# RPM for pen mills?



## underdog (May 20, 2012)

Just wondering what RPM is recommended for pen mills? 

I've just started having trouble with mine chattering in my drill press, and I haven't ever had any trouble before... The only variable I can think of is RPM or wear in my quill :frown:.


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## HoratioHornblower (May 20, 2012)

Have you ever sharpened it? It could be dull.


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## ed4copies (May 20, 2012)

underdog said:


> Just wondering what RPM is recommended for pen mills?
> 
> I've just started having trouble with mine chattering in my drill press, and I haven't ever had any trouble before... The only variable I can think of is RPM or wear in my quill :frown:.



One other variable--the angle of the blank.  Are you using a pilot that completely fits your blank?  (a 10 mm pilot shaft for a 10 mm blank)?

If not, your mill is contacting more deeply on one half of its' travel than it is on the other half---this is how I have blown up more resin blanks than any other SINGLE cause.

So, I no longer use a mill.


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## SteveG (May 20, 2012)

The chattering could be the result of the mill getting dull, or maybe the result of uneven sharpening. Some use these mills turning them by hand: very slow. A few years ago I made a little jig to use with my belt sander to square blanks. (See library article.) I have not used the pen mill since that time...not even once!


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## Dustygoose (May 20, 2012)

I have turned an insert with a 7MM tube for every kit I use.  I also sharpen my mills.  There are instructions in the Library.


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## gimpy (May 20, 2012)

I don't use pen mills, I use a dic sander


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## Xander (May 20, 2012)

Since no-one has addressed the question, just given opinions on the 'best' way to square a blank, I will.

The best speed for a pen mill is ... slow. I use mine on the lathe and the lowest I can go is about 700rpm. Slower would be better.


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## PenPal (May 20, 2012)

Jim,

Pic enclosed taken 5 yrs ago of the original penmill I ever bought in the late 80,s cost about 20 of our dollars (not for the faint hearted) then.

This was the only penmill available (made in America) at that time it is what was called at that time a Stepdrill. The smaller diameter is still a snug fit in the Slimline brass, the step is at the end of the 1/4 ish and beautifully reams the brass lightly at an entry angle and cleans any residue in the brass facing the blank at the same time.

Now I predominately make Slims and derivatives and have made huge numbers of pens, I use this on every Slim I make it is in top nick to this day made from tool steel. I have tried in this my Country Australia to get another reproduced however also in the US mixed success.

There are untold numbers of Engineering Companies in the US who grind high speed drills or Carborundum as a Step Drill to specification.

Now you dont have to take my direction only know this is the best for me and I glued a handle on it and only use it this way. I love the fact that it does not penetrate the other end of a blank like the commercial ones now they can cost you through inattention both skin and vital bits from your holdin hand this one is safe, the ones now protude past the end of the blank (ouch)

IMHO Step Drills of various sizes are the ideal used by hand.

All of my mates over the years used their Step Drills like this in battery drills or lathes all are history years ago.

So my answer is use by hand whatever you choose.

I use a right angle device on a sander disk platform after cutting the glued blank close to size to acheive a clean hole to sit the blank square to the disk the rubbish (excess glue etc) needs to be removed somehow I use this stepdrill.

Sounds like a hobby horse? well it is and this question is raised ie yours ad infinitum and will continue for the duration of the IAP.

Please look in the Library of the IAP for the multitude of facing, drilling devices, methods this is mine. Works for me.

Kind regards Peter.


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## 76winger (May 20, 2012)

I use the hand drill when I'm using my pen mill, and probably only running it a 200RPM or less. 

Mine too is getting dull and chatters on occasion. Needs replaced (since it's carbide tipped and I don't have anything to sharpen it).


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## Jim Burr (May 20, 2012)

76winger said:


> I use the hand drill when I'm using my pen mill, and probably only running it a 200RPM or less.
> 
> Mine too is getting dull and chatters on occasion. Needs replaced (since it's carbide tipped and I don't have anything to sharpen it).



+1 & yup. More control and a good finish. Mill heads are easy to sharpen so keep an eye on 'em. After the trimmer, I always run a counter sink to flair the inner barrel. Helps with pen part insertion.


