Thunder Blade by Alan Lewis

NOTE: I have sold this game so I no longer have it.



Although I'm not a video game fan I am a sucker for video games hooked up to large complicated mechanisms!

Well, I found one on sale locally and I couldn't what do I do?

This is a 1987 Sega Thunder Blade sit down game. It was also offered as an economy upright cabinet game. Same game, different cabinet. Here's how my brain works:

 Upright cabinet game: No Interest at all.

 Sit down cabinet game: Wow, What a Great Game!

BUT......always a big but with used arcade machines: They are never in good shape by the time you get them, years after they have been used and abused in arcades. This one was no exception. Very dirty, scratched up, cracked monitor housing, extremely sloppy control stick assembly, fuzzy monitor image, etc.






Here is my machine after being fixed and cleaned:

FIRST ITEM TO FIX: Cracked plastic monitor housing. This one is pretty easy, remove all the screws

and separate the two halves of the housing. Clean the inside surfaces and use a fiberglass repair kit

from an auto parts store (the one with the glass matte and the resin). Bond the repair matte over the

cracks from the inside, after flattening the cracks so they fit together tightly.

I took the glass monitor protector off and cleaned it. Then I noticed that there was a fluorescent lamp

over the monitor for backlighting the gauges. I didn't realize it was there when I bought the machine.

I replaced the starter and lamp to get it to work. I also had to add some self stick foam weatherstripping

tape along the top edge of the glass protector to stop the light from washing over the monitor surface.


SECOND ITEM: Fuzzy monitor image. Since the housing is off might as well fool around with the monitor

adjustments. The image was very washed out and out of focus. It seemed to me like it had the brightness

cranked way up. But nothing is that easy, is it? Well, sometimes it is that easy. I turned down the brightness

and bingo.....the monitor image was crisp and clear and had great color. I also found a sticker inside that

said the monitor had been rejuvinated in 1996. Good to know.


THIRD ITEM: Appearance. I cleaned the entire machine. Then I removed the step and sanded it down and

painted it matte black. I painted the skids semi-gloss black. I used auto rubbing compound on all the

remaining painted surfaces to bring back the color and smoothness. The decals were also very dirty and

the rubbing compound cleaned those up very well.


FOURTH ITEM: Sloppy control stick. This was the challenging one! I had to completely disassemble

the control stick mechanism both outside and inside the cabinet. Here's what it looks like:






Here are the wear items:

 The plastic ball joint where the control stick enters the cabinet.

 The universal joints connecting the stick to the fore/aft carriage

 The carriage nylon guide strips

My machine had about 1/2" of free play in all directions (1" total movement in a dead zone). It was very difficult to play this game and this free play caused a lot of damage to the mechanism and cabinet over the many years of ignorance. You had to slam the control stick with a lot of force to get small movements out of the helicopter. Time to fix this!

The plastic ball joint was worn way down, it moved 1/4" back and forth in the socket.

NOTE: There is a new plastic ball joint from IGUS that could be pressed into a housing and sleeved to fit the control stick. I decided to try the repair approach, using the new piece as a backup plan.












The repair of the outer ball joint housing consists of separating the housing (it's two pieces), cutting a section out of the top piece and screwing it back on. Then making a new spacer block to put underneath. This tightened up the ball socket fit.








The ball I.D. was completely worn away and rounded. I found that a 1" copper plumbing pipe fit perfectly over the control stick metal tubing. I sanded the plastic ball I.D. to be a press fit onto the copper pipe. I pressed the pipe into the ball and filled in the gaps with JB Weld epoxy.

Remember that the copper pipe must slide up and down on the control stick metal tubing, not be a tight fit.

This is what it looks like when done and slipped over the control stick.

Put some lithium grease on the control stick so the copper pipe is lubricated. The plastic ball must be able to slide up and down the control stick during game play.

I made the copper pipe long to take out some of the free play due to the clearance of the pipe to control stick.







Next is tightening up the fore/aft carriage that the control stick is connected to. Mine was completely mangled and worn out. Someone had actually hammered one side of the carriage to tighten it up! If it would have been fixed properly years ago this game would have been still collecting good money in an arcade.

The carriage side piece was bent back to be flat.

The carriage uses nylon wear strips as guides for the back and forth motion of the control stick. Sure would be easy to just buy the wear strips and replace them. But as you know from the rule of thumb.........

I figured out a way to get new flat surfaces back into contact with the carriage sliding guide pins. Remove the nylon strips, cut them in half lengthwise, flip them over and drill new mounting holes in the carriage and strips.










This shows the nylon wear strips after being cut, flipped and screwed back on the carriage sides.










After assembly of the carriage I added two threaded rods across the side plates to stiffen the assembly and allow minor free play adjustment as the nylon wears.

The last item to fix on the carriage was the universal joint. The cross bolts that fasten it to the control stick and the carriage were loose, lots of free play. No matter what size bolt I put in the joint had a lot of free play.

I decided to change how it was fastened. I changed to using set screws in the universal joint contacting a flat on the shafts. I ground a flat area on each shaft and drilled and tapped a 1/4-20 thread in the universal joint housing, top and bottom of the joint.

After slipping the u-joint onto the shafts the set screws are tightened. This took care of the free play in the u-joint.









After the carriage is installed the control stick is dropped into the ball joint housing. Lithium grease lubricates the plastic ball joint.

The control stick is slipped into the carriage u-joint and the set screw tightened.

The top ball joint housing piece is screwed onto the bottom. Tighten the screws enough to have a tight joint for free play but loose enough to rotate freely











Later I added a thicker spacer underneath the ball joint. I wanted to raise the ball as high on the stick as I could to reduce the amount of motion for the helicopter to move. It makes the game respond quicker to control stick movement.

I use MDF for the spacers.


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