Microlux mini lathe part

[redvan22]

Hi,
I was doing a cleaning of my mini-lathe after learning a few things from my post about lubrication and saw that the retaining blocks under the carriage were cracked and once loosened, fell away into pieces. I looked up the part number (#36) on the exploded image in the manual and its C2A0505.

I tried an internet search but results were less than exciting so, I thought I would make new parts out of steel but then there's the hardening issue which would lead to another post of how to do that.

I'm guessing, looking at the fragments, that the original pieces are cast iron.

What are my options?

Red.

 

[ThinWoodsman]

mini-lathe.com has a section describing brass replacements. been considering that for when mine go, eventually.

 

[homebrewed]

Most folks who replace the carriage slide plates go to a simplified version where the clearances between the bottom of the bed and plate are established with shims (the OEM approach using jack screws is really fiddly and not very stable). I made plates from molybdenum sulfide-filled nylon (obtained from McMaster-Carr) and dumped the jack screws. A drawing for the plates can be found in the Files section of https://groups.io/g/7x12MiniLathe. Just be aware that the step heights used to set the clearances may not apply to your lathe, so make some measurements before you cut the steps.

FYI the mounting holes straddle the step, and that is deliberate -- the fellow who designed them says that makes it possible to more-finely adjust the clearances. He used MDS-filled nylon, too.

 

[redvan22]

Brass it shall be, thanks for the link Homebrewed.

 

[royesses]

Another way is to make tapered gibs for the carriage. I made them for my mini and they make gib adjusting as easy as turning 2 screws. Here is a link with the instructions and drawings.
http://warhammer.mcc.virginia.edu/ty/7x10/vault/Lathes/7x10-7x12-Projects/TaperedSaddleGibs/

Roy

 

[redvan22]

Ive noticed two things on my Microlux mini-lathe;
1- the are two useless allen set screws on the left side of the carriage over the ways.
2- there is a twisting slop of the carriage over the ways, even when adjusted properly.
Is there a way to eliminate this twist slop and what are these two allen screws for?

 

[ThinWoodsman]

Ive noticed two things on my Microlux mini-lathe;
1- the are two useless allen set screws on the left side of the carriage over the ways.
2- there is a twisting slop of the carriage over the ways, even when adjusted properly.
Is there a way to eliminate this twist slop and what are these two allen screws for?

1. The allen screws are for mounting the follower rest.

2. I have not yet found a way - I have the same lathe and got so frustrated with it (and the Taig mill) that I went out and built a bigger shop and bought full-sized machines. I'm sure there *is* a way, as many people do fantastic work on these machines. Tuning the Mini-Lathe helped a bit. But I think the cross slide is the weak point, so I'm going to replace the gibs on that once I finish the beefier carriage lock (a two-piece that fills the space between the ways and spans the entire tailstock side of the carriage), then probably spend a lot of time getting the fit on the dovetails perfect. Probably have to repair/replace the pillow block on the cross-slide leadscrew too, it wobbles a lot. It has been said before, these things are a kit not an out-of-the-box tool, but I did not anticipate how much the fundamental mechanisms need work just to be usable.

 

[homebrewed]

If the carriage twist occurs while cutting, it could be due to a couple of issues. The carriage slide plates could be broken or poorly adjusted, or the compound gib screws could be too loose. Of course, you don't want the compound backed out too far so its base of support is significantly reduced.

In normal use the narrow axis of the compound is more-or-less parallel to the bed, so it is easily disturbed (i.e., canted over) by cutting forces. Parting-off is especially troublesome in this regard. If you're not using the compound for an operation try locking it down by tightening the gib screws. Unfortunately you can't use the lathe when the compound is rotated 90 degrees -- if you could, the compound would be much better at resisting the cutting forces. That being said, you might try rotating the compound as much as you can to see if that improves things.

Some folks have solved the problem by replacing the compound with a riser block that is bolted to the cross slide. Swap in the compound if cutting tapers or threads.

I agree with the observation that as received these machines are more of a kit than a turnkey get-and-use item. Some are better than others -- mine was relatively usable right out of the box but YMMV in this regard.