KMB1 Conversion

[Bob La Londe]

Here is the new Z-Axis for Metal Nibbler 3. Its going to be a temporary stop gap Z. The spindle I'll keep, but the linear actuator has some things I don't like. The problem is its hard to make it the way I would without an actual working machine. (The Taig is down due to controller issues on one axis.)

This one was cheap and I got it fairly quickly. There are parts on it from 4 (5 when I get the servo mounted) different manufacturers to allow me to assemble it quickly.

[FannBlade]

Thinking of you when I ran across this today.

Air Turbine - ITC :: Industrial Tooling Corporation Ltd.

[Bob La Londe]

I've looked at air turbine spindles before. Have some neat specs on a lot of them, but boy howdy they do cost don't they.

[FannBlade]

I couldn't afford to ask!!

[Bob La Londe]

The best price I have found on a new one with good enough specs and speed to consider was $2.7K. It was only 1/4HP. Most I have really been interested in have been in the $5-8K range. All of a sudden those Chinese spindles start to look awfully good don't they. LOL.

[Bob La Londe]

Making parts to fix the machines that make the parts.



I sometimes forget that Wood Ripper 1 started life in my shop as Metal Nibbler 4. My big mill stuck the quill a couple weeks ago, and my little mill suffered a controller failure leaving me trying to make precision parts on my manual mill. Then it came to me that I could cut aluminum with light cuts on my CNC router too. This is nearly dry machining. I rubbed a bit of cutting oil all over the surface of this 6061 aluminum bar stock and let her rip. Its cutting at about 100 inches per minute, but its only taking about .005 depth of cut and 40% step over int he pockets. The math says I could be more aggressive than that, but this is working so far. Besides this machine has the rigidity of an aldente noodle.

Special thanks to Dragonfly in the CamBam Forum for suggesting I make this plate to fix a problem on the Hurco. I had mounted and trammed the new spindle and Z, but the flex was horrible. He suggested that making a longer face plate would sacrifice travel, but might increase rigidity. I'm trying it.

[Bob La Londe]

Now to figure out how to get it out of that epoxy bed in that MDF jig. LOL.

[Bob La Londe]

I know my approach isn't always orthodox, but I am always trying to learn something.



This is going to be the main high speed aluminum mold cutter for CNC Molds N Stuff (We don't make "cheap" molds, but we try to do a good job for you.) sometime in the next couple days. *Here I am being silly and testing at 500 IPM (inches per minute) and acceleration of 40 i/s/s (inches per second per second) *When I tested at 600 and 50 it faulted the drive. *I might be able to go faster with the acceleration of 40, but it will certainly run for a long time at my goal of 200IPM *and 20i/s/s to match the other axis of the machine. *I may run the acceleration faster than 20 to speed up rapid Z movement and decrease job time for 3D milling.

I feel a little silly testing like that since this really is a temporary Z axis.

I am so glad I ordered a new drive with that new servo motor because the old drive was bad. Its funny because it was still working right up until the quill just wouldn't move anymore.

[Bob La Londe]

Now I need to figure out how I want to cap off those two oil lines. The ones that went to the quill, and the original ball screw. The new linear rails, and ballscrew are grease lubricated.

[Bob La Londe]

I never thoroughly cleaned off the base of the machine, so I never noticed the drain. When I tested the oiler and everything was getting adequate oil I never pulled the back plate. If I had I might have discovered the tank inside the base of the machine and that big ass 3 phase pump in there. This thing has a built in coolant system? You know when I removed the pre-existing coolant nozzle you would have thought I'ld have followed the hose back to the pump, but I never did. Heck, if I hadn't needed to cap off the old oil line going to the old z-axis when I changed it I might never have known there was a sump, and a pump, and several inches of oily sludge in there.

I'm not sure I'll use any part of it anyway, but it blows me away that I never realized it was there. I run so much coolant flooding aluminum I doubt that little drain could keep up, and with the tank built into the base of the machine I don't see how I could clean it out very effectively from fine aluminum chips that would build up in there.

Well, at the very least I need to slime the shop vac and suck that sludge out of there.

[FannBlade]

Glad to hear you finally found the drain! I have pulled my pump unit and have it ready to mount a 1ph motor I have here with same HP and RPM. That way there is no need for VFD....although it would be nice to control RPM. I know exactly what you mean about SLUDGE!!! Took awhile to get mine all cleaned out.

[Bob La Londe]

I got in there this afternoon with a Shop Vac and sucked out several gallons of gunk. It looked like the top inch of it was all way oil. There was a brown sludge in the bottom half that looked that nasty brown color motor oil gets when you crack a head or blow a gasket and pump water into it. When I got down to the last of it I could suck up it finally looked like there was water or remnants of water based coolant in the bottom.

