Pen Turning Questions

[Paul Fitzgerald]

Hey everyone!

I'm having a bit of trouble and was hoping someone might know what I'm doing wrong.

Question 1: I've noticed the tubes fit more snugly in harder woods than softer woods. I just got done drilling a Jatoba blank and there wasn't any slop when inserting the blank. Earlier I drilled some Cherry and noticed the tube fit more loosely. Is this common or do I need to check the runout on my drill press?

Question 2: I'm using Pen Maker's CA Super Glue (http://www.pennstateind.com/store/PKGLUE61.html) and a Basic 7mm Barrel Trimmer (http://www.pennstateind.com/store/PKTRIM7.html) from Penn State. I've tried letting the glue cure for anywhere from 5 minutes to 3 hours, and I'm having trouble with the tube coming out of the blank when trimming the ends square. I put the barrel trimmer in my drill press at about 3000rpm, hold the blank with vice-grips, and push the blanks into the cutter. I have to push pretty hard to get it to cut and it seems like the friction is heating the tube pretty good. Would this cause the tube to come out or am I not using enough CA glue?

TIA,

Paul

[Bill O'Conner]

never had much luck with CA glue for tubes. I like to use 5 minute epoxy for glueing in tube. I also use a hand auger drill the one that you turn the middle part to clean up the ends lets me be more gentle on the tubes. Might need to sharpen your trimmer ?


Bill

[michael gallagher]

Paul-

Slow down that drill press!!

One of the (many, I might add) problems i had when I first started pen turning was problems with my initial hole for the pen tube. By drilling too fast, it led to cracking, slight movement of the vice holding the pen blank - which caused the hole to be off center or "larger" in other areas, etc. I now drill the pilot hole at about 500 rpm's, which is about as slow as I can get my drill press per the digital readout.

I always make sure to take small cuts, backing out the drill bit to let it clear the shavings and not let the inner portion of the blank to get hotter than necessary.

I pretty much use thick CA glue to glue the tube into the blank. However, before applying the glue, I make sure I rough up the tube with a low grit sandpaper (like 60 or 80, whatever is available), to increase the surface area and friction points for the glue to stick not only to the tube and the inside of the blank. I also use an old screwdriver or chopsticks to coat the inside of the blank with CA glue prior to inserting the tube. Invest in a box of disposable latex gloves from somewhere like Home depot or Lowe's - 100 for about 9 bucks - to avoid getting that stuff on your hands.

Despite claims of quick cure, even after spraying an accelerant on there, I let the tube cure overnight to ensure a good bond: why take a chance on an expensive blank and blowing it out because you were impatient to get started? I typically make up a dozen or so at one time as my shop time is limited / sporadic. That way, when I am ready to turn there is something ready to go vs. sitting around and waiting.

I also use epoxy from time to time, but also let it set overnight vs. believeing the "quick cure" as I've been burned too many times.

Now, concerning the barrel trimmer - slow it down!!! The key here is light cuts that you can manage vs. going real fast, pressing down super hard on the blank, and having a large chunk taken out (see expensive blank comment above). I put my blank to be squared up in my vice, and put the barrel trimmer in my cordless drill. Then, I lightly start taking it down until I see a few brass curlies coming off. This doesn't take but about 30 seconds and is well worth it.

Hope that helps, and looking forward to seeing some of your finished product!

[Ken Fitzgerald]

Paul,

Michael gave you some pretty sage advice.

BTW...I just came in from the shop. I had destroyed a glued in tube by using the barrel trimmer at too high a speed.:mad:

I'm slowing it down on the next one!

[Paul Fitzgerald]

Wow! Good stuff!

Oops. 3000 was a typo. I meant 1000rpm. My trusty drill press speed chart said 1000rpm for 1/4", which is pretty dang close to 7mm... So I figured 1000rpm would be good for the drilling and the squaring.

I'll give 500rpm a try and see if that helps.