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## tool-man (May 20, 2012)

A pretty good discussion of this subject can be found in this thread:
http://www.penturners.org/forum/f14/barrel-trimmers-51926/


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## underdog (May 20, 2012)

To answer several questions...

The pen mills in question are both almost brand new. One is a 7 mm from Arizona Silhouette, and the other is the 7 mm from the Whiteside set I got from Woodcraft. I've only made 5 or 6 slimline pens between the two of them...

So no, they're NOT dull... and no I'm NOT trying to use them in the wrong size brass tube....

And yes, I'm slowly coming around to just sanding them. I just figured out I had everything I needed to do it too...

The adjustable mandrel goes in the tailstock with the shaft reversed, and the keyless chuck goes in the headstock with a bowl sander pad... and aWAY we go...

It did a very nice job on the ends of my last pen after I put a nice CA glue finish on between centers. Didn't chip it up like the pen mills tend to do...

I'm getting there. I think I'm actually ready for my pen turning demonstration tomorrow night..

Wish me luck!


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## Paul in OKC (May 20, 2012)

Guess I go opposite end. I run mine in a hand drill full speed and a light touch. Get less grabbing that way, at least for me. The chatter can be from it getting dull, as said.


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## ed4copies (May 20, 2012)

Paul in OKC said:


> Guess I go opposite end. I run mine in a hand drill full speed and a light touch. Get less grabbing that way, at least for me. The chatter can be from it getting dull, as said.



I had a mill that was sharpened by Paul once-----he has a totally different idea of SHARP!!  Which would make this a GREAT tool at any speed.  He even showed how to do it.  

I was NEVER successful at sharpening one even CLOSE to his.


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## underdog (May 20, 2012)

I will say that the AZ Silhoutte mill is quite a bit more sharp than the newer Whiteside...


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## Robertsmeets (May 20, 2012)

For what it's worth, I moved to a disc sander some time ago and it seems to work just find on all kinds of materials....


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## Crashmph (May 21, 2012)

Here's my two cents...

I think the Whiteside pen mills are great for the diameter of the inserts.  No slop there.  But the Mills are not that great from the factory.  If you get a mill that is all black, it will need be sharpened immediately.  There are some mills from Whiteside that have a noticeable grind on them, those are sharp right of the package.

I use my 18v cordless drill at the slow speed and it works for me...


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## Xander (May 21, 2012)

underdog said:


> To answer several questions...
> 
> It did a very nice job on the ends of my last pen after I put a nice CA glue finish on between centers. Didn't chip it up like the pen mills tend to do...


 
Why are you using a pen mill (or anything) after applying CA finish ? 

1) Cut blank to length, plus a little
2) Drill
3) Reverse paint if needed
4) Glue tube
5) Square blank ends ... whatever method works for you. I use a pen mill on the lathe.
6) Turn
7) Sand and Apply CA (wood blanks)
8) Sand/MM/polish

9) IF needed due to CA 'creep', use a jewlers file to clean ends. Just a few light passes

10) Assemble


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## leehljp (May 21, 2012)

Xander said:


> underdog said:
> 
> 
> > To answer several questions...
> ...



For me, when using the mandrel, breaking the edge between the CA'ed blank and bushing sometimes caused the CA to break unevenly. I used a sander penmill to even it up. I did use a knife to cut the excess off but the sandermill did it more evenly and smoothly. So, why not use a mill?

After I went to TBC some years ago and started finishing without bushings, the CA would still overflow the ends. Again, I continued to use a sanding pen mill to get the excess CA off the ends and smooth the ends to the brass/blank. I will add that after I use the sander mill to get the excess CA off of the ends of the tubes, I put the blank back on the lathe TBC and smooth/polish the edges up. 

I don't see anything abnormal about this to cause confusion.

