Upgrading a Shaper Motor

Should a woodworker beef up the motor on his shaper when the original one breaks down? It's a questionable call. May 5, 2007

Question
I'm right in the middle of manufacturing an entry/passage door package, and my shaper motor went out. There is no NEMA frame size on this motor, and according to the manufacturer (Grizzly - it's a 5hp 1ph 4 speed shaper), my only option is a direct replacement from them.

I need to know what kind of motor to be looking for, as I need more power. I'd need at least 7.5hp, but would prefer 10hp or more. Yes, I realize there will probably be some fabrication involved, and I know I'll need new controls for the larger 3ph motor.

I've searched high and low for a 3450 rpm reversing/reversible motor, but can't find anything! Please help, as I'm stuck with a counterclockwise rotation 5hp table saw motor until I can locate and retrofit the new motor, and as you can imagine, a non-reversing shaper is quite a pain to make doors with.

Forum Responses
(Architectural Woodworking Forum)
From contributor T:
In order to relieve the short term pressure, have you considered outsourcing this entryway until you can get your production equipment needs sorted out?


From contributor J:
I'm not sure I would want to do this unless I was in your predicament, but if you're running a 3 phase motor, you can switch two legs and the motor will run in the reverse direction.

From contributor C:

Sorry to hear about your dilemma. One way you could accomplish what you are trying to do is with a new motor and frequency drive or other digital control, which will do all of what you need and them some, as well as help your electric bill. Cost wise, you could probably just get a new shaper. I'm guessing $750-1000 for a drive that size, plus a motor.

If you put your calipers on the shaft and measure the mounting hole locations, you may be able to find something close through Grainger or other industrial supply store, and field modify it to fit.

However, understand that that your motor probably died for a reason, and the fact you "need" to go to a 7.5 or 10 HP motor now makes me suspect that the shaper you have now is undersized or insufficient for your needs. If you just put a bigger motor on and keep trying to make cuts that the machine wasn't designed to do, you will destroy the bearings, or the shaft, which of course will happen while you are using it, resulting in a mess and a bunch of paperwork.

I think contributor T is right. If you're crushed for time, call in a favor or find someone to cover what you need right now while you take some time to research what shaper is really what you need. I'm sure you can find someone close to you through this site or your suppliers who can help you out.


From contributor B:
What in the world are you cutting that makes you feel you need a 10hp motor? I can't imagine a need to have such power for anything thinner than 12/4 stock... which is what I would consider the prerequisite for a 10hp shaper. I have an approximately 7 1/2 hp SCMI and can tell you I've never even come close to taxing the motor. I did replace it after 15 years of use, but I consider that an acceptable lifespan.

I suspect the problem is more in an underpowered "5 hp" motor from Grizzly. Many Taiwan motors are notoriously bad... so much so that some of the better importers offer American motors as an option.

So, I'd suggest going to an American made (Baldor, or at least something out of Mexico) 5 hp motor. Use the Grainger catalog to match up a frame size that closely matches your existing motor.

When I replaced my SCMI motor, I came as close as possible with that method and made a few minor alterations (drilling new bolt holes) to make it fit. Don't forget to look at shaft diameter, length and position off the base.


From contributor G:
Try Lesson motors. In SO CAL, Chicks electric. I have some Griz tools and have replaced, upgraded the motors with Lesson or Baldor. Measure the base... NEMA is a world wide industry standard. Google electric motors, woodworking motors - spend a little time surfing and you will find what you need.

From contributor P:
I agree that 7.5 to 10hp is an enormous amount of power. That coupled to a shaper that is not designed to handle it is dangerous. A good true 5hp Baldor or Leeson motor will give you all the power you need. I have an old Oliver with a 5hp that can run all day taking a huge cut. Anything more on your machine is kind of scary.

From contributor I:
I don't know why this hasn't been mentioned yet, but all 3 phase motors are reversible. The drum switch is just reversing any two of the three wires feeding the motor. And I agree with a previous poster that it is a problem with the Grizzly motor being underpowered, and a decent US made motor of 5 horse will be sufficient.

From the original questioner:
Thanks for all the help, advice and sources. I finally have all my parts cut with the jury-rigged tablesaw motor/shaper. And as of about midnight last night, assembled all but 4 of the door slabs. (I use an old Taylor 6 section carrier with 40" clamps, and a wall rack with 20 additional 48" clamps, so I made up some time during final assembly).

By the way, I have the Grizzly 5912z, which is offered with a 7.5hp 3phase motor. I have found a 10hp motor which will be close enough to the original motor's dimensions, and since my quad pulley was badly damaged, I'll be replacing it with new ones anyway.

I like to cut my panels in one pass. That is with a right rotation and left rotation panel cutter stacked on the same spindle. 1.75" and 2.25" panels cut within .20" of full profile is a lot of material to hog off at 20 fpm, so I don't really think I'm out of line swapping in a 10hp motor.

Excellent point, contributor I. I now know why I couldn't find anything listed as a "reversible three-phase motor" since all 3-phase motors are reversible in the first place!

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