I don't have anything to sharpen the pen mill, but a friend told me Lowe's has a small diamond stone by the knives. Sharpening the pen mill couldn't hurt. :D

I do take light cuts, let the chips clear, and try to keep the bit as cool as I can. I also rough up the tube with 80 grit sandpaper and run a small piece of paper towel through the hole in the blank to clear out any residual dust prior to glueing.

I'll also try spreading some glue in the hole before inserting the blank.

Thanks!

Paul

[Don Carter]

Paul:
Michael has given great advice. I do rough up the tubes wit low grit sandpaper before gluing. I have used CA, epoxy, and even tried gorilla glue. I always turn back to medium CA. I have never had a tube come out. I do however, keep the pen mills sharp and I also make sure that my drill bits are sharp. I made some handles for pen mills and I do the barrel trimming by hand. Good luck and post how you are doing.
All the best!
Don

[Billy Dodd]

My brother taught me a trick on the hole drilling. If the tube doesn't slide in real easy I redrill it. I used to have a problem with the blanks cracking over a little time. Since I started making sure that the tubes have a little clearence I haven't lost any.
And as Don said, I made a couple handles for the pen mills and turn them by hand. Slower but accurate. I use a bit in my dremel to sharpen mine.
I also use 5 minute epoxy after sanding the tubes. And a regular pencil works great for inserting the tubes.

[Joe Pfeifer]

I used that same glue from Penn state and had similar problems. I switched to a thick CA from Rockler and haven't had a tube fail since. Glue it, slide it in and almost out once, and then quickly push it in to final depth. It will be set by then.

[Steve Mellott]

Michael:

1. I think the tubes should fit the same, regardless of the wood. Are you securing the wood in place while you drill it to keep it from moving?

2. I use the pen state barrell trimming kit in a hand drill while holding the pen blank in a clamp. If you are cutting the pen blanks to the right length, you should only have to trim approximately 1/16". You don't need to apply much pressure.

3. I use 5 minute epoxy and let it harden overnight. (I also sand the tubes before gluing and have never had a failure.)

Steve

[Russ Peters]

After doing a batch of pens I noticed that my trimmer seemed to be more "grabby" in the tubes. I cleaned the shaft with some acetone and it was like new again. Not sure if you would notice that with a drill press but if the shaft has build-up on it, it could pull the tube out. Just a thought.

[Paul Fitzgerald]

After doing a batch of pens I noticed that my trimmer seemed to be more "grabby" in the tubes. I cleaned the shaft with some acetone and it was like new again. Not sure if you would notice that with a drill press but if the shaft has build-up on it, it could pull the tube out. Just a thought.

I cleaned my barrel trimmer and it seemed to help.

I also sharpened it, which helped tremendously.

Unfortunately, I think the shaft is bent... it visibly wobbles. :(

Here's the Jatoba pen:
97481

Sanded to 600 grit, MM to 12000 grit, BLO, then Mylands Friction Polish.

Two things...

1) Do you sand with the bushings in place? If so, how do you keep from introducing metal flakes into the grain of the wood? If not, how do you sand?

2) Anyone have any tips on how to accurately turn and sand down the proper diameter? I seem to be having a bit of trouble in that arena. It's either a bit too small or a bit to large. Though I'm probably the only person who would ever notice.

Thanks!

Paul

[Ken Fitzgerald]

The bushings are a guide. Supposedly, if you turn them to the bushing size, they shoulf fit....HOWEVER....

I have better luck using a dial caliper and measuring the size of the parts that will mate with the upper and lower barrels. I turn them using a skew to about 0.007 larger and sand and finish from there.

[Paul Fitzgerald]

The bushings are a guide. Supposedly, if you turn them to the bushing size, they shoulf fit....HOWEVER....

I have better luck using a dial caliper and measuring the size of the parts that will mate with the upper and lower barrels. I turn them using a skew to about 0.007 larger and sand and finish from there.

