Need help with drill press motor

[msweig]

Measure the distance on the original (dead) motor from the shaft center to the mounting surface, and measure the shaft diameter.  If the shaft to foot distance is 3” with a 1/2” shaft, it’s a 48 frame.  If it’s 3-1/2” with 5/8” shaft, it’s a 56 frame.

Ok, the old motor has a D145 frame.  The ebay one was XD42.  Not exactly common. And the shaft to mounting surface distance is a bit less than 3 1/4" on both.  So if I go with a 48 frame I should be able to take up the slack with the motor mount.  


I also double checked, the shaft is 1/2".  All the grizzly ones are 5/8, and have a key (I need the one with the flat slot, or at least that is what the old ones are.  If there was some way to knock out the key I might be able to get the set screws down into the groove, but I have no idea if that is a good idea or not).  If that isn't a problem let me know because that might open up some other motor options.

I think, between barryvabeach, TDKPE, and the grizzly instruction manual that was on the motor linked to, I get the gist of how to wire the thing.  Didn't realize you looked at the rotation from the bottom, but either way I'd probably hook it up, make sure I got the ability to turn the thing on, then change the rotation if needed. 

It looks like the switch I have is a two pole (see photos).  The nice thing with this switch is that it easily connected to the pull rod for turning it on and off (I don't want to have to reach behind to the motor to do that).

   

   

   

I agree with Poindexter.  In order of importance, you want to have the same frame and diameter and length of shaft ( makes mounting it much easier ).  Ideally, you would want same RPM -  either 3,600 or 1,750.  HP is pretty flexible, it is a drill press.  I am no real expert, but IIRC on my cheap drill press,  I have an open drip proof motor, like the one Poindexter linked to, which is usually cheaper than a TEFC motor like the Leeson you linked.  The Totally Enclosed Fan Cooled motor is much more important where the motor will be in a dusty environment, like a table saw, jointer or bandsaw.

Good to know about the type.  I'll look into some of those.  Maybe one will have a longer shaft (I'm pushing it on the Leeson, it is right at the edge of what will work, and maybe even slightly short (like one of the two set screws will be right at the top)

Let me know where you are,  I have an older Sears motor that may work,  depending on the frame and shaft.

Barry, I'm in Houston.  My guess is the motor you have doesn't match the above, but if it does let me know.

[barryvabeach]

I am in Virginia Beach, so even if it fit, shipping would be prohibitive

also double checked, the shaft is 1/2".  All the grizzly ones are 5/8, and have a key (I need the one with the flat slot, or at least that is what the old ones are.  If there was some way to knock out the key I might be able to get the set screws down into the groove, but I have no idea if that is a good idea or not).  If that isn't a problem let me know because that might open up some other motor options.

As long as the pulley is round, not D shaped, yes, it would be a little work, but you should be able to knock out the key and use set screws to hold it in place so long as the shaft is the same size as the original.  In every motor with a key that I have seen, the shaft is round ,  a slot is milled into the shaft  ( sometimes a half moon shaped slot, sometimes a long rectangular slot ) and the key is inserted in that.  They can get a little difficult to get out, but with screwdrivers and a vise grip, it should come out.  I have never seen one with a key cast as part of the shaft.   On the pulley, most that I have seen have a round hole, and the flat on the shaft is just to help give the set screws some place to grip to keep the pulley from rotating on the shaft.  If the pulley has a d shaped hole, it would be a bit of work with a grinder to grind down the shaft to match.  Since the pulley is used to drive a belt, you don't have to get the pulley exactly concentric to the shaft -  a few thousands either way probably won't be noticeable.   Another thing to consider, if 5/8 shaft motor is much cheaper and would work, you could see if you could find a similar pulley with a 5/8 opening.  I have never dealt with these folks, just a google search popped it up  https://www.zoro.com/congress-58-or-12-f...HIQAvD_BwE   and https://www.amazon.com/Chicago-Die-Casti...0312&psc=1     You don't need the diameters to be identical to the original, but it would help to have the top and bottom be close in size to the original. 

[msweig]

As long as the pulley is round, not D shaped, yes, it would be a little work, but you should be able to knock out the key and use set screws to hold it in place so long as the shaft is the same size as the original.  In every motor with a key that I have seen, the shaft is round ,  a slot is milled into the shaft  ( sometimes a half moon shaped slot, sometimes a long rectangular slot ) and the key is inserted in that.  They can get a little difficult to get out, but with screwdrivers and a vise grip, it should come out.  I have never seen one with a key cast as part of the shaft.   On the pulley, most that I have seen have a round hole, and the flat on the shaft is just to help give the set screws some place to grip to keep the pulley from rotating on the shaft.  If the pulley has a d shaped hole, it would be a bit of work with a grinder to grind down the shaft to match.  Since the pulley is used to drive a belt, you don't have to get the pulley exactly concentric to the shaft -  a few thousands either way probably won't be noticeable.   Another thing to consider, if 5/8 shaft motor is much cheaper and would work, you could see if you could find a similar pulley with a 5/8 opening.  I have never dealt with these folks, just a google search popped it up  https://www.zoro.com/congress-58-or-12-f...HIQAvD_BwE   and https://www.amazon.com/Chicago-Die-Casti...0312&psc=1     You don't need the diameters to be identical to the original, but it would help to have the top and bottom be close in size to the original. 

