Next up - mounting the heating element.
You might have noticed that the mounting holes (for the element into the machine), in my disk were not the same as for the Elma. Well, one look at the casting for the National Machine's base will explain that.
The whole base is a quite substantial, one-piece alloy casting. It must have been a sod to produce back in the days before computer aided design.
The original ceramic heating element, was secured by a single screwed bolt through it's centre, with an asbestos/ceramic tile between it and the metalwork on it's underside. Mine would have to attach by either two of three mounting points around its circumference. The pictures explain all.
A couple of drill holes later and I was done. The one thing I did not have to hand was some spacers to raise the heater away from the metal web of the base. I made do with an extra couple of nuts to provide the correct spacing, till I get some proper spacers. (He said - knowing full well, it will likely stay like that forever now...).
If money wasn't an issue, I'd go for a high-quality press. As oldhippy says: "Buy the best and it will last a lifetime". Not only that, over time high-quality tools are the most inexpensive as you never have to replace them. Being a hobbyist though I have no idea how many crystals I'll be needing to replace. It is a predicament, and as per usual I really don't want to wait until that perfect used tool becomes available for auction, and then I might still lose the bidding.
Haven't really made up my mind, but I'm leaning towards giving the press I linked to a chance. The seller has a 100 % reputation and the description says: "Heavy and precise spindle press for safe pressing in of glasses, for careful positioning of steady rests and for safe closing of pressed housing bottoms. Extremely precise work due to finest spindle actuation." The seller also claims: "Proven Ernst Westphal Premium Quality - we only supply with products which meet our high standards as a traditional German wholesale specialist for fine watchmaking and jewelry supply for more than one hundred and twenty years." Plus covered by the "eBay Money Back Guarantee".
It would have been interesting to read the post @jdmwas referring to but (as usual) I'm unable to find it...
I have no problems with mine. you had one or are you speaking with the usual prejudice about Asian tools?
Another type I recommend is the Aluminum one withe the screw in between pillars.
No need to spend big money or go hunting vintage when it comes to decent tools.
With the PTC Heating Element arrived, it was time for some metal bashing.
Actually, it briefly got a bit more "high tech" that that. I needed to try and replicate the Elma Heater, based upon what the Elma spare part heater looks like from catalogue pictures. A quick estimation on my part seemed to indicate a mounting plate size of around 90mm diameter (the element being 75mm on it's long side). Where to sort it from?
A quick conversation with an old work-mate turned up the opportunity for a catch-up and a bit of "metal bashing" for the cost of a light lunch.
A bit of mild steel around 1.5mm think was run through his laser/plasma cutter in no time and I had my mounting plate. Once back home, it was drilled to attach the heating element. So that job done, now to mount it in the machine.
In my opinion, it's not a bad replication of the original Elma spare part and I cannot imagine that it would be any less efficient.
SO - if you cannot get hold of the Elma Heating element, all you need is a relatively cheap PTC Heating element, and a good mate with around £35,000's worth of plasma cutter!