Is the 0.007" to account for what's removed while sanding? If so, do you sand down to the exact size of the parts or leave them a little proud?

Paul

[Don Carter]

I do use the bushings but I check them with a caliper on a regular basis to make sure they are true and that the barrels are true. I have begun to do some closed end pens and some pens not using bushings but that is a discussion for another time.

Can you straighten the barrel trimmer, I believe mine can removed with set screw and you could roll it on a flat surface and see if it is the barrel or if it is a problem with how it is held in the cutter head.

All the best.

Don

[Ken Fitzgerald]

Paul,

Yes, the 0.007" is to account for sanding. I've read but haven't measured the thickness of a sheet of paper...supposedly it's approximately 0.003. If you lay a sheet of paper on a smooth surface and run your finger on and off the paper you can feel the edge. So you can feel that.

If you are going to error...make the wood just proud.....at least that's what I do.

[Paul Fitzgerald]

Can you straighten the barrel trimmer, I believe mine can removed with set screw and you could roll it on a flat surface and see if it is the barrel or if it is a problem with how it is held in the cutter head.

All the best.

Don

I think it's a little of both. I took the shaft out and straightened it the best I could. But upon putting it back into the cutter, it's still a bit wobbly. I think I might have been too rough on it getting a stuck brass tube off. Oops. :)


Paul,

Yes, the 0.007" is to account for sanding. I've read but haven't measured the thickness of a sheet of paper...supposedly it's approximately 0.003. If you lay a sheet of paper on a smooth surface and run your finger on and off the paper you can feel the edge. So you can feel that.

If you are going to error...make the wood just proud.....at least that's what I do.

Guess I need to go ahead and get me that fancy Wixey Digital Caliper I've been eyeing. My cheapo set only does 100ths of an inch.

I think that ought to help out tremendously.

Paul

[Steve Mawson]

I always sand with the bushings on the mandrel. Never had any trouble with metal coming off the bushings. Perhaps you need harder bushings.

Also, have had much better luck letting glue cure overnight. Rarely break wood off the tube since I started that.

[Paul Fitzgerald]

I always sand with the bushings on the mandrel. Never had any trouble with metal coming off the bushings. Perhaps you need harder bushings.

Also, have had much better luck letting glue cure overnight. Rarely break wood off the tube since I started that.

Steve,

So far I've been using the ones that came with my mandrel (http://www.pennstateind.com/store/PKM-FLC.html), which have a black coating of some sort on them.

I have a set of regular bushings (http://www.pennstateind.com/store/PKM-BUSH3.html) but haven't used them yet. These may be of better quality... I'll give them a try and see how they do.

Thanks,

Paul

[John Nowack]

this has been round and round but I has the same problem but it was a differetn casue in my case--I took mine back to WC--they did not have a any more but said it looked faulty because there is a raised taper up by the blades---this caused alot of friction and stretched the tubes---I just took some sand paper to it while it was spinning and knocked that part down--it has worked great ever since

[Brian Brown]

Hey everyone!

Question 1: I've noticed the tubes fit more snugly in harder woods than softer woods. I just got done drilling a Jatoba blank and there wasn't any slop when inserting the blank. Earlier I drilled some Cherry and noticed the tube fit more loosely. Is this common or do I need to check the runout on my drill press?



I don't have alot of experience with pens yet, but I had a thought about your hardwood/softwood question. Are you certain that the wood is really dry? If there is more than 6%mc, the water in the wood will turn to steam at just over 200 degrees. 200 degrees is not very hot for a drill bit, and a common occurance. This steam will cause the wood to swell. It is easiest for the swelling to go toward the bit, causing the bit to cut just a bit more wood. When the wood cools, and returns to original size, the hole may be slightly larger than when the wood was swollen. This would happen more in softer wood, because the more open cellular structure allows for larger pockets of water, and hence more steam. I may be all wet (or steamy) with this one, but would be interested to hear what others think.