mini-lathe - getting it right...maybe

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zeeprogrammer

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Twmaster said:
Come on Zee... get with the new lingo! ;)

What I was trying, and failing to say, is to remove the silly set screw setup from the carriage retainer gibs. Put shims in there. It took a bit of time to get right but worked great
Gibs? Between the carriage and bed? The only gibs I have are on the cross-slide and compound. Pics!

It's not your failure...I just can't get the lingo.

know it jack?
feeling the scritch?
understandin' the toe?

Yeah. Me neither.
 

rudydubya

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Zee, if I may, a few pictures may help with what Mike is saying. When you look at the bottom of your carriage, you'll see that it's held to the bottom of the ways, both near and far side, with retainers held on with three cap screws, with two adjustment setscrews between them. (Yes, I have a tiny assistant who crawls underneath my lathe to take pictures for me.) The set screws are supposed to be adjusted to provide just enough clearance between the retainers and the bottom side of the carriage to allow the carriage to slide along the ways, yet keep the it tight enough so it won't rock back and forth. I never did get them adjusted right with that setup.



You can get rid of those adjustment setscrews and duplicate their function with shims of the appropriate thickness, say from brass and/or aluminum, and put them between the retainer plates and the underbody of the carriage.



I used a feeler gauge to get an initial idea of the thickness I needed. Wound up using some soda can aluminum and brass shim stock I got from the hobby shop. If you look closely you can see the shims between the bottom retainer plates and the bottom of the carriage.





It did take me a little while to get an acceptable fit, but it was one of the better mods I made to my lathe.

Hope this helps.
Rudy
 

zeeprogrammer

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Ah thanks Rudy. That made it clear for me. (And thanks again Mike N).

I did take a look last night and wondered if it might be them. (Have to admit I was looking for one, not two, and that was one reason I was confused.)

In any case, I noticed the plates aren't square to the carriage. Even though the carriage seems to be running smooth with no slop...I worry about wear. It can't be riding right. I can see how the shims would be a benefit.

Thanks again.
 

Twmaster

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That's what I was trying to say. Thanks Rudy. Proof that a photo is worth a bucket of words.

I had to fit, try again and refit a few times to get it right. And as Rudy said worth the effort as it's a good mod you almost never had to ever fool with again. Go one better... Make a new pair of plates out of brass so they slide better.
 

zeeprogrammer

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Twmaster said:
Go one better... Make a new pair of plates out of brass so they slide better.
Ah yes. That means taking the mill apart, cleaning it up, and doing some adjusting to it as well. It needs it bad and I'm very optimistic that I'll end up with a much better working machine.

Now if I could just get to it...

All the garage is in the basement while the garage is walled, painted, and cabinets and shelves put up. It'll be a while...but the upside is the stuff on the other side of the basement will have a place to go and I can set up some small woodworking stuff to make display bases, small boxes, and frames.

Even better...a place to set up a train set. Woo woo.
 

zeeprogrammer

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I have my shop back...mostly.

I cleaned up and adjusted the mini-lathe. The increased rigidity is noticeable.

I also replaced the blade on my horizontal bandsaw. I must have done better this time...no hip-hop action and it cut through a bar of aluminum without trouble...twice. Said bits of aluminum used to raise the mini-lathe...



Next step is to clean and adjust the mini-mill.

I also need to choose my next project. I'm thinking a marine engine of some sort. I'm also looking for a boiler. Suggestions are welcome. Work has not decreased much (no complaints), so progress will be slow.

Some of you may be wondering about the little loco. Not to worry. It's sitting right here. ;D

I mentioned it elsewhere on the forum...I plan to be at Cabin Fever. I hope to meet some of you there.

BTW Pat...in addition to 'most often taped out of his shop' I can probably win in the categories of...

most kits bought of the same engine until he got one running
best use of shop oil
best legs in a tu-tu

Happy Holidays everyone.
 

zeeprogrammer

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Thanks Pat. I just wanted a bit more room under the mill to make it easier to clean.

Started cleaning up the mill...stripped it down and found this...



The base is not square with the shaft holder. See the gap? It's bigger at the point closer to you than farther away. (Yes the bolts are loose...I had noticed this before I loosened things up...then decided to take a picture.)

I don't know if it came this way or if I put it back together this way when I first got the mill and cleaned it.

I'm not sure how to make it square. Any thoughts?

They've changed photobucket! I don't like it. Took a while to figure out how to get the pic in this post. And I'm getting warnings about malicious URLs again. Grumble.
 

