Wow I thought my projects where big , Intresting stuff this and good use of scraping seems like I black art worth knowing
Scraping is an interesting, rewarding, theraputic and, if you're reconditioning machines, an essential tool. It's also likely to drive you nuts, because part of the skill is earning to read the flatness of something you had previously machined, and thought would be flat.. this, ultimately leads you to look at your machine, and it's ways, with thoughts of how to fix it.....Wow I thought my projects where big , Intresting stuff this and good use of scraping seems like I black art worth knowing
Table is upside down on the Fritz Werner tonight. Started scraping the flat ways - 2 thou low in the middle. Scraping, scraping, lots of scraping....One thing I noticed last night whilst sniffing around the knee and carriage, the rhs dovetail is being held slightly off by the leadscrew. I had thought about the vertical difference (this was cancelled out by machining the whole bottom face) - but of course as the carriage drops, the dovetail moves away - by the sin of the angle times the drop or something like that. Anyway, it seems the lead screw nut holder needs to be able to move sideways, so will need to elongate the holes sideways...View attachment 320734View attachment 320735
Correct that man - but I assumed when I picked up the scraper and set to that the bow underneath was wear (which is what you would expect given the wear everywhere else). Since them I started wondering about the whole thing drooping, or relieving itself, whatever.A 2 thou dip on the underside is an upward bow on the top
Here's what I mean when I say dovetails moved together..You missed the bit that said "and then there is this". Fair enough my badly worded post didn't help.
First things first, the table lead screw. That has bearings, handwheel (one end), gearbox and another handwheel the other end. The movement on this will be what I scraped off the underside of the table and the top of the carriage - flat ways. 4 to 5 thou.
The nut holder sits under the carriage - has the in/out lead screw going through it. As far as height is concerned, there will have been a couple or three thou scraped off the top of the knee, and a bit more from under the carriage, but this has been compensated for. So just the 3 though might need to come off its mounting face. However, this same nut has to deal with what's happened as a consequence of all this scraping - namely that the dovetails from the knee and carriage have moved together, so the carriage has moved left as well as down. So the holes for the (vertical) mounting bolts need elongating to allow this.
I suppose I could drill them oversize and then move the counterbores along slightly? Bit of a bodge though?
I need to calculate it properly first.