One way to mount a VFD on a Bridgeport - PICS!

[mxtras]

If you end up with a three phase Bridgeport (or any other equipment for that matter) one method of operating it on common household "single phase" is with the use of a VFD,or Variable Frequency Drive. Not to be confused with a Volunteer Fire Department - two different things. Don't get confused - the results could be bad.

Low speed torque is a problem with VFDs. In this case it is a step pulley machine so the speed can be approximated with the belt first, then fine tuned if necessary with the VFD. It comes in handy.

Depending on the HP rating of the motor and it's intended use, a VFD can be had for relatively cheap - the one in this thread was about $160 and can be remotely controlled, which will come in handy in the near future for this machine.

This is one way to mount a VFD on a Bridgeport. It may be a temporary home for it as this machine is slated to be converted to CNC within the next few months, but here's some pics anyway - might give some of you ideas.

I do not have any dimensions or even a sketch of this thing. I put it together using scrap and simply cut to fit as I went. I kinda had a plan, but I more or less designed this on the fly.

It was made from a piece of 4" aluminum angle, a piece of 1/4" AL plate and a piece of 1/8" AL sheet - all scrap sized pieces. All of the material was cut on a 14" miter saw with an 80 tooth carbide tipped blade. It was all rather sloppily TIG'd together - some of the material was in rough shape and should have been acid etched prior to welding.

If this was a final installation, the wiring would have to be covered and secured and so forth - but for now it is good to go until the retro-fit. Only the safety grounds are hanging out but you will notice there is no strain relief on the cables. It was mounted direcly to the belt housing with 4 #10 tapped holes in the housing. The shield on the right of the VFD is to keep belt dust out of the VFD. The belt and pulleys create a nice, gentle breeze which will help keep heat build down.

This is a single phase installation as you might be able to see by the 3 prong plug mounted to the pole behind the mill. I ran wires for the third phase but I will likely leave this the way it is. Undecided.

There is another thread about the mill here:

http://www.cnczone.com/forums/showthread.php?t=10535

And another thread about the shop in general:

http://www.cnczone.com/forums/showthread.php?t=14398

Enjoy the pics, guys.

Scott

[Jamf2]

You are the man!!!!

Keep it up!!!

[2muchstuff]

Ok, fess up. You didn't really buy a new VFD for a mere $160 did you. If so you must tell us.

[Cold Fusion]

Very very nice install. I'm inspired to do the same with mine, whenever I get the time.

[HuFlungDung]

Good idea, Scott. I had a similar idea for one of my mills when I replaced the original motor with a new one that had a foot mount bracket on the motor frame, as well as having the C-face flange. Since the foot mount was stuck up there doing nothing, I cabbaged my VFD bracket onto that.

[mxtras]

Originally Posted by 2muchstuff Ok, fess up. You didn't really buy a new VFD for a mere $160 did you. If so you must tell us.

http://www.driveswarehouse.com/Drive...p_10=&x=24&y=9

Hopefully the link works. They list it now for $210 - Hitachi model #L100-007NFU. The NFU stands for "Not Screwed Up". Don't get the AFU model....



I recall paying right at $178 with shipping in January of 2005.



Scott

[jwag]

Any info on the paint you used for the BP? How did you prep it? Was it completely dissassembled?

Thanks,
jW

[mxtras]

Look at post #21 in the following thread -
http://www.cnczone.com/forums/showthread.php?t=10535

I will also scare up a pic of the paint - update - it's attached.

Yes - the thing was torn completely down and stripped to bare metal, pressure washed, sanded, filled, sanded, filled, sanded, filled.....then primed and painted piece by piece. It took about a month to have it back in one piece.

My advice? Remove only the loose filler and clean the crap out of everything then fill only the areas you need to, blending back into the factory fill. The filling process can get expensive quick since the rough casting is exactly that - rough. If you want it smooth and you take it down to nothing like I did, you will probably use at least 1 or 2 gallons of filler and spend a lot of time covered in dust.

Scott

[jdelaney44]

Question? Are you going CNC with this guy or are you staying with cranks?

If you are going CNC you are going to want the VFD as close to the PC as possible so you minimize the potential for noise getting into the system. This assumes you want the spindle speed under computer control. That means the VFD goes in the control box and the control buttons & such go on some kind of remote panel mounted right where the VFD is now.

This is THE most pristine machine that I have EVER seen!!! Very nice work on the machine AND the shop.

Best,
-jd

[jdelaney44]

OH. What's under the cloth?

[mxtras]

Not sure which pic you are asking about - one pic is where I was drilling and tapping the mounting holes for the bracket - the rag is keeping chips out of the pulley housing. In another pic - in the background there is a tool grinder covered with a rag. Was that the question? i am a freak about keeping stuff clean - except when I am in the middle of something - then everything is everywhere...

As far as the CNC of the mill? Yes - I am going to CNC the thing. In fact I came on here after making progress on the first bracket for the X axis. I came on to post the first progress pics in many months.

The link to the write up/progress log for the conversion is listed above in post #8.

Thanks for the comments, JD. I have been spot checking your progress, too! Thanks for the tip about the VFD. I am not sure I understand - it seems like the noise would be worse by putting the VFD near the controller - or am I not thinking straight?

Scott

[RDFeil]

Hi Guys,
I am new here, but I noticed the awe at the
$165.00 VFD. Well let your jaw drop... Check out www.automationdirect.com they have 1hp 230 volt drives rated for single phase input / 3 phase output for $125.00. I am in the automation business and buy a lot of stuff from these people, they are great to work with and ,unfortunately for me (ha ha) will sell to anyone with a credit card. I just got a 1 Hp Bridgeport series 1 and needed 3 phase for it. These little drives are great for machine tools, they have input options for start/stop forward/reverse and even a jog (bump) feature as well as the variable speed, they make life way to easy. I hope this helps some with the costs.

Robin