Barrel Trimming

[darthintel]

Hello,
I have noticed a small gap between the nib end and the turned blank...very annoying - especially when I used a barrel trimming tool. The tool in question is a 2 blade carbide trimmer....could this be too aggressive on wood blanks? Bad tool ? It seems like when using the 4 blade HSS trimmer I don't have the problem.

Has anyone else experienced this problem with a barrel trimming tool?

Advice?

 

[Andrew_K99]

Is the trimmer cutting at 90°? If after sharpening it is tappered out at all you will get a gap.

 

[cwolfs69]

Hello,
I have noticed a small gap between the nib end and the turned blank...very annoying - especially when I used a barrel trimming tool. The tool in question is a 2 blade carbide trimmer....could this be too aggressive on wood blanks? Bad tool ? It seems like when using the 4 blade HSS trimmer I don't have the problem.

Has anyone else experienced this problem with a barrel trimming tool?

Advice?

i always do the last tiny trim with the barrel trimmer by hand. i turn and polish, C/A, etc all but the last few steps, remove the blank from the lathe and gently trim the tiyest amount by hand, then finish blank completely.

 

[raar25]

There are a couple possible issues here. First is the gap all the way around or just on one side? If it is on one side there may be too much clearance between the trimmer shaft and the copper tube so it is not cutting square. There should be very little slop between the shaft the brass tube. If so try buying a new shaft.

The second condition yields a gap on two sides as you hold it up to the light. Check to see if there is a tiny gap between the mill cutter and the shaft. You may be leaving a small sliver of brass tube proud above the wood so the nib does not push all the way in. This is easy to detect if you try to grab the end of the tube after squaring with your finger nail and it catches, there is high metal. Of course if the cutter is cutting a nice sharp corner and the nib has a slight radius on it the tip willl have an interference as well. Both issues can be fixed by cutting a chamfer on the end of your blanks with standard countersink tool.

Hope this helps.

 

[darthintel]

The 2 blade carbide trimmer is new ....I have not sharpened it...as it's very sharp. I will check the brass tube for a burr, and also check the trimmer to the shaft.

 

[nava1uni]

I use Rick Herrell's sanding mill and it works great. Check out his site. http://www.penturners.org/forum/f172/custom-made-penturning-tools-accessories-92501/

 

[Dorno]

The carbide trimers you have mentioned ? Where are they for sale I have not seen these anywhere ?

Thanks Ian

 

[dansills]

I use Rick Herrell's sanding mill and it works great. Check out his site. http://www.penturners.org/forum/f172/custom-made-penturning-tools-accessories-92501/

You use it to square the blanks or just to clean them square after applying CA?

 

[RichB]

If it is a slimline the tube get's up between the pilot shaft and the cutter and is not trimmed. Sanding works the best with a pilot.

 

[hunter-27]

If it is a slimline the tube get's up between the pilot shaft and the cutter and is not trimmed. Sanding works the best with a pilot.

Or one of these:

 

[Dorno]

The carbide trimmers you have mentioned ? Where are they for sale I have not seen these anywhere ?

Thanks Ian

 

[darthintel]

The carbide trimmers you have mentioned ? Where are they for sale I have not seen these anywhere ?

Thanks Ian

Penn State Industry has the carbide barrel trimmer..

7mm Barrel Trimmer: Carbide Cutter at Penn State Industries

 

[Joe Burns]

I use a barrel trimmer in a hand drill once I glue in the tubes. After I put the finish on I use one or Ricks sanding mills for the final fit. Works like a charm.

Joe

 

[leehljp]

I use Rick Herrell's sanding mill and it works great. Check out his site. http://www.penturners.org/forum/f172/custom-made-penturning-tools-accessories-92501/

You use it to square the blanks or just to clean them square after applying CA?

You can use it for both. I often made delicate blanks and the problem with "cutters" (sharp, carbide or non-carbide) is that they can catch and ruin an expensive blank with one snag! For that reason, I use a Rick Herrel type of sander. I have two, one is with course SP (sandpaper) and one is with fine. It might take a half a minute longer sanding down to size (and squaring at the same time) but I don't have any snags or catches as with a bladed cutter. For final sizing and cleaning up of CA, I use the fine SP.

 

[wouldentu2?]

Piece of sand paper on a flat surface and rub end of tube back and forth a few time. Easy, fast, fool proof.

 

[jlord]

Piece of sand paper on a flat surface and rub end of tube back and forth a few time. Easy, fast, fool proof.

