frame mortiser

I've been working on my mortising system for making frame molding. It's going to be a little circular saw that runs on a track. A web search on specialty saw blades turned up what looks like a very fine manufacturer! http://www.ravikengineers.com/hss-saw-blades.html.

Now, I want a small blade, maybe 4 inches in diameter, or even 3, with small teeth, mounted on the shaft of a small motor, a longish shaft, and the motor has to be tough. RPMs will be decidedly modest. The idea is to cut under gentle pressure and not too fast. I want a motor that will sustain, say, 60rpm, under a range of loads, if that's possible, or one that will sustain a range of rpms, say, from 60 to 120, under a range of loads, say 1/4 once feet to 1 once foot of torque.

Here's how I derived the above: Cutting speed will be a function of cutting pressure, blade speed, and depth of cut. Let's say we apply 4oz of pressure, making a 1/4" deep cut in soft wood, and turn the blade at 60rpm. How fast would the blade cut, say, in inches per second. Now, applying a certain amount of pressure to the blade in a cut of a certain depth will produced a certain amount of torque, which is the amount of torque the motor must deliver to maintain the desired cutting speed, and then, for safety, I want the motor to slow as more torque is applied, and stop when the torque applied doubles.

Please note that the above calculations are not correct. They don't properly account for blade diameter. Let's see, a 4 inch blade means a 2 inch radius, so pound feet of torque is one sixth the rotational resistance of a blade uder the specified load (cutting pressure).

So, how many amps is the motor going to require? Now, ultimately, what I want is a blade mounted on the motor, a power supply with on off button, a cuttoff switch, pressure activated, and installed, and the motor on a sliding mount. I might be able to assemble the parts myself, but I wonder if these guys can do it all for me - the calculations, the parts, all ready to go.

I should add that I plan to have the rails and supports made locally from wood. I'm working up the design in the last few days. (This plan has been on my mind for years.) Vaguely, but always, the plan is to market the device to crafters. I just have to talk to my ip guys about it. I don't know enough about what to do.