hollow chisel bit not fitting well
#21
The oak is only a backer so I don't get tearout. I'm making a through mortise for the piece I'm building.

While I appreciate the input, in truth, I'm not really looking for tips on cutting the mortise. My original query had to do with the mortiser bit not fitting well. I'm just curious if anyone else has had this issue and if they've found a successful work-around. I tried shimming it in with some tin foil and it made a difference but it didn't solve the problem. Upon further investigation, I realized that only one part of the drill bit was actually rubbing. I took a file to it and tried it again with slightly better results. The struggle continues...
How do you know you're learning anything if you don't screw up once in awhile?

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#22
Can you not find shim material about .005 to wrap around the top of the bit?
Gary

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#23
(09-05-2021, 10:36 AM)Gary G™ Wrote: Can you not find shim material about .005 to wrap around the top of the bit?

I don't know where to look for shim stock and I doubt I can get the tiny bit I need without having to buy a bunch. I've got a few different varieties of tin foil that I'll try out. I'm sure one of them is pretty close.
How do you know you're learning anything if you don't screw up once in awhile?

My blog: http://birdsandboards.blogspot.com/
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#24
(09-07-2021, 10:42 AM)mr_skittle Wrote: I don't know where to look for shim stock and I doubt I can get the tiny bit I need without having to buy a bunch. I've got a few different varieties of tin foil that I'll try out. I'm sure one of them is pretty close.

Try McMaster Carr - they have lots of shim stock i a bunch of sizes

Rick
Rick

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#25
If the difference in diameter between the bit and the socket is .005" then you would actually need a .0025" shim to wrap around and fill the void. Since you want to be able to get the bit in you should go a little less and probably try a .002" shim.
I recommend you try customer service again and ask them if one of their technicians can measure the shaft of another bit with a micrometer to verify it is within specs. and try and determine if your bit is actually out of specs.
If you simply want to try shimming the one you have drop me a PM and I can send you the small piece of shim you would need. It would fit in a simple envelope and only require a stamp. I always carry a shim stock assortment in stock for my own uses in the fabrication shop. My shim stock is made of spring steel and at that thickness you can easily trim it to fit with a good scissors
Proud maker of large quantities of sawdust......oh, and the occasional project!
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#26
I don't understand why it is tilting to the side when it is tightened.  I could understand not being centered when tightened but not tilting unless the part you tighten to is not parallel to the chisel part.    Have you tried  rotating the bit in the holder 180 degrees and see if the bit hits on the same side of the chisel or in the same direction in relation to the machine.    It seems that the bit would just press against the back side of the holder but not tilt and may not be centered.   Roly
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#27
Sorry it's been a while... Life, Am I right?

It's the set screw that is making the chisel shift. The set screw is just a threaded insert that tightens with an allen wrench. Since there is slop all the way around between the collar and the top of the chisel, the rotation of the set screw is causing the top of the chisel to basically tilt in the clockwise direction as the screw makes contact and tightens up. No matter which direction I spin the chisel, the business end cocks to the left just a little bit whenever I tighten the set screw down all the way. If somehow the collar, or the top of the chisel, was oval-shaped and fit snuggly on the sides, then the screw would just push it to the back of the holding collar.

I still haven't had any luck getting things working but my motivation has waned. I've been on the home stretch of a big build and thinking about how to rework the design of my beer carrier so that I can eliminate the big mortise. I'm leaning towards the fact that a 5/8 mortise isn't really in the capabilities of my hobby quality, bench top mortier. Considering it can easily do 1/4 or 3/8 mortises all day with "economy" qulity bits, I think that what I'll stick with.
How do you know you're learning anything if you don't screw up once in awhile?

My blog: http://birdsandboards.blogspot.com/
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#28
(09-18-2021, 07:51 PM)mr_skittle Wrote: Sorry it's been a while... Life, Am I right?

It's the set screw that is making the chisel shift. The set screw is just a threaded insert that tightens with an allen wrench. Since there is slop all the way around between the collar and the top of the chisel, the rotation of the set screw is causing the top of the chisel to basically tilt in the clockwise direction as the screw makes contact and tightens up. No matter which direction I spin the chisel, the business end cocks to the left just a little bit whenever I tighten the set screw down all the way. If somehow the collar, or the top of the chisel, was oval-shaped and fit snuggly on the sides, then the screw would just push it to the back of the holding collar.

I still haven't had any luck getting things working but my motivation has waned. I've been on the home stretch of a big build and thinking about how to rework the design of my beer carrier so that I can eliminate the big mortise. I'm leaning towards the fact that a 5/8 mortise isn't really in the capabilities of my hobby quality, bench top mortier. Considering it can easily do 1/4 or 3/8 mortises all day with "economy" qulity bits, I think that what I'll stick with.

I do the machine repair at a public woodshop and I run my own shop too. I would say that 5 thousandths of an inch on that is pretty insignificant. I doubt it would cause a big issue over the inch to inch and a length of the chisel goes through the mortiser collar. I would start by replacing the set screw, the tips of set screws can become damaged and cause a lot of issues. I've replaced several on pulleys and collars that solved problems. Does your delta have a removable collar insert, some machines do to allow different size chisels in them. You may find the rocking is from wear beyond the chisel and insert. it could be in the collar to machine connection. Since you say that you are applying a lot of pressure to get the bit through, try extending the drill bit out a tad further than on smaller bits, a 5/8 inch hole creates a bit more chips. Check for gib adjustment if the head moves at all, check for movement with someone else applying pressure. Often times I have to look beyond the initial problem to find the culprit. Did you compare the size of the LV chisels to other chisels you have? I have a set of Lee Valley premium chisels and they work well. I hope this helps. 

Paul 
Bel Air, MD
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#29
Why was the word s h i m starred out of this post?
Proud maker of large quantities of sawdust......oh, and the occasional project!
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#30
OK, I googled it and the word can be a derogatory term loosely meaning she him. 

What are we supposed to call the thin material we have been using in machine shops and in construction to adjust things for much more than a hundred years?  

Is this what is referred to as cancel culture?
Proud maker of large quantities of sawdust......oh, and the occasional project!
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