770 First impressions

I've had my 770 for a month or so now. I haven't gotten as much time with the machine as I'd like, but I have run it enough to develop some likes and dislikes.

The machine seems like a great little mill. I have never run Mach 3, so I just went ahead and installed PathPilot. I have not had any trouble at all with PP, and I find it very easy to use.

1. I had a problem that some here may remember me discussing in a thread about my spindle being noisy. About the time all that was going on, I received an email from Tormach just checking up on my purchase. At that point, I was kind of undecided of whether or not I wanted to pursue the noise, so I mentioned it. I was immediately contacted by a tech that helped me out tremendously. He walked me through several things to check, and after doing all of that, he decided to replace the spindle motor. It seems like most of the noise is coming from the motor itself. They sent one UPS and I installed it the night it came in. I'll say it is better, but not as good as I thought it might be. I guess maybe my expectations of how loud the machine would be are just a little off. it seems fine at lower RPMs, say 1000-1500, but when you max out at 3k plus, I pretty much have to wear earplugs. The noise becomes a nuisance and not really bearable after a few minutes. the machine is in my garage, and I can hear it running from inside the house with the door closed to the garage. Not sure if this is normal or what others have experienced, but it is what I am.

2. The jog Shuttle. This little thing is awesome. I really like the fact that the little ring around the center thing increases and decreases in movement speed as you apply or remove more pressure. I'm not exactly how to explain that, but those of you that have it know what I'm saying. This is really nice because I don;t have to worry about changing the jog movement speed with a knob or button, I can do it on the fly. The only thing I don;t like is the lack of common features found on other pendants, like start, stop, feed hold, single block, and spindle and feed override controls. I've had several times where the machine started to make a noise I wasn't crazy about while running, and I found myself fumbling with the mouse, trying to locate the cursor on the screen while moving it, and getting to the feed hold button. I'm usually standing in front of the machine watch closely as it runs, especially on a program that hasn't been proven, and I'd like to have controls in my hands right there.

3. Spindle speed readout. This is l fine up to 3250, but when the belt is swapped to the upper position to run the higher RPMs, the screen still reads 0-3250. I have no indication of what speed I'm actually running. On top of that, the Override on the path pilot screen does not start affecting the RPM until it is slid down to around 25% (If I remember right). So in other words, the effective range of the override is like 0-25%. I decreased the spindle speed yesterday trying to find a sweet spot for a program, and I have no idea what it was at, other than it sounded a little slower than max speed.

4. Tool holders. WHY IN THE WORLD does Tormach only offer set screw holders down to 3/8"??? I'm sure every one of us would jump on tooling that was ranged down to 1/8" if they made them. They have got to see the demand for this. I don't mind ER tooling holders, but the problem I have with them is clearance. I can get into much tighter spaces with set screw holders than I can with ER holders. Talking to a member here, we were discussing sleeving the tools. I can see that as a solution, but I still think Tormach needs to get on the ball and offer some smaller holders.

I guess I just didn't do enough research, but I really wish that I had gotten the little enclosure that goes around the table. I don't have that and have so far rigged up an enclosure made mostly of welding curtain. This wasn't so much an issue until coolant was used, and then it was a "have to". I May order that enclosure for the table soon.

All in all, a great little machine that will work great for my needs, especially as I get more familiar with it

Tormach used to offer at least 1/4" set-screw holders. I have a few but they are pre-TTS so maybe that's part of it.

the keyboard space bar should act as feed hold. Handy to hover a hand over that when watching the machine do a first run program.

The other PP things you should report to Tormach and see what they say-- it sounds bizzare to me.

Maybe there is a belt position switch in PP that tells the control that the belt is in the upper position. I will look in my manual and see about that.

Some thoughts.

1. I don't have a 770, but that still sounds like way too much noise. I can run my 1100 wide open- roughly 5800 rpm on the tach- and barely hear it in the room immediately above the shop. Right next, a bit noisy, but no need for ear protection unless cutting steel. Talk to Tormach some more.

3. Speed readout. This just sounds wrong. When I swap my belt (Mach3 controller) I also have a soft switch to change in Mach. If I don't change it, Mach won't let me go faster than the low speed limit.

4. Tool holders. Search the forum and you'll find some discussion. As I understand it, the issue is runout. A few thou on a 3/8 or 1/4 cutter with a 3/8 shank is no big deal; 10 thou is 4% on a .250 cutter. On a 1/8 cutter, it's twice that. Bad finish and broken cutters soon follow.

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Originally Posted by GLCarlson

4. Tool holders. Search the forum and you'll find some discussion. As I understand it, the issue is runout. A few thou on a 3/8 or 1/4 cutter with a 3/8 shank is no big deal; 10 thou is 4% on a .250 cutter. On a 1/8 cutter, it's twice that. Bad finish and broken cutters soon follow.

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A decent set-screw holder should have no more than a few tenths of runout. NO holder should have "a few thou" of runout! Even the cheap Chinese knock-offs are better than that.

Regards,
Ray L.

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Originally Posted by GLCarlson

Some thoughts.

1. I don't have a 770, but that still sounds like way too much noise. I can run my 1100 wide open- roughly 5800 rpm on the tach- and barely hear it in the room immediately above the shop. Right next, a bit noisy, but no need for ear protection unless cutting steel. Talk to Tormach some more.

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I have had a 770 for about two years and that seems *FAR* too loud. As I believe that I wrote previously I can easily hear the cooling fan at the top of the control cabinet and the steppers when I have the spindle running but not cutting. If you can't TALK TO TORMACH!

Have you considered the ER16 rather than ER20 holders? I frequently use 1/8-inch shank bits but with 1/16-inch cutting areas and haven't had significant problems with clearance for most jobs. Perhaps posting some pictures of your setups would elicit suggestions for workarounds.

They do still have set screw holders in 1/4 and 5/16. In metric down to 6mm.

I always try to buy my smaller mills with 1/4" shanks when they are available.

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Originally Posted by J S Machine

3. Spindle speed readout. This is l fine up to 3250, but when the belt is swapped to the upper position to run the higher RPMs, the screen still reads 0-3250. I have no indication of what speed I'm actually running. On top of that, the Override on the path pilot screen does not start affecting the RPM until it is slid down to around 25% (If I remember right). So in other words, the effective range of the override is like 0-25%. I decreased the spindle speed yesterday trying to find a sweet spot for a program, and I have no idea what it was at, other than it sounded a little slower than max speed.

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You have to set the spindle range. There is a button in the Manual Control Group that you have to click to select the appropriate range. See Spindle Controls in the manual. If that doesn't work, you should file a bug report with Tormach.

bob

The noise definitely doesn't sound right and could be an indicator of a problem. I would keep talking to Tormach. They are ABSOLUTELY AMAZING at trouble shooting. Like you've experienced, you had a somewhat minor sounding problem and they sent you a free replacement motor. Can you imagine a car dealer replacing a major component purely because you told them "this doesn't sound right"? I promise you, if you pursue this issue with Tormach, they will send you parts/ troubleshoot until the problem is 100% sorted out- they really stand by their products.