# Woodchuck pen pro cutter life question



## Xander (Apr 8, 2012)

Just a few days ago I got a pen pro. I turned maybe 1/2 of an acrylic blank and one Black Tru-stone 2 piece blank. While turning the Tru-stone I noticed one 'corner' of the cutting edge seemed to be getting dull. So today I turned an acrylic 1 piece blank for a sierea and ... the pen pro wouldn't cut it. I ended up using my Benjamin's 3/8 Carbide spindle gouge.

Is this normal? Does Tru-stone dull the carbide that fast?


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## thewishman (Apr 8, 2012)

The black stuff is pretty hard - it may wear out a side of a cutter. Good thing there are three other sides.


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## chriselle (Apr 8, 2012)

Ebonite will do a number on the cutters, too.  On the difficult (dulling) materials try turning slower until you get down to the final passes and then crank it up.


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## EricJS (Apr 10, 2012)

I usually get about 20 pens per cutting edge. That's a mixture of wood, acrylic, trustone, & other exotic materials. Generally 3-5 of those are Tru-stone. Then I sharpen the cutter and do it again. 

If you have a fine diamond stone, lay the flat "top side" of the cutter on the stone & work it back & forth. (Always use a lubricant.) You'll be amazed how quickly you can resharpen the cutter.


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## Robert Sherlock (Apr 10, 2012)

I've noticed there are different types / grades of diamond stones...can you give specifics as to the one you use?


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## ashaw (Apr 10, 2012)

Acrylics - 20 - 30 pens before rotating the cutter.
True Stone - 10 - 30 pens before rotating the cutter - Depending on color.
M3 - 5 - 10 pens before rotating cutter.
Lava - 5 - 10 pens before rotating cutter.


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## Xander (Apr 10, 2012)

ashaw said:


> Acrylics - 20 - 30 pens before rotating the cutter.
> True Stone - 10 - 30 pens before rotating the cutter - Depending on color.
> M3 - 5 - 10 pens before rotating cutter.
> Lava - 5 - 10 pens before rotating cutter.


 
Well I was struggling to get 1 tru-stone with a NEW cutter. After that it would not cut acrylic. I'm going to have to factor in the cost of cutters into pen price. I'd say maybe 4 - 6 pens per cutter (not per edge, PER CUTTER) with Tru-stone. Still have not used it enough to see how it stands up to acrylic / wood.


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## EricJS (Apr 10, 2012)

Robert Sherlock said:


> I've noticed there are different types / grades of diamond stones...can you give specifics as to the one you use?


 
Robert, 

The one I have is a DMT Daimond Whetstone. They usually sell 4 grits; Extra Course, Course, Fine, and Extra Fine. I have the "Fine" and it works perfectly. Any size or configuration will work, as long as there is room to rub the cutter back & forth.


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## hunter-27 (Apr 10, 2012)

I'm guessing there are different qualities of inserts out there.  I have been using the same cutter for a long time, something like 40-50 pens of varying materials. I am on the last rotation but I expect to get another 10-20 out of it before it starts dulling too much to cut cleanly.  I'm sure variation in technique will also affect its life but I believe you should try a new insert before pushing the panic button.

Landon


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## KenV (Apr 10, 2012)

If you are using one of Ken Ferrell's Pen Pros with his cutter, you should be contacting him and talking about the short life  -

If you are using a knock off with a different insert such as those used in helical planers, the life will likely be much shorter --


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## darthintel (Apr 10, 2012)

I have the wood chuck pen pro and bought a round carbide cutter. Currently I have cut 75 pens with it ....5 deer antler, 2 Ebony, many acrylics and hard woods.

When I ran out of new cutting head, I placed the flat top side of the cutter on a fine diamond file and sharpened...didn't take much at all. I even tried an area using the file on the beveled edge with same results. Still cutting good! 

I have another new round carbide head as a back up if all else fails. 
I still cannot get the square inserts to cut ...as the round cutter does a fantastic job !


