[crclark]

I have read through many treads regarding milling / CNC and I appreciate the input and help so many of you offer to everyone. My PM25MV mill showed up to day. I've been busy researching and spending money since I ordered my mill. I will post some pictures of the mill shortly as well as a item list of electronics. it seems everyone of these BF20 clones is different.

[crclark]

I get a "security" error with the attachment manager, have to figure that out. Maybe it doesn't like Mac OS X

[crclark]

Surprising motor control components, Schnider Electric relay and a real KB Electronics KBLC-240D configured for 110VAC.

[jeremy0203]

Surprising motor control components, Schnider Electric relay and a real KB Electronics KBLC-240D configured for 110VAC.

remember it is from China so its more than likely knockoff lol

[crclark]

very true, maybe someone can give us some insight into the authenticity of the controller. I believe I've heard the usual controller in the BF20 clones is a copy and that the copies dont have the HP resistor which this one does.

[crclark]

Here's a list of items that should be here in the next couple of days.


List of items ordered


1 G9612 - Test Indicator 0.0005" Resolution
1 G9629 - Universal Indicator Holder
1 G9756 - 20 pc. HSS End Mill Set
1 H2678 - Measuring Tool Set - 6pc
1 H2939 - 4 pc. Edge Finder Set
1 H5930 - 4 pc. Center Drill Set 60°
1 T21561 - 0-1" Digital Fractional Indicator
1 T23018 - 0-4" Digital Snap Depth Gauge and Indicator

2 570 oz steppers
1 960 oz steppers
2 KL-5060D drivers
1 KL-8070D driver
2 5VDC power supplies
1 12VDC power supply
1 48VDC/20A Toroidal power supply
1 electronics enclosure
1 C6 speed controller
1 C35 breakout board
1 laser tach
1 Lenovo M55 desktop with XP 32 bit and IEEE compliant parallel port

1 less than great vise was sent with the mill
1 58 piece hold down set

[crclark]

So I've run the break in routine for the spindle and decided to increase the speed on the motor controller. I had read that most people didn't have much left to go on the max pot of their controllers and can only obtain approx 3000 rpm. I decided to do the same so I slowly cranked the pot and much to my surprise I quit turning it a about half way because I was already at 3500 rpm and decided that was plenty fast for the stock bearings. The bearings were still quite warm from the break in, I only ran it for less than a minute at 3500. I believe its a genuine KB electronics KBLC-240D controller set for 110VAC. Ok now the draw bar seems to be to long, I decided to stick a end mill in a R8 collet but the collet is sticking out a good half inch with the draw bar hand tight. I inserted the collet in without the draw bar and it fits in the mill flush and will hold a tool just fine if I could draw it in properly. I compaired my draw bar length to CAD drawings of the PM25MV I purchased and indeed my draw bar is over a inch longer than it should be.

[Mad Welder]

Nice to see another project starting i converted the BF20, and I messed around with the speed pot too and likewise I was getting 3,500+RPM. You won't be sorry with the digital stepper drivers either i'm using three of KL8070D's it looks like you are going to using the NEMA 23's, your digital drivers will out put enough amps for your 4 wired steppers.


good luck with the project and keep the progress pics flowing:cheers:

[Starleper1]

So I've run the break in routine for the spindle and decided to increase the speed on the motor controller. I had read that most people didn't have much left to go on the max pot of their controllers and can only obtain approx 3000 rpm. I decided to do the same so I slowly cranked the pot and much to my surprise I quit turning it a about half way because I was already at 3500 rpm and decided that was plenty fast for the stock bearings. The bearings were still quite warm from the break in, I only ran it for less than a minute at 3500. I believe its a genuine KB electronics KBLC-240D controller set for 110VAC. Ok now the draw bar seems to be to long, I decided to stick a end mill in a R8 collet but the collet is sticking out a good half inch with the draw bar hand tight. I inserted the collet in without the draw bar and it fits in the mill flush and will hold a tool just fine if I could draw it in properly. I compaired my draw bar length to CAD drawings of the PM25MV I purchased and indeed my draw bar is over a inch longer than it should be.

