Upside down reverse threading

[JonParticipant @jon]

I know its impossible using a drill chuck to mill – taken about 15 years ago done about 600 patterned out to leave 0.8mm wall x 6.5mm thick with milling cutter in keyed chinese drill chuck. Drill holes to go on pcd.

How do you honestly think these can be done by hand as one offs and beat cnc in china on price. Again drill chuck done well in excess of 1900 in 26 years, no cutters drop or chuck dropping out, materials 18mm thick.

Must not do it again blah blah blah

[Nick HulmeParticipant @nickhulme30114]

Posted by SillyOldDuffer on 13/05/2019 20:41:45:

Perhaps your chuck is jammed, it's a well known Myford problem…

Incorrect guess, guess again, it's what you're good at

[Nick HulmeParticipant @nickhulme30114]

Posted by Jon on 14/05/2019 22:29:24:

How do you honestly think these can be done by hand as one offs and beat cnc in china on price. Again drill chuck done well in excess of 1900 in 26 years, no cutters drop or chuck dropping out, materials 18mm thick.

Nice job!
I'm interested on the "Beat China on Price" bit though, what hourly rate did you base that calculation on?

[jacques maurelParticipant @jacquesmaurel42310]

look at my video:

**LINK**

JM

[ChrisBParticipant @chrisb35596]

Regarding holding an endmill in a drill chuck, I think it can be done ( thats what I had to do before I got direct collets) but, it depends on what chuck you use. I was using an old keyed chuck with a threaded arbor. I would be a bit concerned using a keyless chuck with just a jacobs taper to the arbor. Sideloads may knock the chuck off the arbor I think.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Jon on 14/05/2019 22:11:10:

Posted by Circlip on 14/05/2019 12:13:00:

"

Whats the problem with that?

Is it because its not a drill or a D bit or any other kind. "

Try milling with it. Once you've seen one rattle and exit the chuck, you won't do it again.

Absolute garbage been doing and not diy for 28 years, not once has anything worked loose except using ER collets

Seems unlikely given the way drill chucks are made: three jaws pushed together down a cone by a disk. Drills occasionally spin in mine due to their relatively poor grip and vibrating milling cutters come loose rather quickly.

My key type chucks are obviously inferior to ER32 for milling. Perhaps Jon is using a different type of drill chuck than the ordinary 3-jaw type, or has a better technique, or a stiffer machine than average? Can you tell us more Jon? Intriguing to know how you manage whilst others avoid milling with drill chucks due to poor results.

I must admit my keyless drill chuck grips rather better than the ordinary Jacobs key type. Perhaps it's OK for milling – I've never tried it.

Dave

[Nick HulmeParticipant @nickhulme30114]

Drill bit shanks are left soft specifically to give drill chucks reasonable purchase, milling cutters have hard shanks with a good surface finish, ideal for slipping in an inadequate holder and for encouraging the unwary to apply far too much tightening torque to said inadequate holder in an attempt to make it hold

As an aside, if tools are slipping in your ER Collets you are not following the correct procedures for using them 😀

[Author]

Posts