Thread: How flat is a file?

Originally Posted by GSRocket

With a good quality file....

There's your problem right there - obtaining one.

Use a fine diamond plate.

You need to work out which bit has the wear - pointless filing out a presumed high spot if the majority of the wear is on the other part. For machine tool flatness purposes a file is probably not dimensionally stable enough - ideally you want something that has a movement range in tenths of microns.

Michael

All you will do is wreck something with a file... What will probably will be worn is the dovetail section that is on an angle... it is not a hard job to fix, just very time consuming... Not even expensive to buy the tooling to fix it... One of those $100 Carbotec surface plates would probably do... If you were closer I would happily help out...

As RC says, It's fixable, and there are well known and proven procedures to follow, first... don't go crazy filing at random. You need something known to be absolutely straight to use as a reference to blue against, that will tell you where to scrape.

Here are a few videos to give you the general idea.

https://www.youtube.com/watch?v=esAqz6bCVyQ
https://www.youtube.com/watch?v=8hEMTmM1mBQ
https://www.youtube.com/watch?v=D1eOQa1gYiU
https://www.youtube.com/watch?v=dt9f2QiVbt4

Nick Mueller's is probably the pick.

Ray

If I recall long ago, we were taught a file isn't flat, bowed.

Nick should've fed the siamese before he directed that clip

Watched the videos...eazypeazy, piece of cake, like laying bricks, the easiest thing the world till you have a go at it.
Couldn't even get the bluing to work. I think I must be putting it on too thick, because the pieces stick together after sliding them back and forth forth a few times. Then spilt the blue over the phone, another +1 for the Otter case.

I don't have a flat surface so I'm working on the assumption the base of the cross slide is flat. It does seem to be a custom unit made from a good quality steel whereas the top is the original cast iron.
As long as I get a noticeable improvement I'll be happy.

Would it be possible to get a couple of parallel ROLLERS out of a roller bearing, that will go in the dovetail, so that measurements could be taken, which will give an indication of variances, I know mine is about .011mm. It's sloppy at the furtherest point away from the chuck and gets better on the way in, except for a small section in the middle where it gets tighter marginally.
Kryn

Originally Posted by GSRocket

Watched the videos...eazypeazy, piece of cake, like laying bricks, the easiest thing the world till you have a go at it.
Couldn't even get the bluing to work. I think I must be putting it on too thick, because the pieces stick together after sliding them back and forth forth a few times. Then spilt the blue over the phone, another +1 for the Otter case.

I don't have a flat surface so I'm working on the assumption the base of the cross slide is flat. It does seem to be a custom unit made from a good quality steel whereas the top is the original cast iron.
As long as I get a noticeable improvement I'll be happy.

Are you using Bearing/Prussian blue or Lay Out Stain? If you spilt it over your phone it sounds like you may be using the latter.

Originally Posted by Techo1

Are you using Bearing/Prussian blue or Lay Out Stain? If you spilt it over your phone it sounds like you may be using the latter.

The old guy that gave it to me said it was "not bearing blue". He said it was for scraping. Smells like metho and dries
very quickly. I'm wondering if I should smear it more lightly and wait till it dries before sliding the parts together.

What you have is L.O.S. This is not suitable for what you are doing, just get a tube or bearing blue from Repco or other automotive parts suppliers.

I notice that you are in Newcastle. Flick a PM through to Joe (jhovel) as he's looking for someone to visit up that way in about a week. He's done the scraping course so may be able to help you out with regards to technique and point you in the way of the correct stuff.

Michael

Thanks Techo, was definitely using the wrong stuff. Bearing blue from Repco for $13 was the go.
It has showed up a bow in the slide top. Had a bit of a scratch and it has improved a little but more time needed on it.
RC is on the money too. I just used some round tooling and sliding callipers to check the dovetails, just a little short of
Nick Muellers standard but enough to tell me its out from one end to the other by about 0.1mm.

I'd also welcome a visit from Joe but with the way trees are falling over here, time is a real problem. Normally I would
just take the day off.