VFD on my Bridgeport Mill: Enclosure Build, Wiring, Remote Panel

chip_slinger

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I'm plunging back into working on my shop and mill after a busy summer with too many other distractions. The current project is working on converting my Bridgeport over to using a VFD. I read a bunch and searched a lot, but I didn't find many guides on designing and building the VFD enclosure, so I thought I would document how I am going about doing mine. I'll update this post as I go along with more build details and documentation. Let me know if you guys are interested in anything specific and I'll try to address it. Alright, here goes.

In preparation for this project, I bought a big metal control cabinet off of eBay a couple of weeks ago. This one is 20" wide x 24" tall x 12" deep and had some DIN rail and plastic wireways. It has a bunch of holes I will have to fill, but the price was right. Here it is out of the shipping box with a 6" scale on top:

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I started today by cleaning out the enclosure, removing the backpanel and giving everything a wipedown. Then I stripped off all of the parts from the backpanel (DIN rail, wireways, etc.) Paint may come later, but it's not a priority now. I decided I would mount the enclosure to the mill before I did the interior layout and wiring, just to give myself some motivation.

My mill has a ProtoTRAK retrofit and that control cabinet lives on the right side of the mill's base casting, so I decided to put the VFD enclosure on the left side. Plus, that puts it closer to the motor wiring. The base casting doesn't have a large enough flat area on the side to accommodate the enclosure, so I have to build it out with a frame.

I have a stockpile of 80/20 extrusions and fittings, so I figured that would be a great frame. I started with two horizontal sections about 16" long. I drilled four holes in the casting with my hand drill and tapped them. A couple of clearance holes in the 80/20 and those were mounted:

yra9eqab.jpg

mevyvusy.jpg

Now I needed to cut down some L brackets that would attach to the vertical sections. I haven't gotten to wiring in my horizontal bandsaw yet, so I grabbed my portaband and used the horizontal's vice. Now I have my L brackets ready to go:

8y9upa5e.jpg

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Two 36" vertical sections are next:

y6e3ahuv.jpg

Enclosure in place and mounted to the vertical sections:

ry2a2ada.jpg

ugapaber.jpg

I punched two holes in the side for the master on button and the emergency kill switch. Mounted them up:

6e6y5yga.jpg

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OK, now I'm moving on to the interior layout and wiring. I sketched out my schematic over the last week and have been ordering parts. The easiest way for me to work is to do a layout of all the parts with my schematic next to me, and go back and forth between the two:

edesegyz.jpg

Here's how the backpanel is shaping up so far. There is the VFD, braking resistor, enclosure fans, fan relay, thermostat for the fans, fuse holders, terminal blocks, enclosure power contactor and ground bar. I'm missing the VFD's fuses.

3azagu9y.jpg

That's about as far as I got today. Next up will be mounting everything to the backpanel, mounting fans to the enclosure, mounting the backpanel into the enclosure and wiring.
 
I'm assuming the spaces in between the paragraphs were supposed to contain pictures, I see none so I'm supposing they didn't upload.

From what I read I believe you are putting the VFD on the mill not mounted remotely, if so you may want to ask some of the more experienced electrical guys if that is ok or not. I believe I was told you are not supposed to because of potential harmonic resonance. Just a heads up it may be fine.

Pictures appeared after I posted, must be an issue on my end
 
Yes, I remember you now. You are the guy that has his shop in a palace with wains-coat walls and a maid. The par-qua floor gave it away!

From what I see, you are doing a bang up first class job so far. My Bridgeport has a door in the column behind where you mounted the enclosure. I made a floor and back plate for the hole to mount the VFD and other pieces on and pretended that is what Bridgeport meant to happen. I have built and rebuilt many an enclosure. The two rows of openings on the left side, I would seal them all off at once with a single plate. They make a double-sided rubber tape about 1/2" wide. Use this to stick the plate in position and secure with screws or rivets. Plugs them all at once and saves the cost of all those oil-tite hole closures. Same for the larger openings on the right side. Just a suggestion to save a little time and money. A squirt of gray on the outside and a squirt of white on the inside and all is cheers. A blind man on a fast horse at midnight will never notice.

