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PM932 CNC Build

Discussion in 'MACHINE BUILD LOGS' started by jbolt, Mar 11, 2014.

  1. TomS

    TomS Active User H-M Supporter-Premium

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    Jay - Here's the pictures.

    Tom S.

    Backside view of the pump and recirc plumbing. The valve in the picture is the recirc/bypass valve. Yes, that's a 1" tube dumping back into the reservoir. This pump puts out something like 650 gal/hr. at 50 psi.
    20161101_093018_resized.jpg

    Don't look too close at the pump mounting bracket. I set this up quickly to see how well it worked and haven't got back to making a proper mount.
    20161101_093027_resized.jpg

    A view of the pump discharge piping. Suction line at the bottom and the feed line to the mill coming out of the left side of the tee.
    20161101_093045_resized.jpg

    I routed the feed line through a hole in the mill stand and up through the column then drilled a hole in the sheet metal panel on the back of the column and ran the feed line to the distribution manifold. You can see the right side nozzle below. You can also see the tee fitting behind the vertical way cover that feeds my wash down garden hose nozzle.
    20161101_094558_resized.jpg
     
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  2. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    Looking at the pump manual it says it is not self priming. Are you using the supplied check valve? Any issues with startup?

    Aslo are you switching the pump on/off in Mach3 or just running it constant and using a solenoid to turn the spray nozzles on/off?

    I'm using a solid-state relay to switch my current pond pump on/off w/Mach3. It "should" handle this pump......
     
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  3. TomS

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    Yes, I'm using the supplied check valve. Had to prime the pump once on initial startup. Haven't had to do it since.

    I have an on/off switch mounted on my enclosure next to the door. When I start a run I flip the switch and when done flip it to the off position.

    I turn the coolant nozzle valves off when doing a wash down. Besides not having to deal with coolant spraying out of the nozzles it also keeps the coolant from draining back to the reservoir thus keeping the pump primed.

    Tom S.
     
  4. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    More updates to the machine. With the new enclosure I mounted the computer and monitor to the enclosure frame. The new computer is a Dell Inspiron Micro desktop running windows 10. With only a 32gb HD drive they are not much good except for web surfing and email but it's perfect for a small dedicated windows based machine controller. I found this on fleabay refurbished for about $100. when not in use the keyboard folds up and the whole assembly fold in. The monitor mounting plate and keyboard tray are aluminum sheet and were cutout on the CNC router.

    1002.png 1004.png 1005.png 1006.png 1007.png
     
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  5. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    Next is the revamp of the coolant system. I went with the pump TomS is using. I found a couple threads on another forum where they had installed a whole house filter in the feed line to filter out small particles. With the higher volume pump I thought this might be a good idea. We will see. I'm also going from two spray nozzles to four. Sometimes two does not cover the tool path. I'm still waiting for the additional nozzles before I can test. I'm also going to try a new coolant, KOOL Rite 2290. All the home shop users I have found using it have very favorable reviews. Fingers crossed. I also relocated the mist system to the side for better access to the spindle.

    1008.png 1009.png 1011.png 1012.png
     
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  6. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    After swapping out the original stepper drive and power supply I finally got the 4th axis up and running.

    Nothing special to look at. I was going to make a cover for the motor and coupler but I think I will just use a plastic bag. I may swap the stepper for a shorter body stepper and shorten the shaft to make it more compact. As it is now the motor sticks out too much to close the enclosure doors to use flood coolant.

    Rotary Table 01.png
     
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  7. TomS

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    What brand and type of angular contact bearings did you use in your spindle? I've started searching for bearings for my spindle but the suffix codes are confusing. I'm trying to find an abec 3 bearing (abec 5 and 7 pricing is through the roof) that will operate at 10000 rpm or higher. Then there are the contact angles, e.g. 15, 20, 29, 40 degrees. Which contact angle did you go with? Anything else I should consider?

    Thanks,

    Tom S.
     
  8. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    I'll see if I can find the order. What size are the bearings? I replaced the bearings on the spindle on my other mill around the same time.
     
  9. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    I think it is this bearing. You should verify the size. Same bearing from Amazon.

    ABEC-5, 15 deg (15-18 are recommended for mills), resin cage. The data from Nachi says the max RPM for grease is 18,000.
     
  10. TomS

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    Thanks. You answered my questions.

    Tom S.
     
  11. TomS

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    Your information was very helpful. It helped me understand the suffix codes so that I could focus in on the correct bearings for the application. Found the bearings I need on eBay at a fraction of the cost (less than $100 for both). One is an ABEC 5 and the other is an ABEC 7. Two different brands but both are well known (SKF and NSK). The mechanical part of the conversion is coming together.

    From what I understand VFD's put out a lot of electrical noise. How much separation is recommended between the VFD and the electronics (BoB, motor drivers, etc.)? If I remember yours is mounted on the wall behind your machine. Is this for convenience or is noise your concern?

    Tom S.
     
  12. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    My VFD is mounted to the side of the control box. This was the easiest place to mount at the time.

    There are no sensitive components in the control box.

