Pen mill woes

[angboy]

I seem to be pen mill-challenged, and I'm wondering if anyone has any ideas or suggestions. When I first started using my pen mill, it seemed like everytime I tried to change to a different shaft, I couldn't get the cutter head off of the shaft it was on. There would be visible burrs on the shaft above the cutter head. It would seem like the set screw had moved some to where it was off of the flat side. So I would file the burrs off and finally be able to get it apart, or more often, I still couldn't get it off and the surrogate would do it for me, and would tighten the set screw on the new shaft I wanted to use, to be sure it was on there tight and wouldn't move.

Somehow, in my dumb logic, the set screw seeming to get offset well below the top of the cutter head, was causing these burrs near the top- I know, makes no sense. [] Finally, my dad was able to help me figure out that what actually seemed to be happening was that the whole pen mill seemed to be turning in the drill. So I got a drill that had an actual key to it, so I could (hopefully) tighten it tighter than the keyless one.

That's seemed to work for awhile, and it seems to make sense. But lately, I haven't had reason to change the cutter head to another shaft, b/c I've been doing a lot of milling on 3/8" tubes. So finally I go to change it last night, and once again, I can't get the stupid cutter head off! There are some more burrs that have developed! Not as bad as before, but still there. I tried filing them off and couldn't do it, but even if I did, I really don't want to have to use that solution everytime! No surrogate available, so I have to try to figure this out for myself now. [V]

I've felt desperate enough that I've thought about buying a cutter head for each shaft I use and just never changing them. I've seen, on a recent thread, someone (Don I think) refer to making shims to use, and then apparently not having to change the shaft/head everytime, but I'm not sure what exactly that means. I did recently get a combo belt/disc sander, so I could try that approach, but I have a feeling it may be over my skill level. Anybody have any great ideas? [?][?]

 

[clewless]

<Snip>I've seen, on a recent thread, someone (Don I think) refer to making shims to use, and then apparently not having to change the shaft/head everytime, but I'm not sure what exactly that means.<snip>

Angela,
You can increase the diameter of the mill shaft by taking a 7mm tube and essentially making a slimline pen piece to fit inside the larger diameter tubes of other pens creating a "shim" or "bushing".

I use the universal holder (see Jay Pickens' article)to dress the ends on the sanding wheel and have made bushings for the 7mm rod to fit the Sierra, Atlas and Cigar tubes etc. and now only use the pen mill on 7mm tubes.

 

[Daniel]

Angela,
I have the same problem with the Pilots I bought from P.S.I. or CSUSA. Most of my burs do happen from the set screw though. If I use the same pilot on several blanks, fine dust getting between the cutter head and pilot shaft will also make it hard to remove.
making sleeves for the 7mm pilot is the best way to not have to change the head. simply get a package of 7mm tubes. glue them into some fairly hard blanks. then turn them to the needed size for the various tube sizes. I've done this before. for me it was a fairly tedious task that required slow careful checking that I got the spacer turned to the right size. I also found that the whole thing was a bit to fidgity for me. the spacer wants to fall off the pilot while on the drill press. put it in the pen blank first and then you have to keep it from falling out etc.
A better solution for me was.
At work I have access to several machine shops and the machinests that run them. I managed to get one of them to agree to make me several pilots in various sizes. He told me what steel rod to buy, I believ it was 4140. the new pilots are harder and do not gather burs like the others. since then I have started making my own with my mini metal lathe. I have a collection of about 20 different pilots and have far less problems with changing the cutter head with these. dust will still cause problems now and then. But not as much as the burrs do. I to have thought of buying a head for every pilot.
I am thinking of trying to make my own cutter head though because 20 plus heads would be a lot of money.

 

[KenV]

From the discussion, I am suspecting that you are using the penmill for more than a few thousand of an inch at the end. Rich K makes the point that you should be able to use the pen mill in a handle (eg hand held instead of machine powered if the blank is trimmed on saw or sander to just over size. I made the switch and it is working much better as there is less torque on the end mill.

Paul in OK will sharpen the pen mill for a reasonable fee. A sharp one makes all the difference.

I purchased a few cheap piloted endmills from E-bay and use them on the heavy/hard woods.

