I'm setting up my shaper for some T&G doors and would appreciate a sanity check on my calculations.
Using the charts on page 22 of Eric Stephensen's book "Spindle Molder Handbook", ...
I'm using a steel Whitehill 120mm HSS insert head.
Looking up a 120mm steel insert head (PH) with high speed steel cutters (H), the blue line for the insert head (PH) hits the top axis for a 120mm head, which indicates a maximum speed of 10,000 RPM.
My choices are 4200, 8400, and 12,000, so I picked 8400 RPM.
For the feed rate, the chart on the next page says: for 8400 RPM and a PH (insert) head, my feed rate should be 10 metres/minute, or roughly 33 feet/ minute for the best finish, so I picked 33 fpm.
Performing a test 7mm*6mm long grain rebate cut on poplar, the finish was crisp, as if sanded...
1. So do these number seem reasonable?
According to how I understood the book, the species being cut only affects the type of cutter one would use, and has no direct impact on RPM or feed rate for a given head size/type.
2. So would I use the same RPM and feed rate for the MDF door panels ?
The book also describes 2 types of cutters: HSS and tct.
3. Is tct the same as carbide? Any one know what tct stands for?