Well.... Another "new" greenie

[dlbristol]

I am leaving the house right now to go look at a "very old" Mark V. It was on Ebay, did not sell and I could not get to see it before the end of the auction.
I called later, still available. I have my upper limit in cash, so I can't get in trouble with the management/ accountant. I don't know what I'm going to do with it yet, but if it is in reasonable shape I will grab it, and then I will see.

[billmayo]

I don't have this model headstock so I can't check myself but is there enough room to drill and tap for a screw without weakening the casting?:eek: I think I would fabricate some sort of a clip.

In the attached photo, notice that the casting has been beefed up somewhat and that there is a pad that has been developed for the top screw. This pad area is also visible in the images of the casings that Mike posted.

The screw located at 7 o'clock is in the eccentric. I had not noticed this before. This screw appears to limit the inward motion of the eccentric while the other screw limits the outward motion.

[ATTACH]8381[/ATTACH] [ATTACH]8382[/ATTACH]

You will notice in the bottom picture that the washer does not stop the bearing from coming out the back of the headstock, only the eccentric bushing. I have been using #8 body washers drilled for the #10 screw to secure both the eccentric bushing and the bearing from working their way out of the headstock. If you over tighten the eccentric set screw, if any, the bearing can make a clicking noise. So when only tighten just to hold the bearing, the set screw can work loose in the eccentric and cause the idler shaft to work it way out the back of the eccentric if the washer does not stop the bearing. This also destroys the upper belt and can cause the motor belt to hang below the tips of the control and idler sheave. This will destroy the motor belt and the motor belt can jam the idler shaft. The latest eccentric bushing is cut at the thinest part with no set screw and has the screw to prevent the eccentric bushing from going into the headstock when assembling the headstock.

I have found this problem on a few of the older Mark Vs. I have never see any example of the eccentric or bearing going into the headstock as the motor belt always keeps pressure on the idler sheave, therefore the idler shaft and bearing.

Yes, I throw away the early Greenie clips that holds the eccentric bushing and drill and tap for a #10 screw above the eccentric bushing. I find the clips keeps the upper belt from aligning with the drive sleeve belt pulley in most cases.

[JPG]

Dusty: You make a relevant point. I was echoing what Bill Mayo has described elsewhere.

Does the eccentric have the pointy set screw that secures the bearing in the eccentric by way of a groove in the bearing?

I will post pix of retainer later today!

[JPG]

Dusty; Thje 'pointy set screw' I was referring to is in the thicker part of the eccentric and the end retains the bearing by going into a groove around the middle of the bearing. This screw can cause problems if over tightened. Though I have not encountered it, I can see Bill's point about it being too loose. It is not visible with the bearing/eccentric set when in the bore(unless it is rotated such that the setscrew is directly under the slot that the bolt squeezes).

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[dusty]

Dusty]8385[/ATTACH]

So are you saying that I have a set screw (in the eccentric) that I may never see unless I either rotate or remove the eccentric from the casting? Another way of asking: Do all eccentrics have this set screw?

Notice on the images I posted to this thread that my machine has two screws; one at high noon and one at 7 o'clock. Might it be that in some machines the combination of these two screws (with washers) serve the same purpose?

[JPG]

[quote="dusty"]So are you saying that I have a set screw (in the eccentric) that I may never see unless I either rotate or remove the eccentric from the casting? Another way of asking: Do all eccentrics have this set screw?

Notice on the images I posted to this thread that my machine has two screws]

See post 42(Bill Mayo). From that, I believe you do not have the set screw, since you do have the '7 o'clock' screw!

[dusty]

See post 42(Bill Mayo). From that, I believe you do not have the set screw, since you do have the '7 o'clock' screw!

Thanks for calling my attention back to Bill's post. I had read that but I misread and was somewhat confused (thinking he had said 'set screw'.

[JPG]

Idler bearing eccentric 'KEEPER' pix!


First is the retaining clip(which ss refers to as a keeper).
[ATTACH]8386[/ATTACH]

Next shows the outer arm length. It will prevent the bearing from drifting out the back. The small arm on the other end will prevent the eccentric from drifting into the headstock.
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Next shows it all assembled.
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Notice this makes the assembly proud of the casting(an early sandcasting).

For purposes of accuracy, note that the idler shaft is a poly-v version.

As for the eccentric set screw coming loose, it should be long enough that the inside of the bore prevents the tip from coming completely out of the groove in the bearing. I defer to Bill's experienvce that says they come loose. If the set screw is aligned with the bottom of the bore, it could come out, but that position is unlikely even with a new belt(eccentric set for minimum separation from idler to main shaft.

[dusty]

Is that two 'keepers' that I see. Is this the standard assembly?

The old castings are a lot rougher than I thought. Maybe I have to quite complaining about how rough my table castings are (were). I used the conical disk and did some edge sanding on most of my tables to get rid of the rough edges left by the molds. Now I have to get around to painting them. Hmmm...good job for while I am still on this weight lifting restriction.

Thanks for the photos, JPG. That cleared things up for me.

[JPG]

I believe ONE keeper is 'standard'. I recently acquired the casting, and it had two! I am keeping them on the casting so I won't 'misplace' them.

MIKE: What does yours look like?????