table saw motor

[Mike Stanton]

I have a jet 1 1/2 hp contractor saw and I want to put a bigger motor on it I want to put 3 hp if possible on it Mike

[Tim Morton]

I have a jet 1 1/2 hp contractor saw and I want to put a bigger motor on it I want to put 3 hp if possible on it Mike

I think that when the time comes that you find your self needing a 3HP saw its might be best to buy a 3HP cabinet saw. I would not feel comfortable runing a 3HP motor on a contractor saw....but thats not to say it is not possible. You can sell your jet for say $500? factor in at least 300 for a 3HP and you are at $800...a couple hundred more and you now have a cabinet saw.....FWIW.

[Mark Singer]

Tim gave you the right advice. Sell and get a 3 hp saw...big trunions and solid! Big difference!!!

[Steve Clardy]

It can be done. Just use the same frame #. But as above, I'd go with a bigger saw if you want 3hp. Bigger table, nicer fence, heavier saw.
Steve

[Allen Bookout]

Mike, Some other things to think about. I am not trying to discourage you but the cost will add up in a hurry. I experienced the cost factor myself as I just finished building a base and supplying 2hp to a new bandsaw top. In addition to the approx $300 for the motor you will need a new switch that is rated for 3hp and would be a good idea to be magnetic, between $50 and $60 (available from Grizzly). You will also need to run three belts to handle that kind of hp, so you will need two new three belt pulleys and three new belts. I do not have a price on them but you can check. You might get by with two but I know that three will do it. Also you will need heavier electrical cord and plug to make new connection from your motor to receptacle. I also think that you should beef up your motor mount and make it where you can tension the belts and bolt it solid in that position. You are now well over $400 plus any shipping charges and or taxes. If you already have the motor or can get one real cheap it might worth a try but if you are going to have to purchase new I go along with Tim, Mark and Steve. Sell high and buy low.

[Jim Becker]

I will discourage you from putting anything more than a 2hp motor on that contractor's style saw...the weight and tourque really will not do well on that tool. Upgrading to a 2hp motor will give you a little added omph if you frequently rip thick materials, but you will see little or no difference in most cutting operations by changing the motor.

[Kevin Herber]

I would be concerned about the added stress to the arbor from the bigger motor hanging off the back. You are changing the belt tension with the heavier motor. The bearings may not be rated for that much weight.

I too, recommend a cabinet saw.

- Kevin

[Fred Ray]

Okay, I'm not about to argue that a good cabinet saw is far better than a contractor's saw. But, let us consider the following: (I own a Delta CS Jet is very similar but may not be exact).
1. Harbor freight sells a 3 H.P. 56 frame, 230 volt motor for $69-79 on sale. This motor fits Delta CS exactly. Probably will fit Jet also.

2. Motor has 5/8" output shaft. Saw arbor is 5/8" at pulley and at blade. Seems to me 5/8" steel is 5/8" steel in terms of shear strength. (I know different steels are different, but if 5/8" can handle 3 H.p. at motor, why can't it do same at saw arbor??) Weight of larger H.P. may be more, but mounting arrangement on CS's is such that arbor sees only a fraction of the weight - just enough to maintain tension.

3. Magnetic starters are very nice and have several advantages. However, recent model Delta CS's come with a 2 pole, 20 amp rated swtch - More than adequate for a 3H.P. motor at 230volts. Don't know it Jet's switch is same or not.

In my case, I could increase to 3H.P. for under $100 after buying new power cord and plug - I have the 230 volt outlet available.

So---given these circumstances, why not upgrade to 3 H.P.????

[Curt Harms]

Here are my thoughts:
Okay, I'm not about to argue that a good cabinet saw is far better than a contractor's saw. But, let us consider the following: (I own a Delta CS Jet is very similar but may not be exact).
1. Harbor freight sells a 3 H.P. 56 frame, 230 volt motor for $69-79 on sale. This motor fits Delta CS exactly. Probably will fit Jet also.[\quote]

Disclaimer-I haven't had a Contractor style saw for years, so take this for what it costs. Check the rotation on that motor. Some of the less expensive HF motors are CCW rotation and not reversible. I'd also wonder if the 3 h.p. are 3 "sears" h.p. i.e. maybe 2 real h.p. Asian motors are not known for their efficiency, so amps drawn may not be a good inidicator either. I replaced a 3/4 h.p. Grizzly motor that drew 13 amps. with a 1.5 h.p .G.E. that draws 15 amps. Should be about the same power, right? NOT EVEN CLOSE! G.E. really does have 2X the power, for 2 amps more.

[QUOTE=Fred Ray]2. Motor has 5/8" output shaft. Saw arbor is 5/8" at pulley and at blade. Seems to me 5/8" steel is 5/8" steel in terms of shear strength. (I know different steels are different, but if 5/8" can handle 3 H.p. at motor, why can't it do same at saw arbor??) Weight of larger H.P. may be more, but mounting arrangement on CS's is such that arbor sees only a fraction of the weight - just enough to maintain tension.[\quote]

Weight on the arbor may not be the main concern. If you tilt the saw, the motor may put more of a twisting load on the 2 bars that support the motor than intended and they may twist and put loads on the rest of the frame that were never intended, causing distortion of the trunion mounts. The blade won't heel properly when cutting at a bevel. A true 3 h.p. cabinet saw is so nice and doesn't take any more room than a C.S., perhaps less.

