes to the other side. This allows the black piston to move forward further into the cylinder providing the damping action needed by the car to absorb bumps.
It is fairly complicated by today's standards but very cool.
Unfortunately these unique shock shafts are impossible to find, so when the original shafts wear out from use or are damaged there is no way to fix the shock while keeping the original piston design. The simple solution is to find a modern replacement shock with the same specifications (length, diameter), but I wanted to find a way to use the original shock cylinders, springs and external hardware while swapping the piston and shaft for something modern in order to keep maintenance easy while keeping the original look.
Here is what I came up with. The design is based around the re-released Kyosho Optima shocks.
I used the following parts:
Kyosho OT239 Front Shock Shaft (2pcs/OPTIMA). Two packs are required to rebuild three Rocky shocks.
Kyosho OT209 Shock Piston (OPTIMA). Two packs are required to rebuild three Rocky shocks.
Kyosho W5181-03 Shock Pistons. Only the small washers will be used from this pack. There are 8 washers, enough to rebuild 8 Rocky shocks.
Kyosho ORG03BK (Black/10Pcs). This pack has enough o-rings to rebuild 10 Rocky shocks.
Team Durango TD310671 O-Ring 9*1mm (10pcs). This pack has enough o-rings to rebuild 10 Rocky shocks.
Alternatively, Kyosho W5181-04 Shock Seal O-Ring (S) can be used, but this part is getting harder to find, is more expensive, and only comes 4 to a pack.
The original Rocky shock parts that will be used are:
The cylinder, spring, end cap, retaining washer, spring retainers and screw.
How to build the shock assembly:
Step 1: Install a small white washer from W5181-03 into the end cap.
Step 2: Install a 3mm o-ring from ORG03BK.
Step 3: Install an end cap seal o-ring from TD310671 (or W5181-04).
Step 4: Assemble the shock shaft and piston assembly using OT239 and OT209 and the supplied e-clips. There are three piston styles (A, B, C) to choose from in the OT209 pack. I used style C, but you can use whatever piston you want.
The small spacer in OT209 is used to limit the maximum extension travel of the shaft to match the original stock Rocky shocks. In the following picture the spacer is slid up to the piston.
Step 5: Install piston shaft assembly into the Rocky cylinder and fill the cylinder with silicone shock oil up to where the end cap threads start. Remove all air bubbles by tapping on the cylinder and moving the shaft up and down.
Step 6: Install the aluminum retaining washer into the cylinder, making sure it seats uniformly on the inside lip of the cylinder wall. This washer prevents the o-ring from popping out of the end cap.
Step 7: Put a drop of silicone oil on the inner o-ring in the end cap to help prevent damage to the o-ring when pushing the threaded shock shaft through the end cap. Screw the end cap in to the shock cylinder. Make sure the retaining washer remains seated properly while this is done. Also, test and make sure the shock shaft can be fully pushed in to the cylinder and fully extended. If the shock shaft is hydro-locked when pushing it in, loosen the end cap to allow some oil to come out and then tighten and re-try. Since there is no bladder and the shock volume is small it is difficult to have a perfect smooth feel to the shock movement and some air will likely be present, but with some trial and error it should be possible to have a good feeling shock with minimal air inside.
Step 8: Install the external hardware (spring retainer w/screw, ball end, etc.) and you now have a finished shock.
Here is one of my Rockys with the shocks installed:
There may be cheaper solutions for replacing Rocky shocks, but in order to keep the vintage look I think the extra cost is worth it.
If you have found another way to restore or rebuild your Rocky shocks, I would love to hear about it in the comments below.
I have finally finished the Kyosho Lazer ZX restoration that I have been meaning to get done for what seems like forever. The last time I posted about this car was way back in late 2011 when I completely rebuilt the chassis from scratch. The rebuild included some vintage hop-ups and original repair parts that I had bought not too long after I acquired the car way back in 1993. If you haven't read that post before, I recommend viewing it before continuing with this one. Here are a couple pictures from the rebuild:
The final piece of the restoration that was missing was the body, under tray and wing. I had bought a reproduction body and decal set from MarwanRC in 2011 with plans to finish the work during the following summer of 2012, but that never happened. Other things came up, plus I didn't feel like I was in the right mood to do it justice. I knew it would be a difficult body to fit to the chassis. I also knew masking the body for the box art color scheme would be a fairly complex undertaking. I figured the painting itself wouldn't be too difficult to do as long as the masking was done properly. It's just two colors, after all. One sticking point was the yellow trim lines between the two main blue and white colors on the body. How would I do that? Triple mask for three colors or trim tape on the outside (or even inside) the body? My own self-doubt prevented me from attempting the work.
Fast forward to now, in the middle of summer 2015 in the northern hemisphere, and I can say that I have finally finished one of the most complex body fitments I've ever done.
Here is a quick overview of the work involved.
There were four main steps to finishing the Lazer ZX body set:
- Cutting, trimming and testing fitment of parts to the chassis
- Masking
- Painting
- Decaling
Cutting, Trimming and Fitment
Trimming the body parts and getting them to fit the chassis took the most time for this body set. There are four parts to the Lazer ZX body set: The main body shell, under tray, main wing and secondary wing. This is twice as many parts as a "normal" car, which usually has just the main body and wing.
Fitting the main body shell to the chassis took the most time due to the complex cutouts required around the front shock tower, rear shock tower and right side gearbox. Lots of fine-tuning the fit was required so that the body did not press or rub against the chassis, gearbox cover, and shock towers.
