First real project - bearing housing for compound slide wheel

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Lone Watie

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I've been working (as time permits) on my first lathe project - adding a bearing to my compound slide handle (I have Micromark 7x16) for my lathe. I'm using the plans from

http://aardvark.co.nz/pjet/lathefix.htm

The only differences are dimensional. On the cited web site, his compound slide shaft diameter is 10 mm. Mine is 12mm. I ordered a 28 mm OD by 12 mm ID by 8 mm wide bearing from McMaster-Carr and a 12 mm drill bit from them. They arrived quickly.

That's the only thing metric about my bearing housing. My lathe wheels are in inches, so I've been taking all my measurements accordingly.

I have a basic question about boring. My bearing fits well into the housing I've made, but I'd been eyeballing it and taking little cuts to get her where she needs to be. I tried to do some math and use the graduations on the wheel but wasn't having much luck. My boring bar is lined up perpendicular to the cross slide, so I believe my .001" graduations on the compound wheel are truly .001". Is this correct?

Another question concerns the graduations as a whole. If I'm at, for example, an inside diameter of .232 and I need to bore out to .314 than
I would turn my wheel almost 9 graduations, is this correct?

Or if I have to make a .156" deeper cut from one depth to a deeper depth, that would be 156 graduated turns, is this correct?

I don't want to eyeball stuff - I want to do it the right way. As you can already see, I don't have an DRO's on this machine.

Thanks. In case anyone is interested I'll post my progress and add some pictures.
 
Many people put a 1" indicator to bear against the toolpost to measure exactly how much you are actually moving the tool. Take care to align the stem with the axis of movement, and after a while, you will learn when to trust your dials and when not to.
 
My South Bend Lathe is direct read dials, But it wasn't working out so I put a dial indicator on it when the dial said I moved it .020 the indicator said .016 so you need to check yours also.

Paul
 
Old Iron said:
My South Bend Lathe is direct read dials, But it wasn't working out so I put a dial indicator on it when the dial said I moved it .020 the indicator said .016 so you need to check yours also.

Paul
Click to expand...

Thanks for the advice on that - as soon as I figure out how to mount my indicator I'll do so. I'm not looking to get anything super accurate off this chi com lathe, but do want to be in the ball park so keep my 'eyeballing' it to a minimum. I do have a plan to mount these cheap tire tread indicators on there, just need to cut off some unnecessary plastic off of them and get them on there. They'll work for now until I really get into this and start making precision parts.
 
It's standard that compound dials are one to one.
In other words if you move the compound by 0.001 inch on the dial the compound reads travel of 0.001.

My cheapo Chinese lathe had a one to one cross-slide as well.
I turned a 10 tpi acme shaft and nut. Then made a new dial.
When I now dial in 0.001 it only travels 0.0005
It works much better now and I did it on the lathe I needed to improve.
Keep a list of the improvements you want and can do yourself.
Watch for the materials and tooling needed and try to catch those good deals.
Material, tooling, and skills, it all comes together in time.
 
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