[QUOTE=Fred Ray]3. Magnetic starters are very nice and have several advantages. However, recent model Delta CS's come with a 2 pole, 20 amp rated swtch - More than adequate for a 3H.P. motor at 230volts. Don't know it Jet's switch is same or not.[\quote]

In my case, I could increase to 3H.P. for under $100 after buying new power cord and plug - I have the 230 volt outlet available.

So---given these circumstances, why not upgrade to 3 H.P.????

[Don Baer]

Mike;
I looked at the motor you are considering here is a link to the HF spec sheet.
http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=7570&CategoryName=null&SubCategoryName=null

It only runs Counter clockwise.

I'n my opinion if you wanted to use it and it is very small in size. The 56 frame will cause it to run hot. The 5/8" shaft is simply too small for the amount of torque that it would produce.

IMHO

[Allen Bookout]

This is getting real interesting!

Fred, If I understand it correctly I think that you are talking about something different than Mike. I think that you are talking about upgrading your cabinet saw to a higher hp. I see no reason not to give it a try. What can happen? It seems that the worst thing that could happen is that it just will not work out well. No problem - only out one hundred bucks - just go back to where you were to start with or try something else. The best thing - it will probably work out very well as long as the motor holds up. I have no idea about the quality of their motors. I would be leary due to the selling price.

Mike, I have not seen a response from you since you started this thread. I say that after reading what has been said so far and you still want to risk the outlay of cash, however much that may be, give it a go. What could happen to you? The worst - could be that you would damage your current saw because of the weaker components and then you would have nothing of value to use or sell except the new motor and new parts that you would now have. The best thing that could happen - it would work out OK for what you want to do with it. I do not think that it would be a long term thing but might give you enough time to get ready to buy a new saw that is made to take the power that you desire.

Where is your sense of adventure guys???? Give it a try and let us know how it works out after a test period of hard use.

Good luck and be careful! Allen

[Mike Stanton]

I am still thinking of upgrading the motor but maybe to a 2hp.Have not made up my mine yet. Thanks for the ideas Mike :rolleyes:

[Jim McCarty]

Mike, I have a 2 hp Baldor motor on one of my Delta contractor saws. It's plenty of power. The 3 hp was just too heavy when I upgraded. I was afraid of damage and my saws have to be loaded and unloaded at jobsites. Jim

[Rick Lizek]

I used to get that question a lot when I was a tech for a dealer and the salesmen hated
me because I killed a lot of deals on bigger saws. Most guys were using combo blades to cut 8/4 msterial. I showed them what a dedicated rip blade could do and most of them were happy with keeping the contractor saw. There's a 10 tooth rip blade that cuts even faster. The finish is a little rougher but most folks hit the edge on a jointer or whatever.

[Fred Ray]

This is getting real interesting!

Fred, If I understand it correctly I think that you are talking about something different than Mike. I think that you are talking about upgrading your cabinet saw to a higher hp. I see no reason not to give it a try. What can happen? It seems that the worst thing that could happen is that it just will not work out well. No problem - only out one hundred bucks - just go back to where you were to start with or try something else. The best thing - it will probably work out very well as long as the motor holds up. I have no idea about the quality of their motors. I would be leary due to the selling price.


Actually, I have no specific plans for changing anything. I was questioning why Mike couldn't/shouldn't do what he was thinking about at a reasonable cost of $100 or so.

Don has come up with the best reason I've heard so far - the counter clockwise rotation only of the motor. Though. I'm not 100% convinced that one couldn't open the motor and make the change. Changing rotation in a single phase induction capacitor start motor requires swapping the two leads on the centrifugal switch.

Don also said: "The 56 frame will cause it to run hot. The 5/8" shaft is simply too small for the amount of torque that it would produce."

When one does a search of Baldor's website, they manufacture several 230 volt, single phase 3 h.p. motors in a 56 frame, all of which have a 5/8" output shaft. Therefore, one has to assume that 5/8" is indeed enough to transmit a full 3 h.p.

