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View Full Version : Disaster to a sort-of rescue!



Gav
24-06-13, 07:44
So after an good start with a couple of slimline pens i got a bit adventurous and bough a couple of Classic Americana Fountain Pens from The Turners Workshop with a black European acrylic blank to go with them.

Got excited, hit the garage and despite things going well up to the turning stage, I ended up with this:

775

A total disaster left me with a very good reason to go to church on Sunday:vangry: and total bemusement as to where I went wrong!

This was on Thursday, and as I was away over the weekend, it played on my mind, which is probably taking a bit too seriously, but I needed to understand, it's the Engineer in me!

So, going through each step I think I've pin-pointed the areas that contributed to this 'experience'.


Drilling - I don't have a vice at the moment, so I hold the blank as best I can and go for it, what I noticed last night was that by doing this the blank wobbles (unsurprisingly) and the hole is flared at the top, so a gap exists between the barrel and the blank, so I guess when i got close to the final shape, there wasn't enough material and it just disintegrated.


Drilling Mk. 2 - Blunt drill bit, what is the best bit for drilling acrylic?


Turning - Tools not sharp enough, a cardinal sin I know, but I think I got too excited with getting to the final shape, and when I got to the final shaping I didn't touch up the tools and got a bit of chatter going on, I was forcing the cut a bit, and I guess that would lead to putting too much force through the blank with little material and thus snap!


Turning Mk 2 - This is just plain idiocy and was learnt last night too, lack of concentration led me to leave the tool too close to the work, it slipped forward and again chipped another end off :nonono:. Oh dear.

So, I think that between it all I've learnt a valuable lesson, mainly in the concentration stakes, as that could lead to some serious pain.

All this basic analysis led me straight back out to the Garage last night as I got home, and I had another go at the same pen.

This was when i realised the lack of drill vice led to the flaring at the top of the hole (filled it in with CA glue around the barrel) and how much of a difference sharp tools make.

I ended up with this:

776

The red band is due to the lack of concentration, some thing happened again, but this time I tried something to rescue it!

I'm happy to be torn to shreds over my newbie errors, and would love some advice on working with acrylic in general!

I won't lie, I'm not happy with the finished pen, the joint between the two acrylics is not as clean as I'd like and the diameters are out, especially at the band at the end of the cap.

I've learnt so much from this little episode though, and can't wait to turn the second of this pen I have as it writes lovely, and SWMBO has requested a pink one!

Sorry for going on a bit!

Jimjam66
24-06-13, 07:59
A good story, Gav. We all learn new things all the time, and sharing helps the rest of us too. I've found (as you say) that sharp tools are essential to passable results. Acrylic doesn't like heat much, and blunt tools generate heat which softens the material.

Its not too expensive to rig yourself up for drilling on the lathe. Have a look at Arc Euro Trade (http://www.arceurotrade.co.uk/default.aspx), Amadeal (http://www.amadeal.co.uk/), Warco (http://www.warco.co.uk/) and ??? (Dang, forgot the other one. Alex buys there, he'll chime in.). One of them sells a watchmakers scroll chuck (50mm jaws) for about 40. And most of them supply 16mm Jacobs chucks on MT spindles. And voila! You're drilling on the lathe, flaring is a thing of the past!

stevenw1963
24-06-13, 09:04
Gav,

Been there, done that, got the video & the T shirt :funny::funny::funny:
We all have.

As David said a Jacobs chuck is probably the most inexpensive way of drilling blanks & done on the lathe too.
A simple drilling jig that holds the blank in the drill press & is clamped to the press so no movement is another option.
I rather like the pen, even with the faults - it don't look half bad, nicely saved too.

bellringer
24-06-13, 09:45
i think the one dave has forgotten is MSC Industrial Supply Co. (http://www.mscdirect.co.uk/cgi/insrhm) and for dills i go to Metal Cutting Tools - Reamers, Small Hole Drilling, Drill Bits - Drill Service UK (http://www.drill-service.co.uk/) if you cant find a drill they will know were to get if the dont have it

Gav
24-06-13, 12:52
Thank you for your replies and comments Gents.

I'm afraid that drilling on my lathe is out for the time being, as it's an old Draper model and the tail stock doesn't have enough 'travel' (maybe half an inch) to drill without having to constantly undo the bolt that holds it in place on the tube it travels on. I'd put a picture up, but it's embarrassing!:whistling:

Does a job for now.

