New VFD for a Round Column Milling Machine

Yep. I bought a round column mill. If you've seen my drill press mill video, you won't be surprised. This JET mill is 23 years old and needed a bit of reconditioning. As part of that, I installed a new 3-phase motor, a VFD and a tachometer. That gives me infinitely (nearly) adjustable spindle speed. Turns out great. If you have a Jet or one of these Rong Fu mills, it's a worthwhile upgrade.

[@brimstone260]

Sat here with a knackered back wincing as you wrestle the motor into place! Nice job on the mill, real smooth.

[@sacriptex5870]

what a dream!! a heavy duty drill press who does not need any mod to be a light milling machine besides the cross slides

[@gatorsgymcanada644]

Great video Robert!

[@RobertAdairWorkshop]

Thanks!

[@bensbobbershop33]

That turned out nice! One day i will get a mill and a lathe! I was a machinist before i joined the service and hope to get back to it soon!

[@digitaloverdrivesystems]

I am in the process of adding a vfd to my rf25. Great info. Well done video with good content and no hype or bs. Thanks for your efforts. Cheers from Floridas space coast.

[@b.malnit8983]

Great job. Bob. Really enjoy your ingenuity.

[@GaryT1952]

Very interesting RA...your fab and welding skills are inspiring...nice job

[@F1DesignUS]

Very well presented and a nice addition to the shop for sure!

[@RobertAdairWorkshop]

Thanks 👍

[@frankm1776]

Great video! Thanks for sharing your knowledge.

[@Cz9mmp10]

Like your content. Hope your channel grows. From Namibia

[@stevemedlock8192]

Superb video. Thank you. I'm hoping to do pretty much the same process.

[@older-wiser-better]

Very informative, thank you 🙏

[@robert574]

I have a few of those sensors I was playing around with the other day and I found out that they sense just plain iron or steel better than they do the magnet, at least the inductive ones I have do. Mine have a 4mm sensing range, and they did with just plain steel, but were 3mm with the magnet even if I stacked some magnets together. Just a thought if you ever worried about chips getting in somewhere and sticking to the magnet (probably not here, but maybe on something else you might do). It also detected aluminum at about 2mm and copper at 3mm. It seems that they would sense on any kind of metal "bump" that might be coming around and may not need the magnet at all. Also, some of the RPM counters have two buttons on the back and you can store a multiplier less than, equal to, or greater than 1. You can measure correct rpm on an engine with multiple cylinders or even count the spokes on a pulley and covert that to something else like sfpm on a conveyor (a pretty cool feature). They are about the same price

[@user-xj6bm5rg1d]

Turn the mill head all the way around. Lift your motor onto the mill table. Move the table so you can lower the head to mount the motor. When I did it I needed to put some wood blocks on the table under the motor so it would reach high enough. Lower the head to mount the motor.. Move X and Y to position it. Doing it this way allows you to accurately adjust the motor height when you tighten the bolts.

[@RobertAdairWorkshop]

That is brilliant! My way was dumb. I’ll keep it in mind for the next time I yank the motor.

[@user-xj6bm5rg1d]

Yeah I'm 74 so If I don't use tricks it won't get done. I'm just finishing putting in a VFD. I bolted the VFD left side of mill just above and behind the column lock handle. It just clears the elevation crank. The mill is nice soft iron so it is easy to drill and tap. @@RobertAdairWorkshop

[@RobertAdairWorkshop]

Skip to 13:49 if you just want to see the mill working with the VFD but aren't interested in the steps to get there.

[@robert574]

A lot of the vfd's don't have the braking circuit built into the board. If you did it there would be a place to mount a braking resistor. Some have DC braking. Went thru the same with mine and learned to live without it.

[@robert574]

It looked new after you got done with it.

[@RB-yq7qv]

Hi Robert. It's amazing how many of those VFD's have faults, some brands are not worth the investment. The mill looks and runs great, one thing I would be concerned with is spindle speed as the bearing the machine come with may not be rated at high speed operation. I would have changed them out for better quality bears rated for high speed operation.

[@RobertAdairWorkshop]

I had that tought too. I matched RPM ratins on the two motors and sticking with the stepped pulleys gives me the same max speed the mill had with the fixed-speed motor. Surprisingly, this version had SKF bearings in it when I pulled it apart. I replaced the two on the belt idler and spindle drive with new ones from McMaster. I think they were FAG. I did repack and reuse the SKF tapered bearings in the spindle though I am having second thoughts about that. I think I'll take your advice and swap those out so that I do know their rated max speed.

