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Posted: Sun Dec 29, 2013 12:16 pm
by billmayo
Since I do a lot of mix and match different year parts, many times I find a part or parts that just does not want to work with another part. Using another part and relocating that part to another machine takes care of any problems. I have assemblied several headstocks that vibration, heat and/or noise was greater than what I found acceptable. I ended up putting another set of headstock parts into that headstock and the problem would go away. I was able to use the removed parts in other different headstocks with out any of these problems occuring again. Just changing one part at a time could not make the problem go away. I made many attempts trying to determine what part or parts were causing the problem but without success. So lately, I just replace all the headstock parts and motor and use those parts later in different headstocks. I find the same thing with table legs and carriages. Never found any specific problem but changing parts worked.
Of course, my best guess is that manufacturing tolerances was causing some of these problems but never did confirm this.
Posted: Sun Dec 29, 2013 12:55 pm
by joshh
billmayo wrote:Of course, my best guess is that manufacturing tolerances was causing some of these problems but never did confirm this.
This would be my assumption also. Two parts at opposite ends of the tolerance range.
Posted: Sun Dec 29, 2013 1:16 pm
by JPG
joshh wrote:This would be my assumption also. Two parts at opposite ends of the tolerance range.
Having worked in QA in the distant past, I was always amazed that tolerance ranges allow dis function. The 'thinking' was with large production volume, the odds were against the opposite/worst parts being 'mated'.
Hence we sometimes have to 'make lemonade':(.
Statistics: Bah Humbug!:D
Posted: Sun Dec 29, 2013 9:44 pm
by skou
billmayo wrote:Since I do a lot of mix and match different year parts, many times I find a part or parts that just does not want to work with another part. Using another part and relocating that part to another machine takes care of any problems. I have assemblied several headstocks that vibration, heat and/or noise was greater than what I found acceptable. I ended up putting another set of headstock parts into that headstock and the problem would go away. I was able to use the removed parts in other different headstocks with out any of these problems occuring again. Just changing one part at a time could not make the problem go away. I made many attempts trying to determine what part or parts were causing the problem but without success. So lately, I just replace all the headstock parts and motor and use those parts later in different headstocks. I find the same thing with table legs and carriages. Never found any specific problem but changing parts worked.
Of course, my best guess is that manufacturing tolerances was causing some of these problems but never did confirm this.
You guys are going to throw the (cast iron) brick at me for this, but I've currently got parts of 4, ERs. I can mix-n-match with NO issues, unless I've got a damaged, 65 year old part. (This is just my current batch. I had 3 at the time of the trailer fire. One was an E model.)
If you read the article that I've seen, about the old San Francisco plant, they would grab parts, from all over the plant, and assemble an ER headstock. New parts, old parts, the rare re-worked part, didn't matter. Average spindle runout was .001. Some weeks, .0005! .0015 would cause a re-work. Just one more reason they're STILL building Mk5s with E models and ERs.
The only "issue" I've seen, the bore on the tailstock is just "too" good. If you don't slide it on just right, it will cock off to one side, and be a bear to move. By "just right," I mean 5 or 10 thousandths off.
Sorry guys.
steve
Posted: Sun Dec 29, 2013 11:38 pm
by JPG
skou wrote:You guys are going to throw the (cast iron) brick at me for this, but I've currently got parts of 4, ERs. I can mix-n-match with NO issues, unless I've got a damaged, 65 year old part. (This is just my current batch. I had 3 at the time of the trailer fire. One was an E model.)
If you read the article that I've seen, about the old San Francisco plant, they would grab parts, from all over the plant, and assemble an ER headstock. New parts, old parts, the rare re-worked part, didn't matter. Average spindle runout was .001. Some weeks, .0005! .0015 would cause a re-work. Just one more reason they're STILL building Mk5s with E models and ERs.
The only "issue" I've seen, the bore on the tailstock is just "too" good. If you don't slide it on just right, it will cock off to one side, and be a bear to move. By "just right," I mean 5 or 10 thousandths off.
Sorry guys.
steve
No CI bricks from here!;)
Posted: Mon Dec 30, 2013 12:43 am
by skou
[quote="JPG40504"]No CI bricks from here!]
'Course not. You "ain't" gonna waste your good stuff.
Guys, for some reason, I think the older stuff, (cars, aircraft, Shopsmiths, et cetera) was just made better.
New cars, well, they handle better. But, is that engine held to closer tolerances? Is the water jacket thick enough to withstand 2 or 3 boring out processes?
Some stuff is REALLY getting better, like the new-fangled Mk7. (But, they're STILL making it with ERs.) Kinda makes you wonder.
steve
Posted: Mon Dec 30, 2013 1:31 am
by JPG
skou wrote:'Course not. You "ain't" gonna waste your good stuff.
Guys, for some reason, I think the older stuff, (cars, aircraft, Shopsmiths, et cetera) was just made better.
New cars, well, they handle better. But,
is that engine held to closer tolerances? Is the water jacket thick enough to withstand 2 or 3 boring out processes?
Some stuff is REALLY getting better, like the new-fangled Mk7. (But, they're STILL making it with ERs.) Kinda makes you wonder.
steve
No doubt in my mind. 100,000 mi used to be an upper limit back in the 10E days. Oil changes every 2k mi. Boring less needed today.
Posted: Mon Dec 30, 2013 7:04 am
by dusty
I don't know what the problem is or how to fix it but I do know that I have that one Table and Tie Bar Assembly that does not function smoothly in any of the three carriage assemblies to which I have immediate access.
There will be no further testing for a few days now. This is going to be a week wasted in the doctors' waiting rooms.
Posted: Mon Dec 30, 2013 8:17 am
by joshh
Call the mothership? They may send you a replacement.
Posted: Mon Dec 30, 2013 8:35 am
by dusty
joshh wrote:Call the mothership? They may send you a replacement.
I seriously doubt that, joshh. This Table and Tie Bar Assembly came with my Mark V when it was new. That was many years and several different shops ago. It has seen a fair amount of wear and tear and probably some abuse. I would not feel right even just asking for a replacement. Now if it was new - by all means.
I swapped the tiebars between the Crafter's Station and the Shorty. The Crafter's Station doesn't have the same sort of carriage and whatever causes this issue is not apparent with the Crafter's Station. The Carriage and Tie Bar Assembly that are now on the Shorty work fine. Through all of this, the goto machine was hardly disturbed at all; I temporarily swapped complete table assemblies while attempting to isolate the problem.
All Systems All Go:)
Opps, not yet. Gotta do an alignment on the Shorty. The table to blade is about .015" after the trunnion removal and reinstallation.