Yes, the hole in the pulley is round.  Good to know I can consider the ones with the key, and I'll look at the other pulleys.  Thanks for the help.

[TDKPE]

Yes, the hole in the pulley is round.  Good to know I can consider the ones with the key, and I'll look at the other pulleys.  Thanks for the help.

If the bore of the step pulley is 1/2", then you can't use a NEMA 56 frame motor unless you either bore out the step pulley, or turn down the shaft of the motor. 

It may be possible to bore out the step pulley, as back in the days when that DP was made, it was common for Delta to use the same step pulley casting with different bores, often up to 3/4" diameter.  So there may be adequate hub wall thickness to allow boring out to 5/8".  A shop that can bore it out can also broach a keyway, or just run the set screws into the keyway in the motor shaft.  Dodgy, but it'll work.

The motor pulley on my Delta radial DP is a Cat. No. 985 with 2.156" OD on the smallest and 5.25" OD (measures slightly smaller) on the largest, and was available with 1/2" bore with no keyway up to 3/4" bore with keyway.  So there's a good chance yours is the same, and can be bored out with no adverse affects.

Oh, and it looks like your old motor has a Delta 6" frame, as Delta called it, with 3-1/4" shaft center to mounting surface and 1/2" x 1-7/8" usable shaft length with flat.  That's according to my old Delta catalogs.

[Admiral]

I'm amazed by the extent of knowledge shared here. Outstanding, kudos to all who contributed to this!

[msweig]

If the bore of the step pulley is 1/2", then you can't use a NEMA 56 frame motor unless you either bore out the step pulley, or turn down the shaft of the motor. 

It may be possible to bore out the step pulley, as back in the days when that DP was made, it was common for Delta to use the same step pulley casting with different bores, often up to 3/4" diameter.  So there may be adequate hub wall thickness to allow boring out to 5/8".  A shop that can bore it out can also broach a keyway, or just run the set screws into the keyway in the motor shaft.  Dodgy, but it'll work.

The motor pulley on my Delta radial DP is a Cat. No. 985 with 2.156" OD on the smallest and 5.25" OD (measures slightly smaller) on the largest, and was available with 1/2" bore with no keyway up to 3/4" bore with keyway.  So there's a good chance yours is the same, and can be bored out with no adverse affects.

Oh, and it looks like your old motor has a Delta 6" frame, as Delta called it, with 3-1/4" shaft center to mounting surface and 1/2" x 1-7/8" usable shaft length with flat.  That's according to my old Delta catalogs.

Yea, the catalog I have shows the same part number.  Didn't notice that they came in the different bore sizes. 

So it looks like my options are:
1) buy a frame 48 motor and use that. 
2) buy a frame 56 motor, get a new pulley or adapt the one I have, and get a new belt (because the Frame 56 is 3.5", which means my current belt isn't long enough).

Is there any reason to even really consider option #2?  I can find Frame 48 motors that are 1/2 HP if I am worried about power.  Yea, it might cost a bit more, but probably cheaper or a wash considering needing a new/altered pulley and a belt to go with the Frame 56. 

Am I missing something?

[TDKPE]

Am I missing something?

Nope.  Just trying to give you some options is all. 

You can bore the existing sheave out yourself if you have a lathe and the right type of chuck, and a tailstock chuck for a drill bit.  Gotta be careful and test the bore on the motor shaft first, though, as most drill bits are not precision reamers and may make an oversized hole. 

Or pay someone to do it.  It's easy work, and won't cost much to have someone do (die cast aluminium cuts easily).

Or pay for a NEMA 48 frame motor and just assemble it all.  The one you linked to looks like it will be a bolt-on replacement, with a little belt adjustment, and it has the added bonus of being a TEFC frame (no dust inside, though that's a trivial matter on a DP).

Edit: I should add that I bought my Delta radial DP new when I was in high school in the 70's, and it's had a few motors on it, from antiques, to the present furnace motor from an old belt drive air handler.  It's on a resilient cradle frame, as were the others, which I like because it makes it easy to change speeds without having to loosen anything.  The present one is a 1/2 hp split-phase motor, but a DP being an easy load to start means it has no trouble starting.  The one before that had a 1/2" shaft, and I had to bush the step pulley bore, which didn't run terribly true like that on such a short shaft but being a belt driven DP, was good enough.

   

   

[msweig]

Thanks!

Neat looking drill press

[TDKPE]

Thanks!

Neat looking drill press

It's a variation on yours, but with the unfortunate plastic belt guard rather than the metal one. 

   

[barryvabeach]

Poindexter,   love the photo.  BTW ,  the motor mount looks similar to the Craftsman 113 table saw mount on a saw I just rehabbed for a friend.