IH Conversion questions

[ninefinger]

Moving drivers around is ok in theory, but usually the driver has the configuration (tuning) done on it and moving it from one machine to another will result in less than optimal tuning for that machine. Also there is risk of damaging a drive if you disconnect it while its energized.

The reason I went with small servos is as Arizona mentions - you can only get so much out of a gecko drive (or equivalent). There are lots of other drive options out there - you just need to shop around for them. For DC servo drivers Viper drives is one, CNCdrives is another - now sold thru cnc4pc.com CNC4PC, DMM tec as I showed earlier is yet another (AC drives)Servo products

Mike

[Ed from NY]

Yeah, I have to think this over well. It is easy to get carried away

One thing that is interesting is that the large DMM motor is rated at 2.9 N.m, but the max RPM is only 1080. The large Keling (KL34-180-90) is 1.6 N.m but goes to 3200 RPM. So the DMM with a 1:1.8 reduction is equivalent to the Keling with a 1:3.2 reduction. But at those reduction ratios the Keling reaches 200 IPM with a 5 TPI screw and the DMM tops off at 122 IPM.

Did I get the concepts right?

So far I have not found any bigger (or as big) servos in this price range.

[ninefinger]

One thing that is interesting is that the large DMM motor is rated at 2.9 N.m, but the max RPM is only 1080. The large Keling (KL34-180-90) is 1.6 N.m but goes to 3200 RPM. So the DMM with a 1:1.8 reduction is equivalent to the Keling with a 1:3.2 reduction. But at those reduction ratios the Keling reaches 200 IPM with a 5 TPI screw and the DMM tops off at 122 IPM.

In comparison I'm driving my mill with 1.4 N.m at the ballscrew (.353 N.m servos and 4:1 reduction). You could direct drive (or 1:1 pulley for mounting ease) with the torque available on those servos and then you have both more torque than you need and higher speed (216 IPM)

[Ed from NY]

In comparison I'm driving my mill with 1.4 N.m at the ballscrew (.353 N.m servos and 4:1 reduction). You could direct drive (or 1:1 pulley for mounting ease) with the torque available on those servos and then you have both more torque than you need and higher speed (216 IPM)

Oh! I thought you would need more from Arizona's comments. Yes, I'm really looking to direct drive it (no reduction). It makes the assembly much simpler.

[skullworks]

Keep in mind that on a mill the size of an IH and the reversing torque it may see you might have less backlash with a servo belt drive vrs a shaft flex coupler unless your ready to spend commercial CNC part prices like $200+ for that shaft coupler.

Also, using a belt drive on your Z axis will allow more options for mounting a break to stop head drop.

As to rapids... Run a few parts which have a grid of holes which get Spot drilled, peck drilled, reamed, c-bored, and final edge chamfered and add up the cycle times with different max rapid and accel numbers. At the end of the day you may have saved a few HOURS.

My Hurco allows 300IPM jogs and 400ipm rapids. After running Kitamura's, Mazaks, Okuma's and Mori Seiki's at my day jobs which have rapids starting at 740ipm the Hurco seems to be crawling.

There is a cold hard truth - The only time the machine is making money is when its making chips, if its on and not making chips then its costing you money.

[Ed from NY]

I hear you Skull. Thanks for advice, specially on the belt/coupler stuff.

To get to that kind of rapids I think we would be talking $1200+ per axis. And without an ATC... well -- Though it would make peck drilling bearable

BTW, funny, I was looking at a possible Hurco rebuilt... but I need to renovate in order for it to make it in. Which one do you have? I was looking at a SLV40. The thought was to replace all the electronics, but keep the spindle. Have not given up on that idea completely yet

[skullworks]

Not so!

