Tormach 770 vs 1100 for aluminum

[LazyMan]

For aluminum work, will the 10,000 rpm spindle of 770 allow for higher material removal over the 1100 for tooling .25 inch-.5 inch tooling? With .5 less horse power than the 1100, am I going to end up taking lighter passes at at higher feedrate vs deeper passes at lower feed rate and end up at the same mrr?

[philbur]

A quick run with MEPro seems to indicate that for those sizes in HSS the 1100 wins easily. Its only when you go to carbide at 0.25" diameter and less that the 10,000 rpm starts to show some advantage. Of course if you do a lot of profiling with small cutters then the 10,000 rpm wins every time.

Phil

I edited this one but it didn't show up so here it is again: It seems that standard HSS end-mills at those sizes will run out of steam before either machine runs out of HP. A 1/2" carbide end-mill might give the 770 a run for its money on HP though.

For aluminum work, will the 10,000 rpm spindle of 770 allow for higher material removal over the 1100 for tooling .25 inch-.5 inch tooling? With .5 less horse power than the 1100, am I going to end up taking lighter passes at at higher feedrate vs deeper passes at lower feed rate and end up at the same mrr?

[LazyMan]

This is what I was speculating. I was trying to find excuses to save money buying the 770, but it really doesn't save enough money compared to the 1100. They increased the price on the 770 stand and when the new series 3 comes out I imagine they will increase the price of the mill too.

[philbur]

The 770 possibly only comes into it's own if you are running small cutters in the 3mm and below range or if you want to do a lot of fine 3D profiling.

Phil

This is what I was speculating. I was trying to find excuses to save money buying the 770, but it really doesn't save enough money compared to the 1100. They increased the price on the 770 stand and when the new series 3 comes out I imagine they will increase the price of the mill too.

[PriddyShiddy]

another important factor to consider is the ability to add a PDB and ATC later on the 1100. if your goal is to grow and you are successful in that goal, you may soon be cursing yourself every time you hear the spindle stop and you have to stop what you are doing to go manually loosen the drawbar and change tool.

I don't trust my code/machine enough to leave it unattended for the first few runs on a part, but I do find myself engaging in secondary operations like deburring etc while it works. I can only dream of the day I can hit CS and come back to parts that have 5+ operations done and just swap them out for more blanks

[LazyMan]

yeah, I was considering the PDB and ATC situation. I read that Tormach is working on a PDB for the 770, but it is not priority for them for right now. As for ATC, I don't know. It would certainly be a dream come true but I think I would be more likely to invest in a 2nd machine before spending $4200 on the ATC. For me, the PDB and not having to touch off tools is already a dream come true. I think I am already set on the 1100 because the only advantage of the 770 for the work I want to do with it is less space and price.