How to avoid chipping out blank at nib

[Dominic Greco]

I've been working on some CSUSA European pens and have been having a small problem.

Mostly it's been with hard, dense woods like Bloodwood, Brown Mallee, Cocobolo, and hard brittle woods like Beech, Zebrawood, and Zicote. They're all so hard that they then to crack pretty easily. I find this happens with stabilized, as well as natural wood blanks.[?]

After roughing the blank to a cylinder, I use a freshly sharpened skew chisel and take peeling cuts. I can get an ultra smooth surface and this helps to cut down on the sanding time. However, when I get close to the nib, I seem to always chip out a bit near the end. Not all the time. But when it happens, it's just enough to be noticed and cause me to want to scream!

I normally rough the blank round, then taper the ends towards each bushing so that I don't blow out the blank (sort of make a saugsage shape). But as I sneak up on that final shape, I get a small chip out, or something similar. Am I being to heavy handed with the skew?

Anybody experience this? Any tips on avoiding this chipping out?

One thought was that this be a case where being too heavy handed with a barrel trimmer has caused stress fractures in the end. But this seems to only happen at the nib and not the other end of the blanks. Any ideas about that?

Thanks in advance.

 

[Ron in Drums PA]

Did you try a planing cut with the skew going towards the bushing?

 

[Dominic Greco]

Originally posted by Ron in Drums PA
<br />Did you try a planing cut with the skew going towards the bushing?

Ron,
When you say "planing cut", do you mean coming in at about a 45 deg angle, like a shearing cut? Cause that's what I do.

 

[GregD]

Dominic,
Try cutting your blank a little longer than necessary. I was having the same type of problem when using the skew. You might want to try a straight scraper with a light touch.

 

[Ron Mc]

Dominic,
After I glue in all tubes and square up my blanks I apply a small amount of CA to the ends of my blanks. I don't care if it's stabilized, hard wood, spalted, I do this with all of them. I haven't had a "chip out" since I started doing this.
It's especially handy with a heavily spalted wood.
Hope this helps,

 

[Old Griz]

Dominic, when you make the cut to shape the nib ends.. start the cut from nib end and work toward the middle of the blank... DO NOT cut off the blank... it is similar to doing the edge of a bowl (and I know you can do that, I have seen your work).. the concept is the same, just more important with a pen blanks...
I also do my finishing cuts with a Lacer ground skew that is scary sharp and presented almost 90 degrees to the blank, almost like a scraper.... basically taking a dust cut to finalize shape..
If you are ever down in the Hagerstown MD area in your travels let me know and we can play in the shop... I am home virtually all day...

 

[Ron in Drums PA]

These movies where made by Ken Grunke

Peeling cut movie
http://wr.avwa.org/turning_vids/02peeling.mov

Planing cut movie
http://wr.avwa.org/turning_vids/03planing_beveling.mov

More movies
http://tinyurl.com/9cqf8

 

[wayneis]

I was told a long time ago that if you started your cut at the ends (bushings) and ended the cut in the middle of the blank you will not have the chip out.

Wayne

 

[RussFairfield]

I have always been told that starting the cut at the bushing is the only way to do it. I could do that on a straight pen; but I don't make pens with straight barrels, and I can't get the shape right while cutting uphill.

I use thin CA glue to harden the wood after using the barrel trimmer. Cut a little long, a couple drops of thin CA, squirt acelerator, and cut to length. The CA won't get inside the tube if you are careful.

 

[CPDesigns]

Dom,

You can also cheat a little bit. After you get your blank turned to a cylinder, use a parting tool to bring the ends down close to the bushing. Just be sure to leave enough room for sanding. This will give you sort of a wooden bushing at each end. Then turn the pens with your skew until you meet the parted ends. When I first started I'd do this with my slimlines because I kept splitting the wood down to the brass as I'd be finishing my last cuts and it got frustrating. My technique has since improved enough that I don't do this anymore, but it sure saved quite a few blanks from the dustbin.

 

[ed4copies]

Dom.
I have a simple answer.

If you only get the problem on the nib end, are you always going in one direction? Perhaps, since you are not having it at the other end, you may want to finish the "cap" side, then re-mount the blank in the opposite direction and finish the nib. I favor turning right to left, my results are better in that direction. My nib is ALWAYS at the headstock. NO PROBLEM.


Another consideration, if the nib that's being "chipped out" is always on the tailstock end or next to a middle bushing (as in Baron and some other rollerballs), could it be "out of round" and therefore it is catching your skew?
Over time, you should try to improve in BOTH directions. As a practical matter, you want to make usable pens in the meantime. CHEAT!![][][]

 

[woodscavenger]

Here is my 2 cents. I had similar issues many pens ago.

I never cut from the bushing. I start at the middle and slide toward the bushing. It helps me get the curves right. When I have a wood I know I might have problems with (Curly koa, DI....) I get the shape and the nib down to within 1/8" then I put a sharp skew, short side about 1/8" from the bushing and roll the skew down toward the bushing. The finished cut looks like one of Ed's small, steep beads. This gives me a very clean cut eadge near the bushing. then I go back and finish the curve you started with. Just be careful you don't cut too steep or too quickly and end up cutting below the bushing.

 

[Dominic Greco]

Thank you all for the great (and I mean GREAT!) tips. I used a combination of several of the techniques mentioned and I ended up with a perfect pen.

BTW, I saved this topic to a MS Word file and will print it out and 3 hole punch it. This kinda' stuff is gold!

Thanks again.

 

[Rifleman1776]

Griz, what's a Lacer ground skew? [?]

 

[Ron in Drums PA]

Frank

Do a google on Alan Lacer, you'll find his skew