Split Blanks

[Possumpoint]

Today has been a very interesting day. Early this morning the shaft on my old pen mill wrung off just behind the cutter head and it is no longer usable. No big deal, knowing that I've ordered a new cutter head for the newer mill. Two hours later, the new head arrives via UPS. I ordered a new carbide cutter head because I was disappointed at the short time the steel one lasted.

Very soon I find that the new head has a strong tendency to grab very hard hard wood and in fact, splits two glued up blanks. It works very well in softer woods however. I pulled the old steel head out of the trash and by eye sharpen it with a file. It does a much better job in very hard wood then the carbide bit, who knew.

It appears that there is such a thing as being too sharp. I really love learning all these tid bits the hard way.

 

[alamocdc]

Possum, it actually sounds like you're using too much pressure while milling. That's the only time I've had any wood catch and split. But I don't have a carbide mill, so I may be all wet here.

 

[JimGo]

I have one of the carbide trimmers, and Billy hit the nail on the head. Unlike the traditional trimmers (especially when they get dull), you don't have to push down hard at all; in fact, you want to use a light touch.

 

[OSCAR15]

Ditto to both answers...One thing I have found in sharpening the NON carbide head....
Put a flat diamond sharperner (fine grit) on a flat surface and run mill head on it. This keeps the four cutters the same lenghth, and the angle is perfect....

 

[Sylvanite]

Originally posted by Possumpoint
<br />It appears that there is such a thing as being too sharp.

Um, actually HSS will take a sharper edge than carbide. It just doesn't stay sharp as long. Some woodworkers prefer steel cutting tools over carbide for that reason. They simply sharpen a lot more often.

I have a carbide pen mill and am happy with it's cutting performance in all materials, but then I use it in a drill press and am very gentle with the cuts.

One problem I do have (and I don't know if it's common with the HSS version) is that it doesn't cut all the way down to the mandrel. That is, if I happen to touch a 7mm tube, then I wind up with a blank where the tube end sticks up a little beyond the milled blank end. This is easily rectified with a few swipes on a diamond block, but is still a nuisance. Does anybody else have this problem? If so, what can you do about it?

Regards,
Eric

 

[C. Scott]

I am very interested in buying the carbide mill from PSI. I do have a question though for folks who have them. Have you tried running the cutter at a high speed? The reason I ask is this. My router bits are carbide and it cuts at a very high speed. It seems like the carbide mills would do better with a fast speed and slow feed/light pressure.

I know it's been a long time since I have posted. I've just been too busy. BTW, I have tried the plexiglass finish and I love it!

 

[Possumpoint]

Based on suggestions given in another forum, I tried a different method with the carbide cutter on the pen mill. I used my 14.4 v cordless drill set on it's slowest speed and used a very light touch. The blanks are mounted in a mechanics vise on the work bench. Much better results.

G. Scott this is the carbide cutter head sold by PSI. I would think very high speeds would be very difficult to control the cutter, how fast or deep it cuts. My biggest concern would be safety in that I doubt it is built for that high a speed like a router bit. I experienced my biggest problems with it at the high speed my corded drill produced.