The ultimate is to get a cobalt steel piloted endmill but they are so sharp they are dangerous. Use for pens only with by hand and carefully (See MSC for cobalt end mills).

I use corian sleeves to avoid changing inserts or buying more inserts for Emperor, elGrande, etc. Good use for scraps of corian

 

[woodmanplus]

I have use the same mill now for unnown number of blanks.
when I got the mill I turned a handle for it and epoxied it in. I have had no problems with burrs,(prayer) as of yet. The articles on shims is helpful.
Just my humble attempt.

 

[its_virgil]

If you missed this thread, maybe going back and reading it will help. someone even posted a picture of his shims to use one mill on all pens.

http://www.penturners.org/forum/topic.asp?TOPIC_ID=13238


Do a good turn daily!
Don

Originally posted by angboy
<br />I seem to be pen mill-challenged, and I'm wondering if anyone has any ideas or suggestions. [?][?]

 

[Pipes]

I haven't tried it yet BUT a guy at woodvrat that makes some nice pens ! TOLD me to put my pen mill in a old drill chuck and use it by hand and not to griond much just til it nicks the brass !! dino what he means as I have yet to turn a pen BUT I try to remember all this kina stuff !!!

 

[johnnycnc]

Hi,
In response to your predicament,I dug up my pen mill that I
no longer use.(the cutter head was dulling too quickly for my taste)
I use a disc sander and my version of a squaring jig.
As a machinist/toolmaker with 19 yrs expeience,I can say that Daniel's
use of a better grade steel for the pilots is a huge step in the right
direction.(a step further would be to use a hardening type steel,
machine the pilot complete, and heat treat,to harden the steel further).
The basics are that the set screws are marginally harder than the pilots,and rotational forces eventually push the harder set screw
around through the softer pilot steel.
The solution to using what you have is a minor modification.
The set screw needs a slight countersink to recess into the shaft.
With cutter head off,the flat area on pilot needs a shallow "hole"
machined into it,immediately under the set screw location.
This can be accomplished by a machinist,or at home by using a
(probably) cobalt drill,same size as,or
slightly smaller than the set screw diameter.
You could probably find one at a home center,thinking have seen these
at menards.Clamp to drill press table with flat facing up and drill into pilot about the angled tip depth into the shaft.As an alternative,a dremel tool with cone pointed stone could be used to
plunge this recess in, I suppose.
The idea here is that when you run set screw in,it goes on into
the recess, and mechanically locks the assembly in place,preventing
the set screw from migrating aruond the flat,pushing material(burrs)
as it goes.To be 100% effective,you also need to modify your set screw
or purchase "cone pointed" type set screws.You could carefully
modify yours on disc sander by grinding a slight chamfer around end
that goes into recess hole.(think sharpening a new pencil only a few turns,so to leave about half the screw diameter at the tip still flat,
and dont grind back up the length of screw more than 2-3 threads,or it wont have enough threads left to hold properly).
I would offer to modify your components for free labor if you wish,
shipping to be at your expense.(this might take me all of 10 minutes
at the shop I work at).Any ?
Sorry so long winded,hope this helps in some way!
John

 

[JimGo]

John, that's a great idea, thanks! I'd be curious to see what you designed for your jig.

 

[angboy]

Originally posted by KenV
<br />
From the discussion, I am suspecting that you are using the penmill for more than a few thousand of an inch at the end. Rich K makes the point that you should be able to use the pen mill in a handle (eg hand held instead of machine powered if the blank is trimmed on saw or sander to just over size. I made the switch and it is working much better as there is less torque on the end mill.

Uh oh... busted! You must have been talking to my dad during the last couple of days, after he was just here and was rather aghast when he saw how extra long I cut my blanks and how much I end up milling down. In fact, once he commented on us trimming a blank to "Angela length" which translated to "just too damn long!" []

And I've acutally gotten MUCH better and much more willing to cut things close, literally, but I know that I still leave way too much material hanging out at the ends. And there have been a few blanks that have shattered, and I knew that maybe if I hadn't been trying to mill down 1/4", I wouldn't have had that problem.

Anyway, you've all given me some good ideas to try- but I'm going to start with a PM to John, and by trying even harder to cut my blanks to as close as possible to the right length.

