Hi Dave,
I don't think you looked at the Tormach sample test certificate. It includes an actual test piece so dynamic performance is included. It also includes metrology requirements/standards. The test are very extensive. Of course it could all be one big lie, but then that's a whole different ball game.
For me, looking at a display example of a machine at a show, in a showroom or in hi res photos is not a good way to judge the quality of the machine you are going to be taking out of the box. The IH website includes extensive details on lapping the ways, which I have to admit is untypically honest compared to some sellers, but it also tell me a lot about what to expect out of the box. Why does the IH website not have any details regarding precision, other than a theoretical resolution? I can only take this to mean that the precision guaranteed to be whatever you find. If you where a commercial buyer looking for a mill what would you be most concerned about, it looks good in the showroom or it has extensively documented performance criteria and verification.
To be fair I should point out that I have ordered a Tormach 1100. I didn't have the opportunity to see either in the flesh (I live in Norway) so for me comparing the technical content on each website resulted in no contest. If your have no choice but to laydown 6 or 7,000 USD sight unseen then the Tormach is a much more convincing argument.
Regards
Phil
Originally Posted by wizard Yes they do but that tells you nothing about dynamic performance. Many a CNC machine can slew back and forth and get excellent repeatability while doing nothing. More important is how the unit holds up while actually doing real work. Will the ways be stiff enough to maintain repeatbility and is there enough mass to provide for good surface finish?
A person can gain a certain sense about how well something is assembled and designed by looking at pictures. It is the next best thing to being there. This is certainly not a substitute for measured parameters but such parameters don't mean alot to me unless I'm there observing the measurements. That may be pretty course but I spent a few years working in a machine tool rebuild operation and have seen many a questionable measurement technique.
Now I'm not saying that the IH machine is the best thing since slice bread. What I'm saying is that I've seen the unit online and at NAMES and can see that it is a nicely done CNC conversion. Is it an optimal solution, nope but improvements have been discussed here and on IH's web site.
So until I can see the Tormach machine first hand or get a better impression from some photos I can't really support it. That may very well change if I start to hear alot of comments from people using the machine with extensive machine tool experience and good metrology methods. As it is now though I have little to go on with respect to the Tormach machine.
Thanks
Dave |