List of milling machine features I am seeking

Yep, most of these new improvements involve routing wires properly and writing configs and commands.

The "hard stuff", however, involved more of same. The whole project was not mechanically challenging, it was mostly about learning how to use various functions and connecting wires and cables. It was complicated, but required no big physical efforts or mechanical knowledge.

I agree.

Jon, practically speaking, how fast do you run your spindle when rigid tapping with small taps?

Say you are tapping with 10-32 taps, how fast would you run your spindle.

It should be a manual button, I think, I have not yet figured it out. I thought about it last night, all the delays etc, it was painful to think about. This is also a somewhat riskier function to debug (compared to, say, flood), because of how a brake may fight the VFD.

I have to look at the brake fuction more closely.

My current thinking about the brake is that the pneumatic system is already made, such that that the brake engages with a delay, but withdraws instantly. If so, then, the built in delay may be sufficient to let the VFD stop the spindle.

I recently put a brake resistor on the VFD, and can stop faster than I used to.

i
Reply to
Ignoramus29207
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People did closed loop speed control with a VFD. I saw that. I have not seen implementations of speed control with a varidrive. And I did ask on the emc-users list.

This vari-drive control from G code is relatively rare, so I am not surprised. Most modern VMCs simply have oversized spindle motors and VFDs, whereas most older CNC and retrofit mills do not have pneumatic varidrive control.

What I will do is, the S instruction will control VFD (S1000 == 60 Hz), and practically I will not use it much. And my M141 instruction will adjust the varidrive whenever I see fit. Normally there is rarely a need to adjust speed, besides use of tapping after drilling.

i
Reply to
Ignoramus29207

Automatic lube (ways & ball screws)?

Automatic tool changer?

Reply to
Mike Henry

The mill has that already.

This is too hard, I would not do it.

i
Reply to
Ignoramus29207

Ignoramus29207 fired this volley in news:Zuednd7IpPy9gP3RnZ2dnUVZ snipped-for-privacy@giganews.com:

The interface is easy. Heck, you could build an "extension ring" for your rotary table to act as the tool holder.

But you do have to have a power drawbar that can be controlled by EMC. I don't recall your saying if you had one.

LLoyd

Reply to
Lloyd E. Sponenburgh

I do not have a power drawbar. Based on some abysmal past experiences, trying to implement something like this will lead to a disaster.

i
Reply to
Ignoramus29207

ATC is nice, but far from critical for a home shop. You already have a quick change spindle, so as long as you can keep standard tools pre-set in their holders and numbered for quick change with the tool length offsets and whatnot properly entered into the control, manual tool changes should be fast and easy.

One addition that might be worthwhile would be to install a tool length sensor probe at a far corner of the table to allow fast automated tool length measurement.

Reply to
Pete C.

I agree with all of the above.

i
Reply to
Ignoramus29207

FWIW, I do all tapping at 200 RPM in back gear. I'm sure you can go faster.

...

FWIW, I use the VFD and resistor to stop spindle, then bring in brake to hold it there.

Karl

Reply to
Karl Townsend

Karl, I want to do the same thing. Using whatever you used, how did you specify brake delay?

i
Reply to
Ignoramus29207

I'm a bit late to your thread... been fighting the new 'puter and helping "the kid" all weekend.

As to list of new things to add. Consider a servo on the knee and link it to tool height when doing a manual tool change. Your 2 1/2 axis machine suffers from too small a Z range and this solves the issue.

Karl

Reply to
Karl Townsend

On Mon, 09 Aug 2010 11:55:09 -0500, Ignoramus29207

brake delay?

here's my logic: (different language than yours)

[[STOPSPINDLE]] #34=0 'make sure CCW is off #35=0 'make sure CW is off SPINSTOP LIGHT 4;OFF SLEEP 1.0 IF #66=1 THEN #44=0:\122=0:LIGHT 10;ON 'if brake is in ON position, turn off brake release or brake on, flag for brake \121=0 'flag for spindle off

looks like I just wait 1 second after turning the out off.

Reply to
Karl Townsend

Aside from that -- Iggy's spindle has a quick-change locking ring for the NTMB/NMTB-30 (whichever) holders. This requires a hook wrench to lock and release it. So to have a power drawbar (ideally with the finger cluster to grip a pull ball on a CAT-30 holder or a BT-30 on a power drawbar).

I agree that adding a tool changer to your machine is not a practical project for the present. If you stumble across an alternate head for the machine, with the different spindle and the mounting points for the turret -- then you might reconsider this project.

Enjoy, DoN.

Reply to
DoN. Nichols

I have wimpy servo drives, about 5 A peak. I also was still learning how to set the thing up, and hadn't put a filter in the velocity command to the VFD. I was having a couple problems. The VFD slammed to a stop so suddenly the Z axis couldn't always follow it, and I got following error trips. Also, the electronic motor protection was enabled, and was tripping the VFD offline. The Bridgeport "pancake" motor is insanely derated, and is meant to do plug-reverse tapping all day. I just turned the motor protection off, and added a filter to soften the reversing action of the VFD. So, after these fixes, I was happily tapping 4-40 at

1000 RPM. I suspect I could go even higher now.

Hmm, I think I did some 10-32 tapping at 800 RPM. I made a 12 x 24" fixture plate with 288 holes. Rigid tapping is WAY cool on a tedious job like that! I mounted the plate on spacers, indexed the position, and then did spot, drill through, and tap in one setup, then moved the plate and did another section.

You could interlock them, so the button doesn't work when the motor is on. I have turned on my VFD when the manual brake is locked, nothing horrible happens, and the belt slips. This may be less desirable with a varispeed drive. If it takes you too long to react, the VFD will just fault. I have the VFD fault relay wired into my E-stop chain.

EMC1 had a delay built in for the brake, this has been removed, I think. But, putting in a delay would be easy in HAL.

Jon

Reply to
Jon Elson

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