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Mcostello
02-24-2017, 10:28 PM
For those of Us that use small tools such as boring bars in bigger tool holders this is an idea that makes using shims to get the tool holder high enough a moot point.http://s558.photobucket.com/user/mcostello/media/Tool%20holder.jpg.html

danlb
02-24-2017, 10:46 PM
I'm guessing that the mod is to add a screw that will lift the holder above the body of the tool post?

Dan

lakeside53
02-24-2017, 11:01 PM
Nice.

A small square of steel works under edge of the round thumb wheel too.

Mcostello
02-25-2017, 12:38 AM
Correct on the mod, shims get lost and take time on multiple parts, did not show lock nuts to hold position.

BCRider
02-25-2017, 12:47 AM
Sets of holders that come with the tool posts typically include a boring bar holder. The one I got has a holder that is set up to take a 1 inch bar and to hold it easily in the mid range of the post adjustment range with the bar at center height.

So why not use this holder and to hold smaller bars drill a piece of 1 inch cold rolled stock along it's axis to accept the size of the shank on the smaller bar? Drill and tap for a set screw or two and you can use the boring bar holder to hold the 1" to whatever adapter and use whatever you want. And it will keep the tool holder in the center of the clamping range like they should be used.

Of course there's more than one road to Rome. Whatever works.

LKeithR
02-25-2017, 12:53 AM
Nothing special there, all Multifix toolholders are made that way--of course they have a locknut so once you've set the correct tool height you
can lock it in place...

lakeside53
02-25-2017, 12:53 AM
Maybe you missed ? but this takes it above the range of the usual adjuster which only works until the tool holder is flush with the top of the tool post.

BC Rider - I have those but now use I use an ER25 with 1 inch shank for that. I also have a 5C native holder.

BCRider
02-25-2017, 01:14 AM
BC Rider - I have those but now use I use an ER25 with 1 inch shank for that. I also have a 5C native holder.

Well if you really must go all deluxe on us I suppose that's OK too.... :)

That would certainly be the classy way to hold various smaller shank boring bars. And the price on that sort of tooling has sure come down a lot in the past 10 years.

When I first learned about ER collets about 20 or 25 years ago the prices were such that I was pretty sure that ER stood for "Extra Rich". A condition that the person doing the buying needed to be. They are now down to where even lowly home hobby types can easily afford the collets and a number of various holders.

In fact I might just need to copy your idea when I'm shopping on Fleabay the next time around.

lakeside53
02-25-2017, 01:17 AM
It works great for drilling also!

Look for one that has a decent though-hole. Some have none; mine has about 9/16.

Some are almost free :http://www.ebay.com/itm/143mm-x-42mm-Straight-Shank-Collet-Chuck-Holder-for-CNC-Milling-C25-ER25UM-100L-/401265667975?hash=item5d6d4c2f87:g:sgAAAOSwLEtYiaB q

http://www.ebay.com/itm/C25-ER25-150L-Collet-Chuck-Holder-Straight-Shank-for-CNC-Milling-/222297528605?hash=item33c1f7191d:g:VcYAAOSwcUBYFHH w

MattiJ
02-25-2017, 03:14 AM
It works great for drilling also!

Look for one that has a decent though-hole. Some have none; mine has about 9/16.

Some are almost free :http://www.ebay.com/itm/143mm-x-42mm-Straight-Shank-Collet-Chuck-Holder-for-CNC-Milling-C25-ER25UM-100L-/401265667975?hash=item5d6d4c2f87:g:sgAAAOSwLEtYiaB q

http://www.ebay.com/itm/C25-ER25-150L-Collet-Chuck-Holder-Straight-Shank-for-CNC-Milling-/222297528605?hash=item33c1f7191d:g:VcYAAOSwcUBYFHH w

These cheapo ER chucks and collets are perfect for small round boring bars in lathe where small runout and exact tolerances are not needed.

LKeithR
02-25-2017, 05:30 AM
Maybe you missed ? but this takes it above the range of the usual adjuster which only works until the tool holder is flush with the top of the tool post.

No, I didn't miss it--Multifix toolholders allow you to position the top of the toolholder block above the top of the toolpost...

sawlog
02-25-2017, 09:25 AM
I have made bushings like used on CNC lathes to mount my boring bars in the holder for boring bars in the Aloris type holder. I need to make some for the Grizzly some day https://uploads.tapatalk-cdn.com/20170225/087ca160cef651798efb364b11247a1f.jpg.

This was for my small lathe that used AXA post


Sent from my iPhone using Tapatalk

TN Pat
02-25-2017, 09:35 AM
On the note about ER chucks - yes, they work great for holding boring bars as well as drills or end mills. In fact, I believe they will hold a boring bar with more rigidity than a vee-groove tool holder and two set screws. The only thing to watch for is clocking the bar the right way.

MTNGUN
02-25-2017, 11:49 AM
I have yet to encounter a problem with tool height, but length and rigidity can be an issue with small tools. A simple solution is to drill a scrap piece of metal to hold the bit, clamped with a couple of setscrews.

On the left, a piece of scrap holds a short bit so that it can protrude further. On the right, a piece of scrap is used to help clamp a 1/8" bit.
https://c1.staticflickr.com/4/3902/32294572873_a4f56dfd2b_b.jpg

danlb
02-25-2017, 12:28 PM
I noticed that you numbered your holders. That's a fantastic idea. I may use 3 or 4 at a time for a project, and they end up on the bench next to the lathe till I put them away in random order. Then have to look through all of them to find the exact one that I want. With the numbering I can put them back in the same order every time.

I'm stealing that idea.

Dan

quasi
02-25-2017, 11:47 PM
I noticed that you numbered your holders. That's a fantastic idea. I may use 3 or 4 at a time for a project, and they end up on the bench next to the lathe till I put them away in random order. Then have to look through all of them to find the exact one that I want. With the numbering I can put them back in the same order every time.

I'm stealing that idea.

Dan

me too.

lakeside53
02-26-2017, 12:57 AM
show us the other 44 (or more)!

MattiJ
02-26-2017, 03:56 AM
show us the other 44 (or more)!

If I win in lottery first thing I'll buy is 44 multifix style tool holders! :D

garyhlucas
02-26-2017, 10:49 AM
If you made a round holder for a small boring bar where the hole is as far off center as possible you could get additional height adjust by rotating the eccentric holder.

MTNGUN
02-26-2017, 11:17 AM
show us the other 44 (or more)!

They're mostly small boring bars, drills, and miniature form tools. Nothing exciting.

The number ID's are necessary for CNC tool offsets.

BCRider
02-26-2017, 01:01 PM
If you made a round holder for a small boring bar where the hole is as far off center as possible you could get additional height adjust by rotating the eccentric holder.

But if you use the boring bar holder it is already set to put the holder within the sweet spot of the clamping range when the hole is centered. So while it is a nice idea there's really no need.

Getting back to the original idea of allowing the holder to sit on the base so it is higher than the top face I wonder about the clamping power and forces on the wedge and in the main post body. Seems I recall that the metal left by making the cut outs to accept the moving wedge key leaves the post body a little thin in some places around the two cutouts. So not supporting the wedge along a good portion of it's length with a tool holder might not be a wise idea. Or at the very least perhaps it will reduce the clamping power by having the tool holder outside of the intended range of travel?