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Speed Control Set Problem 1015 to 5193 rpm

#74453 by allsas » Thu Sep 09, 2010 3:04 am

I just pulled the idler shaft to check the idler sheave clip because I CAN'T get down to 750 rpm.

Previous set was 1045 - 5215. I thought that the sheave clip wasn't in the idler shaft groove. (Tachometer used to check setting) Clip was in the groove.

Ended today with 1015 -5193. Difference in upper speed was a change in the stop (setscrew - jam nut). I have no trouble moving / setting the indicator dial. When reassembled , the speed control knob moves easily from Fast to B+. B is 1016, C is 1068, D is 1190. At B+ the handle became hard to move and I didn't want to apply any more force.

I was careful to position Speed Control Assembly on headstock and tighten the three self tapping screws evenly. The spring steel clip strip of the quadrant is centered on the control sheave bearing. Speed Control Handle is close to Speed Control Dial , not canted on headstock.

I was able to get a 620 - 5000 range setting a greenie a week ago and thought that was GREAT, but can't get this goldie slowed down.

If it was EASY, I'd do it myself.


MK V 520; MK V 510 w/PP DIY Upgrade; MK 5 500; Jointer; Bandsaw; Sliding Table; Conical Sanding Disk; Sharpening Guide, Lathe Duplicator, Jigsaw, Scrollsaw, Beltsander, Ring Master, Biscuit Joiner.

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#74462 by Ron309753 » Thu Sep 09, 2010 10:03 am

One thing you may want to check are the teeth on the quadrant (porkchop). They can get boogered and make it hard to turn especially at low speeds. You can test it by removing the speed control and reattaching the handle. If it is difficult to move the problem is in the speed control. If not, look for another issue. If they are boogered I suppose you could take a small file and square them away.

Hope this helps!



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#74473 by beeg » Thu Sep 09, 2010 1:06 pm

[color="Blue"]Have ya done a speed adjustment yet?



how to do a high speed adjustment.PDF
(382.25 KiB) Downloaded 215 times


SS 500(09/1980), DC3300, jointer, bandsaw, belt sander, Strip Sander, drum sanders,molder, dado, biscuit joiner, universal lathe tool rest, Oneway talon chuck, router bits & chucks and a De Walt 735 planer,a #5,#6, block planes. ALL in a 100 square foot shop.


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Slowest Speed too Fast

#74500 by billmayo » Thu Sep 09, 2010 7:47 pm

I find that a badly used/worn V-belt or too long a V-belt will prevent reaching the slowest speeds.

Slide the belt cover away from the headstock and when setting the speed control dial/handle to its slowest (lowest) speed, check the location of the V-belt on the Control/Idler sheaves. The outside (back) of the V-belt should be even to 1/8" inside the Control/Idler Sheave tips.

Also in the slowest speed position, I use both hands to pull on the motor Floating Sheave (on each side) to see if it will move any more toward the end of the motor shaft. If it does, then the belt is too long and needs replacing. I find that lubrication of the Control Sheave and the motor Floating Sheave can help with reaching the slower speed settings.


Bill Mayo [url][/url]
Shopsmith owner since 73. Sell, repair and rebuild Shopsmith, Total Shop & Wood Master headstocks, SPTs, attachments, accessories and parts. US Navy 1955-1975 (FTCS/E-8)

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#74709 by allsas » Sun Sep 12, 2010 10:40 pm

The Poly V belt has the eccentric set at 9:00 , The V Belt is a Shopsmith Belt. It has a width of 1/2". The V belt does not appear to be worn or frayed.

At the slowest speed setting achievable, the V belt is almost even ( 1/64 in) with the top of the Idler/Control Sheaves. The Floating Sheave can be moved about 1/8" towards the end of the shaft.

I tuned up a Speed Control Assembly to make it easy to move the worm drive down the quadrant and off the quadrant gears. The quadrant gears and worm drive were lubed with wax and graphite. The original quadrant assembly had a low speed setting 1015, The tuned up quadrant was installed and high speed set at 5200, the low speed was 1017. The belt was even with the top of the Floating Sheave / Fan Sheave ( yielding a speed of 5200 (easily changed by setting the high speed stop, currently below the jam nut edge).