    The router we built for the school has all the electronics in the same enclosure. On recommendation from an Industry expert in electrical noise we created compartments within the enclosure separating high voltage, low voltage and signal wiring. Except for the VFD to spindle wire all other shielded wires, the sheilding is terminated at the enclosure. Shielding within the enclosure acts like an antenna.

    The enclosure that houses the BoB, motion controller & drives on my mill has mixed high low volt and signal with all sheilding terminating at the enclosre. Noise has never been an issue.

    I suspect an open loop stepper system is less susceptible to noise than a servo/encoder system.

    Sent from my SAMSUNG-SM-G900A using Tapatalk
     
  13. TomS

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    Got it. Thanks.

    Tom S.
     
  14. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    Update on the coolant system. My diy check valve lasted until the spinning action created by the coolant flow cut the thin wall arrrow shaft serving as a guide rod in half. I replaced it with a solid rod and it worked for a few days and then would not pump even though it had a prime. I tried another check valve at the same. I removed the pump and flushed it out and reassembled with the commercial check valve. It ran for one tool op and quit at the tool change. I like the pump when it runs but too much time wasted fiddling around with it.

    I picked up a 1/2 hp sump pump from HF. They are changing brands so this one is branded Drumond. There previous 3/4 hp pump which a lot of diy CNCers use was rated at around 2800 GPH. They didn't have any pumps in 3/4 hp so I just opted for the 1/2 hp. I didn't bother to read the label. It is rated at 4400 GPH. Holy crap this thing moves fluid. with the bi-pas valve at 70% open it will overwhelm the drain 1-1/2" drain outlet so it is about 85% open. No check valve needed and it has almost no startup delay. Much much better now. The 1/3 hp model of this pump would have been more that sufficient.

    I had to laugh at the labels on the pump.

    That's a short waranty...

    20170105_185724.png

    Indoor use only? I guess they don't want it to get wet...LOL

    cp02.png

    I also up sized the coolant tank from 7 gallons to 12 gallons. No chance of sucking air now.

    cp04.png cp03.png
     
  15. TomS

    TomS Active User H-M Supporter-Premium

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    Sorry to hear the original pump didn't work out. Sounds like you found a solution to your problem though.

    Reading the labels it's clear that the pump warranty is valid only if you don't use it. LOL

    Tom S.
     
  16. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    No worries Tom. I like the pump but it does not like me. The new one is a lot noisier. Makes the machine sound bigger than it is. LOL We will see how it holds up.
     
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  17. TomS

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    Jay - I've got my AC bearings and the Kluber spindle grease will be here sometime this week. Been surfing the net reading up on bearing preload but there doesn't seem to be much agreement on how to do it. Some say tighten the upper bearing lock nut until end play is removed then snug it a bit more to set preload. Others say leave a small amount of end play because the spindle will grow with heat and take up the end play and then some. And there are those that refer you to the manufacturer's technical literature. I'd need a PHD in mathematics to understand the formula's let alone calculate them. I'm a hobbyist and like most of us don't have the tools nor a climate controlled shop to accurately measure within a couple of tenths.

    I like your approach to preloading spindle bearings. If I understand what you did you seated both bearings against their respective shoulders using a piece of pipe and shim. Where did you put the shim? Under the upper bearing outer race? Why a shim when you can use the lock nut to set preload? Did I leave something out?

    Tom S.
     
  18. jbolt

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    Hi Tom,

    What happened was that when I inserted the spindle while everything was free fitting I did not tighten the lock nut to fully seat the inner race at the upper end of the spindle. When the temps normalized the inner race was tight to the spindle and would not budge with the nut. This left some up-down play in the bearings. I'm trying to remember what it looked like but the pipe and shim set the max amount I could press in the inner race to seat the bearing and a few thou for preload. I had some concerns about getting it too tight. So far so good.

    Had I done things correctly to begin with I would have tightened the nut until the bearings were starting to get stiff and then backed off a little. Not very scientific.

    The lock nuts are a bit problematic in that they are retained by a star lock washer where you have to bend one of the star arms into a slot on the nut. If I recall I used some thin shims under the nut to get the lock nut to align with the lock washer.

    My spindle temps only get a few degrees above ambient, never much warmer than that. Mine are both C5 so if you have C7 they may be more susceptible to heat expansion but I'm not sure what that would be.
     
  19. TomS

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    Now I understand. I polished the spindle upper bearing journal so the bearing just slides on. That should help with assembly. I like your idea of using shims under the lock nut to get the proper preload and have the slot align with the lock washer tab. I'm going to steal your idea.

    Tom S.
     
  20. MontanaAardvark

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    Is that the 6" table from Wholesale Tools? I just got one in December.

    Putting the motor mount on it and getting it running is fairly close to the top of my To Do list. I have motor mounts I made for the Hoss Phase 1 conversion and was hoping one of them would be useful.

    I haven't even looked for a way to take it apart, yet, so no idea of dimensions or anything.


    Bob
     
  21. jbolt

    jbolt United States Active User H-M Supporter-Premium

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    It is a Phase II rotary table I got from Enco. Mounting a stepper to it was straight forward.

    The tricky part was finding a 4th axis Mach3 post processor for HSM Works. Most Mach3 3-axis post processors are 4th axis ready but it is disabled in the code.
     

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