How do you square?

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JohnGreco

JohnGreco

Member
Joined
Dec 9, 2011
Messages
740
Location
Sewell, NJ 08080
Hi folks- I've seen a lot of different methods for squaring blanks and have been using a round cutter head from PSI in my handheld drill with the appropriate size shaft/sleeve. It leaves a bit to be desired to say the least and I'm finding myself less and less satisfied with this.

What do you recommend for a good precise method?
 
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I bought the little aluminum jig from PSI to use on my disk sander but it's so cheaply made it doesn't stay square. What a worthless waste of money.

I think what you're using is probably the best thing to use.
 
Put a drill chuck in your head stock, mount the barrel trimmer in the chuck, slide blank onto shaft.... press against cutter.
 
Been using the round cutter for a couple years before I replaced for a new one, did not relize how dull the old one was. After I turn the blank , if I use ca as finnish, I use a file to smoothe the edeges. But same as you , round cutter in hand drill . What problems are you having ?
 
I seem to be getting some slight wobble that requires cleaning up after I turn the blank. Could it be as simple as a bad/cheap kit? I recently replaced just the cutter head and have the same trouble.
 
I think I had the same issue. Does the barrel trimmer have a flat side? Mine does. I have to make sure the flat spot is not in the jaws. If it is even just barely in the jaws I get wobble. If I make sure it is not at all in the clamping teeth I get zero wobble. I also make sure the sleeve I have fits perfectly into the tube. If not then I make one that does.
 
How old is the cutter. Mine does a lot of chattering when it gets dull. I can typically sharpen the cutter once on my 1" belt sander but then have to replace it next time. When it is sharp and I have the right size shaft and sleeve I have always gotten a very good/square finished end. I normally hold the blank in a gloved left hand and use the trimmer in my cordless drill.
 
Seems to be all of the sleeves. They do fit somewhat snug, but the 7mm one also tends to leave a slight rim of brass on the inner edge once I get the cutter head in contact with the tube.
 
If you've got wobble on your barrel trimmer, something isn't fitting correctly. The shaft should fit snugly inside your brass tube (the inside the adapter, which should be snug in the tube) yet turn freely. Check to ensure you don't have glue inside the tube, causing you to use the wrong size shaft or adapter.

Even if the cutter was on the shaft slightly lop-sided, which would be just about impossible anyway, the lowest point is going to make contact all the way around as you spin it, keeping the edge of the tube pretty much square. I wouldn't recommend continued use in this scenario, but light pressure against the cutter get a pretty square end until you can get a replacement trimmer or cutter head.

I can't think of another scenario that would affect these things, the whole concept is pretty simple.
 
Xander said:
Put a drill chuck in your head stock, mount the barrel trimmer in the chuck, slide blank onto shaft.... press against cutter.
Click to expand...

Excellent idea. I mostly trim blanks on disc sander, and then lightly touch up with the barrel trimmer. I like your idea better than using the trimmer in a hand drill.
 
i have to sharpen the cutter head on mine pretty frequently. i clamp it in a vise and sharpen it with a file. when sharp it works great.
 
76winger said:
If you've got wobble on your barrel trimmer, something isn't fitting correctly. The shaft should fit snugly inside your brass tube (the inside the adapter, which should be snug in the tube) yet turn freely. Check to ensure you don't have glue inside the tube, causing you to use the wrong size shaft or adapter.
Click to expand...

The problem is that the wobble exists in the unit itself, I can see it when it is chucked up and spinning. :beat-up:
 
JohnGreco said:
Seems to be all of the sleeves. They do fit somewhat snug, but the 7mm one also tends to leave a slight rim of brass on the inner edge once I get the cutter head in contact with the tube.
Click to expand...

There are a couple of different size heads, 1/2" and 3/4"(I think, never really worried about the size). I do get a heavy burr if I use the larger one on 7mm tubes. The brass tube is almost smaller then the clearance ID of the cutter teeth so they tear more then cut therefore I only use the bigger one on larger tubed pen blanks and reserve the smaller one for the 7mm ones. Like 76winger said, make sure your sleeve is the right size, if you don't have one the right size make one out a scrape blank on a 7mm tube. Some of the trimmers come with multiple shaft sizes and a few sleeves but even then the set doesn't have a combination of shaft and sleeve to fit every size pen tube out there. I have had to make a couple and I have two complete pen mill sets.
 