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## Xander (Apr 10, 2012)

KenV said:


> If you are using one of Ken Ferrell's Pen Pros with his cutter, you should be contacting him and talking about the short life -
> 
> If you are using a knock off with a different insert such as those used in helical planers, the life will likely be much shorter --


 
When I bought mine the Woodchuck site was having issues so I get one from another vendor but it is listed as a WOODCHUCK PEN PRO and came with the R2 and R4 cutters. I am confident it is a genuine pen pro with quality inserts.

People have said the black Tru-Stone is unusually hard so I'm not going to 'panic' at this stage. I'll do more regular pens and see what kind of life I get out of it. The use of a diamond file is a possibility I'll look into.

Thanks everyone for the input.


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## SCR0LL3R (Apr 11, 2012)

I have a different brand carbide cutter with a smaller disk. I have to rotate it at least once to do a black Tru-Stone two-piece pen. I use a progression of 3 diamond stones to sharpen it (I forget the brand I have), I think they will pay for themselves in not very long. I didn't originally buy them to sharpen these cutters but I'm glad I have them now.


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## leehljp (Apr 11, 2012)

I bought the Pen Pro back in January directly from Ken and have used it considerably although I have done only one pen. On the pen it was segmented with brass. The wood and brass turned without a problem and very smooth.

Going after the blank and letting the insert get hot and stay hot, - that can wear it down fast. I never will forget the first time I put a carbide blade to turn mild steel and did not use a coolant!  I didn't get a millimeter before the blade was ruined! You are not turning mild steel, but none-the-less, if the insert is getting too hot to touch, and continuing to cut without pulling back, or doing light cut - it will go dull quickly on hard material.

Sharpening it is simple, as others have said.


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## GoatRider (Apr 11, 2012)

Xander said:


> People have said the black Tru-Stone is unusually hard so I'm not going to 'panic' at this stage.


Not only that, it's extraordinarily messy. It produces a fine powder almost like laser printer toner. But it is gorgeous!


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## BSea (Apr 11, 2012)

GoatRider said:


> Xander said:
> 
> 
> > People have said the black Tru-Stone is unusually hard so I'm not going to 'panic' at this stage.
> ...



As has been mentioned, the black is really hard on cutting tools or all kinds.  And ditto on the mess.  I may never do a black tru-stone again.  But it is pretty.


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## carpblaster (Apr 11, 2012)

I got all 3 of the pen pro, only turned the pen pro with R2 in int once, use the other square one for close work on ends, the round one is kind of slow for me use it on dips and circles,but still the best tools on the market, I do  not use it on my deer antler till i get it close to finished,almost any sharp object will get the antlers turned down,if there is no marrow, if a lot of marrow i use the sharpest pen pro,love those tools


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## Xander (Apr 11, 2012)

GoatRider said:


> Xander said:
> 
> 
> > People have said the black Tru-Stone is unusually hard so I'm not going to 'panic' at this stage.
> ...


 
 NOW you tell me. 

I had to find out the hard way. Spent forever cleaning my apartment afterwards. My workshop is the dining area, only place with a hard wood floor.


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## PenMan1 (Apr 11, 2012)

Just a check list to make your cutters last longer and cut smoother.

1. NEVER use a Woodchuck Pen Pro (round or square insert) to round a blank!!!! Especially trustone, m3 or petrified wood. While the Woodchuck will accomplish the task, you have just "dimpled" the very sharp cutter. While you may NOT see this effect without a jeweler's loupe, this is much like shaving your face with a razor blade that has been used to cut leg hair. ALWAYS KNOCK OFF SQUARE EDGES WITH A BELT SANDER OR ROUGHING GOUGE.

2. Make sure that the Woodchuck is slightly ABOVE the center axis of the workpiece. Having the cutter too low will result in "cutting above the beveled cutting edge", again, ruining the cutter blade.

3. Do NOT overtighten the screw. While the insert should be tight enough not to move back and forth, the insert needs to be able to "co ck slightly left" to cut effectively.

4. If you hear the tool chattering or it renders "chippy" swarf rather than "ribbons". Stop the lathe and find the cause. (usaually a dull insert or tool rest out of parrallel).

5. Keep the tool rest as close as possible to the work piece. AND make sure that the cutter head stays level!!!!! Dipping the cutter head and getting it caught under the work piece can have devistating and dangerous results.

