Delta Table Saw bogging down and overheating

[Chris Glatz]

We have a Delta 36-5100 Contractor saw at work, probably about 2 years old. Lately we have been ripping down a lot of 2x4s for our shipping crates, and even with a brand new rip blade the motor will bog down and stop completely unless I feed the wood REALLY slow. Even then it will overheat and cut off after about 20-30 minutes of work. '

These are clean, straight SPF (spruce / white pine / fir) 2x4s. I have double-checked that the fence is parallel to the blade. There doesn't seem to be any wobble / runout in the arbor, and I took apart the motor housing to check for any sawdust buildup (there was actually a lot in there, but cleaning it out made no difference). Again, brand new rip blade right out of the package.

I hate this saw for this and many other reasons. I'm actually hoping that the motor burns out completely so we can finally get rid of it, because that's the only way my boss will approve a new saw. This thing won't die though, it seems to be hell-bent on doing a bad job forever. Has anyone else had this issue? Am I just expecting too much from a 13-amp saw, or is there anything I can do for better performance? Any help much appreciated.

[Andrew Hughes]

Start pushing crooked boards thru that should help kill it sooner.I remember have a job site saw that would never die.I did finally get the motor to smoke,just be careful about kick back even those little motors can launch wood.

[Jamie Buxton]

Sounds like low supply voltage. Low voltage means the motor draws more current to get the same power. More current means more heating. Maybe a bad connection inside the box. Maybe a long, too thin, power cord.

[Lee Schierer]

How wet is your wood and is the blade being pinched? How many teeth are on the blade you are using? It is common for construction grade lumber to pinch shut on the blade as the cut is made which will make the saw work harder and seem to not be cutting well.

Another thought. Has anyone checked the alignment of the blade to the miter slots and the fence to the miter slots? Misalignment will also slow down your rate of cut. A well aligned saw will perform far better.

[Paul F Franklin]

Not sure if that motor has a run capacitor, but if it does, check it.

[Bruce Wrenn]

Not sure if that motor has a run capacitor, but if it does, check it.BING, BING, we have a winner!

[Mike Henderson]

Not sure if that motor has a run capacitor, but if it does, check it.

Assuming that the motor is an induction motor and not a universal motor, the run capacitor should not cause that problem. An induction motor does not need a run capacitor - most induction motors do not have a run capacitor.

But, if you have one, check it just to be sure.

Given low power and overheating of the motor, I'd favor a low voltage situation. It's possible a connection somewhere between the plug and the guts of the motor is corroded and is essentially a high resistance connection. That is, if you have normal voltage at the plug to begin with.

Mike

[This is a bit of a stretch but if the bearing were really bad they could put a drag on the motor and cause it to overheat. But if they were that bad, the motor probably wouldn't be able to start up - or would have difficulty starting up.]

[lowell holmes]

If your Delta saw is like mine, you should be able to convert it to 220 volt just by changing jumpers on the motor.

My saw had issues and bogged down easily like yours. I changed over to 220 volt power and the issue pretty much. disappeared.

I had to mount double pole switch on the saw. I added a new switch in a new box to the front of the saw,

[Andrew Hughes]

I thought the op wanted to get rid of the saw and you guys are not helping.:mad:
2x4 can be hard to rip because of pitch and just the nature of the wood.
Really should up you machine to something with horse power.
Save the cute little portable saw for very small stuff.

[Wayne Lomman]

+1 for Andrew! Cheers

[Charles Lent]

You should also check the saw arbor and motor bearings. Unplug the saw, then remove the belt and try turning the saw blade by hand. It should turn very easily. Now do the same thing with the motor pulley. It will be a little harder, but should also turn easily by hand. Iff the motor needs new bearings, Fastenal, Grainger, McMaster industrial supply companies, or a bearing specialty store should have them, or it may be easier to take the motor to a motor repair shop for capacitor and bearing replacement.

Internal electrical shorts in the motor windings due to overheating of the motor, could also cause low output power and overheating. A motor repair shop can best determine this.

There are 2 capacitors (in 2 bumps on the outside of the motor of a Delta Contractor Saw), One is a start capacitor and one is a run capacitor. It's usually best to replace both when you suspect that one might be bad, but only replace them with the exact same electrical rating and physical size (not all capacitors of the same electrical rating will be the same physical size). They need to fit under those metal covers. Also, make certain that you don't mix them up when changing them. Label the wires for each with the capacitor rating as you remove them so you can put the new ones in the right place. Tgese are AC capacitors, so it doesn't matter which wire goes on the terminals, just one wire on each terminal. Grainger, McMaster, or similar industrial supply, or a motor repair shop would be good local sources for these capacitors. Motor shops can also test capacitors.

If the saw is running on an extension power cable, this could be the problem. The cable should be 12 or 14 gauge and not 16 or 18 gauge. Look at the writing on the side of the cable. If you don't find this writing or if you find that the cable has higher numbers than 14, replace it with a heavier duty 12 or 14 gauge cable.

Changing the motor connections and then running the saw on 240 volt power will get you less current draw, therefore less voltage drop in the power cable. It will also get you 1/2 hp more power. Delta contractor saws have motors that produce 1 1/2 hp when connected to 120 volt power and a full 2 hp when connected to 240 volt power. Look at the motor label if you don't believe me. If you change the motor over to 240 volts, be sure to change the plug to one of the standard 240 volt plugs and make certain that the wall outlet matches so it can;t be confused with a 120 volt power source, or someone might try to use the outlet to operate a 120 volt tool or try to run the saw from a regular 120 volt outlet. This could not only destroy the tool, but could seriously injure or kill the person holding the tool.

