Drill PR ????

[RDH79]

I just cracked 2 PR stopper blanks that I was drilling for wand Kalidascopes. I was drilling slow with little pressure. My question is should PR and aluminite be drilled at a slow or fast drill bit speed? I leave extra so I can trim but I have been cracking too many. Thanks Rich H.

 

[Daniel]

Drill bit speed chart. Hut has one that works well for me. Slow or fast is determined by what you are drilling and the bit size you are drilling with. Plastics have a problem when you exit, use a backer block

 

[Manny]

Use Pam butter flavored on bits to reduce heat.
step you drilling from small diameter bits up to the diameter you need.
that helps a tons for me.

Manny

 

[BigguyZ]

Use Pam butter flavored on bits to reduce heat.
step you drilling from small diameter bits up to the diameter you need.
that helps a tons for me.

Manny

Recently, I started using MS with a squirt bottle on bits during drilling. Found it works really well, and I already had the bottle/ MS for sanding so it's not an additional item in my shop.

YMMV

 

[bitshird]

Also clear the drill bit often when drilling Acrylics, the drilled out material expands in the process notice what it does when you pull the drill bit out of the hole.

 

[Daniel]

Ken, My thought when i read your post is that the expansion is just the wastes frantic attempt to melt solidify and permanently bond your drill bit into the blank. So Rich do not feel at all bad about having problems with it. PR Is in fact out to make us all look like fools.

 

[THarvey]

Use Pam butter flavored on bits to reduce heat.
step you drilling from small diameter bits up to the diameter you need.
that helps a tons for me.

Manny

Any particular reason for the butter flavor? :biggrin:



I have used Pam. I have also found that a few drops of water, a slow drill speed and keeping cleared works well.

 

[Monty]

I drill mine on my lathe at the slowest seed possible with a forstner (sp?)bit . So far no problems except some minor chipout.
(Now watch closely as I blow out the next several I do.)

 

[Manny]

Any particular reason for the butter flavor? :biggrin:



I have used Pam. I have also found that a few drops of water, a slow drill speed and keeping cleared works well.

Everything is better with butter flavor on it..... duh.....

 

[DozerMite]

No one will probably believe me, but I hate to change the belt back and forth on the lathe, so I drill my own casts on the lathe at 1800 rpm without any problems. I only clear it out when I adjust the tailstock to finish the hole. The shavings just stream out on their own.
The blank does get warm, but it only takes about 30 sec. to drill it and I set it aside to cool down gradually so it doesn't crack as if you would shoot air through it.
I haven't had any problems so far, but haven't tried it on anything but my casts.

 

[BigguyZ]

No one will probably believe me, but I hate to change the belt back and forth on the lathe, so I drill my own casts on the lathe at 1800 rpm without any problems. I only clear it out when I adjust the tailstock to finish the hole. The shavings just stream out on their own.
The blank does get warm, but it only takes about 30 sec. to drill it and I set it aside to cool down gradually so it doesn't crack as if you would shoot air through it.
I haven't had any problems so far, but haven't tried it on anything but my casts.

I believe you. I drill and finish at 1800, turn at the fastest speed (3600 I think? Whatever a 1014 can do).

 

[DozerMite]

I drill,turn and finish at 1800. I hate moving that belt.

 

[Manny]

do you turn the lathe off when you are backing out?

Be warned
If you use a drill chuck on a taper on the dead side.
The vibration when you unlock the tail stock can cause the chuck slip out of the tailstock as you slide it back. At 1800rpm the blank will fold under the weight and fling the drill chuck and drill across the room. DAMHIKT

Manny

 

[Spec Grade]

Since I'm new here, what does PR mean?
Also, is there a section for acronyms?

 

[BigguyZ]

do you turn the lathe off when you are backing out?

Be warned
If you use a drill chuck on a taper on the dead side.
The vibration when you unlock the tail stock can cause the chuck slip out of the tailstock as you slide it back. At 1800rpm the blank will fold under the weight and fling the drill chuck and drill across the room. DAMHIKT

Manny

I make sure to seat the drill chuck well with a deadblow first, but I have had it go loose and start spinning along with the blank! Never while backing up the tailstock though, so it didn't go anywhere...

Not fun, either way.

 

[Manny]

I drilled my MT and use a drawbar on it.
MT's just scare me especially at high RPMs

 

[DozerMite]

Yes I turn the lathe off when I move the tailstock and when I back out the bit. Haven't ever had the chuck come loose, but better to be safe. I usually had a little trouble getting the chuck loose from the taper, I make sure it's seated well.
I don't encourage this method, especially those that have no or little experience, but this is just how I do it. If anything were to catch at that speed, it's going to hurt!

 

[Daniel]

PR= Casting Resins of various types and or the blanks made from Various Resins. I am pretty sure the PR specifically was used in place of Polyester Resin and has become commonly used for all resins.

 

[maxman400]

Since I'm new here, what does PR mean?
Also, is there a section for acronyms?

Yes look in the library section.

 

[RDH79]

Thanks for the ideas. I have used water but it seems that the bit doesnt cut to well unless i apply more pressure. I was wondering about the Pam. Do you clean the inside of the blank out with acetone. I was afraid that the oil would not let the glue stick. I will be trying Pam this evening if i can sneak it by LOML. HAHA

 

[Daniel]

Watch the sharpness of yoru bit as well. PR and other plastics are really hard on cutting tools.

 

[el_d]

I agree ith Daniel, The only time I get breaking or cracking is when the bit is dull.

 

[Glass Scratcher]

The only plastic that has given me a problem drilling is extruded acrylic rod. Have to use water.

PR I drill at 1800rpm, with a sharp bit and draw the bit out when shavings stop coming out. Haven't lost one yet. knock my wooden head.

 

[ed4copies]

Well guys, we're kinda talking apples and applesauce here.

I believe everyone is relating to their PEN drilling. Wonderful, but not always applicable.

I drill mine on my lathe at the slowest seed possible with a forstner (sp?)bit . So far no problems except some minor chipout.
(Now watch closely as I blow out the next several I do.)

The hole for a kaleidoscope is about 3/4" so your experience with a "pen-size" hole MAY not be repeated with a hole of this dimension.

I drill lots of them, on the drill press. I go slowly (but that's ME). Mostly, I use a fair amount of water in the hole to keep it cool. Also have the advantage of getting LARGE blanks (all the ones that harden before Dawn is ready to pour, turn into kaleido blanks) So, I am NOT close to the edge-I believe this is another MAJOR factor in success.

 

[Daniel]

According to my speed chart
3/4" bit in Acrylic
twist bit N/R (Not Rated) but hardwood and brass are listed as 500 R.P.M. and 400 R.P.M. respectively

Bullet point bit is listed as 1600 R.P.M.
brad point bit at 250 R.P.M.

It looks like the very slow speed is the best bet.

 

[randyrls]

Since I'm new here, what does PR mean?
Also, is there a section for acronyms?

Yes; The IAP-Wiki has a page of acronyms and slang.

http://www.penturners.org/wiki/Glossary

 

[fredabe]

I keep a wet rag handy at the drill press when I'm drilling acrylic. I pull the bit out regularly and apply the wet rag to keep it cool. Haven't had any problems with it yet doing it that way

 

[DennisM]

Any particular reason for the butter flavor? :biggrin:



.

Its so when it flys off the drill bit in your face, you get a little flavor to go with the plastic...