How much power should I expect?

[DLB]

...I believe the poly V was tensioned at like 1/8" deflection when pushed with a finger and the "motor" belt was well over 1/2" deflection (hence the slip). Correct me if I am wrong, but isn't the rule of thumb to tension the "motor" belt to no more than 1/4" deflection? So, I went about adjusting the "motor" belt until I got to 1/4" deflection but at this point the poly V deflection was I don't know how much. Let's just say it was tight, much tighter than 1/8" deflection at that point. I finished my cuts without binding and ordered new belts. Even with new belts after this, what I have noticed is that my Mark V always has much larger deflection on the "motor" belt than on the poly V belt. The problem, as I see it, is there is no independent way to adjust belt tension on the poly V belt relative to the "motor" belt. Is all this normal, or is it possible that something is wrong with my Mark V since I can't get what the expected tension is on both belts with the eccentric adjustment alone?

I'm fairly certain that the only thing tensioning the motor belt when running is the spring on the end of the motor shaft (conventional headstock only). When you change speed, moving the control sheave, it either increases or decreases the tension and the floating sheave moves in response to balance the tension. The motor belt always seems to have low tension because if you press on it you will compress the spring. There is no procedure in the manual for tensioning or checking motor belt tension on the conventional headstock that I've ever seen. The eccentric adjustment is only for the upper belt tension.

It's different in the PowerPro. Both belts are under tension. So turning the eccentric will tighten one belt while loosening the other.

- David

[RFGuy]

I'm fairly certain that the only thing tensioning the motor belt when running is the spring on the end of the motor shaft (conventional headstock only). When you change speed, moving the control sheave, it either increases or decreases the tension and the floating sheave moves in response to balance the tension. The motor belt always seems to have low tension because if you press on it you will compress the spring. There is no procedure in the manual for tensioning or checking motor belt tension on the conventional headstock that I've ever seen. The eccentric adjustment is only for the upper belt tension.

It's different in the PowerPro. Both belts are under tension. So turning the eccentric will tighten one belt while loosening the other.

- David

David,

Thanks. I am confused then. Adjusting the eccentric tighter did raise belt tension on my "motor" belt. IF the sheave spring is the only tension adjustment on the "motor" belt, then that implies that it was poly V belt slipping that caused my binding before, but why wasn't 1/8" (or less) belt tension sufficient for it to not bind in hard 8/4 cherry? I didn't measure deflection after tightening, but by eye it was very, very taut (much, much less than 1/8"). Tightening the eccentric fixed it for this one case. I know only one instance, but still trying to make sense of what I remembered with how the machine is supposed to work. I know you guys have A LOT more experience in this area, so just trying to learn here with my ?'s.

[JPG]

The eccentric adjusts poly-v or gilmer belt tension only. Any resulting change in motor belt tension will be removed once the pulleys are rotating by the floating sheave/spring which determines motor belt tension.

All this ONLY applies to NON Power Pros headstocks. The Power Pro eccentric adjustment attempts to equalize tension of both belts.(AIUI)

[RFGuy]

The eccentric adjusts poly-v or gilmer belt tension only. Any resulting change in motor belt tension will be removed once the pulleys are rotating by the floating sheave/spring which determines motor belt tension.

I am confused then because I still had "good" tension on the "motor" belt after that eccentric adjustment. I mean I checked it more than once after it ran, so if the spring tension was supposed to move the "motor" belt back to the lax setting, this didn't happen after my eccentric adjustment. I have already eaten up too much of this thread and distracted from solving the OP's problem, so I will step out of the convo for now. Just wish I could explain what I have seen in the past.

[robinson46176]

Am I missing something here? We seem to be talking about both "slipping" and "stalling" which are two very different things. If the discussion is "stalling" then did I miss the part where the shop wiring was discussed concerning such factors as it being possibly:
1. Too small of wire?
2. Too long of a run?
3. The whole electrical service possibly already near its limits?
4. How many times has this motor been "stalled" including by the previous owner? Is there a chance that some of the important smoke leaked out?


.

[JPG]

WE were gonna get around to the house power part as soon as WE got off the slipping part.

Since he has a 3/4 hp motor, motor stalling is a distinct possibility which could be caused by those things you just mentioned.

You are correct that if the motor is stalling then all this belt conversation is moot.

As usual fer me I tend to try to cover all the bases for reference later by souls who are experiencing similar tribulations.

The 3/4 hp motor/low housepower is de reason for the turn speed down before shutting off mantra(one of the reasons).

[robinson46176]

Here is a wee thought to chew on for a minute... We have long been taught to operate a table saw with the blade extending only about 1/8" up through the wood. That is great for saving blood and fingers etc. but it is power sapping. At that depth far more of the blade circumference is in contact with the wood. If you run the blade up high (with a guard) far less of the blade circumference contacts the wood and the gullets don't get as full.
Note that I am not saying to do that, just that it is a factor in load. If you want to better understand a table saw pick up a handsaw and play with it on some scraps.

