Check with the razirtip manufacture...I believe they make scale burning tips inseveral sizes. Also check with
www.fishcarver.com Ed Walicki runs that site and he had different scaling tips available, plus material and instructions for making you own tips.
Or you can do what I did and make your own tips for one of the "hobby" burners, available in the craft stores for around 15 to 30 bucks.
I believe these burners all take a 3/16" standard thread for their tips. Anyway, find what thread you need to insert the tips. Either turn down youself, or have someone turn about a half inch thread length on a short piece of brass rod that is the diameter of the size scale you want to reproduce. Let's say you want to produce a 5/16" diameter scale. Using a 5/16" brass rod, cut a length about 1 1/2" long, and turn one end (1/2") down to the 3/16" thread diameter, and thread this end.
Now turn the rod around in the lathe so the 5/16" end is out from the chuck. Chuck a 1/4" drill into the statonary spindle and run that into the 5/16" rod about 1/2", giving you a brass rod with a 1/4" hole in the center. Now take a countersink, chuck that into the statioary (non turning) spindle and run that up into the 1/4" hole till the taper just meets the end of the 1/4" hole.
At this point you'll have to take the new tip out of the lathe and hold it in a vice while you file away half of the 5/16" dia portion that has been drilled and countersunk. This will leave you with a short brass tip, threaded for 1/2" length on one end, and having a half circle shaped burning end on the other. This can then be screwed into the El-Cheapo hobby pen and used to burn the scale pattern.
I only used the 5/16" rod size as an example....you can make these up to whatever diameter you want bu using either larger or smaller brass rod. Heavier tips will take a little longer to heat up, but retain the heat longer for larger scales.
Hope this helps.....if unclear, email me and I'll send you a sketch or a phot
Al