- Machine as shown in auction catalogue looking OK.
For a customer's machine last year I had to recast a new golfing figurine for this rare game as the original literally fell apart in my hands when I tried removing him! I was being very careful as the castings were showing the tell tale signs of early pot metal cancer with tiny cracks all over. But someone had already been there before me and used an epoxy glue to put the head back on, both ankles, and repair the arms in multiple places along with replacing the missing shoulder attachments using wire. The figure wears a knitted jumper and had been heavily repainted to hide the repairs, so not much to see in the auction photos my friend purchased this from.
- Figure fell apart when I tried to remove him from the playfield. Felt sick for a moment until I realised it was nothing to do with me!
Since the metal was decaying anyway there was no way of saving the golfer for the long term. And this man is unique to the Chester Pollard Junior machine, different to the floor standing machine they made. But he was still good enough with some restoration to use as a casting pattern. Sending off to my foundry to be sand cast in alloy would've been a nice simple option, but in this case no good. Because the shrinkage would've caused huge troubles refitting the man to the existing playfield. The geometry is very important here in matching up with the internal gearing for the main shaft, and the position of the golf club head where the ball sits!
- Arms glued and restored with reproduced shoulder joints. After this it received several coats of primer and light sanding to hide cracks.
Because of this I opted to make my own rubber molds with a heat resistant silicon (Elastosil M4670 High Temperature RTV Silicone Rubber) that has no shrinkage at all. And then cast myself using a low temperature hard pewter (Casting Alloy Stick JA12) that also has barely any shrinkage. It all worked out perfectly in the end. But a lot of time in mold making and fine tuning the finished piece to make it run smooth as silk. I also liked the fact this pewter is so close to the original pot metal they used and really I don't think anybody would be able to tell the difference.
- Half the arm mold made, ready to pour the other half.
The figure doesn't really take too much force but since I've never used this hard pewter before I chose to make sure it was strong enough by over engineering. And strengthened the weak point which is those ankles by running steel rods right up inside the legs. Originally bolts threaded from under the playfield into the feet, and of course the ankles snapped right at the bolt ending points. Whereas I decided to have thread stick out of the feet and extend right up the legs.
- Arm mold with casting above. The black in the molds is a dusting of graphite which helps fill any tiny voids and helps demolding.
To make sure all the needed holes were in the right places I installed brass inserts into my molds that easily removed after casting. I also wasn't sure how well the pewter would wear inside the leg casting as the main steel shaft rotates in there. So I installed a brass bushing into the mold before casting, this was just scrap tube with thread outside which insured non movement.
- Torso mold showing all inserts installed before casting, though missing the locating pin in the main steel shaft. And sample casting below that didn't have a shaft installed.
I also chose to slightly alter the way the torso was cast, originally the main steel shaft was fitted to the torso after it was die-cast using a taper pin. But to make sure it was exactly in place I chose to pin the steel shaft first and insert it into the mold before casting. This way when it came out of the mold I knew it was already correctly centred and I could then clamp that steel shaft straight into my lathe to machine the inner waist area which has to snugly, but loosely mate with the leg casting.
- Leg mold with reinforcing rods installed before casting.
Was an interesting problem to overcome and luckily my customer was willing to throw decent money my way to have it solved the best way I could figure out! Is actually a fairly rare machine with probably less than a dozen surviving.
- Legs as they came from the mold.
Here's a link to the casting alloy and there you'll find associated links to the suitable silicon:
http://aldaxstore.com.au/p/373936/casti ... 12-kg.html
- New figure on left, original on right, showing basically no shrinkage!