Charley

[andy bessette]

If you're not using a good quality carbide rip blade, you're not trying hard enough.

[glenn bradley]

Really no reason that saw shouldn't be able to rip straight and true lumber all day with a proper rip blade. I too vote for an inadequate or improperly provisioned power source; long extension cord of light gauge, bad building wiring, shared circuit, etc.

[Chris Glatz]

Thank you guys, the extension cord is adequate (12g, 15ft) but I will check the capacitors and the voltage at the saw. All other things are good... bearings spin freely. Blade, fence, and miter slots are all parallel. Converting to 220 seems like a step up from trashing it, but we would have to have an electrician run a line over to this area and that would cost almost as much as getting an appropriate saw. You don't have to convince me that it's worth it, I'm already on board, but unfortunately that decision is not in my hands.

[lowell holmes]

I converted mine to 220 and It does indeed run better. It's like a different saw. I did it several years ago. I run a 10" Forrest blade.

[Chris Glatz]

Thanks Mike, I pulled out both caps and tested them. Results were confusing.

The run cap is fine. Rated for 40 MFD / uF and my meter read 41.
The start cap is rated for 324 MFD and I got a couple of brief, random nF (Nano, not Micro) readings before the meter settles on OL.

So it sounds like the start cap is failing... but the saw never fails to start. My next thought was that the meter is bad, but the readings have been repeatable and consistent, and it read the run cap accurately. What am I missing?

[andy bessette]

You failed to mention the blade.

[Chris Glatz]

You failed to mention the blade.

I mentioned it twice.

[Chris Glatz]

How wet is your wood and is the blade being pinched? How many teeth are on the blade you are using? It is common for construction grade lumber to pinch shut on the blade as the cut is made which will make the saw work harder and seem to not be cutting well.

Another thought. Has anyone checked the alignment of the blade to the miter slots and the fence to the miter slots? Misalignment will also slow down your rate of cut. A well aligned saw will perform far better.

Thanks Lee. Without a moisture meter I don't know how wet it is. I've always heard 15-20% for dimensional lumber which seems about right. Some of the boards do close up as they are cut, and on those I would expect the motor to bog down... however some boards open up, and they are no easier to push through.

Currently using a Freud 32T carbide tip. I aligned the blade and fence to the miter slots a few months ago, and checked today that they are still parallel.

[Chris Glatz]

I converted mine to 220 and I does indeed run better. It's like a different saw. I did it several years ago. I run a 10" Forrest blade.

I'll keep that in mind for my saw at home. Unfortunately this one is at work, boss man won't approve the cost of having an electrician run a 220 line over to this area.

[scott spencer]

You mentioned that you're using a 32T Freud blade, but I'm not familiar with such a blade, so am assuming you mean a 30T, which would likely make it one their Glue Line Rip blades....like an LM74 or LM75? The GLRs are actually only intended for materials up to 1". They have really tight side geometry that adds a lot of resistance....great for clean cut, not great for heavy bulk ripping. If my assumption is correct, you'd be way better of with a 24T TK blade like the LU87 for that task.

Also, I thought the 36-5100 has a 15 amp motor, which should handle what you're cutting with the right blade.

[andy bessette]

I mentioned it twice.

You referred to it, but never identified it.

Unsubscribed.

[Tom Bender]

Sometimes the answer is right there and you just don't see it. Is the blade installed backwards?

Done this once and seen it done once.

[Chris Glatz]

Thanks I'll look into that blade!

[Jim Andrew]

I used to have an old Craftsman table saw that had problems ripping 2x lumber. I made stakes and such from scraps on my jobsite. First changed it to 220, then started using smaller diameter blades. The motor got weaker over the years and last I used 7 1/4" blades, with success. The old motor got so weak I had to kick start it, and had so little power it would not turn a 10" blade, and I gave it to a friend and bought a new Unisaw. Bought the old cman saw used about 40 years ago, and the Uni in 05. The previous owner of the cman saw had put a delta fence on it, much better than the original cman fence.

[Charles Lent]

You should also check the motor to make sure it's set up to run on 120 volts. If somebody changed it to 240 volts the motor certainly would not behave well when run on 120 volt power. If it was mine and I was having problems like this I would replace the capacitors even if they tested good. How old is the saw? more than 10 years old deserves new capacitors. They are cheap when compared to the time wasted trying to find other causes of this problem. New ones would assure that they aren't the problem.

Put your nose near the hole that the capacitor wires come out through. Does it smell like someone let the magic smoke out? If so, It's time to take it to the motor shop to see if they can put the smoke back, or sell you a new motor.

Get a better blade for this purpose. Others have suggested this, and I agree with them.

Charley

[Rick Malakoff]

I have had 2 10'' contractors over the years 1974 -2008 and both sucked at ripping SPF 2x4's, we just went to the Skil 77 with a rip fence. Problem solved.
FWIW
Rick

[rudy de haas]

If you are working with fresh wood that has internal tension, and your riving knive (I believe that's integrated on these, but it's been some time since I have seen one) doesn't match the blade for thickness, it will cause the problems you describe because the wood will pinch the blade.

[Chris Glatz]

Just wanted to post a resolution in case anyone finds the thread through a search. I bought a riving knife and it didn't help (it's a worthwhile safety feature though), then I tried a cheap 24T blade and it made a world of difference. I assumed the 30T Freud rip blade was the best option, not for pine.

[Art Mann]

I used a saw similar to yours for decades. Contrary to popular opinion, that saw is perfectly adequate for ripping 2X4s if it is in good working order. Ont thing that helped me to compensate for the weaker motor is to go to a thin kerf blade. They require considerably less horsepower than a full kerf blade to do the same job.