I cut a lot of aluminum, and the chips do build up in my coolant tank. I can't see using this internal tank. I'ld have to open up the back of the machine and pump it all out every day or two if I was running a lot of jobs. I have been using a 3 gallon pickle bucket, and just swapping buckets so I can clean them out, but the bucket is a little small. I need about 3 times that much coolant to keep up on hard cuts with blasting streams.

I think I am going to eventually weld up a custom coolant tank out of aluminum to go around the foot of the machine in the front.

I am still searching for the fitting I need to terminate the oil line I will no longer be using. The oil lines are all either 5/32 or 4mm. I either need a coupling to eliminate a T or I need an NPT adaptor so I can cap the end of the line.

[Bob La Londe]

D**N!!! D**N!!! D**N!!! D**N!!! D**N!!! D**N!!! D**N!!! D**N!!! D**N!!! D**N!!!

*AM*!!

I think I may have unfairly accused a previous owner for the damage to the quill. As I have been desperately trying to get things working again I found that the air valve providing air to the oiler was leaking. It may not have been putting out enough oil to properly oil the quill. Hopefully the similar valve that provided air to the spindle brake is still good, and I can repurpose it.

[Bob La Londe]

Well, the other valve works... and while I was testing the timer failed. SIGH.

[Bob La Londe]

Got the timer fixed. Got a pump installed to cool the spindle. Got the spindled tied into the VFD. Got the VFD tied into the breakout board. Spent some time figuring out the VFD programming, and finally got the spindle under Mach Control for start and speed. I may do some test cuts or even some work cuts with it as early as tomorrow.

I am reinstalling my flood coolant system, and my splash enclosure yet this afternoon.

Monday I am getting in a new Charter Oak CNC Mill (maybe - its already going to be 8 days later than the expediter said, and 6 days later than the trucking company said, and four days later than they said when I asked when it was really going to arrive). I'm also supposed to be getting a new Tennsmith 48" brake on Monday. That I believe is likely. Anyway, since I'll be bending metal for an enclosure on the new mill I think I'll remake the one for this mill as well.

I need to get this enclosure back in place though atleast temporarily. I have jobs that are behind schedule.

[Bob La Londe]

I have to say that I am a bit disappointed in the performance of the 2.2Kw spindle. I've calculated all the loads at less than one horsepower, and it bogged down and tripped the inverter a couple times. It has also already developed some end play, and it sounds almost like the bearings are dry or nearly dry. I need to take it apart and check it out soon. I'm not sure HOW to take it apart though. The back cap opens the water passages and exposes the electrical wires going into the motor from the connector. (There was no frame ground as I expected so I connected one.) There is an oval shaped bolt head with two flats on the back end of the shaft. If I need to grip that I'll probably have to make a socket to do the job. There is what looks like a threaded lock ring on the front end of the shaft with pin wrench holes on the face. Its made of aluminum so the usual short cut of tapping it with a punch and a hammer probably isn't a good idea. I'll probably have to make a pin wrench for it unless one of my angle grinder pin wrenches just happens to fit.

[purple_jeep]

Hi Bob,

Your Inbox is full

Also with the Lube pump there are actually two timers in the original setup, one that triggers every 15min or so (mounted on the side of the right cabinet) which drives a time delay relay (mounted on the relay board right cabinet) which actually drives the solenoid for the lube pump. I am trying to work out the delay on the relay as I bet that is also what you are missing.

Cheers

Chris

[Bob La Londe]

The electromechanical timer is a time delay activation. All in one. You may have a different setup.

[purple_jeep]

That's quite possible the documents on http://www.cnczone.com/forums/hurco/...downloads.html don't show the relay but the documents I have do show that on the relay board (if you still have it, I threw mine out before I realized) the left top relay should be a time delay one and all the other 7 should be regular relays.

If you want to check and send me the part number for the top left one we could confirm for sure .

Cheers

Chris

[Bob La Londe]

Very little of the original equipment is in the cabinet anymore. Most of it finally went in the dumpster a couple weeks ago. I only have a handful of relays, and they are all new 5VDC ones controlled by my breakout board. Anyway the timer is an electrical clockwork dial with a gap. It takes about 15 minutes to do a full cycle. When a roller on a microswitch reaches the gap it operates the 3 way solenoid valve that sends air to the lubrication pump. A while later the back end of the gap engages the roller and it closes off air and vents the pressure on the lub pump side.