Careful upping the motor speed, you could end up like a lot of other folks with these burnt up motors/controllers. Every motor has a voltage rating it was designed to run at and should not be exceeded for it could potentially ruin the motor. The "max pot" is actually what controls how much voltage that is supplied to the motor. The proper way to do it, is to set it with a volt meter to the voltage on the name plate of the motor. i.e. Motor plate says 90VDC, set the controller to 90VDC.

[crclark]

Thanks for the posts, I wont run the spindle over 2500 to be safe. I'm dead in the water as far as running or making anything with the mill because the draw bar provided is too long. I've spent weeks going over both Starleper1 and Mad welders builds and they are both exceptionally well done. I'm completely new at all this so any help is greatly appreciated.
I simply want to get the mill useable so I can start making the motor mounts for a CNC conversion with the stock screws (budget is getting low) here's a picture of my draw bar dilemma. I'm already glad I bought Starlepers1's CAD drawings of the mill.

[SCzEngrgGroup]

Thanks for the posts, I wont run the spindle over 2500 to be safe. I'm dead in the water as far as running or making anything with the mill because the draw bar provided is too long. I've spent weeks going over both Starleper1 and Mad welders builds and they are both exceptionally well done. I'm completely new at all this so any help is greatly appreciated.
I simply want to get the mill useable so I can start making the motor mounts for a CNC conversion with the stock screws (budget is getting low) here's a picture of my draw bar dilemma. I'm already glad I bought Starlepers1's CAD drawings of the mill.

Just make a spacer to go under the head of the drawbar....

[Starleper1]

It's amazing this machine made it out of the factory that way. As I see it you have three options. First due as Himy said and make a spacer. Second, cut the draw bar to the proper length and re-thread the end. Or last, throw it on the scrap pile and make a new one.

[crclark]

I did use Himy's idea to get going, thanks Himy. I guess mine isn't the only one that came that way. I think they are going to send me the proper one in a couple of weeks.

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[Mad Welder]

.............I've spent weeks going over both Starleper1 and Mad welders builds....................I simply want to get the mill useable so I can start making the motor mounts for a CNC conversion with the stock screws (budget is getting low)...........

Aw shucks thanks for the nice comment...I too used the stock leadscrews just to get me started and I made my own motor mounts too just like you want to do.....so start making chips

My motto is "do I need it, can I machine it, if not how much" these CNC projects/builds can swallow huge amounts of money and hard earned at that, so if it's any encouragement yup make your own mounts and put the money aside for stuff you can't make, and don't stop asking questions either!

[crclark]

Oh ya money disappears fast for sure I was wondering if your machine came with the Z axis lead screw that is only supported on the top. My lead screw has nothing on the bottom, its just loose. When a person switches to ball screws is it done the same way? The drawings on grizzly's site show the same Z lead screw I have but Starleper1's CAD drawings show a full length Z lead screw.

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[Mad Welder]

Yeah my clone is the Optimum BF20 and no there is no lower Z axis support and I also didn't machine/include a lower Ballscrew baring block in my build either I figured that if any lateral movement of the Ballscrew while minute would not induce backlash in the Z axis as my Gib’s are fairly tight on the ways without being too tight and the only backlash which would be of concern here is vertical and as I don’t have any vertical play in the baring block so that only leaves play between the Ballnut's steel balls contact with the Ballscrew, you can fit oversized steel balls as some have done but you can also use backlash compensation within mach to allow for this ……

hope this helps to explain it a bit better:cheers:

[arizonavideo]

Their is no advantage for a short screw to be held from both ends.

Whipping is not a problem with only 8" sticking out of the ballnut so it only makes things harder.

[crclark]

Perfect, thanks both of you for replying. I just got the pc I'm using for Mach 3 / linuxCNC. It's perfect I think. 3.4 Ghz pentium D processor, 4 GB ram and a IEEE 1284 compliant parallel port for about $100 shipped. Just setting it up now.

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[crclark]

Oh by the way its a Lenovo M55P 8808 of ebay

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[Mad Welder]

Perfect, thanks both of you for replying...................

You're more than welcome:cheers:, glad to be of help.... have a look here too at this chaps videos and check out his full CNC electronics series too as they're pretty good for explaining the electronics to get you up and running[ame=http://www.youtube.com/watch?v=uglCm_qsojk&feature=related]CNC Electronics 5 -Testing the Parellel Port.wmv - YouTube[/ame]