Clausing D/P What motor/VFD should I use?

Hello all,
This is my first posting, I just found this website yesterday! I have searched for awhile trying to find an answer to my questions, but I have not been able to fully answer them. SO..... I hope that I don't bother you folks with a question that has been asked before, but here I go. I am rebuilding a Clausing 20" drill press (thought it was going to be a cheap project) and found that the motor has a bent shaft. Dayton 3 phase/220v. I currently do not have any other machinery with 3 phase, so it has me wondering what would I should use. I don't fully understand the benefits of 3 phase or a VFD. I have a small fabrication shop, mostly cut and weld. I would enjoy being able to run a tap to cut threads with the DP if possible. What would be the ultimate set-up for this since I am going to keep this until I'm gone.... Thanks for your help! Jimmy, Portland Oregon

Jimmy - good to see another PDX member . . .

how is your present motor mounted? (is it a foot mount motor or a C-Face mount?) What is the HP, frame size and rpm?

Knowing this will make it easier to make a recommendation for a motor.

As far as drives go - you will have half a dozen folks making recommendations here and they are all likely good. Personally - I like Emerson CT drives and Siemens drives. One of my guys in the shop just grabbed a 10 year old CT drive out of surplus and made himself a welding positioner drive with it. Works well with 230V single phase input and 3-phase output.

We have used as many as 200 drives a year of different brands - if cost is your criteria you will get a different "best" solution than if performance is your criteria or support or warranty or any other criteria. These things are becoming commodities . . . anything under 2HP is becoming cheaper than a tank of gas.

Thanks for your info... but I am so uninformed about this sort that I don't know what a CT drive or a Siemens drive is! I don't know the mount either. I will get the info from the Dayton motor that was on it, hopefully this will help.
I think at this point, I am going to spend the money on the best options out there as I am going to keep this unit for many years. This is why I was wondering about the VFD's and other options..

Thanks....

How many hp were in the clausing to start with? Smaller motors (under 3/4 hp)
can be fitted with a 120 volt input drive.

The advantages are you can run the drill press with nearly full torque available,
at very low speeds. And you can change speed simply by turning a knob.

Jim

What horsepower is the motor??

The FIRST thing we need to know is what the horsepower rating is of the motor. VFDs 3hp and under are cheap, and most accept single phase or 3 phase WITHOUT having to de-rate them. I personally like Hitachi VFDs (because that's what I have), other common brands people around here use are teco (westinghouse), LG, AC tech, and some others. Vfds allow variable speed, and 3 phase output from single phase with 100% motor output. As for tapping, I'd suggest using a tapping head instead of trying to tap rigidly. Usually, you NEED instant reverse, which a VFD won't allow. VFDs have to slow the motor down gradually, and start gradually. THe motor just doesn't come on at full speed and instantly reverse like it does with utility 3 phase power. A single phase motor that can be reversed won't reverse instantly either, it has to be allowed to stop before throwing the swtich into reverse, or it just keeps spinning in the same direction. While it's possible to tap using a VFD on a drill press without a tapping head, it's NOT easy. You have to predict how far the tap will spin AFTER you hit the stop button. You can tinker with the settings in the VFD so it will spin up/reverse faster, and add an external braking resistor (makes the motor stop faster so it can reverse), but you can EASILY exceed the duty cycle for the braking resistor while tapping.

Excellent! That really help me understand. The current motor is a
Datyon 1 1/2hp 3ph. So if I'm correct, for my intended use of this machine, a VFD would not really be of much use. With the 3 phase set-up, I can instantly reverse the motor with the drum switch? It seems the VFD would be very usefull on lathes and milling machines though....
As with regards to the previous reply, I do understand the mechanics of the DP with the variable speed... I have the whole unit completely disassembled and am in the process of rebuilding the idler pulley system. I just get lost with
the electrics....no matter how much I read about it, I just can't seem to hold
onto the info... Thanks for all the help!

Get whatever motor makes you happy that will fit the mount and hit eBay for a tapping head. The tapping head will give you instant reverse at an accelerated speed once you let off the feed pressure. Do a search for tapping head and cross-reference to a good machine tool supply catalog to make sure that head will fit your needs as they come in a wide assortment of sizes...Enco, MSC, whatever. Top brands are Procunier and Tapmatic, but I've been very happy with my Enco.

The current motor is a
Datyon 1 1/2hp 3ph. So if I'm correct, for my intended use of this machine, a VFD would not really be of much use.

Click to expand...

I'm running a 2-HP 3-phase motor with a VFD that is fed with 220 VAC single-phase power with no problems at all. It won't instant reverse but that's not an issue if you don't mind using a tapping head on the drill press. I use a Procunier but Tapmatic is another popular brand.

Mike