# How big of a straight edge



## Shotgun (Sep 29, 2022)

The power feed on my Sebastian locked up last weekend.  Once I got is apart, I figured out that if the clutch engagement pieces had ever seen oil or grease, it was on whichever WWII submarine the lathe had been installed on.  That lead me to do what I should have done when I first got the thing. . . tear it completely down, clean and oil each and every part.

Well, now that I've got it torn down, I'm thinking about how I can remove some of the bow in the ways.  Close as I have been able to measure, I've got about 5 thou of wear in the center section.  I measured with a  .0005 indicator mounted on the tailstock, dragged from end to end.  As an additional indicator, the .0002 level goes from centered, to locked to one side, back to center, from headstock to tailstock.

So now I'm thinking about scraping.  The Sebastian H model used 4 flame-hardened V-ways.  Two for the carriage, and two for the tailstock.  Most of the tailstock ways still show the original scraping, as does the very ends of the carriage ways.  The ways are 6ft long.  If I have to buy a 6ft straight edge, this project is out of the question.  But, what length could I get away with?


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## Richard King 2 (Sep 29, 2022)

If the bed ways are hard you won't be able to scrape the bed.  I would take it to someone and have it ground.  The guys grinding beds on Youtube with some sort of contraption in my opinion are not worth the effort.  It is best to use a straightedge longer then the surface as it is alot less measuring and lifting, less chance for error.  You could use  a shorter 24" to a 60" .  Like I said more work the shorter.  We call it lap scraping.  Start at the lowest point, finish that area then move out and do the next section of 75% of the SE length, and all the way to the ends.  Keith Rucker has a new You Tube show on lap scraping his Lucas Horizontal Boring machine.  Yes it's not a lathe, but it shows how to lap scrape.  Keith learned to scrape by me.  He has hosted 5 or 6 of my 1 week scraping classes.  He bought probably $20,000.00 in tools too or people gave him them at a super deal or free.


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## DAM 79 (Sep 29, 2022)

Richard King 2 said:


> If the bed ways are hard you won't be able to scrape the bed.  I would take it to someone and have it ground.  The guys grinding beds on Youtube with some sort of contraption in my opinion are not worth the effort.  It is best to use a straightedge longer then the surface as it is alot less measuring and lifting, less chance for error.  You could use  a shorter 24" to a 60" .  Like I said more work the shorter.  We call it lap scraping.  Start at the lowest point, finish that area then move out and do the next section of 75% of the SE length, and all the way to the ends.  Keith Rucker has a new You Tube show on lap scraping his Lucas Horizontal Boring machine.  Yes it's not a lathe, but it shows how to lap scrape.  Keith learned to scrape by me.  He has hosted 5 or 6 of my 1 week scraping classes.  He bought probably $20,000.00 in tools too or people gave him them at a super deal or free.


On the talk of scraping bed ways and such And making different contraptions to grind a bed or V way . I’m interested to see what you and steve are coming up with to make for when he does his 10EE


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## Richard King 2 (Sep 29, 2022)

Steve Watkins?   He and I are not working together anymore.  He uses my tools and my name to increase his You Tube shows it seems.  He planned my 4' Straight-edges I left at his shop and never paid me for them.  I have 2 granite surface plates there too that he never paid me for.  He got mad at me because one of my Facebook moderators erased his link to making a jib crane.  He said I did it.  I never did.  I had warned him not to post it in my rebuilding forum.  I told him to start his own forum.  Then he did something again and one of my 2 moderators deleted his post.   I could say more, but won't.  I would appreciate not mentioning his name to me again.


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## DAM 79 (Sep 29, 2022)

Ok  I am so sorry I had No idea and Definitely did not mean any disrespect to you in any way what so ever i had did not know any of that it was something that I saw on YouTube that he was talking about and after what you just said that guy will have one less subscriber because of it !!! 
I’m just a small hobby guy starting out and I hope you don’t hold it against me for this because you are Godfather when it comes To scraping and rebuilding and I hope you don’t hold it against me because you have replied to me several times about a K&T mill that I was looking at and didn’t get . But was lucky enough to find another in much better shape


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## Richard King 2 (Sep 29, 2022)

I didn't mean to come off mad at you, sorry if I did.   I have 2 students near Baltimore and they volunteer at.  I would suggest you have to decide on how good you need to have it when you use it?  They could help you learn to scrape.  Grinding the bed will cost $500.00 to $1200.00.  You could call Moglice.com in Philly as they have a way grinder.  Call them and ask for Cody.  He is an old friend.  You could put some Moglice.com on the saddle too.   https://tuckahoesteam.org/collectionspages/collectionsmachine.html


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## Bone Head (Sep 29, 2022)

Straight edges are somewhat expensive.  So here at my home garage I use a 8 foot fluorescent tube.  But I'm not scraping ways.  Just a thought.


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## Shotgun (Sep 30, 2022)

The Moglice in combination with a 6ft flouresent tube sounds interesting.  I looked very carefully.  The headstock end has about half the scraping scraped away for 3" to 6".  The tailstock has 6" that looks like it has never been touched, then another 12" before it completely disappears. If a flourescent tube could be counted on for a thou or so of deviation, then I think I could mix the Moglice to a thick consistency, paint it in the gap, and then use the tube as a spreader, constrained on each end.

I'm not expecting to bring it back to like new condition.  Just getting it to "not so bad" on a budget.


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## Richard King 2 (Sep 30, 2022)

I used to be a Moglice rep, that's why I know Cody and Drew Devitt.  Before you try that call him up and ask him.  We put Moglice on non exposed areas and a minimum thickness of .030", preferably .060" .  They have a product to fill scores called Score X but that's not made to be spread on like that.


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## Shotgun (Oct 1, 2022)

I sent them an email through the site you linked to above.  Thanks for the heads-up on Moglice.


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