I've cut so may pens with a Woodchuck that the handle needs replacement. Following these instructions will keep your Chuckie cutter cutting like the razor that it is and will also help to keep you safe.


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## SCR0LL3R (Apr 11, 2012)

PenMan1 said:


> Just a check list to make your cutters last longer and cut smoother.
> 
> 1. NEVER use a Woodchuck Pen Pro (round or square insert) to round a blank!!!! Especially trustone, m3 or petrified wood. While the Woodchuck will accomplish the task, you have just "dimpled" the very sharp cutter. While you may NOT see this effect without a jeweler's loupe, this is much like shaving your face with a razor blade that has been used to cut leg hair. ALWAYS KNOCK OFF SQUARE EDGES WITH A BELT SANDER OR ROUGHING GOUGE.



I suppose this is the main reason why my cutter dulls so quickly... Of course if I round the blank with a roughing gouge I already did more than half the work without the carbide... might as well keep going with the HSS at that point. :/ 

At least I know what's causing the wear... I'll sand off my corners next time and see how much it helps.


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## Xander (Apr 11, 2012)

PenMan1 said:


> Just a check list to make your cutters last longer and cut smoother.
> 
> 
> 2. Make sure that the Woodchuck is slightly ABOVE the center axis of the workpiece. Having the cutter too low will result in "cutting above the beveled cutting edge", again, ruining the cutter blade.


 
The instruction sheet provided with the pen pro (written by Ken Ferrell) says...

"REMEMBER TO KEEP THE TOOL ON OR VERY SLIGHTLY BELOW CENTER!"

I can't go below center as my tool rest does not go that low, but I do have it just at center.


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## SCR0LL3R (Apr 11, 2012)

PenMan1 said:


> 3. Do NOT overtighten the screw. While the insert should be tight enough not to move back and forth, the insert needs to be able to "co ck slightly left" to cut effectively.
> .



Huh? Sorry, I'm not following your meaning. Either it can move or it can't. And why left and why does it have to be able to do this? I'm not trying to be an ass here, it's a serious question.


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## ashaw (Apr 11, 2012)

When turning I also use the Pen Pro.  I have not use any other tool since getting this.  I can get about 20 pens per edge on Black onyx true stone.  It cuts like hot knife going through butter.  Tool rest placement is critical.  I fact  I have a mark on all of my tool rests 
so that I do not have to guess placement.  If you are getting only one pen blank from a cutter talk to the person who you brought from.  I can tell when I have to rotate the cutter if I am trying to push too hard on the tool.  I by 10 inserts at a time.  They generally last me for about six months.


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## Whaler (Apr 11, 2012)

ashaw said:


> When turning I also use the Pen Pro.  I have not use any other tool since getting this.  I can get about 20 pens per edge on Black onyx true stone.  It cuts like hot knife going through butter.  Tool rest placement is critical.  I fact  I have a mark on all of my tool rests
> so that I do not have to guess placement.  If you are getting only one pen blank from a cutter talk to the person who you brought from.  I can tell when I have to rotate the cutter if I am trying to push too hard on the tool.  I by 10 inserts at a time.  They generally last me for about six months.



Like you the PenPro is my go to tool so I solved the exact height problem with an automotive hose clamp on each of my tool rest at the height for the PenPro. Any other tool I use I will have to raise the rest, the just drop it down on the hose clamp and ser for the PenPro agai.


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## Xander (Apr 11, 2012)

Well, this sucks. Either I got a 'bad' insert or .... the Tru-stone I got was exceptionally hard. Either way I have to say I'm disappointed.

I will contact the vendor but it's not their fault.