So, I'll look at putting something together for the drill press.

Jim
24-06-13, 18:23
As stated Gav, we have all been there and its a great learning curve, but its also good when you know your mistakes. A Jacobs chuck is what i use for drilling on the lathe, but my biggest contributor's are the Colt drill bit and pin jaws for holding the blank ...

It wont be to long before your looking back laughing at the mistakes that you used to make ... :thumbs:

yorkshireman
24-06-13, 19:35
Don't beat yourself up about it Gav. The main thing is to learn from it and above all enjoy yourself. Ask questions on here and you'll get lots of advice and encouragement, plus the odd bit of mickey taking but thats compulsory. The pen in the picture is a good effort but your next one will be better and I look forward to it

keith

wm460
24-06-13, 19:48
it's the Engineer in me!


Are you an Engineer?





Drilling - I don't have a vice at the moment, so I hold the blank as best I can and go for it, what I noticed last night was that by doing this the blank wobbles (unsurprisingly) and the hole is flared at the top, so a gap exists between the barrel and the blank, so I guess when i got close to the final shape, there wasn't enough material and it just disintegrated.


I do most of my drilling on my lathe now, got a great vice for the drill press but D/Press has too muck run out, proberly a result of 30+ use on a farm.



Drilling Mk. 2 - Blunt drill bit, what is the best bit for drilling acrylic?
I like this type of drill bits, there was a post a few weeks ago of where to buy them in the UK

Dewalt DT7926 XJ 29 Piece Extreme HSS R Metric Drill BIT SET With Case | eBay (http://www.ebay.com.au/itm/DEWALT-DT7926-XJ-29-Piece-Extreme-HSS-R-Metric-Drill-Bit-Set-With-Case/161016307130?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3 D1%26asc%3D27%26meid%3D8609334173277141034%26pid%3 D100033%26prg%3D1011%26rk%3D1%26sd%3D161016307130% 26)


Great save, excellent colour combonation :thumbs::thumbs:

Gav
25-06-13, 07:52
Are you an Engineer?

Yep, a Civil one so more used to massive buildings and roads than fiddly little pens!

I am a tenacious bugger though, and had a another go last night with the same pen kit, and rescued the tubes i made a mess of in the first picture.

783

Lessons learnt and applied:

Slower drill speed, I was drilling way to fast, so dropped it to about 560rpm, worked a treat.
Sharper tools, just a touch every now and then made all the difference to getting the shape as i liked.
Concentration, I took my time, little cuts, and stopped and checked from time to time! Obvious really :rolling:

Thank you for your input on this gents, really appreciated!

Gav

mervyn cadman
25-06-13, 08:22
Hi Gav Colt drills are the way to go I use the Extream2 and the Colt drill both has fine flutes and spur points.

Acrylics and resin blanks don't like vibration they also don't like slow speeds, drilling is a bit confusing as I have done in the past is to drill at a high speed (but with light cuts and a sharp drill), metal cutting drill bits are the best for drilling resin blanks, colt drills are just 2nd to none.

Most blanks explode because of the drilling if people are not comfortable with drilling say a 10.5 drill into a 20mm diameter blank then just drill a 7mm pilot hole first.

So vibration is your enemy sharp tools, high speed in the right conditions will be your friend

Regards Mervyn

:thinks::down:

mervyn cadman
25-06-13, 08:29
I will also add guys that some blanks will explode when turning or drilling because of the amount of hardener (catalyst) that was added to resin also blanks that have Pearl-Ex powder can have a tendency to crack.

Hope it helps

Merv

sbwertz
03-07-13, 00:48
One of the quickest, easiest and cheapest pen vises can be made from a wooden clamp (The kind with two screw handles.) Cut or file a v-shaped notch in each jaw. It doesn't have to be big...a quarter inch will do it for a pen blank, and still lets you use the clamp for other purposes. Make sure they are exactly opposite one another when the clamp is closed. Mark the center on your blank, and clamp it in your new wooden vise. Then position the wooden clamp so that the blank is properly centered under the bit and clamp the wooden clamp to the drill table with a couple of c-clamps to hold it in position.

Thank you for your replies and comments Gents.

So, I'll look at putting something together for the drill press.

clumsysod
03-07-13, 08:25
Cut or file a v-shaped notch in each jaw. It doesn't have to be big

Doesn't have to be V shaped simply drill through the joint, as long as it's at 90 degrees the two parallel lines each side will hold a pen blank square with no problem.