weak MKVII motor

[lahola1]

"How about front to rear table alignment. This can also cause the blade to bind and can be confused with other symptoms."
If anything I could see a slight gap between the board and the fence at the back of the blade.

" If the windings get burned or scorched they will continue to function until the windings either short or open. If the motor is actually stopping I would suggest that you check for a loose connection at the main switch or the centrifugal switch in the motor"

Thanks, that's the kind of info I'm looking for.
If they are burnt, can they be repaired before it fails completely?

[JPG]

My $ is on the lack of a RIP blade.

The MVII switch is a possible culprit.

Did you replace the poly-v belt with M5 belt or the wider MVII belt?

Scorched enamel insulation will not make a motor weak. Burnt/shorted is another matter entirely.

[lahola1]

Replaced poly v with the M5 belt.

[JPG]

Replaced poly v with the M5 belt.

9 rib vs 13 rib.

Ya need to determine if the belt)(s) slip or the motor stalls.

I think stalling the motor will cause cb to trip.

[lahola1]

"Scorched enamel insulation will not make a motor weak. Burnt/shorted is another matter entirely.
The MVII switch is a possible culprit"

JPG, So what you are saying is there is no such thing as a "weak" motor internally (electrically; possible bearing problem). If it's electrical, it's a resistance issue upstream; switch contacts, connections, frayed wires?

[JPG]

There MAY be connection issues internally as well, but not likely since all connections are crimped(or soldered if old). Once up to speed start circuit(switch capacitor, winding) becomes irrelevant.

Slip on line cord connectors also.

[RFGuy]

So, if you open the headstock cover, there is no whiff at all of burnt rubber? I still wonder if it couldn't be a belt slipping, but if not I would think it has to be an intermittent electrical issue as JPG mentioned.

Also, your post does make me wonder, e.g. how a Mark V compares to a similar HP tablesaw for ripping performance. I believe the Rigid 2412 has a 1.5HP motor, but your 1980 Mark V only has a 1-1/8HP motor, right? Of course, the Mark V has a variable speed transmission and we don't really know how much transmission loss there is in the sheaves, so I do wonder if you would see a noticeable difference in power when ripping between the two? The Ridgid probably has at least 50% more power reaching the blade than your Mark V. I have only used my Mark V for the past few decades and the last time I used another tablesaw was a Sears model my Dad had before his Shopsmith. So, I have no frame of reference really. Perhaps you notice a difference between the two because there is a real and noticeable difference, i.e. at the same feed rate your Mark V bogs down whereas the Ridgid does not. The corollary to this is I have heard others report a noticeable difference in sawing on the PowerPro (1-1/8HP vs. 1-3/4HP), so a half HP either way is likely noticeable.

[algale]

I believe the Rigid 2412 has a 1.5HP motor, but your 1980 Mark V only has a 1-1/8HP motor, right? Of course, the Mark V has a variable speed transmission and we don't really know how much transmission loss there is in the sheaves, so I do wonder if you would see a noticeable difference in power when ripping between the two? The Ridgid probably has at least 50% more power reaching the blade than your Mark V.

Define "power" in this context. Slow the Mark V down a bit and you'll increase the torque at the saw tooth well above anything the Ridgid can generate. Feed rate may need to be slowed.

I'm putting my money on improperly tensioned belts or twisty 2x4s. ("No, I will not be jointing my 2x4's to make construction 2x2s.").

[RFGuy]

Define "power" in this context. Slow the Mark V down a bit and you'll increase the torque at the saw tooth well above than anything the Ridgid can generate. Feed rate may need to be slowed.

I'm putting my money on improperly tensioned belts or twisty 2x4s.

Alan,

Your argument is that the variable transmission (sheaves) provide more torque at the blade than the Ridgid, is that correct? Well, I have never seen any torque curves or related specs for the Mark V so I have nothing to go on here. We know that the Ridgid 2412 has a motor rated for 1-1/2HP and the Shopsmith has a 1-1/8HP motor, but how much torque, power, etc. do you get to the blade for both? The Ridgid has transmission loss through a belt, one set of pulleys and friction. I would argue that the Mark V has more transmission loss with the sheaves and two belts, but I don't think we have any data on it. I also think about it in terms of automotive, e.g. your restored muscle car may have 1000HP under the hood but until you Dyno it you don't know how much of that power & torque is getting to the rear wheels. Similarly, I am just wondering how much power & torque is reaching the sawblade for the Mark V versus this Ridgid 2412. Anyone want to setup a Dyno to measure their Mark V and report back to us?

P.S. IF Shopsmith had published power and torque curves for the Mark V and Mark 7, I might have already purchased a PowerPro by now!

[lahola1]

JPG wrote:"I think stalling the motor will cause cb to trip"
I guess I would agree with this, so now I'm leaning towards you guys are saying about belts slipping. With my hearing aids turned off and hearing protection on what I was hearing could be belt slipping instead of motor stalling

RF GUY, I took the cover off and smelled the ploy v belt. Could only detect a faint rubber smell; not nesessarly burnt rubber.

Now your 2nd comment is getting to my 2nd question; mechanical power loss and apples and apples.
Which is more accurate; amp rating (13a vs 14a for ridgid) or HP rating (1 1/8 vs 1 1/2).
Yes, and how much transmission loss is in the SS? That's the question. I could turn the SS speed down to get more torque but my experience from the other day I think the blade would be turning pretty slow. So I would say that if the amp ratings are correct , then there is considerable transmission loss in the SS but if the HP rating is correct and you say there is 50% more power in the ridgid, then not so much transmission loss in the SS.