.

[HopefulSSer]

Am I missing something here? We seem to be talking about both "slipping" and "stalling" which are two very different things. If the discussion is "stalling" then did I miss the part where the shop wiring was discussed concerning such factors as it being possibly:
1. Too small of wire?
2. Too long of a run?
3. The whole electrical service possibly already near its limits?
4. How many times has this motor been "stalled" including by the previous owner? Is there a chance that some of the important smoke leaked out?

Thanks for the additional thoughts!
1. SS power cord (original? it does seem perhaps a bit small) plugged directly into the wall socket. Wiring panel to socket is 14/2. Probably wouldn't be the worst thing to replace the current power cord with something a size larger.
2. SS power cord is maybe 8' max. I haven't measured it. Direct distance from socket to panel is ca. 20'. Double that at least for wire length (up the wall to the attic, across, and back down).
3. 15A circuit with only a few low-power consumers on it (a Raspberry Pi 4 and a few pieces of networking gear. Other stuff is plugged in but if it's turned off it doesn't count ). There's also a 20A circuit (12/2) in the garage but I'd have to run an extension cord to reach it so no net gain there.
4. No idea! All the smoke appears present but I haven't counted it.

Cheers!

[lahola1]

My Mk V is an earlier one with the 3/4 hp motor. I know later they uprated the motor to 1.125 hp which implies to me that mine will be somewhat underpowered. But how underpowered?

I'm finding that with a combination blade installed (freshly sharpened in 1992 per the sharpie marker on it, but it seems little used since then) and trying to rip a soft pine 2x4 in half, I can very easily stall the motor unless I use a painfully slow feed rate, much slower than I would use on my grandad's old Rockwell table saw. I tried some JPW on the blade -- that helped a little but not much. Does this sound typical? Am I getting all that I should expect from it?

HopefulSSer -Not meaning to change the trane of thought this thread has gone but getting back to your original post and my experience with the same problem. I've done general woodworking for 50 years with full size tablesaws (Craftsman, Ridgid) and never had bogging down problems trying to rip 2x4s with combo blades ( I've never had a rip blade until 2 months ago). Then I recently (2017) got a SS with a 1 1/8HP motor and recently tried ripping a 2x4 for the 1st time and immediately had bogging down problems. After discussing it here I finally got a rip blade and had no more bogging problems on my SS.
So I concluded: 1. Get a rip blade; it should solve your problem.
2. The SS is a totally different animal. there appears to be considerable power loss (transmission loss) in the SS variable speed power system compared to the typical full size table saw with comparable 13 amp motors.
I'm not saying it's a worse machine; just different. It's got it's advantages and disadvantages that I'm still learning about.

[dusty]

My Mk V is an earlier one with the 3/4 hp motor. I know later they uprated the motor to 1.125 hp which implies to me that mine will be somewhat underpowered. But how underpowered?

I'm finding that with a combination blade installed (freshly sharpened in 1992 per the sharpie marker on it, but it seems little used since then) and trying to rip a soft pine 2x4 in half, I can very easily stall the motor unless I use a painfully slow feed rate, much slower than I would use on my grandad's old Rockwell table saw. I tried some JPW on the blade -- that helped a little but not much. Does this sound typical? Am I getting all that I should expect from it?

HopefulSSer -Not meaning to change the trane of thought this thread has gone but getting back to your original post and my experience with the same problem. I've done general woodworking for 50 years with full size tablesaws (Craftsman, Ridgid) and never had bogging down problems trying to rip 2x4s with combo blades ( I've never had a rip blade until 2 months ago). Then I recently (2017) got a SS with a 1 1/8HP motor and recently tried ripping a 2x4 for the 1st time and immediately had bogging down problems. After discussing it here I finally got a rip blade and had no more bogging problems on my SS.
So I concluded: 1. Get a rip blade; it should solve your problem.
2. The SS is a totally different animal. there appears to be considerable power loss (transmission loss) in the SS variable speed power system compared to the typical full size table saw with comparable 13 amp motors.
I'm not saying it's a worse machine; just different. It's got it's advantages and disadvantages that I'm still learning about.

Yes, the Shopsmith is a different animal but I don,t follow the logic that concludes power loss in the variable speedn system. The drive line is nothing more that a "pulley arrangement". Set at mid-range (L/M on the speed dial) the shafts are turning at the same speed (3450rpm) and the pulleys 1:1. Where is there power loss that does not exist in any equivalent 1:1 pulley set up.
'
Don't think of the speed control as a variable. At any speed position the pulleys are set as some ratio and are "fixed".