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JohnGreco said:
76winger said:
If you've got wobble on your barrel trimmer, something isn't fitting correctly. The shaft should fit snugly inside your brass tube (the inside the adapter, which should be snug in the tube) yet turn freely. Check to ensure you don't have glue inside the tube, causing you to use the wrong size shaft or adapter.
Click to expand...

The problem is that the wobble exists in the unit itself, I can see it when it is chucked up and spinning. :beat-up:
Click to expand...

Do you always use the same shaft? Maybe it is bent.
 
JD Combs Sr said:
JohnGreco said:
76winger said:
If you've got wobble on your barrel trimmer, something isn't fitting correctly. The shaft should fit snugly inside your brass tube (the inside the adapter, which should be snug in the tube) yet turn freely. Check to ensure you don't have glue inside the tube, causing you to use the wrong size shaft or adapter.
Click to expand...

The problem is that the wobble exists in the unit itself, I can see it when it is chucked up and spinning. :beat-up:
Click to expand...

Do you always use the same shaft? Maybe it is bent.
Click to expand...

That was what I wondered at first, then I thought "What are the odds all 4 shafts in my kit are bent?" It could be my drill but I don't have trouble with any drill bits wobbling around on me.

Maybe I just need a higher caliber cutter set?
 
Don't know about other folks but I am out of Ideas. Not sure what else could be wrong. All I can tell you is I use barrel trimmers on a regular basis and don't have any problems until they start dulling then I sharpen or replace the head and I am off and squaring again with no problem.

Edit: When I first started making pens I initially tried the mill in my drill press but thought is was way too aggressive and that is when I went the gloved hand route. Haven't had a problem since. I mention this because of the suggestion to put it on the lathe. I would make sure I ran it at the slowest speed if I used the lathe.
 
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There are only a few things I can think of that can be causing your problem. First is a bent shaft, or the shaft is not the right size for the tube you are using. ANother is the cutter is not tightened onto the shaft and is moving. Check that the set screw is on the flat of the shaft and is tightened down. One other possibility is the tube is moving in the hole. If that does not fix things then look at your drilling and gluing procedure. Make sure that the hole in the blank is the right size and that there are no gaps. Make sure you have complete glue coverage especially at the ends of the tubes. Let the glue cure adequately. I like to go overnight even with CA just to be safe. If I am rushed, I still wait at least an hour.

The good news is that with a barrel trimmer, there only a few places where the inaccuracy can come in. Something is moving that shouldn't, either the shaft, the cutter, or the blank/tube. Address all three and you should solve the problem.

Hope this is of some help.
 
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If you put a new cutter head, i could be that the shaft is not made for it and a little bit smaller diameter so the the set screw bent the head a little and it's not perpenticular to the shaft. Some cutter head from china where causing that problem once. You had to get the shaft that goes with the head. (OK guys, don't fool around with that one ok, my main language is french and i might use the wrong words sometimes :))
 
Here is a thought.

First try this: grab the shaft and cutter head. Is everything tight? Is there any play at all. If no play then keep reading

This is not something that has happened with a pen cutter but has happened with a precision marine tool we bought. Like a barrel trimmer there is one head and several things that go on depending on the model being worked on. Everything fit perfectly but was working correctly. The problem was the hole in the head, instead of being true it was drilled at a VERY slight angle. Here is how we proved the issue to Volvo (they did not believe us until we proved it)

Use calipers to measure the thickness from the edge of the shaft hole to the outside of the head. Do this in several places. Then do the same on the other side of the head. This could prove that you have that one in a million tool that sat askew when it was drilled. This will put your mind at rest.

At this point, no matter what the cause is it sounds like you need to replace the whole trimmer, sleeves and all.

Hope this makes sense.
 
I've recently changed my method after watching a video Ed posted. I use to usd a barrel trimmer before turning the blank.

I now cut the blank closer to the finished size (I did this before but I pay more attention to it now), glue in the tube and then turn the pen to final size.

After this I put a pen mandrel in the tail stock with ±3" of rod sticking out. I then mount a 3" face plate I had (which I put a 1/2" piece of plywood on) which has sand paper on it held on with double sided tape. I then put the blank on the mandrel and move the tail stock in close to the face plate. Start up the lathe and slowly slide the blank into the face plate to sand to perfection.

