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Posted: Tue Dec 07, 2010 12:44 pm
by mickyd
ddvann79 wrote:Thanks, Mike! I hope you didn't draw up that illustration just for me! That's exactly the kind of thing someone as dense as me needs.

Mike, I think Magna may have used "metalic drive screws" of differing hardness between the 10er and Mark 5. The rivets in my headstock were definitely steel but they were soft. I got out to the shop last night and proceeded to drill them out before I read your post. :o

....
That was a custom print I want you to know. Three hours design time, 2 hours design validation, documentation review board....... scheeze!! :D

Glad you managed to get the drive screws out. Are they magnetic? Current ASME spec calls out material to be either stainless (aka drillable) or hardened steel or "as mutually agreed upon by the manufacturer and purchaser".

Posted: Tue Dec 07, 2010 12:49 pm
by mickyd
ddvann79 wrote:Here's how the table gauge turned out after peeling off the paint from the scale with a razor blade. What's that about imitation being a form of flattery, Mike? :D

[ATTACH]11159[/ATTACH]

I'm starting on some Christmas presents for the wife this week and much to my dismay, I don't have the Shopsmith back together, as I had expected. This project is taking much longer than I had anticipated but has been one of the most enjoyable I've had in a while.
Paint looks great Dalton. Nice texture.

Posted: Tue Dec 07, 2010 4:56 pm
by ddvann79
dusty wrote:I painted over the original "rough gray" texture. This worked and I like the color I chose. Guess it could have been a lot worse.[ATTACH]11164[/ATTACH]
I like that texture on your carriage, Dusty. Was that done with the Hammered Silver? Maybe it was a bad batch?

Posted: Tue Dec 07, 2010 5:13 pm
by dusty
ddvann79 wrote:I like that texture on your carriage, Dusty. Was that done with the Hammered Silver? Maybe it was a bad batch?

Thank you. Rustoleum calls the color "Dark Bronze 7218". The texture that you see here is, I believe, the texture of the original paint. I did not strip or sand before painting. Without good light, it appears to be black. In the sunlight it appears to be a dark gray.

Correction: The carriage was sanded smooth. I regret that now but it was an eBay item and the surface was really gross. Something had been spilled on it and the residue was sorta tacky and discolored. I might have been able to retain the texture but I did not think that through. At the time, I did not have any of the other parts.

Threaded Steel Rivets

Posted: Wed Dec 08, 2010 9:41 am
by ddvann79
mickyd wrote:Glad you managed to get the drive screws out. Are they magnetic? Current ASME spec calls out material to be either stainless (aka drillable) or hardened steel or "as mutually agreed upon by the manufacturer and purchaser".
The rivets are attracted to a magnet. They are also fairly untarnished. I'm guessing it's a basic steel that might be stainless. A quick internet search indicated magnetism of stainless has something to do with the nickel content and to a lesser degree, chromium. I don't know much about alloys.

Posted: Wed Dec 08, 2010 3:49 pm
by mickyd
ddvann79 wrote:The rivets are attracted to a magnet. They are also fairly untarnished. I'm guessing it's a basic steel that might be stainless. A quick internet search indicated magnetism of stainless has something to do with the nickel content and to a lesser degree, chromium. I don't know much about alloys.
They're probably steel, maybe zinc plated if they aren't rusting. 400 series stainless (400 series = no nickel content) is magnetic but I've never heard of that series of steel being used for drive pins. 300 series stainless is used from drive pins but 300 isn't magnetic (300 series = ~18% chrome and ~8% nickel). Now you gots material schmarts too. :D

Quadrant Assembly Wear

Posted: Sat Dec 11, 2010 11:24 am
by ddvann79
I started cleaning up the pork chop last night. I initially thought it was in good shape but once I got all the sawdust cleaned off and began putting the screw through its paces, I am a little concerned. The Quadrant Assembly rack teeth are pretty worn, and on one side at that. The drive screw (worm control shaft) is much harder than the cast aluminum so it dug in.

This shot illustrates what I'm trying to describe.

[ATTACH]11190[/ATTACH]

The screw turns freely though about 2/3 of the range but it begins to bind about the position shown in the picture below. It takes some wiggling to get any more movement out of it but once it passes that first bind it does OK until it reaches the about the same point in next revolution.

[ATTACH]11191[/ATTACH]

Looking back through my photos, I believe this position corresponds with the slow end of the speed range. I cleaned up the "squeeze out" edges in the aluminum with a micro file but it doesn't move any better.

1. Is this the normal position the worm screw would stop at the low end of the range?
2. My gut tells me I should go ahead and replace the quadrant assembly but do I need to?


I'm also wondering if this condition might have something to do with the problem tsaguy was having.

Posted: Sat Dec 11, 2010 12:37 pm
by beeg
Listen to your gut, replace it.

Speed Control Quadrant Mod

Posted: Sat Dec 11, 2010 3:32 pm
by billmayo
I have been replacing the quadrant roll pin with a bolt, star washers and nylock nut when installing a reconditioned or new quadrant for many years now. A lack of oiling the Control Sheave is normally the cause for abnormal teeth wear and a bent leg on the Speed Control Bracket. Contact me for information, instructions and pictures. Thanks.

[ATTACH]11193[/ATTACH]

Posted: Sat Dec 11, 2010 5:20 pm
by JPG
That displacement of the worm gear relative to the quadrant gear is quite common, and is indeed corrected by the method used by BM. It will also decrease the likelihood of it repeating.

As far as the abnormal wear, when the worm gear meshes properly, that portion of the quadrant gear teeth with the wear will not be in use.

Replacing the roll pin with a bolt and straightening the leg will produce a very smoothly operating assembly even with such badly mangled parts.

There is one caveat, and that is whether the worm gear shaft is bent. As far as the sudden binding near the end of its range, that may not be due to a bent shaft. The increasing mis-alignment at the near-end position causes an increasingly binding interference(mashed teeth).

In any event the parts needed are inexpensive and well worth the effort!