This works ok as long as you can hold your blank perpendicular to the table top. Its like drilling a hole with a hand drill some perceive they are perpendicular when they really aren't.

 

[BSea]

Piece of sand paper on a flat surface and rub end of tube back and forth a few time. Easy, fast, fool proof.

This works ok as long as you can hold your blank perpendicular to the table top. Its like drilling a hole with a hand drill some perceive they are perpendicular when they really aren't.

If you have a drill press, and some punches, you can put a punch into the drill press, and a piece of sandpaper on the drill press table. The punch helps keep the blank perpendicular to the sandpaper. And instead of sliding back & forth, just twist the barrel by hand. There will still be some play between the blank & the punch, but it works much better than doing it free hand.

Obviously, just don't turn on the drill press.


EDIT: Having said that, my sanding mill from Rick Herrell should arrive today.

 

[wouldentu2?]

If you have already squared up the blank and turned it the amount of freehand sanding you need to do is next to nothing.

 

[IPD_Mr]

I use Rick Herrell's sanding mill and it works great. Check out his site. http://www.penturners.org/forum/f172/custom-made-penturning-tools-accessories-92501/

You use it to square the blanks or just to clean them square after applying CA?

Your blanks should be pretty square before you start turning. This should be done with a barrel trimmer. I have never cared much for the two blade trimmers. The only way to get carbide is if someone makes them for you. We had a member that was able to do some group buys a few years back and we have tried that avenue again but the guy doing it is no longer in business.

So suggestions:
Go with a four blade trimmer and keep it sharp. If you are unable to sharpen it evenly you might be able to talk to Paul in Oklahoma. He does the best sharpening of the trimmers I have ever found. It is great if you have a couple of these so that you can rotate them and always have a sharp one ready because the one you are using will always go dull at the worst possible time. Make sure you are trimmed and flush with the tubes before you start turning. Run a chamfering tool on the inside edges of the tubes to remove any burs and help the bushings to slide into place. Turn to size and finish. Now use a sanding mill to finish off the ends of the blanks. You can either buy a really nice quality one like what Rick sells or you can mount your trimmer upside down on the pilot shaft and use a piece of self adhesive sanding paper. Rick's is much easier with his punch and you can make a bunch of discs up ahead of time and stack them on a nail that has been hammered through a board.

Anyway I think that the two edge trimmer is the main downfall as you can probably get the blank out of square without an super tight fit on the pilot shaft and only two points of the blank/barrel being supported by the two cutter edges. These are just suggestions and worth just what you paid for it. Good luck and keep us informed of your progress and what corrective actions you choose. At some point this thread may help out a new turner down the road.

 

[WWAtty]

If you have a benchtop disc sander, there is a plan in the IAP library's "Tools & Jigs" section for a simple blank squaring jig. I made one and use it with a fine grit disc. I just give the blank a light touch against the disc until the excess material is gone. Follow up with a few twists of a reloader's chamfer tool to remove the burrs from the inside of the tube ends.

 

[nava1uni]

I use Rick Herrell's sanding mill and it works great. Check out his site. http://www.penturners.org/forum/f172/custom-made-penturning-tools-accessories-92501/

You use it to square the blanks or just to clean them square after applying CA?

I use it for both things. It works great. I have two and have different grits on both. I use it for final clean up on trim before and after turning and after I have completed the finish. If CA gets inside I use either a dental pick or a brass brush that fits inside the tube. I buy them by the set at Harbor freight or at a sporting goods shop in the fire arms section. They sell them for cleaning the barrels of guns and they come in different sizes.

 

[nava1uni]

If I am using a trimmer I use one with 6 blades. I bought it from Timber Bits a few years ago and it works great. I sharpen it with a credit card diamond sharpener.

 

[blade.white]

A two bladed carbide trimmer will cut a small devit into the softest spot on the end of the pen blank. Once it starts to cut deeper into the soft spot it is hard to get it square. Stay with the 4 bladed cutters or the 6 bladed cutters. There are many members taht have some good ways to sand the end of pen blanks on the lathe.
Take your cutter head and turn it around on your pilot shaft, set the pen blank back on the pilot shaft and you can tell where it is cutting the divet. You can also cut a small piece of sand paper , use a 7mm tube punch a small hole in the sand paper. Put the sand paper on the back of the cutter with the pilot shaft in backwards and flat sand the end of the pen blank.