Newb error

[Mog]

Went to work on my second pen today and now I've gone and done it. I melted my drill bit to an acrylic blank. The bit was just breaking through 2 3/4" and I locked her up. The two are now married tight. Is there anything I can do to save the bit and/or blank?

 

[Drstrangefart]

The blank is a loss. I've chipped a lot of melted plastic off my drill bit, and then bored as deep into some scrap hardwood as possible repeatedly until the excess was cleared out of the bit. Could work for you.

 

[Knucklefish]

Big hammer

I had this happen. No way to back out the bit. I had to take a hammer and break the blank loose and saved the bit. I just set it on the floor and pounded it until the bit came out. WEAR EYE PROTECTION!

 

[Mog]

One BFH, comin' up!

 

[76winger]

I have to wonder: What causes this? I've made almost 300 pens and pencils in the past thee years and have never had this happen to me yet.

Are you drilling them by hand instead of drill press?
Are you drilling straight through without backing out frequently to clear out shavings?
Are you forcing the bit through too fast, and thus heating things up too much?
Are your drill bits dull and generating too much heat?

Just wondering, because if your melting the blank something's not right in the first place.

 

[graham murfin]

SAVING DRILL

Went to work on my second pen today and now I've gone and done it. I melted my drill bit to an acrylic blank. The bit was just breaking through 2 3/4" and I locked her up. The two are now married tight. Is there anything I can do to save the bit and/or blank?

Hi
put it in your logburner, it'll be fine in the morning
graham

 

[Live2Dive]

I've turned coming up on 200 pens, and this has not happened to me either. I would maybe guess too high speed and not clearing the bit every so often.

 

[Mog]

Are you drilling them by hand instead of drill press?
Are you drilling straight through without backing out frequently to clear out shavings?
Are you forcing the bit through too fast, and thus heating things up too much?
Are your drill bits dull and generating too much heat?

I'm drilling them on my lathe with a 4-jaw in the head and a drill chuck in the tail.
I think I went for too much without backing out enough.
I may have been pushing the bit too fast.
Drill bit is brand new. Only drilled one other blank.
I think I was turning way too fast also.

So... lessons learned.
Slow down the turn speed. What is a good speed to run?
Take smaller bites before backing out shavings.
Don't drive in to fast.

 

[Rick P]

Lubrication! use a bit of Pam cooking spray on the bit.......helps immensely! And your left with a far cleaner, truer hole than you can possibly achieve without it.



(Ya I know but dont do it!.....this is a family site)

 

[ed4copies]

Put the blank, with the drill bit in the oven, about 150 degrees.

Bake for, say, 20 minutes. Take out of oven with oven mitt holding the acrylic and a vice grip holding the drill bit. Back out drill bit.

OF COURSE I have NEVER done this, but I have a friend who makes REALLY STUPID mistakes-----HE says it works!!!!

 

[greenmtnguy]

Experience is the mistakes you remember.!

 

[Rick P]

Put the blank, with the drill bit in the oven, about 150 degrees.

Bake for, say, 20 minutes. Take out of oven with oven mitt holding the acrylic and a vice grip holding the drill bit. Back out drill bit.

OF COURSE I have NEVER done this, but I have a friend who makes REALLY STUPID mistakes-----HE says it works!!!!

Of course not Ed! Funny how we all seem to have the same freind though isn't it?:wink:


Mog
Don't hold antler with your hands use the chuck on your lathe, I know this guy whose buddy cut his hands to ribbons that way!

 

[PenMan1]

Ed:
I know that same guy! And the oven DOES work. As long as you do not exceed 165 degrees, the blank may still be useable, if epoxy is used for glue up.

 

[PenMan1]

About you question of how fast, I drill at 500 rpms, simply because that is as slow as my lathe will go.

As soon as my new lathe arrives, I'll drill at 250 rpms.

 

[ed4copies]

Experience is the mistakes you remember.!

"My friend" made this one very often!!!!

Then he saw a demo of the Drill Doctor by one IAP member, named Hilltopper!! :biggrin::biggrin::biggrin:Suddenly, my stupid friend is using sharp bits and the problem, he says, has gone away!!!

 

[Mog]

Thanks for the help. I already destroyed the blank with a large hammer. It chipped off leaving the bit nice and clean. I thought I would be scraping residue for awhile.

 

[76winger]

400-600 is a good RPM range while turning most blanks. I've got the DP on 650 right now and it's been working good for me, but I can take it down to 250, so I may steal Andy's idea and drop it down to see how it works.

 

[studioso]

For me Pam has helped immensely. As well as making sure that the you r drilling nice and square: start with a center bit, if the final hole is bigger than 1/2" I always predrill with a 1/4 or so, and clear chips every 1/2-3/4.

Remember that the importance of lathe rpm is not set in stone, since actual speed depends on bit size.

 

[graham murfin]

melting

Hi
if you use a worm pattern drill it takes out all the cuttings even deep
This spiral is very thin and has loads of room for swarf
graham
http://tradetools.co.nz/category/FH

 

[Chris Bar]

Drilling too fast. Blank gets soft and grabs bit. Had this happen once years ago in ME dept lab...never again. Drill low speed, drill slowly, frequently back out to clear ships and clean bit.