I have found through time it is the little things like this that make a job look like a pro did it or a hack. We all like to display our work and be proud of the accomplishments.

I use my VFD for 1ph to 3ph conversion, ramp up and down for speeds, reversing, and basic motor protection. My Bridgeport has the Reeves vari-drive and I continue to use that with a photo electric tachometer for display. After I added 3 axis DRO I am one spoiled happy camper. I work faster and more accurately then ever once I learned to trust the numbers. I don't know where some of the ideas come from about VFDs but I have always been told one rule is to keep the distance from the drive to the motor as short as possible. #2 rule, never mix power wiring and control wiring in the same conduit.

Fun project. Keep us posted. You are doing well. Want a job? :thumbsup:

You may want to consider mounting that one fan out the top left side rather than the top. Reasoning is back there there is less chance for swarf to get dropped or blown into the interior. A piece of window screen over the fan opening really helps too, and possibly a louver and filter. These are cheap for the home shop guy to include. Just more work.
 
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I am right handed and operate mostly from the right side of my mill. I have mounted the start stop station on the right side of my mill remote from my drive, which is mounted on the wall on the left side of my mill. I did this for easy access to the start stop button so I do not have to reach across the spindle (work area). If you operate mostly from the left side then it seems your present set up will be fine.
 
From what I read I believe you are putting the VFD on the mill not mounted remotely, if so you may want to ask some of the more experienced electrical guys if that is ok or not. I believe I was told you are not supposed to because of potential harmonic resonance. Just a heads up it may be fine.

Actually, you want the motor conductors to be as short as possible, meaning you want the VFD as close to the motor as practical. That way, you are keeping the "antenna" to a minimum.

Yes, I remember you now. You are the guy that has his shop in a palace with wains-coat walls and a maid. The par-qua floor gave it away!

Yup, you got me. But where did the maid come from?!

From what I see, you are doing a bang up first class job so far. My Bridgeport has a door in the column behind where you mounted the enclosure. I made a floor and back plate for the hole to mount the VFD and other pieces on and pretended that is what Bridgeport meant to happen. I have built and rebuilt many an enclosure. The two rows of openings on the left side, I would seal them all off at once with a single plate. They make a double-sided rubber tape about 1/2" wide. Use this to stick the plate in position and secure with screws or rivets. Plugs them all at once and saves the cost of all those oil-tite hole closures. Same for the larger openings on the right side. Just a suggestion to save a little time and money. A squirt of gray on the outside and a squirt of white on the inside and all is cheers. A blind man on a fast horse at midnight will never notice.

I have found through time it is the little things like this that make a job look like a pro did it or a hack. We all like to display our work and be proud of the accomplishments.

I use my VFD for 1ph to 3ph conversion, ramp up and down for speeds, reversing, and basic motor protection. My Bridgeport has the Reeves vari-drive and I continue to use that with a photo electric tachometer for display. After I added 3 axis DRO I am one spoiled happy camper. I work faster and more accurately then ever once I learned to trust the numbers. I don't know where some of the ideas come from about VFDs but I have always been told one rule is to keep the distance from the drive to the motor as short as possible. #2 rule, never mix power wiring and control wiring in the same conduit.

Fun project. Keep us posted. You are doing well. Want a job? :thumbsup:

You may want to consider mounting that one fan out the top left side rather than the top. Reasoning is back there there is less chance for swarf to get dropped or blown into the interior. A piece of window screen over the fan opening really helps too, and possibly a louver and filter. These are cheap for the home shop guy to include. Just more work.

Thanks. I have been accused of being anal, but I really can only live with something if I know I've given it a real good shot at my best effort. I don't like half-a$$ed attempts.

I was thinking about relocating that top fan to keep out wayward swarf, but I have a filter for it and I may make some kind of deflector shield. We'll see when I get some of the interior wiring all set and get back to mocking up the enclosure.

I am right handed and operate mostly from the right side of my mill. I have mounted the start stop station on the right side of my mill remote from my drive, which is mounted on the wall on the left side of my mill. I did this for easy access to the start stop button so I do not have to reach across the spindle (work area). If you operate mostly from the left side then it seems your present set up will be fine.