[Don Baer]

Fred;
I would like to explain why I believe a a 56 Frame motor is simply too small for a three hp load.
First some motor history. In the early days motor manufacturers had to rely on some fairly crude type of insulaion when winding motors, coton cloth covered with varnish comes to mind. The early motors were very large and relied on large casting to act as a heat sink to get the heat out of the motor. In the 50's the National Electricrical Manufacturers Association set up standards for electric motors sizes. These standards were set up so that when given size motors was taken out one of a same frame size could be put in it's place. This allowed interchangability between manufacturers since for a given frame size all of the important demension remained the same. e..g a 56 Frame motors will always have the same diameter shaft, length and shaft height as measured from the center of the shaft to the bottom of the feet.
The early motors were called U frame motors.
In early 70's manufacturers found new insulation materials that allowed the motors to run hotter therefore didn't require as much metal for a heat sink. This allowed the manufacturers to redesign the motors with less metal .
This caused Nema to come up with a new class of motors called the "T" frame motors and this is what you have on the market today. Most motors use insulation in the windings that is rated as Class "F" insulation (remember this is the temperature of the windings not the outside of the motor.)
The insulation classes used in motors are as follows.
Class A - 105 degrees C
Class B - 130 degrees C
Class F - 155 degrees C
Class H - 180 degrees C

Years ago when I would have customers call and complain that there "New Baldor motors were running hot I would ask themif they could lay there hand on it and not have the skin stil to the motors for ten seconds. If they said yes then I would tell them that the motor was not overheating.

I went to the Baldor site and did a search on 1 phase 3 HP 2 pole "General Purpose" motors and found that there were no Moors smaller then 145T frame and most were 182/184 frame motors. A search of the 56 frame 3 HP motors found that they were rated for comercial duty not General Purpose.

Personaly I want my motors to run as cool a possible so I would choose the largest frame size possible for a given application.

More then you ever wanted to know about electric motors

[Allen Bookout]

Fred,

On the subject of rotation of electric motors I have a question. I have a 1 hp electric motor that came off of an old cheap bandsaw that I tossed. I tried to use it on my drill press since that motor had gone bad. The only problem is that it rotated counter clockwise and I needed it to rotate clockwise. It had no wireing diagram on the cover except how to wire it for 220. I experimented until I got it to turn clockwise but it got hot real fast and had a burning smell. I got my neighbor who is pretty good at that sort of thing and he said the same thing that you said about the rotation. We wired it the way that he said and some times it will rotate clockwise and sometimes counter clockwise and sometimes it just sits there and hums. I can get it to start either direction by reaching up and spinning the pulley the direction that I want it to turn and then turning on the switch before it stops rotating. Not a good technique. Still runs hot. When I rewire it the way that it was it always starts and runs counter clockwise and does not get hot. This makes me think that some motors, and I have been told this before, will only run properly in the direction that they were built to run. If this is the case, it would behoove one to make sure that any motor that you are going to purchase can be wired to run either direction if it does not originally run in the direction desired.

I have notice on some motor specs that it will say "can be wired to run either direction" or " can be wired to run CW or CCW".

If you, or anyone for that matter, has any correct information about this subject I would be interested.

[Don Baer]

Allen;
Most single phase motors used today use a starting Capacitor and a set of starting windings to cause a phase shift to get the motor started in the right direction. Some will keep the capacitor in the circuit all of the time others will switch the cap out of the circuit when the motor reaches 2/3 speed. You can even hear the swith engage and disengage when the motor is switch on or off if you listen closely. Depending on the design of the centrifical switch it may not function prperly in one direction. I would guess that this is the problem with your motor. In terms of spinning the motor your self you are acting as the starting winding.

Hope this helps.

[Allen Bookout]

Thanks Don! I appreicate the information. I suppose that there is nothing that I can do about it on this motor. Looks like another purchase. Allen

[Don Baer]

Alan;

For a drill press I would think this motor would do fine. It one from HF but apears to be fairly substantial. If not HF then maybe you can find one likeit.

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I am not a bid fan of HF tools but some of there stuff ain't too bad.

[Paul Canaris]

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p>Selling my Rockwell contractors saw years ago, did more to improve the ease and accuracy of my woodworking, than anything I can think of. I feel that as a generalization, they are a bad design. Time to upgrade to a cabinet saw. IMHO...<o:p></o:p>


</o:p>

[Allen Bookout]

Thanks Don - for looking that up for me. For seventy bucks I am going to give it a shot. Allen

[Fred Ray]

Allen:

Sounds a lot like you may have burned up the capacitor on that motor when you rewired it. Don's description of the capacitor and starting winding is correct. Bad starting winding, bad centrifugal switch, or bad capacitor would all cause the symptoms you describe. A replacement capacitor may be all it needs. Sad part is having a motor shop do the repair may cost more than the new HF motor.

Don:

After 30 plus years in electrical engineering, I am familiar with NEMA motor standards also. As I gather from from what you've said, I generally err on the far side of caution also. I too would rather have the larger frame size. Whole point though, is to answer Mike's original question. If one can buy a cheap 3 h.p. motor that can rotate in the right direction to put on a home use contractor's saw, why not give it a try???

[Jim Hinze]

I am still thinking of upgrading the motor but maybe to a 2hp.Have not made up my mine yet. Thanks for the ideas Mike :rolleyes:


Mike, I think 2hp would be plenty. I have a 10" delta tilting arbor saw circa 1993 which was one of their orig. hybrids, full cabinet with contractor saw trunions. It has a 2hp motor which has LOTS of power. I can rip 8/4 purpleheart with very little difficulty using a full kerf blade.