Steady rest Q

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curtis cutter
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Joined: Fri May 18, 2012 11:46 pm
Location: Curtis, WA

Steady rest Q

Post by curtis cutter »

I have considerable "wobble" at the end of say an 8" drill bit and I want to try to eliminate as much as possible. I thought about making a series of bushings that have the same OD that could be held by the SR with various ID's thinking I can support a drill with the steady rest prior to entering the material being drilled. Obviously, the drill would have to pass through the bushing but that would be minimal wear.

I am sure there is something similar that comes as a set but I cannot locate them.
Gregg
Just let go of it, it will eventually unplug itself.
Mr Ron
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Location: Vancleave, Mississippi

Re: Steady rest Q

Post by Mr Ron »

You could make a fixture that is clamped in the cross feed tool post with a bushing to guide the drill. The closer the bushing is to the work, the better. A SR might take up too much room.
Mr.Ron from South Mississippi
John Hasler
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Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: Steady rest Q

Post by John Hasler »

Buy a set of hardened drill bushings.

You could mount them on the toolpost rather than in the steady rest.
curtis cutter
Posts: 558
Joined: Fri May 18, 2012 11:46 pm
Location: Curtis, WA

Re: Steady rest Q

Post by curtis cutter »

Ron and John, Thanks for the replies.

A BXA holder with a toll that holds the drill bushings with a common major diameter for various hardened drill bushings thus every time it is placed it would be on center height wise regardless of the drill size being used? Just locate the X axis when in play.

Does that make sense?
Gregg
Just let go of it, it will eventually unplug itself.
earlgo
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Re: Steady rest Q

Post by earlgo »

My understanding of your problem is that your drill in the tailstock is not hitting the rotational center of your part in a chuck. If this is the case then one can use a tool-post tool and actually cut a divot in the rotational center large enough for the drill to use as a starting point. I have done this for many years when I wanted an accurately centered hole.
Just my method.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
John Hasler
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Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: Steady rest Q

Post by John Hasler »

curtis cutter wrote: Fri Nov 23, 2018 1:18 pm Ron and John, Thanks for the replies.

A BXA holder with a toll that holds the drill bushings with a common major diameter for various hardened drill bushings thus every time it is placed it would be on center height wise regardless of the drill size being used? Just locate the X axis when in play.

Does that make sense?
Sounds good to me.
Rich_Carlstedt
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Re: Steady rest Q

Post by Rich_Carlstedt »

Do what old timers have done for maybe 100 years.
I teach this method to many newbies and journeyman
Works with any Lantern or Aloris type tool holders and eliminates center-drilling ( Yes !--)
Never need a centerdrill and the holes will start perfect

First, get into the habit of ALWAYS installing a drill bit in the tail stock with the cutting edges horizontal- very important.
Take your tool holder ( or tool bit ) and raise it about 1/8 or more above centerline ( temporarily)
Bring your drill upto the turning work piece. Put your left hand on the cross-slide handle and your right hand on the tailstock handwheel.
This is a 'coordinated move !
Now feed the cross-slide tool in and hit he flute immediately behind the cut edge ( 1/4' ~) ----remember this is not the cuting edge of the tool bit, but is the support area just under the cutting edge !!! -If you have a carbide insert tool, it is the support area under carbide insert.
You want to deflect the drill (away from you) about .010 to .030 " and at the same time, start feeding the drill into the work piece. Your lathe tool will be hitting the non-cutting flute helix
When the cutting lip of the drill is engaged 2/3 rd's of it's width ( For a 3/8" drill, it means when the "chamfered hole is visually maybe 1/4" wide)
gently, but quickly back out the cross-slide while feeding in the drill and BINGO you have a perfectly centered hole.

Why this works. Having the flute horizontal , means that when you deflect the drill, you have converted the drill point inot a single point boring tool. It also means that the drill point will form a small tit in the exact center of the hole , but the tit is smaller than the force being exerted by the drills 118 degree and as you now feed in, the drill itself will drift inward and remove the tit and be dead nuts centered on the turning work piece..
If you hold the drill bit off set for too long while feed in, you will actually get a chambered hole
If you back out the tool cross-slide support too soon or too fast you prevent the drill bit from shaving off the tit in a smooth manner, so it is a learned simultaneous move , but works incredibly well. I cannot tell you how long it has been since i used a centerdrill.

Rich
Rich_Carlstedt
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Re: Steady rest Q

Post by Rich_Carlstedt »

I should add that the deflection I add to the bit is a function of drill size
When I am drilling say a .080" drill bit, I maybe deflect the drill .003-.005 " only
When drilling a 3/4 " drill then i have .040-.050" deflection

Rich
curtis cutter
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Location: Curtis, WA

Re: Steady rest Q

Post by curtis cutter »

Rich_Carlstedt wrote: Fri Nov 23, 2018 4:21 pm I should add that the deflection I add to the bit is a function of drill size
When I am drilling say a .080" drill bit, I maybe deflect the drill .003-.005 " only
When drilling a 3/4 " drill then i have .040-.050" deflection

Rich
Thanks Rich. I am going to try this method.
Gregg
Just let go of it, it will eventually unplug itself.
ChipMaker4130
Posts: 187
Joined: Tue Dec 04, 2007 11:00 am
Location: Ivins, Utah

Re: Steady rest Q

Post by ChipMaker4130 »

Hey Rich, that's a beautiful solution! 50+ years of drilling and I've never heard anything like it. Gonna try it tomorrow.
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