Check out the BP convervison by Himmekibble - (IIRC) he uses the Homeshopcnc servos and gets great speed out of it ( he has posted some videos see [nomedia="http://www.youtube.com/watch?v=78KUDWnz-WU"]YouTube - Big Mill, Moving FAST![/nomedia] )

As to my Hurco. I have a 1991 KM3P kneemill with the MAX32 updated control which replaced the original MAX II. - I did have to pull the spindle motor and Z servo to get it through a 7ft door. It has a 3HP spindle and is for the moment running on a 10hp phase converter. The control is old but it tracks the spindle so it "near rigid taps". I use tension/compression holders but there is only about .030" available movement before the spring pressure might be high enough to snap the tap.

I also have an IH which is slated to be a sort of utility mill for doing prep stuff for the other mill. I have a new Baldor 2hp 3600rpm 3ph motor for it. I just need to take time to make the adapter. I have the X axis powder feed and DRO option since it was intended to stay as a manual mill.

Given the Choice for a quick retrofit, I'd pick up a Hurco KM3 (non P model) and replace the OEM spindle motor with a 5hp inverter spindle and gut the vari-drive and replace with a direct tooth belt drive being able to have full programmable control of the spindle via the sensorless vector drive VFD. Also the OEM brush servos are great, the amps maybe a bit less so depending on age - older ones don't have the fast response that newer units could provide. I do have secondary motive here - the Hurco uses Universal kwik switch 200 tooling, and keeping the tooling common between the 2 machines cuts total costs.

I would use EMC2 and add a 4th axis to the mix. The hardware cost for an EMC conversion would likely be well under $1000, maybe even half that. Plus there are Hurco owners out there looking for parts so some of the parts removed could pay for the replacement upgrades.

But for now I use the Hurco conversational as the MAX32 package on my machine had all the bell and whistle options, and for other stuff I have CAD/CAM that POSTS fine for the older Hurco flavor of RS274-D (G-code).

[Ed from NY]

Rigid tapping would be nice, but that would be a consideration for later, I think. Though I got the impression that you would have to get something like an invertor vector motor with an encoder and change to a belt transmission as a gear box may have too much play. Then somehow you have to tell the controller at what belt ratio you are running.

My car broke down this morning so I'm at the dealers goofing off waiting on them to tell me it is going to cost a million dollars to fix it.

[pete from TN]

About your car... you're at the STEALERSHIP!!! Good luck man!! peace

Pete

[Ed from NY]

About your car... you're at the STEALERSHIP!!! Good luck man!! peace

Pete

Yeah, they just told me they have to flush something something and want 120(?) bucks to do it (cleaning is a maintenance item, not a warranty service) so that then they run the diagnostics on a cleaner engine or something something. I bought it when GMC was Government Motors Corporation. Where is my handout?

[samco]

No fancy vector vfd required with emc2. You just need a decent encoder hooked to the spindle. The spinde needs to be revearsable from emc and slow enough of a revearsal that your Z axis can track.

This was done with just printer port hardware..
[nomedia="http://www.youtube.com/watch?v=C740zS9R9kk"]YouTube - Rigid Tapping M3X 5 750rpm[/nomedia]

This is my conversion (3/4" tap) (mesa interface hardware)
[nomedia="http://www.youtube.com/watch?v=2E3PMooch1k"]YouTube - kearney and trecker rigid tapping at 400rpm 1 inch tap[/nomedia]

sam

Rigid tapping would be nice, but that would be a consideration for later, I think. Though I got the impression that you would have to get something like an invertor vector motor with an encoder and change to a belt transmission as a gear box may have too much play. Then somehow you have to tell the controller at what belt ratio you are running.

My car broke down this morning so I'm at the dealers goofing off waiting on them to tell me it is going to cost a million dollars to fix it.

[Ed from NY]

No fancy vector vfd required with emc2. You just need a decent encoder hooked to the spindle. The spinde needs to be revearsable from emc and slow enough of a revearsal that your Z axis can track.

This was done with just printer port hardware..


This is my conversion (3/4" tap) (mesa interface hardware)


sam

Nice! Now I want to see you tap that square hole, just below, in the second video