I am using the Tormach’s tooling system on my PCNC 1100 as well, and it seems to work well. As far as the higher horsepower on your mill, it depends on how that horsepower is delivered. I notice that the machine comes in a step pulley arrangement and a variable speed arrangement. The 90 RPM speed on the step pulley means it is delivering that 90 RPM at a full 3 hp, which gives quite a lot of torque. The PCNC uses a Variable Frequency Drive, so it has almost no torque at speeds below 200 RPM. If you are opting for the variable speed machine, it depends on whether they use a variable pulley system or a VFD as to whether you have a lot of torque at the low speeds. Low speed and high torque are the combination that makes using the NT tapers with their drive lugs worthwhile on smaller machines. You see it on smaller horizontal mills, as even a relatively small horizontal mill might be swinging a 6" HSS cutter at 50 RPM and full hp. I've used the TTS with up to 3/4" EM in mild steel with no problems. I have to take very light cuts and run at about twice the recommended speed for a 4" HSS slitting saw in steel due to the low power at this speed, so there isn't much strain on the spindle that way. I would determine if the mill you are getting will be the variable speed or not, and if so how that speed is varied. If it uses the VFD for speed control, I think the TTS would do a good job for you. Otherwise, the prior suggestions as to which you can obtain and has the cheapest tooling is valid. If you decide on the TTS system or for anyone using collets, there is a good white paper on the Tormach website on proper preparation of collets for use. I had some problems with tools coming out of collets until I read that and implemented the recommendations. I have no problems with tools slipping now.