Those switches are for master on and master kill of the entire enclosure, so I don't anticipate using them that much. The spindle run and stop buttons will be on a remote panel mounted near the ProtoTRAK interface on the right side.
 
I spent some time on the project this evening after work. I mounted up most of the components to the backpanel. Braking resistor got locked down. Terminal strip for the braking resistor leads got added since the leads were too short. VFD got mounted. VFD fuse block got mounted. Added in a 24V DC power supply that I had forgotten to include for the remote panel indicators.

Here's what the project table looks like at the end of the night after a cleanup:

avadaqyh.jpg

I also started the wiring and sorted out the DIN rail components. The thermostat has a broken solder joint so I'll fix that in the next couple of days. Some wiring pics:

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Here's what I'm thinking for the remote panel layout. Run/stop control, fwd/rev control, speed control, at speed indicator, zero speed indicator, drive fault indicator:

ryhytyve.jpg

Finally, a gratuitous shot of my tool cart with some of the tools I used tonight:

esutesy6.jpg
 
Your doing a nice job there. You're gonna really like the VFD when your done. Since your in the process of building your remote panel, I thought I'd show you the one I built for my Bridgeport. Like you, I mounted my VFD in a separate panel box, but I located my on the rear of the pedestal out of the way. My remote panel box houses all my controls for not only the VFD (power on/off, run/jog, fwd/rev, speed pot, start, e-stop) but also for the accessories on the mill (lamp on/off, vacuum on/off, dro & tach on/off). I always use Allen Bradley 800 series switches and you can see this is crammed into a 10 x 12 x 5 deep box. I have a 2nd e-stop for emergency use at knee level mounted in a small box on it's own. Just thought this might give you some ideas for yours. Cheers, Bill

Mill Panel 2b.jpg Mill Panel 3b.jpg Knee e-Stop b.jpg
 
What a great thread! I'm in the process of painting and reassembling my J Head Bridgeport. I plan to use a Teco VFD mounted in a box similar to yours.

If you're interested in having a tachometer as other have done, check out the MachTach at http://www.machtach.com if you'd like to roll your own with lots of options. I have several of them on machines in my shop.

Please do keep us posted on your progress!

Guy in Sacramento
 
What neat, clean, installations you guys have pulled off. Bravo, Bravo. This is the way all builds should look. Even puts some big companies to shame. :man: Congratulations to you both.
 
Your doing a nice job there. You're gonna really like the VFD when your done. Since your in the process of building your remote panel, I thought I'd show you the one I built for my Bridgeport. Like you, I mounted my VFD in a separate panel box, but I located my on the rear of the pedestal out of the way. My remote panel box houses all my controls for not only the VFD (power on/off, run/jog, fwd/rev, speed pot, start, e-stop) but also for the accessories on the mill (lamp on/off, vacuum on/off, dro & tach on/off). I always use Allen Bradley 800 series switches and you can see this is crammed into a 10 x 12 x 5 deep box. I have a 2nd e-stop for emergency use at knee level mounted in a small box on it's own. Just thought this might give you some ideas for yours. Cheers, Bill

Bill, that's real nice! I like the look of your layout. Is that the machtach that Guy mentions below?

What a great thread! I'm in the process of painting and reassembling my J Head Bridgeport. I plan to use a Teco VFD mounted in a box similar to yours.

If you're interested in having a tachometer as other have done, check out the MachTach at http://www.machtach.com if you'd like to roll your own with lots of options. I have several of them on machines in my shop.

Please do keep us posted on your progress!

Guy in Sacramento

I'll check out machtach. I've seen it before but had forgotten about it. Thanks.

What neat, clean, installations you guys have pulled off. Bravo, Bravo. This is the way all builds should look. Even puts some big companies to shame. :man: Congratulations to you both.

Russ, thanks. You may want to hold your praise for a little while - I found a bit of a flaw with the enclosure mounting interfering with the X axis servo last night. I had to tear apart the mounting and rethink it a bit. I'll update later tonight.
 
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