My deckel FP2 seems to be eating it's leadscrew nut

[DennisCA]

Since we wanted some new threads on this forum I figured I'd post about this. I've noticed it for some time but haven't had the chance to do anything about it. I was seeing a yellowish sheen on the threads after a while and oil that ran out around the sides of the saddle where the lead screw was, would be blackish (on closer examination it glittered like bronze), I guess with bronze particulates. Obviously this isn't good. The backlash doesn't seem to have noticeably increased though.

I was wondering if I had the gibs set too tight but I've tried with them entirely loose and the resistance is about the same.

I took apart the gibs and the gibs are worn, they need to be rescraped for bearing, but the table moves with resistance even with the gibs out.

So I think I also need to scrape the ways on the vertical table which is what moves in the X-axis on my machine.

I removed the nut last night and found it was full of debris.I think some of it was stuff I was not able to get out when I first worked on the machine as I restored it because there was this sleeve on the nut (a cover for the threaded rod, note old picture from when I got the machine):

I wasn't able to get off back then and I just reassembled it, figuring I had cleaned it well enough.... Well I got the cover this time with a slide hammer and was able to remove some more debris that was behind it. I am gonna give it an even better clean now and in the ultrasonic cleaner as well. I can feel burrs on the inside so I will probably need to use something to get rid off the burrs, few licks with scotchbrite wrapped around a dowel perhaps.

I will flush out the inside of the vertical where the nut sat with copious amounts of mineral spirits. Hopefully this will help a little, for now.

Though I feel I really need to take this machine apart again some day and re-scrape the bearing surfaces and backing plates. I have this hunch that the worn sliding surfaces are introducing too much friction and causing this extra wear on the screw.

I am also considering moving to Vactra #2 (68 weight) instead of #4 (220 weight), because while #4 was what I was being recommended, I live quite far north and my shop is quite cold a lot of the year (around 8-10c), I think the way oil might be too viscous under those conditions so I am thinking of moving to the 68 weight oil.

That's my plan for now, any feedback or ideas? Since this is a deckel most of you probably aren't familiar with it, and terms like saddle and vertical table are probably hard to understand. But the forum needs content. Here's an image to help:

[macona]

Once stuff got in there it just ate the nut out. I have used the injectable moglice to repair a nut for the old Artisan lathe I had, it was an odd ball screw that there was no other way to get the nut made short of several hundred bucks from a machine shop. That might work here to rebuild it. though note that since lead screws wear unevenly it will be tighter on the ends than in the middle. They make some circular brushes that go over lead screws to keep the crud out, you might try and find or make some to help.

[DennisCA]

The backlash in the nut isn't bad now. I hope the leadscrew wear is minimal, it's hardened and ground.

[old mart]

Assuming the leadscrew and nut are protected from contamination, then a good clean using a stiff bottle brush while immersed in solvent and similar treatment of the screw should stop any further wear. I have had good results using motorcycle spray chain lubricant. It is easy to move to opposite ends of travel and spray some more onto the threads, occasionally.

[darylbane]

May I suggest Vacuoline 1409 instead of modern Vactra #2. It is the same viscosity old style Vactra #2 but with the tackifiers. On the newer Vactra, this was removed. With Vacuoline,the oil stays on the ways instead of running all over.

I recently got a newish lathe and they had filled the apron with Vactra #2 (the current stuff) and the oil was everywhere, dripping down the front of the apron, a mess. I put up with this until just about empty and refilled it the Vacuoline 1409, totally changed everything, no more mess, just oil on the ways. It even felt better, smoother in the action, but that maybe in my head.

[Fasttrack]

#4 Vactra, when it's cold, has the consistency of room temperature honey. Given that the machine is being used in a home shop with a single operator who is also responsible for its maintenance and upkeep, I think going to a ISO 68 weight oil would be fine. Might make a bigger mess and require more frequent lubrication intervals but I've never seen a Deckel in person. I know zilch about them.

Edit: Just saw DarylBane's post - I remember seeing this elsewhere on the forum. I must have an old pail of Vactra because it's very tacky, almost like (I'm going to say it) chainsaw bar oil <ominous music plays>. Not that I want to open up that can of worms!

2nd Edit: Nope. My pail is Vacuoline 1419 (ISO 220 weight), not Vactra. I just didn't remember correctly. I do have a gallon jug of Vactra #2 and it does not feel especially tacky.

[DennisCA]

I might just buy a smaller 3l can of a generic 68 way oil for testing purposes. No need to stick to vactra I guess.

I was recommended Wurth HHS-K to use on slideways in conjunction with way oil, supposed to be practically magic. Can't buy it here though.

[macona]

I used Vacuoline 1409 in my 10ee and mill. Only bad thing is to find it in less than 5 gal quantities.

[MattiJ]

I might just buy a smaller 3l can of a generic 68 way oil for testing purposes. No need to stick to vactra I guess.

I was recommended Wurth HHS-K to use on slideways in conjunction with way oil, supposed to be practically magic. Can't buy it here though.

Might be same as HHS 2000 here in europe. https://www.puuilo.fi/wurth-voiteluspray-hhs-2000-500ml

[DennisCA]

Yeah that's apparently the replacement for HHS-K and does the same thing, will try and get one of those this weekend, a puuilo opened up in Vaasa