 

[TomServo]

angela: I tend to cut mine a bit over sometimes also, but another option is to cut the excess off with a saw before milling down... I use a pullsaw and do it by hand, but if you've got a bandsaw, more power to you

 

[OSCAR15]

I am not too pleased with the pen mill myself... The steel is soft, and I am on my third cutter head. The allen screw does cut burrs in the shaft. Worst of all, I have experienced a few blanks (One was 10 bucks)
being shattered to pieces while I was trimming the blank. I think I am going to try the sanding method, as it seems a better (but perhaps longer) alternative.

 

[its_virgil]

*Pen mill cutters can be sharpened and will work quite well.
*I don't think pen mills are intended to be used in a hand drill or drill press.
*Make a wooden handle for the pen mill.
*The pen mill is not used to remove LOTS of wood. More judicous cutting of blanks and using a disk sander to get them almost to the correct length will require just a small amt of wood to be removed.
*If the set screws on the cutter head are tightenen the cutter head should not turn on the pilot shaft. I've never had on do that, but I've never used a pen mill as a power tool...just a hand tool.
*Just some of my thoughts on the use of a pen mill.
do a good turn daily!
Don

 

[schellfarms]

I'm new to turning, and someone showed me a very simple jig you can make to mill the ends. Take 2 pieces of wood--I used 3/4" plywood and set them up at 90 degree angles to each other--looked like a capital L. I drilled cut a piece of wood small enough to fit into the miter slot of my disk sander, and attached it to the bottom back edge of the L--just under the 90 degree intersection. I drilled a hole for a dowel rod in the piece of wood facing the sander, and turned the last 3 inches or so of the dowel down so that a pen tube just fits over it snug. Then just pop the pen blank onto the dowel and slide it back and forth across the sander while rotating the blank to ensure a smooth edge. Turn the blank around and do the other end. Works great, is cheap, and easy to turn the dowels for any pen tube size!! Hope this helps. I never use the pen mill anymore.

sarah

 

[Max]

Sounds interesting, but I'm having a hard time visualizing exactly how this works...any chance of seeing a photo of the jig?

thanks,
-Max

 

[Pipes]

After having turned about a 100 pens I went to a disc sander and a jig after about the first 10 pens !! Pen mills IMHO are a waste a time IF you own a decent disc sander !! just IMO only now !!![]
But I had a disc sander already IMO it is so easy to do on a disc sander penmills are useless ....[]




http://affordablepipes.com/

 

[rtparso]

Not to go against the crowd but I use the pen mill in a drill press all the time. I often take off 1/8†and sometimes ¼†when I am a little sloppy. I won’t start another how to sharpen an end mill but I will say use a fine diamond stone to clean the crud off the long face before you use it. Remember it is a scraper not a cutter. It may seem too simple but I haven’t read it in this post, the set screw needs to be on the flat. While you tighten the set screw hold the shaft and rotate the cutter back and forth to make sure the set screw is centered and tight (I know tight is relative). The most important is that the set screw is centered on the flat. I built a sanding jig and did not like it. If you use the pen mill in a drill press it will cut a square a smooth face on wood and antler.

 

[schellfarms]

My hubby went out of town for a week and took the digicam with him. I'll post a photo when he gets back. sarah

 

[loglugger]

Ron, got a new pen mill a while back and it doesn’t have the flat like the old one.

 

[Pipes]

Originally posted by OSCAR15
<br />I am not too pleased with the pen mill myself... The steel is soft, and I am on my third cutter head. The allen screw does cut burrs in the shaft. Worst of all, I have experienced a few blanks (One was 10 bucks)
being shattered to pieces while I was trimming the blank. I think I am going to try the sanding method, as it seems a better (but perhaps longer) alternative.

Ya it does take a LONG time for me about 30 sec on each side IF I leave to much on then it MIGHT take a tad longer ...and some very very HARD woods can take a bit longer also !! But I try to only leave about 1/8 inch total extra I guess thats cuting close I duno BUT it works great for me ..I can even tell when I touch brass !! The disc sander changes its feel and SOUND !! Why anyone with a disc sander would bother with a penmill I swear is beyond me ! ?? Iam reading this to see why Iam wrong I must be everyone seems to use a pen mill in a drill ! even when I used a penmill for short time I used it in a old drill chuck and turned it by hand only jus till I saw the brass go bright !







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