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## bitshird (Apr 12, 2012)

Ed, After reading the entire thread I have seen a couple of bad pieces of advise, 
! keep the cutting edge of the insert at or slightly below center, 
2. the harder materials should be done with the 4 inch radius insert, 
3. I don't use any other tool on a pen, other than a parting tool for tenon's, I turn the blank round with my PenPro, and then cut the blank to lengths and drill it on my lathe.
I'm not trying to be a smart a$$ but do not leave the insert loose as Penman 1 suggested, this will allow the insert to chatter or loosen up to the point of breaking.
I've made pens from the original non pliable tru-stone, and still done 3 or 4 pens per side, But the original is several times harder than the pen making Tru-Stone.
The only material I know of that does dull our inserts is Ebonite, and I don't know why, possibly the sulfur content, but this still hasn't been proven, I've spoken with the engineering department of the German company that makes our inserts and they are mystified as well.
Also you are putting the insert in with the flat to the top? Honestly I'm not trying to insult your intelligence, but this issue has come up in the past, BUT the inserts still cut properly, it just grabbed a lot.
I've never tried the black with gold matrix, so I've ordered a piece to find out what gives. 
also with your lathe, are you able to keep the tool level? or do you have to raise the handle to get the cutting edge to get on center? if you do, let me know, and I can send you a modified tool as presenting the cutting edge at an angle can cause problems, more safety issues than any thing else, but still better safe than sorry.
Also try running your RPM at 2500 or better, see if this helps, This is the first complaint I've ever had about an insert going dull that fast, and we have sold nearly 8,000 inserts in the past year.


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## Xander (Apr 12, 2012)

bitshird said:


> Ed, After reading the entire thread I have seen a couple of bad pieces of advise,
> ! keep the cutting edge of the insert at or slightly below center,
> 2. the harder materials should be done with the 4 inch radius insert,
> 3. I don't use any other tool on a pen, other than a parting tool for tenon's, I turn the blank round with my PenPro, and then cut the blank to lengths and drill it on my lathe.
> ...


 
Hi, thanks for the reply.
Just to repeat my last comment, I do not believe this to the fault of the Pen Pro. I think it's just the Black Tru-Stone I got was way harder than normal.

In answer to your points...
1)I read and followed the instructions. I have a HF lathe and the tool rest just goes low enough to get the cutting edge at center. The shaft of the Pen Pro is rather thick compared to a 'normal' tool.
2) I did ask about which insert would be best and the R2 was recommended. I will use the R4 in future.
I have the insert tight.
Yes, flat side up. This is the only way it can go with the countersink for the screw.
I keep the tool level, parallel to the floor.
I use 2 speeds, slow (about 650rpm) for drilling and fast (about 3000) for everything else.

Once again, I believe the pen pro to be a great tool and I am sure this issue is due to the material and not the tool.

Edit to add. There was some discussion about ebonite and the final thought was that it contains an abrasive which kills tools.


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## kenmic (Apr 16, 2012)

This is just my own personal observations on resharpening the Woodchuck Pro Pen Carbide Insert. I tried it. But, can't recommend it.  I used some honing oil as a lubricant on a fine diamond card file while lightly moving the insert around. Even after a good wiping, some of the oil, metal filings and  other debris accumulated in the screw countersink hole. While the carbide cutting edge was probably rejuvenated, the insert countersink hole was  deformed to the point the screw would no longer seat properly, required over torquing, and kept backing out. A new insert worked fine. I will gladly pay the going price for a new insert than take a chance on damaging another one. I think they are fairly priced compared to competitors, and I get three more sides after the first one wears down. I am very happy with the woodchuck brand.

One of the great things about IAP is all the point and counterpointing that goes on without personally attacking any one.Thanks for allowing my input. 
kenmic


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## PenMan1 (Apr 16, 2012)

Ken:
I fully appreciate your thoughts, and I was at best vague and at worst unclear about tightening the screw. I NEVER LEAVE THE SCREW LOOSE. But, on my tool, overtightening the screw will cause the Chuck to snap the blank (this is especially true with black and gold web trustone, Mexican Agate and mother of pearl). 

As far as rounding, I find that just knocking of the square edges with an 80 sanding belt moves my Tue Stone totals to around 50 pens per insert instead of 15-20. 

Additionally, whether you use the tool with "bevel up or bevel down" would be an important determination on cutting above or below the center. 

Sorry for the confusion.


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## larryc (Apr 24, 2012)

*Reviving this thread to inquire about sharpening*

Has anyone used the WorkSharp to sharpen the cutters for the Pen Pro?


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