Thread: TC-12 Older table saw, new motor

I've heard and read about phase converters that are now quite cheap that will convert single phase to 3 phase.....might be better option to do this and keep your 3 phase motor??

im sure someone else with more knowledge can jump in and confirm....

cherrs

Using a single to 3 phase converter. Good idea, but the price is too high to justify. This way I get a good understanding of what's in the cabinet, how to clean and maintain the saw action, a brand new motor all for approx $500.00. The saw only cost $660.00 and after I've sold all me Triton gear I should be well ahead, Murphys Law not having come into play yet.

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It would appear that swapping the motor out won't be too difficult. Just a couple of bolts. My only concern is the large box that generally sits on the top of the single phase motor. When installed it will be on the bottom. Will it hit the far side of the cabinet when the blade is rolled over to 45 degrees? I'll let you know after the weekend.

Depending on the configuration of the existing motor, you may be able to retain it and drop in a VFD to convert to 3 phase. This is basically a box of set and forget electronics that can mount anywhere on the saw frame or nearby wall. The saw motor 3 phase wiring goes direct to the VFD outputs, and a 240 mains cable goes to the input of the VFD. Motor stop and start is controlled remotely by low voltage switching at the VFD, but the original switches may be able to be used if rewired to suit.

Only issue is motor suitability, must be able to be reconfigured for 240V/415V operation. This involves opening the cable termination box on the motor and repositioning 3 jumpers if the motor can be reconfigured. Look for dual voltages listed on the motor data plate. If it only lists 415V then the motor is not directly suitable, but may be able to be modified reasonably cheaply.

Check ebay for prices etc for VFD, I found a 3KW/4HP unit listed from a regular supplier for $188 delivered, you might be able to do better with a bit of effort, particularly if the motor power is under 3HP and you can go for a smaller unit. No mucking around trying to match shaft sizes, pulleys, motor footprints, motor speeds, avoiding clashing with the saw frame etc, and probably cheaper to have a sparky install/wire than do single phase rewire with new direct acting switchgear. The unit mentioned will operate happily from a 15A single phase outlet with motors to about 3.5HP, no worry about start surges etc as the unit will soft start the motor over a couple of seconds to limit the surge current.

Hi Malb,
Thanks for that info. The existing motor is 10 years old and the plate only shows 415. Also, because the power side of this is so far outside my knowledge/comfort zone, I am progressing down the plan A path. I have ordered a 3 hp single phase motor with accompanying 3 belt pulley from Royce Cross. At $250.00 it seems to be the simplest solution.

I asked RoyceCross for a set of mounting specs and they arrived very quickly. With re-using the existing pulley in mind I scanned the specs looking for a 25mm shaft but it was not to be. It's fair to assume that any pulley you pull of an older motor probably won't match some of the newer ones. Expect to need to order a matching one for 3 V Belts.

I was horrified when I removed the faceplate to the On Off switch. Somehow it had accumulated a significant coating of sawdust and quite a pile in the bottom of the box. Guess it wasn't as sealed as it looked. If you have an older machine it's worthwhile checking for.
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I'll update on the re-assembly process after I've received the motor.

Originally Posted by Petrel

I was horrified when I removed the faceplate to the On Off switch. Somehow it had accumulated a significant coating of sawdust and quite a pile in the bottom of the box. Guess it wasn't as sealed as it looked. If you have an older machine it's worthwhile checking for.
I'll update on the re-assembly process after I've received the motor.

Petrel, Happy for you to go the single phase route if you you feel that's where you wanted to go. Just wanted to point out that the VFD may be cheaper if the motor was directly compatible.

I think you will be up for a new switch system, three phase units generally are configured to require the three phases to be present to work, and you will only have a single phase available.

The sawdust in the switch housing is not a real hazard with that switch as the switching contacts are reasonably enclosed, the material is nonconductive while dry, and there is not a huge amount inside. Some of the contactors on our metal polishing machines could accumulate a similar amount of fine conductive metal dust in a couple of days work, standard maintenance was to blow them out at least twice a day (after unplugging) to ensure that it did not accumulate to a dangerous level.

Malb - I just thought I'd be thorough. Check this out...
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You comments on the wiring/switch are spot on. The old motor wiring will have to be removed and fresh connections to the new motor and a new switch installed. I did everything to date in the back of my box trailer, so later this week I can take the unit to the sparky, not the other way around. I should be able to finish this up on the w/e so will post a single story with costs and conclusions in case anyone else is interested in this particular path.

How did this go in the end? Am busy doing the same (3ph to 1ph conversion) to my tc12...just waiting on the new motor to turn up, to see if capacitor block on top allows 45deg inclination; may have to get grinder out if not/

Was hoping to do the wiring for new switch myself by reverse tracing the wiring on my band saw magnetic switch...was it particularly hard in the end? Found the following link which may he helpful:

http://www.askthetrades.co.uk/cgi-bi...m=1325979404/0

Cant afford sparky, so needs must when the devil drives...

Anyway, be good to hear how things turned out....

Originally Posted by yourmomm

How did this go in the end? Am busy doing the same (3ph to 1ph conversion) to my tc12...just waiting on the new motor to turn up, to see if capacitor block on top allows 45deg inclination; may have to get grinder out if not/

Was hoping to do the wiring for new switch myself by reverse tracing the wiring on my band saw magnetic switch...was it particularly hard in the end? Found the following link which may he helpful:

http://www.askthetrades.co.uk/cgi-bi...m=1325979404/0

Cant afford sparky, so needs must when the devil drives...

Anyway, be good to hear how things turned out....

It all turned out well in the end. I have a 2.2kw motor (12.5amp) on a 15 amp circuit. If the sparky wires it up it'll have a 15 amp plug on it.
I found that it was much quicker to have a sparky do the wiring. Be certain of the direction of rotation, before installing. Dumbo here got it wrong.

Align the table top carefully when re-installing. Be sure you have the largest blade you can use mounted on the saw and when you replace the top, wind the saw blade to it's highest setting. Make sure the blade can't impact the castings that support the insert when you're aligning the top.

All up I spent $600.00 on the saw table, $250.00 on the motor $250.00 on the sparky. I bought a TS LS system in from the US so am a very happy camper.
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and Yes the lamp is in the way, it's only temporary.