• Thanks for visiting The Penturners Forum today.

    There are many features and resources that currently you are unable to see or access, either because you're not yet registered, or if you're already registered, because you're not logged in.

    To gain full access to the forum, please log in or register now. Registration is completely free, it only takes a few seconds, and you can join our well established community of like-minded pen makers.

Drilling Acrylic/Resin Blanks

angelo49

Registered
Joined
Jun 19, 2013
Posts
2,827
Location
Lancaster, PA Brooklyn, NY USA
First Name
Angelo
When drilling these blanks there is always the risk of a blow out when the drill exits thru
the bottom of the blank.
FOR ME IT'S ABOUT 90%, NO MATTER WHAT DRILLS I USE.
So I cut the blank much longer than needed and drill past the tube length.
Then cut the blank to length and you end up with a fully drilled blank.
But you might end up with an unusable cutoff.
Now I cut the blank slightly longer than tube lenght and medium CA glue a piece
of any wood about 3/4'' in height to the bottom of the blank.
Drill untill you enter the wood, then cut off the glued piece and you're done.
This doesn't take much time at all. I don't remember where I got the idea from, but I'll
do this from now on.
 

Woody

Registered
Joined
Jul 12, 2013
Posts
12,812
Location
at home
First Name
no
Nice one Angelo I always cut my blanks longer than needed and cut the extra off after but as you say sometimes whats left is of no use
 

Vic Perrin

Moderator
Executive Member
Joined
Feb 23, 2014
Posts
8,215
Location
Rugeley Staffs
First Name
Vic
I must have drilled a hundred or more acrylic/resin blanks and you can count the number of blow outs that I have had on one hand. I cut the blanks just over the length of the tubes and drill straight through. I always drill on the lathe with a set of pin jaws. The drills I use are nothing special in fact they are the cheapest that you can get from UK drills. Whist drilling I retract the drill very regularly to clear the swarf. I drill at relatively low speed and the hand feed rate from the tail stock I make sure is very steady. Just before break through I slow the feed rate of the drill . I can hoestly say that I don't find it a problem.:thinks:
 

edlea

Lobbygobbler
Registered
Joined
Aug 1, 2013
Posts
4,693
Location
Blackpool
First Name
Ed
I blew the brains out of one the other day. .normally with very careful drilling I succeed but this time I was thinking of something else and forgot that I was nearing the end :rolling:
 

Buckeye

ペンメーカー
Executive Member
Joined
Oct 15, 2013
Posts
9,697
Location
UK
First Name
Peter
I never get blow outs and I only cut the blanks just slightly longer than the tube. What I do is mark the drill bit so that it has a mark the same length as the blank and as I am getting near to the end of the blank just ease back on the pressure and no dramas no blow outs.

Peter
 

Vic Perrin

Moderator
Executive Member
Joined
Feb 23, 2014
Posts
8,215
Location
Rugeley Staffs
First Name
Vic
I never get blow outs and I only cut the blanks just slightly longer than the tube. What I do is mark the drill bit so that it has a mark the same length as the blank and as I am getting near to the end of the blank just ease back on the pressure and no dramas no blow outs.

Peter

:thumbs::thumbs::thumbs::thumbs:
 

GSteer

Registered
Joined
Apr 9, 2015
Posts
362
Location
Soaked Cumbria, UK
First Name
Greg
I never get blow outs and I only cut the blanks just slightly longer than the tube. What I do is mark the drill bit so that it has a mark the same length as the blank and as I am getting near to the end of the blank just ease back on the pressure and no dramas no blow outs.

Peter

Pretty much the same here. I'm still in low numbers of blanks drilled (<50) but the only blow out I've had was cross-cut black palm. It caught right on the exist and kaboom, tis all a learning process. Can't say I've had any other issues but I'm rather a cautious driller letting heat dissipate as required.
 

angelo49

Registered
Joined
Jun 19, 2013
Posts
2,827
Location
Lancaster, PA Brooklyn, NY USA
First Name
Angelo
It's probably better in a 4 jaw chuck on the lathe, but I hold the blank
in a drill vise and use a drill press. The vise is only clamping on 2 sides.
I have several 4 jaw chucks but none of them are scroll chucks.
These are independent chucks, you have to dial in each jaw separately.
That's a real PITA
I should get a scroll chuck, but................
 

rayf6604

Registered
Joined
May 1, 2014
Posts
2,726
Location
Narrowboat dweller Willington, Derby
First Name
Ray
It sounds to me that you're drilling polyester blanks, and I've had the odd one blow out. Polyurethane or alumilite is much more forgiving. As Vic said, I rarely have a problem, my solution is drill from both ends. :thumbs:

Sent from my SM-G928F using Tapatalk
 

Lons

Fellow
Joined
Dec 17, 2013
Posts
4,753
Location
Northumberland
First Name
Bob
I'm the same as the others and never have a problem. Use the lathe and chuck and my drills are nothing special but they are sharp and I drill carefully. Blanks are always a little oversize and I always drill straight through, it's easy to feel and hear when the drill is nearing the end but I mark the drill anyway with marker pen and just wipe the mark off with cleaner when finished.
 

GSteer

Registered
Joined
Apr 9, 2015
Posts
362
Location
Soaked Cumbria, UK
First Name
Greg
They look interesting for problematic materials, although I won't be jumping about to replace my normal bits. Does anyone know what that particular shape of tip is called?
 

hawkeyefxr

Full Member
Joined
Jan 8, 2015
Posts
373
Location
Yateley Hants
First Name
ken
As the drill emerges from the blank it acts like your cutting brass,it try"s to pull it's way through, the acrylic blank cannot take this stress as the drill pulls it way through and it gives way where it's unsupported with a resulting chunk of acrylic being knocked out..
Set a drill depth stop, i am lucky in that i have one built into my drill, most have the threaded stop on the side with two nuts. I set it so it stops about 3mm from emerging then use my 12in disk sand to sand away the blank from the blind end still it meets the hole.
 
Warning! This thread has not had any replies for over a year. You are welcome to post a reply here, but it might be better to start a new thread (and maybe include a link to this one if you need to).
Top