*As a hint* to some who try to get that perfect match and finish between the ends of the blank and the fittings - IF you oversize the CA finished blank by something like .002 or .003mm and then gently and barely round over the ends with a few swipes of 6000 or 8000 MicroMesh, it makes for a great fit and feel. I have had a few pen fittings that were not perfectly round - out by .001 or .002mm and with a perfectly round CA'd blank, it can be felt. Sometimes and for some people, the finished blanks may be .002 or .003mm out of concentricity with the fittings. A slight overbuild of CA and rounding the edges of the CA with MicroMesh will make for a smooth transition. Sharp, squared endings can be felt if everything is not absolutely perfect.


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## underdog (May 21, 2012)

Lee's hit the nail on the head....

I have had nothing but trouble with apply CA glue finish on a mandrel. If the CA didn't lift and leave a cloudy ring next to the bushings after a wet sand, it would chip on the ends when removing from the bushings. I've tried everything I could think of to fix those problems... cleaning the blank with acetone or accelerator before applying finish, wax on bushings, no wax on bushings, score the finish down to the bushings with a very sharp skew... nothing seemed to help.

So I started turning the blank slightly undersized on the mandrel, and then applying CA glue finish between centers. That way I can build up the CA, then clean it up and sand to fit the hardware, polish it, then come back and mill the ends square again. But the mill tended to chip the finish too..

Hence the sanding instead. Works great! Of course I haven't actually assembled the pen yet... so I may have to use something besides a bowl sanding pad in order to get a good fit.

The process is still evolving, and I like the idea of rounding the ends just a tad to smooth the transition in case it isn't dead on...


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## Xander (May 21, 2012)

leehljp said:


> Xander said:
> 
> 
> > underdog said:
> ...


 
 My only 'issue' with this is .... why use anything as aggressive as a mill after finishing? Just seems counter productive. Yes I have had the occassion to remove excess CA after a CA finish but I'm of the therory that 'less is best', therefore I use the tool that will get it done but be as gentle as posible. I find a good flat jewlers file held square on the end of the blank and pulled in one direction a few times does the trick and needs no further treatment.

This (now off topic) subject of how to remove excess CA has as many answers as there are members of this forum. We can all learn from others experience.


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## underdog (May 21, 2012)

Why use anything as agressive as a pen mill? Because there was _that much_ CA glue hanging off the edges...

But of course I don't do that anymore. And now, the sander is so much quicker (and safer) than even the file.... 

By the way, I wonder what grit y'all are using on your sander/mills?


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## leehljp (May 21, 2012)

Xander said:


> leehljp said:
> 
> 
> > Xander said:
> ...



It may be just me but your statements come across as contradictory. . . "has as many answers" - vs - "anything as aggressive as a "mill' ".

Maybe you don't understand or know what a sanding pen mill is. It certainly is NOT aggressive. And, while hand squaring the excess by hand and a jewelers file can be as square/accurate (in the right hands) as a sanding pen mill, it is not MORE accurate. Remember, we are talking about excess CA that still needs to be squared. That is where a squared sander with 400 grit is exellent and leaves nothing to chance. 

If you have the perfect hand touch, that is great. One thing I have learned on this forum over the years is that not everyone has the same talent and skills. What some can do by hand (as apparently you can), other can barely achieve the same with the most accurate of tools. Jewelers files are fine and on occasion, I will touch one up with that. However, for many people without your skill set, squaring excess is better accomplished with a non-aggressive 400ish SP on a squared sander of one kind or other.


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## underdog (May 21, 2012)

Hmm.... sounds like I should bump the grit up a notch or two. 150 just might _be_ too agressive... :biggrin:


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## nativewooder (May 21, 2012)

Guess I must be old-fashioned but I was taught that penmills (at that time) were to be used in a drill press after the turning and sanding were completed, but before the finish (whatever) was applied.  This was probably before CA finish was more than experimental.  And as I now use a CA finish, I would only use a sanding mill from Rick Herrell to remove any excess.  A sharp penmill has always worked well for me, and I'm grateful for all the good ideas that have turned into improvements.


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## leehljp (May 21, 2012)

nativewooder said:


> Guess I must be old-fashioned but I was taught that penmills (at that time) were to be used in a drill press after the turning and sanding were completed, but before the finish (whatever) was applied.  This was probably before CA finish was more than experimental.  And as I now use a CA finish, I would only use a sanding mill from Rick Herrell to remove any excess.  A sharp penmill has always worked well for me, and I'm grateful for all the good ideas that have turned into improvements.