The main wing was the second hardest part to cut out and trim. As wings go, it's pretty normal in shape but I find that it takes me a while to trim it down to the proper shape while keeping the edges straight and even.
The under tray was fairly simple to cut out and trim due to its mostly flat shape and straight edges. Some extra trimming was required in a couple areas to allow the tray to fit more closely to the underside of the main chassis and prevent it from being stressed at contact points.
The secondary wing piece was the simplest part to trim and fit. It's just a wide U shape with a center notch cut out to fit around the main wing mount bracket. It fits inside the main wing in the finished product to create a "double wing" design.
Masking
Masking the body parts took the second longest amount of time to complete.
For the main body, the main cockpit window was masked first. I know the box art scheme has a black window, but I wanted it clear instead. Then, the areas I wanted white were masked off. Remember, dark colors, like the metallic blue I used, are sprayed first when painting polycarbonate bodies from the inside. After masking was complete, the areas I wanted painted blue were the only sections exposed.
The main wing needed a white stripe down the middle, so I masked it off, making sure it was evenly spaced on both sides.
The under tray and secondary wing pieces needed no masking because they are all blue and all white, respectively.
Painting
I used Tamiya PS-16 Metal Blue and Tamiya PS-1 White straight from the can.
This step is probably the simplest, but at the same time one of the most frustrating. The very narrow space on each side of the main wing makes it practically impossible to get spray paint there. I kept spraying and spraying, but the paint wouldn't go in. In the past I've moved the paint can nozzle closer to the wing but it usually results in too much paint hitting the surface which ruins the metallic effect or results in a dreaded run. I'd rather have it be too light in color than possibly have a drip or run.
The rest of the body parts painted nicely. The main body was easy to do. Many light coats were applied until it became mostly opaque. I wanted a dark, rich metallic blue color and I knew white would be backing it so I made sure the paint was thick enough not to have the white affect it too much. The under tray was the easiest because it was mostly flat which allowed the paint to coat it evenly.
After the blue paint was applied and left to dry for a while, I peeled off the masking which exposed the parts of the body I wanted to be white. The cockpit window mask was left in place. I sprayed the entire main body, main wing and secondary wing with Tamiya PS-1 white until it had nice coverage. After the white was dry, I removed the cockpit window mask and then removed all of the protective film covering each part. I let it dry for a few days before moving on to applying the decals.
Decaling
I think that applying decals to a body is the most enjoyable part of the work. No fiddling with sharp knives under tension, no plastic shards and no dust. Also, there are no smelly paint fumes to deal with. Just plop down in a chair with the TV on and play a bad movie while carefully cutting decals, dipping them in a soapy water solution and sticking them to the body.
It is certainly a time consuming process, but very straightforward. Each decal has a specific location where it needs to go and it is just a matter of cutting it out from the sheet and positioning it precisely on the body. The soapy water really helps with the final positioning. It lets you move the decal around instead of just having it stick where the decal happened to touch the surface of the body. It's also possible to remove the decal, re-dip in the soapy water solution and place it down again to get more time for positioning. The larger decals benefit from this more than the smaller ones, but when trying to get the perfect spacing every trick has to be used.
With the main decals finished, there was just one more thing: That yellow trim line between the main blue and white colors on the main body. I purchased some Pactra Trim Tape in yellow which comes as a roll of 8 different widths ranging from 1/32" to 1/2". I used the 1/16" wide strip.
[Side note: I discovered during my research for trim tape that Testors, the company that owns the Pactra brand, had begun to phase out most Pactra products as of mid-2013, including trim tape. You can still find it, however. It is also available under the Testors name, although the rolls are not as long. It comes in various colors, including blue, red, yellow, silver, white and black.]
I did not use any soapy water with the trim tape. It was strong enough to withstand removing and re-applying it over and over to get it in the correct position, so I decided that the soapy water wasn't necessary. It bends around curves and corners well. It is important to not stretch it as it is being applied, especially on concave surfaces. After a few hours it will try to return to its original length, so it will pull back and away from the surface. Use of a hair dryer or heat gun helps activate the adhesive and relaxes the tape, allowing it to adhere to the surface better.
Final Result
It is perfect? No, certainly not. I made a couple of rookie mistakes, like not ensuring that the masking tape was firmly pressed down in a couple places which allowed some paint to go under the tape where it shouldn't have. I always seem to have a couple spots like this. Luckily the two spots on this body are not too noticeable.
Am I happy with it? Yes, for two reasons: First, it's finally done after all these years. It is certainly a good feeling of accomplishment. Second, it looks quite nice, especially in person. These pictures don't really do it justice. I am my own worst critic because I know every flaw, every mistake and every shortcoming about it. I wish I could have done a better job than I did. But it is what it is.
Enjoy these pictures of the final product.
Vehicle: Kyosho Lazer ZX (originally released in 1989)
Body: MarwanRC Reproduction Lazer ZX
Decals: MarwanRC Reproduction Lazer ZX
Trim Lines: Parma Trim Tape (Yellow, 1/16" width)
Paint Scheme/Layout: Lazer ZX Box Art
This first set of pictures show the vehicle with the following wheels and tires:
- Wheels: J.C. Racing 2.2" Yokomo YZ10 5-Spoke
- Tires: Pro-Line Racing Caliber 2.2" (8211-02 front, 8210-02 rear)
This second set of pictures show the vehicle with the following wheels and tires:
- Wheels: Pargu2000 Aluminum Optima Mid Front Narrow Wheels (ms0020)
- Tires: MarwanRC Reproduction OT66 (rear), Kyosho Square Pin Narrow (front)
