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Mark 5 fixup

Posted: Thu Jan 08, 2015 10:06 pm
by JPG
Over here http://www.shopsmith.com/ss_forum/viewt ... 2&start=40

a discussion has been taking place as a new member attempts to get his Mark 5 up and running

He has a broken control sheave loop, and a control sheave stuck in slow.

The belts appear good and he does not want to destroy them.

He has suggested that he may need to take take the floating sheave off the motor.

So my initial reply is:

No you do not want to take the floating sheave off. That is quite difficult enough with the belt already removed.

Since the control sheave seems to be 'stuck', the approach I would take, is to first remove the speed control. The knob has a small set screw that is a bit of a challenge to locate, then loosen. After removing the knob, there are three screws that secure the speed control to the headstock casting. One has a leaf spring attached(upper right). Remove those three screws and since the loop is disconnected from the porkchop, the speed control should now be removable.

The hole under the speed control is quite small on an "A" headstock, but it does give you access to the control sheave. Penetrating oil and gentle prying may allow the control sheave to move away from the idler sheave and possibly off the inside end of the idler shaft.

That will allow the floating sheave on the motor shaft to close, or provide slack for the belt so it can be taken off the motor pulley.

That will allow you to remove the motor pan/motor. The idler shaft can be removed towards the front of the headstock(goes IN). There is a screw that squeezes the casting around the idler shaft bearing, and a set screw that holds the eccentric to the bearing. With the screw loose, the eccentric can be rotated to slack the internal belt(Gilmer or Poly-v). The set screw can be accessed through the slot under the bearing.

Nuf fer now! ;)

Re: Mark 5 fixup

Posted: Fri Jan 09, 2015 12:02 am
by DMcCam
Hi JPG, I can't thank you enough for your generous help with my Mark 5. I actually removed the speed control earlier today and as suspected, the whole lot needs replacing. Like you said, there's not much of an opening on this model but it does help a lot.

I'll try the penetrating oil direction tomorrow... I would assume you try and not get any on the belts, correct? If you do, what's the best way to clean it off them.

I'm mechanically inclined but not experienced in restoring machinery.

In Gratitude,

Dave

Re: Mark 5 fixup

Posted: Fri Jan 09, 2015 11:02 am
by JPG
Getting penetrant on the belt may be a given.

Any degreaser(dish washing detergent) should clean it up.

Make sure the penetrant is just that.

Kerosene, pbblaster, kroil, but not wd40.

Re: Mark 5 fixup

Posted: Fri Jan 09, 2015 1:22 pm
by DMcCam
Thank you for saving my belts JPG, I would have used WD40. I'll go get PB Blaster.

Hi Guys,
Thought it was about time to show the project ahead.
M5_01.jpg
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Here's the M5 as it stands this morning.
M5_02.jpg
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This shot shows the floating sheave spring and retaining nut. I'll need some help on the best way to remove this version.
M5_03.jpg
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M5_03A.jpg
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Here you can see a closer look at the old repair of the drive sleeve ears. Not pretty but they appear to have worked.
M5_03B.jpg
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These little bearing retainers were between the ears. Look to be original to the machine.

M5_04.jpg
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This shot shows why the Speed Control Handle will need replacing.
M5_05.jpg
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The teeth on the Speed Control Dial are pretty soft. Not sure if it needs replacing…
M5_06.jpg
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You'll see in these next pictures why I think the entire Speed Control unit will need to be replaced.
M5_07.jpg
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M5_08.jpg
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More to come. Thank you Gentlemen for your help.

Re: Mark 5 fixup

Posted: Fri Jan 09, 2015 1:54 pm
by beeg
For the speed control you might consider this.

http://www.ebay.com/itm/HOP-MITH-MARK-V ... 1656884163

Re: Mark 5 fixup

Posted: Fri Jan 09, 2015 8:30 pm
by DMcCam
Thank you Bob, He wants $21. for his and SS sells a new one for $29 although not with his stainless teeth. Do the factory Speed Control Handles break very frequently? I'll have to think about this one.

Bad news, the control sheaves are not moving after PB Blaster. Looks like the best solution is to take out the motor. What is the best way to remove the nut without it going balistic with the spring?

All the Best,

Dave

Re: Mark 5 fixup

Posted: Fri Jan 09, 2015 8:41 pm
by beeg
replacing the motor spring. PDF
Maybe this well help?


Re: Mark 5 fixup

Posted: Fri Jan 09, 2015 9:20 pm
by JPG
DMcCam wrote:Thank you Bob, He wants $21. for his and SS sells a new one for $29 although not with his stainless teeth. Do the factory Speed Control Handles break very frequently? I'll have to think about this one.

Bad news, the control sheaves are not moving after PB Blaster. Looks like the best solution is to take out the motor. What is the best way to remove the nut without it going balistic with the spring?

All the Best,

Dave
Fergit the price difference - his will outlast the mother ships one. You will not get 'yours' back unless you request it. If not you will get the replacement almost immediately(snail mail speed both ways).

Yes the gears strip all too often. The mating gear is steel. The original gears are aluminum. That said, mine is 60 yrs old and not stripped. If you do not force the speed control knob, the gears last. FWIW I would always go with the rebuild.

Think through the procedure from Beeg, but it includes switch removal etc. Ok since you will likely need to do that anyway. The nut is indeed a left hand thread. The board with a hole is not well described, but you will figure it out. The board allows depressing/holding the spring and releasing it slowly after the nut is removed. One end slips under the casting and you press on the other(long) end. Since you have an "A" headstock, the short end dimension may need to be different. Putting that nut back on may be a challenge - just persevere!

Re: Mark 5 fixup

Posted: Mon Jan 12, 2015 12:32 pm
by shopsmithpaul
Dave, if I may put in my 2 cents worth. Depending on the condition of your bearings and how far along you are you might just consider upgrading to a poly v belt and double bearing quill. That also would give you a new control sheave shaft and bearing. There would be an expense but I think it is worth it. The double bear quill adds a lot of stability. You might ask the forum what others think. I will not be offended if there is disagreement with my suggestion. Keep working with it.

Re: Mark 5 fixup

Posted: Mon Jan 12, 2015 1:08 pm
by DMcCam
shopsmithpaul wrote:Dave, if I may put in my 2 cents worth. Depending on the condition of your bearings and how far along you are you might just consider upgrading to a poly v belt and double bearing quill. That also would give you a new control sheave shaft and bearing. There would be an expense but I think it is worth it. The double bear quill adds a lot of stability. You might ask the forum what others think. I will not be offended if there is disagreement with my suggestion. Keep working with it.
Hi Paul, I may not have an option but to upgrade. Here's a picture of my gilmer dive shaft. The bearings move very well but belt has worn a low spot in the gear with the belt frayed on the edges. Not looking good here.
M5_11.jpg
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The quill moves a lot inside the outer sleeve even though the bearing feels tight and smooth.

One good thing is that the motor runs very well and the idler Sheave moves freely. Is this motor original?
M5_10.jpg
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Inside it looks a little grungy. The belts have thrown bits to the walls. We'll see how things clean up.
M5_12.jpg
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Oh, I bought the refurbished Speed Control Knob from eBay! First purchase for the restore! :)