90LX_Notch

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Zee,

I would say that gap is meaningless. What counts is wheather or not the face of that casting (where the line for degree indicator is) is square to the ways.

Bob
 

zeeprogrammer

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Thanks Bob.

I agree, the gap in and of itself doesn't matter.

I just don't know how to get the shaft in line with the ways.
 

hobby

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Could you elongate the farthest hole, and a small bit of the middle hole to pull things back square?

Then make a precise shim to fill in the gap to keep from vibrating forward.
 

zeeprogrammer

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Thanks hobby.

I don't think there's a need to modify any of the holes. There's enough slop for the casting to move about...I can eyeball it enough to see it can be made square...I just don't trust the eyeball. (Over the years it has lied to me too often..."she looks great...wait...it's not a she".)
 

PhillyVa

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Hi Zeepster,

The machined surfaces are the ones that need to be Plumb...Level...and Square, the rough casting pay no mind to.

Trgards

Philly

PS, Merry X-Mas to all. ;D
 

hobby

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zeeprogrammer said:
I just don't know how to get the shaft in line with the ways.
One possible way, with the table on the mill base, fix up a dial indicator extended from the table, to bear up against the shaft, then run the table back and forth, as you tram in the shaft, that will at least get it close to parrallel with the ways.
 

Troutsqueezer

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Hi Zee,

What did you do, paint your lathe blue? Maybe you mentioned that already and it didn't register with me. Well, it sure does look purty.

If you make a marine engine, does that mean you're going to make the boat too?
 

zeeprogrammer

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Thanks hobby. Is this what you mean? It looks like it'll work.



On a side note...when I first got my lathe and mill, I broke them down, cleaned them, and adjusted them. Now that I've built a couple of engines I've found it invaluable to do it again. Being more familiar with the machines, their capabilities, and 'something' about machining I am staggered by the improved stiffness (rigidity) and smoothness of operation. (Maybe it's the oil. ;D )

Hi Trout! I don't recall if I mentioned the lathe color before...but there's been pics. It came out of the box like that...Pro-Tech (Cummings I think)...but just like most of the other mini-lathes. Just a different color.

And yes...part of the reason for a marine engine is my dream to build a boat.

I'll probably wait until Cabin Fever to make a decision. This will be my second trip and I know a lot more than I did last year. I'm really looking forward to it.

Oops. I just noticed the ding in the table. Hee hee. There's two of them. They happened shortly after I got the mill. I'm sure no explanation is required for how they got there. :big: You can also see a few marks from having tightened things down a bit too hard.
 

zeeprogrammer

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Bummage.

Some time ago I got a short bit of angle from Rick (black85vette) that he'd used to stiffen the column of his mini-mill.

So I slapped it into the horizontal bandsaw (with the new blade that had just cut two 1"x3" blocks of aluminum). Used cutting oil.

It started cutting...then about halfway through...no more cutting. Blade just spins along...but no cutting.

What'd I do wrong? Wrong speed? Should have been slower eh?
I went up a step in blade quality...but probably not enough.

Foo.
 

Troutsqueezer

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Now, I'm only a Caveman Lawyer (feeble SNL reference) and a newbie machinist but I'm trying to think how, if indeed the shaft is not at 90 degrees (horizontal) to the table, that manifests itself to the accuracy of milling. The spindle/head would be in some degree of rotation to the table yes, but the table moves at X/Y in relation to the spindle. The spindle/head only moves up and down.

Am I missing something? I'm sure I am but not putting it together yet.
 

zeeprogrammer

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I've been struggling with that too. But better safe than sorry.

My thinking went this way the longest ;D ...

When I mount the vise, I square it by moving the table left/right with a DTI against one face of the vise. Cutting left/right should remain square.

But if I cut in/out...would it not be at something other than 90 degree to the vise?

I need to continue thinking about this...but it's time for supper and her food is better than any conversation I could have.

 

Foozer

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A certain amount of Fly poop is allowed in the Pepper

Insect filth and/or insect-mold (MPM-V39) Average of 1% or more pieces by weight are infested and/or moldy (USFDA)

Under that and its OK. Would be nice if that shaft was perfect but i cant see what harm a slight out of whack condition would bring. Important tho that the vertical support be as close to 90 with the table and to that end the focus is fruitful. Line that casting up as best as it will, look up the torque values for those attach bolts and set that sucker in place. Shim as necessary to get the vertical in order.

Looking at a quick sketch, it seems that it'll cut proper anywhere on the arc, course nothing else has gone right today, missed the eclipse due to clouds.

When you get that done come over and dig out my garage :)

Robert

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