*Sanding mill* from Rick is what I use also. Got mine back in '08 or '09 at the latest and loved using that.


Jim,

There is nothing wrong with using 180/220/320 SP also to be more aggressive until one finds their happy and comfort zone. I do use 320 SP on occasion if I need to bring the blank down to the brass. But for CA'ed blanks done with TBC and a good layer overhanging, I don't take chances with over-scratching the end. I know that this is overkill but I am more interested in each blank and pen than I am completeing the pen. I may loose 3 to 5 minutes per blank doing it this way but I am not pressed for time. 

If I were doing this for money, and where "time is money", I would speed up the process and be a tad more aggressive. With that I am sure the experiences would also increase my skill level to the point that 320 or 220 SP would not hurt a thing.

If you are using 150 and it is working for you, keep on! Don't let my personal over-caution scare you. IF it (150) works and those around you like your work, then don't worry about changing.


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## Xander (May 21, 2012)

leehljp said:


> Xander said:
> 
> 
> > leehljp said:
> ...


 
It may be just me but your statements come across as contradictory. . . "has as many answers" - vs - "anything as aggressive as a "mill' ".
 Contradictory? How so. There are many methods for removing CA. A mill is one, but ...in my opinion...it's too agressive. There are better methods.

The original post (if we can get back to that) was asking what speed to use for a pen mill, and problems with chatter. This is therefore NOT a sanding mill. I stand by my comment that, in my opinion, a pen mill is too agressive to use for after finish clean up. A SANDING mill is probably OK if used with fine paper and a light touch, but for me it is way faster and easier to grab a jewlers file and in literally a few seconds I'm done. No setup time ... I don't have a drill press and use the lathe for everything.
OK, enough said, moving on.


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## jzerger (May 22, 2012)

I use a Diamond hone with handle (brand: Foredom)...it's already flat (comes in 400 or 600 grit) for cleanup (and sometimes rounding the edges).  It's easier for me to have the flat surface.


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## underdog (May 22, 2012)

Although I am now using a sanding method to take off the excess CA from TBC, I still have the chatter problem with my mill...

It chatters in my drill press using any of the three mills I have, and it doesn't matter if I turn the speed on the press all the way down to a couple hundred RPM. It still chatters...  It's a new development too. I never had this problem until this past Sunday...


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## jcm71 (May 22, 2012)

underdog said:


> Although I am now using a sanding method to take off the excess CA from TBC, I still have the chatter problem with my mill...
> 
> It chatters in my drill press using any of the three mills I have, and it doesn't matter if I turn the speed on the press all the way down to a couple hundred RPM. It still chatters...  It's a new development too. I never had this problem until this past Sunday...



Sounds like a DP problem. Suggestion:  Take your mills and a blank to another DP and try them out.  Do you have a friend in the neighborhood who has one?


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## Dragonlord85 (May 22, 2012)

Jim, try your mill in a hand drill and see if it still chatters. Sounds like something has gone wrong in your DP.


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## jmbaker79 (May 22, 2012)

What type/brand of drill press if you dont mind me asking? I have a HF Dust Collector...by that I mean a drill press from HF. :biggrin: Worked great for about 6 months, and then "chatters" at the slightest bit pressure. This was a DP problem, not a problem with my mill...the same result came from drilling on the DP.  as soon as it touched it sounded horrible. Produced a nice ocean wavy edge with the mill. It seemed to be the nut on belt pulley. Seemed to loosen, and allow the pulley to move up and down a little. Dont CA glue it in place...DAMHIKT. Anyhow cleaned it up, and really cranked down on it with a socket. Supposedly fixed but I drill on the lathe now, and use my pen mill on the lathe in a drill chuck...Just my 2 cents.


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## underdog (May 22, 2012)

Yeah... I thought I might try milling with a hand drill, mostly because I thought I might not be getting the mill concentric with the tube in my press...
But changing to see if it's the mill or the DP by removing the DP from the picture is a good idea.
Probably is the DP since it's a cheapie- not from HF but probably similar. I think it's a Master Craft brand.


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