I'll have to try a different belt, as the other options have been tried. I have a 35 link Link Belt (green) and compared it as a 36 link belt to the two V belts and was convinced to recount the links and reduce it to a 35 link belt to match the V Belts.


MK V 520; MK V 510 w/PP DIY Upgrade; MK 5 500; Jointer; Bandsaw; Sliding Table; Conical Sanding Disk; Sharpening Guide, Lathe Duplicator, Jigsaw, Scrollsaw, Beltsander, Ring Master, Biscuit Joiner.

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#74712 by JPG » Mon Sep 13, 2010 12:29 am

Just for what ifs:

1) Forget you have a tach until after the 'last step' below.

2) With the ss v-belt installed, run the speed control up until the v-belt is about 1/8" below the od of the motor pulley(fan/idler sheave). If the top of the hs adj screw end is still below the top of the jam nut, you may need to back it out to get the v-belt into the position described above.

3) Adjust the hs adj screw to be even with the top of the jam nut. While turning the shafts by hand, determine how much further the speed control will adjust upward. If the belt and the sheaves are 'normal' the speed control should have moved a minimal amount, and the v-belt should now be no less than 0-1/16" below the od of the motor pulley.(more is ok) The speed control should NOT allow the control sheave to extend out on the idler shaft so far as to interfere(hit) it while rotating.

4) Assuming all is as described in '2', position the speed control outer ring to 'fast' position and reattach handle. Start the ss and adjust the speed to as low as it will go. It should stop at or slightly below 'slow'. The floating sheave should be near(or at) its extreme position(the belt fully into the motor pulley). Three things can affect the effective slow limit. The limit of travel of the idler sheave on the motor pulley and the limit of travel of the control sheave on the idler pulley or the speed control quadrant going past the end on the worm gear(not likely!!!).

You have mentioned the position of the v-belt on the idler pulley, and that can provide clues if all is not responding correctly. Not very meaningful normally.

Keep in mind the only adjustment is the high speed adjustment. That sets the upper speed limit of the control sheave. The indicator dial is set at that condition. The lower speed range is determined by the items mentioned above. All this is dependent upon a 26 1/2" v-belt that is near 1/2" wide at the outer surface. Normal belt wear will decrease the width and MAY cause the belt to stretch slightly. This wear is somewhat self compensating since the narrower belt will ride deeper in the idler sheave(speed increase), but also ride deeper in the motor pulley(speed decrease). Excessive wear can cause the v-belt to ride too far into the pulleys and can become jammed.

One way to check belt length is to mark the edge of the belt. Place that mark at the far end of the outfeed table on the jointer. Carefully roll the belt onto the table making sure the belt does not 'slip'. Continue rolling the belt(past the blades) and onto the infeed table. When the mark again touches the table, mark the table at that point. Measure the distance from the far end of the out feed table to the mark.

Last step!

Get the tach and measure the fast/slow speed. Do not be surprised to find it varies from 5200/700. It should however be close.


╟JPG ╢

Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10E(SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange

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Got it. 688 to 5371

#74748 by allsas » Mon Sep 13, 2010 6:40 pm

Thought I'd try JPG's suggestions before trying to replace the belt... Lowest speed I could get was 1017.

Pulled Speed Control Assembly and started pulling the belt. Since JPG volunteered the circumference of the belt, I thought I should measure the candidates:

35 link LinkBelt(green) 25 1/4
Used ShopSmith 25 3/4
Belt from Bonnie 27 no SS Markings, maybe that's why it has 4L270 label. I have two SS Belts here and this one must have joined the herd.?.

Put the SS 25 3/4" on and backed out the High Speed stop. to 5200. Then checked Speed at Slow =688. Oiled Dial Gear Idler, tightened the Speed Control Assembly Screws and install Speed Control Handle. Rechecked Fast - Slow Speeds. Thanks for the Help...... I'll try to keep my black belts out of groups or read the labels more carefully.

All the suggestions on worn (too long) belts we right. CLAP, I thought those belts were all SS and the same.


MK V 520; MK V 510 w/PP DIY Upgrade; MK 5 500; Jointer; Bandsaw; Sliding Table; Conical Sanding Disk; Sharpening Guide, Lathe Duplicator, Jigsaw, Scrollsaw, Beltsander, Ring Master, Biscuit Joiner.

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