Scraping the underside of the ways

The underside of the ways....you know at the front and back where on most lathes there something attached to the saddle that rides on these surfaces to stops the saddle from lifting.

Whats common practice? scrape them? forget about it? I know the lathe ops the might take advantage of these, but its always seem a bit of a useless feature. As soon as a lathe as some wear these become a bit useless as its not in contact and even ops that might lift carriage, well they're not every day (for me) and not with so much force its doing any lifting. Thinking about it, are they even a bearing surface? I mean there'd have to some small bit of clearance or you'd accelerate wear on the bed and if there is some clearance whats the point of making them a precision surface?

Just wondering what the general sentiment is? Thanks.

You should check the underside of the lathe bed to be sure it isn't worn under there. I am assuming you scraped the top and under there is co-planer to the top. Many lathes have brass shims under the operators side that can be remove. Some don't, some are short and some are long, some machines there aren't any on the operators side. The back side has different types too. Square gibs, taper gibe and just a hold down L shaped keeper I generally leave them so there is .0005" to .001". There is another thing to take into consideration on the back side. If it is worn under there, that means the saddle isn't balanced and tool pressure lifts the saddle or the carriage is heavy and drops down and lifts the back up. Most lathes are designed to have a taper attachment and with one on there that extra weigh back there and the bottom isn't worn. If there isn't a taper attachment, I weigh the apron and hang a steel counterweight back there. Rich

I recently had the bed of my monarch 16CY ground. The guy that ground it also ground the underside of the ways. This was his recommendation, i never would have thought of it.

I agree with Marka12161.
When my Hendey T&G was ground the bottom of the ways were also done. Keeps everything nicely co-planer.

For an odd twist, the outer way on an Axelson is flat, but the bottom side is angled inward, for the also angled 30lb gib, that keeps the rear of the saddle from lifting.

Thanks Donnie for sharing that about the underside hold down, that's slick. The Lathe is a Heavy duty machine, that's for sure.. I see on Page 68 of the following Axelson Booklet it shows that. Steve Watkins is one of our resident members on Axelson lathe expert. Hopefully he will report in. He does have some You Tube shows on them. http://vintagemachinery.org/pubs/2137/4431.pdf

Thanks for all the input guys.

This got me thinking about those surfaces and their function. The remarks that there should be a thou clearance and if there is wear there's a problem suggest they don't do anything unless something goes quite wrong then it stops the carriage lifting. In other words, if there is no contact they aren't affecting machining? Are they just there as a safety thing?

That doesn't explain the setup with a gib Donnie described which suggests there should be contact. Of course then if there is any wear there isn't contact, or if adjusted for the worn part, the carriage wouldn't freely move over the non worn.

A current project is an Emco maximat 10 with a milling attachment (yeah, hobby stuff, but doing it to sell so its therefor commercial ). It does have a lifting force - millling cutter helix, but it just doesn't seem right to try for contact on the top and bottom

Mcgyver said:

Thanks for all the input guys.

...

A current project is an Emco maximat 10 with a milling attachment (yeah, hobby stuff, but doing it to sell so its therefor commercial ). It does have a lifting force - millling cutter helix, but it just doesn't seem right to try for contact on the top and bottom

Click to expand...

It still make more sense than the bearing surfaces of a Rivett 608. When new/rebuilt that redundancy work. But as soon as there is some wear, the added rigidity provided by the redundant bearing surfaces is gone. At that point one has to hope that the rigidity offered by the non redundant bearing surfaces is sufficient.

Paolo

Yes "watkins at work on Utube!
I watch that guy, of course after watching the Blondi girl!
Believe it or not, the machines he works on are much newer, then the 1940 machine I have, and the WW2 machines that are around here from the shipyards, and other military areas like Hanford, and the chemical weapons depot. All nice thing to have close by.
Axelson made many changes on the machines from the 40s to the 50s, and one was inserted steel bedways.
My machine here has standard iron ways

The gib, sitting on top to the left, fell off the machine during shipping, it and the bolts are still in the chip pan. Adjustment seems from the manual to be by sliding it in an out, but I have not tried reinstalling it.
The Axelson carriage is ridiculously heavy with, another couple hundred pounds of taper attachment hanging over the gib area at the rear, with my use, I doubt I will be lifting the rear of the carriage with such heavy cuts.
Anyway, the ways on this early machine were hand scraped, it has wear, but still good enough.

that looks really awkward