[@johnrussell6620]

@@RobertAdairWorkshop FAG bearings are quality bearings. .. Packing with grease will reduce the maximum RPM ratings, but the original ratings could be very high to start with. There are guides published by SKF & FAG with these details about oil vs grease and what kind of oil or grease to choose. ... p.s. How is the B&S surface grinder progressing? .. Thanks for your content, I enjoy it. .. John

[@NOT-WOKE-007]

I need a follow up on your water system. How is it doing? Please share your recent water report. Thanks much.

[@jenniferfraijo]

Hello , great video and very informative .. I only need a little clarification regarding the2 E stop in series wiring diagram along with wire sizing for those E stops . If you can help that would be great ….. Thank You again

[@RobertAdairWorkshop]

Hi, Jenniferfraijo. It's pretty straightforward. Wire the inlet side of the two switches together and the outlet side together so that when either switch is pressed, it completes the circuit. Since they are wired together, when either is pushed, it'll do that. Then you can wire those two to the VFD pins.

[@everettcass7904]

@@RobertAdairWorkshop For E-Stops, don't you generally want them to be wired such that, the E-Stop is Active by default and rather than pressing the E-Stop to close the circuit when active, it is breaks the circuit when active? I was told for for an older maintenance tech that for E-stops you want it that way, because if there was a fault in the wire, the machine won't run, which you want. Because the alternative is, the machine runs, and you don't find out that your E-Stop doesnt work until you use the E-Stop and it doesn't actually stop the machine. Just some thoughts, great video

[@RobertAdairWorkshop]

@@everettcass7904 That's really good advice. I mean, really good. Something I hadn't considered and easy enough to configure. Those switches are both NO and NC. I'm going to do it on mine. Hopefully others will see your comment too. Going to pin it.

[@alexrains1893]

Thanks for a very thorough tutorial. I recently bought an identical mill and intend on doing the same, this will be invaluable. Will you put on a power feed?

[@RobertAdairWorkshop]

I’ve been going back and forth on a power feed. I usually don’t need one but recently faced some warped exhaust manifolds and a power feed would have been nice. I’m looking at the smaller, cheaper ones made by Vevor. I think I’d like a full DRO first, though. I have one on the quill which is invaluable. Adding a set on the table would be nice, too. I need to save some money for the DRO parts and power feed. It’s a good, versatile mill, and I think those two would make it even better.

[@user-tx2nv1rb9k]

Vey informative! I actually had to return to watch this... I would like to ask what is the base speed you installed the motor with the belt arrangement

[@RobertAdairWorkshop]

I have the pulley such that the mill is at it's second fastest speed that It'll run. At 60-hertz, that come out about 1940 rpm. If I put it in the fastest ratio, I can get about 2600 rpm, but I wasn't sure how that'd impact the low-end performance, so I didn't run it there.

[@user-tx2nv1rb9k]

@@RobertAdairWorkshop Thank you, great work!!!

[@blohnot]

Hi Robert! Would you please be so kind and advise how can I safely remove the pulley that is located above the pinole of the machine? I’ve got same JMD-15 you own. I tried to move it up using the bearing puller, but it didn't move even a millimeter. I'm afraid the puller's feet can break off pieces from the pulley as metallic there is so thin. Any tips will be much appreciated 🙏🙏🙏 Thank you so much in advance for your advice. Warm regards from snowy Russia, Anton

[@RobertAdairWorkshop]

I had to go out and stare at the mill for a few minutes to jog the memory. It’s not what it used to be. The only thing holding the pulley on is that big nut and the taper. I remember thinking I was going to break it when I took it off, too. I used a three jaw puller, ran it down as tight as I could by hand, whacked the pulley around its circumference, then heated it with a torch. It didn’t want to come off, though. So I figured I’d replace the pulley if I destroyed it, and used an impact on the puller and it popped free. It was on there a lot tighter than expected.

[@blohnot]

@@RobertAdairWorkshop Thanks so much, Robert!!! I will try to heat the pulley too. Hope that will be sufficient and there will be no need of using something heavy. 🫣😂 Take care! Very useful channel, btw. I suffered for several days without information and God has sent you 😇🙏🤝🤝🤝👻 Cheers 🍻 Anton

[@graemetho9805]

I swapped my motor for a 2.2kw BDLC motor

[@Roberto-cc4el]

Hi, nice job, I'm also making the same changes to my rong fu rf 25 but I can't figure out how to remove the large pulley to put the rev counter sensor magnet... could you please explain to me how you managed to remove it? Thanks in advance

[@RobertAdairWorkshop]

I removed it once, successfully, and the second time, I broke it. But I did learn how to get it off. Put a two or three jaw puller on it and tighten it up enough that it puts pressure on the pulley. Don't tighten it up so much that you feel it'll damage or break the pulley. Then, while wearing safety glasses, heat up the center portion of the pulley with a propane or MAP torch. Once hot enough, it'll pop off and fall on the floor. Be ready for that. But don't try to just pull it off without heat. Chances are good it'll deform or fail completely.