I am quite happy with this method.

AK
 
Andrew_K99 said:
I've recently changed my method after watching a video Ed posted. I use to usd a barrel trimmer before turning the blank.

I now cut the blank closer to the finished size (I did this before but I pay more attention to it now), glue in the tube and then turn the pen to final size.

After this I put a pen mandrel in the tail stock with ±3" of rod sticking out. I then mount a 3" face plate I had (which I put a 1/2" piece of plywood on) which has sand paper on it held on with double sided tape. I then put the blank on the mandrel and move the tail stock in close to the face plate. Start up the lathe and slowly slide the blank into the face plate to sand to perfection.

I am quite happy with this method.

AK
Click to expand...

The method I show in number 6, here is an improvement over the pen mill approach.

The biggest single factor I run into with people "blowing up" pen blanks is the way they have treated the blank in the "facing" stage.

HOW you face a "finicky" plastic can be the difference between a pricey pen and a pricey "blown up blank"!!

ANY approach that uses sandpaper is LESS LIKELY to destroy your blanks.

FWIW!!!

Ed
 
ed4copies said:
Andrew_K99 said:
I've recently changed my method after watching a video Ed posted. I use to usd a barrel trimmer before turning the blank.

I now cut the blank closer to the finished size (I did this before but I pay more attention to it now), glue in the tube and then turn the pen to final size.

After this I put a pen mandrel in the tail stock with ±3" of rod sticking out. I then mount a 3" face plate I had (which I put a 1/2" piece of plywood on) which has sand paper on it held on with double sided tape. I then put the blank on the mandrel and move the tail stock in close to the face plate. Start up the lathe and slowly slide the blank into the face plate to sand to perfection.

I am quite happy with this method.

AK
Click to expand...

The method I show in number 6, here is an improvement over the pen mill approach.

The biggest single factor I run into with people "blowing up" pen blanks is the way they have treated the blank in the "facing" stage.

HOW you face a "finicky" plastic can be the difference between a pricey pen and a pricey "blown up blank"!!

ANY approach that uses sandpaper is LESS LIKELY to destroy your blanks.

FWIW!!!

Ed
Click to expand...

The biggest thing I got from your video was trimming AFTER turning to size. Before watching this I would use the barrel trimmer before rounding the blank which had to take a lot of material off. Doing it after the blank is turned there is a lot less material to remove so you can control things much better. Using sandpaper makes it a lot better as well.

AK
 
I too got frustrated with the barrel trimmer i had and went to the sand paper on a faceplate and a suitably sized punch from the HF set in the tail stock, I like it and it works fine BUT I wear out that little spot of paper in the center so quickly it is frustrating. I use 120 grit adhesive backed paper, what are others using?
Jeff G
 
One of the most common mistakes I see is cutting blanks too long and using the barrel trimmer/pen mill to remove way too much material. Then we wonder why the mill gets dull so quickly. The tool is for squaring the ends of the blank not for removing a lot of material.

The cutter head can be sharpened but is too often sharpened incorrectly. Check the article in the library for the proper way to sharpen a pen mill's cutter head.

Squaring after turning can be done but as Ed did, use sandpaper and not the cutter head of a pen mill. One catch and the newly turned blank can peel off the brass tube...quickly. A sandpaper squaring mill is a nice way to square the ends but again, the amount of material that is removed should be kept to a minimum. Do the squaring before reaching the final diameter.

A disk or belt sander is a viable alternative to the pen mill. But, the squaring jigs I have seen available for sale leave a little to be desired. There is an excellent article in the library for making a squaring jig for use with a disk or belt sander and the jig will be better than any that can be purchased.

Personally, I use all three but find the disk sander and homemade jig to be my go to method and the pen mill is used when traveling or working away from my shop.

Turn shims for larger tubes and get a better fit than is sometimes obtained by purchasing the various size pilot shafts.

Do a good turn daily!
Don
 
Thanks for all of the tips! I've gone ahead and ordered a new set from a different vendor, I think bent shafts are the trouble here. I'll update to let you know if that does the trick :)
 
If you have a A collet chuck, use your skew to square your blank. Once the blank is square, make a dimple in the end to get your drill bit centered.Works great.
 
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