I am having a new worm gear and crescent fabricated for a Challenge M series press.* I intend to have a couple of extra sets made. The cost per set will be $1,150 with free shipping within the US and Canada. This is less than having a one-off made.
The Challenge census lists forty-one 15MA/MP and four 21MP. The gear diameter is the same for both sizes only the shaft length differs.
My watchword regarding presses is “anticipate failure.” You will be glad to have a spare worm gear and crescent at some point down the road. The price will certainly be higher in the future. Please contact me as soon a possible. I require a 50% deposit with the balance due before shipping.
*Similar to the Asbern A series a crescent is set into a collar that is attached to the end of the tube with set screws. Unlike the Asbern, (or Vandercook) the worm gear is cut into the shaft. This Challenge 21MP is locking up at one end of the worm gear. There are chips in the gear points and the crescent is also worn.
I ended up making only one diamond shaft and pawl set. The final price was $1825.00. I had two extra pawls made and one is still available at $165.00
I am moving ahead with the fabrication this week. Let me know if you want in.
A couple of people have asked how to disassemble a Challenge M-series oscillator. Here’s how I did it.
1) Clean the edges of the end disc with a pick and spray Liquid Wrench, or similar, into the crevice.
2) Remove the three set screws (10-24 x 3/8″).
3) Tap the shaft with a mallet from the non-geared end to separate the end disc from the tube. Conversely, hold the tube vertically about 2 inches above a board, then let it slide down through your hands so that the shaft hits a board. Do this several times until the disc comes free of the tube.