[@ronbianca1975]

Good video! What is the hp of the new motor? Keep up the good videos!

[@RobertAdairWorkshop]

I used a 1HP motor. It's the same rating as the original motor.

[@robert574]

I guess any braking you get out of the vfd is short lived and then switches off. I wonder what it would take to apply a brake long enough to lock the spindle to loosen or tighten the drawbar.

[@RobertAdairWorkshop]

I'm not sure. I have a resistor that I bought for the first VFD, I'll give it a try and see if it works. It's a neat idea. Currently, I hold the belt, but not having to do that would be neat.

[@robert574]

I think they apply DC to AC motors to keep them from turning sometimes and they do have motors that come with brakes. It might be possible to just apply DC directly to two of the motor terminals if you knew what voltage. The VFD shouldn't have a problem with it as long as it was below its rating. The motor would start to warm up, but you would only do it briefly at some reduced voltage. You know someone out there is doing it, there should be somewhere to read up about it. Yep, I just read that some VFD's have it, it's called "DC hold". I think the resistor is only used for slowing the motor down and not holding it. @@RobertAdairWorkshop

[@Connorkmiec93]

Great video. Did you find 1 HP to be sufficient?

[@RobertAdairWorkshop]

Yeah, I’ve been really happy with it. I haven’t found a need for more power, yet. The epoxy fill really improved the machine.

[@jaysinger38]

Hey Robert, great video great job. I have a Wrong Fu RF 31 which I believe is the exact same machine. Could you please tell me the motor model # you have with it? I’ve been calling Motor Comp in my area and they don’t seem to be able to match the one I have. Mine happens to be a 2 hp with my machine. Thank you if you get a chance to answer. greatly appreciate it, Jay.

[@RobertAdairWorkshop]

Hi, Jay. Mine is only a 1 HP motor. It’s 240v 3-phase. It's made by Reliance Electric. Model is: Duty Master A-C Moter, XEX,. Severe Duty, ID number:P14G7505P-KD. 1725 RPM, 7/8 shaft, FL143 frame. I went with that one because it met my specs and was relatively cheap.

[@jaysinger38]

@@RobertAdairWorkshop thank you so much for replying so quickly Robert that was very kind of you. Now that I have that info at least I’ll know what frame size and I can give the information to Reliance and just tell them what would it be for the 2 hp motor. thank you so much once again really appreciate it.

[@kevinmorey6612]

any chance you could post the replacement faceplate model for us that are not so SolidWorks savy?

[@RobertAdairWorkshop]

That's a good idea! Do you want the Solidworks sldprt file, a step file, or the STL for 3d printing?

[@kevinmorey6612]

An .STL would be great, i can work with that. others might want something else.

[@jrocket381]

Can you post the Part number for the new replacement motor.

[@RobertAdairWorkshop]

Yeah. It's made by. Reliance Electric. Model is: Duty Master A-C Moter, XEX,. Severe Duty, ID number:P14G7505P-KD. There are thousands of surplus 3-phase motors on eBay. I searched until I found one that met my specs: 240V 3-phase, 1725 RPM, 1HP, 7/8 shaft, FL143 frame. Here's the exact same motor on eBay (so you can see the model plate): www.ebay.com/itm/290680494865?hash=item43ade85b11

[@jrocket381]

Thanks! 😊

[@deepwinter77]

Hey Robert you should treat yourself to a gas welder, its quality of life improvement 😅

[@RobertAdairWorkshop]

Mine will do gas. I just don't know where to get cylinders, locally. There'd be a whole new learning curve, too. I've been a flux-core guy since I was 10 :)

[@deepwinter77]

@@RobertAdairWorkshop ah I see, you might be able to get just straight CO2 a bit easier locally I'm in Ireland so things will be different but you can get gas from the likes of bar and pub suppliers and its also sold for Fish tanks aquariums and the likes. That's if there's no welding supply or AIrgas in your area. It's definitely not a necessity, it just reduces smoke and spatter a lot and makes the puddle a bit more visible, the welds are no stronger.