Using Carbide Bits on acrylic/resin

[EuroChris]

I recently started using a carbide bit for turning pens. I have no problem turning a wood blank and can find the sweet spot quickly and easily. But when I try an acrylic blank I have problems. I can't seem to find a good angle for optimum removal, let alone a decent removal of material. Any tips or suggestions that anyone might have uncovered would be appreciated.

thanks,
EuroChris

 

[jttheclockman]

Chris

I do not know what you mean about an angle??? You drill as straight as you can using whatever tool you want. It is known that with carbide blades and bits that they can not be sharpened to the keenest edges that tool steel can. They are designed more for longevity. The angle that the carbide bit was cut at may not have been steep enough for brittle material such as acylic.

If I were you I would save the money spent on carbide bits and buy good quality steel bits. Maybe invest that money in a Drill Doctor and you will be way ahead of the game. Just a thought.

 

[LagniappeRob]

I'm thinking he means carbide tips not drill bits

 

[LagniappeRob]

Which tips are you using? I find with a square tip it grabs, I switched to a R2 radius tip and that went away.

 

[ed4copies]

When the blank is round, the radiused carbide tools will do a decent job. If you are starting with a square blank and using a carbide---good luck--I haven't been able to make it work well. (But I really have only tried twice---I can do it in seconds with a skew, why change?)

 

[jttheclockman]

OHHHHHHHHHHHHHHHHHHHHHHHHHHHH

As they say my bad:biggrin:

The only time I use carbide cutting tools if turning metals. I use a skew also and get great results.

 

[keithbyrd]

I have no problem with mine - if the blank is not round yet use the corner it cuts through very quickly then use the tip at an angle as flat as possible - 90 degrees- I find it cuts a little sow but very smoothly! I just got a skew and practicing with that but it is hard not to like how the carbide tool works!

 

[ctubbs]

My BowlPro from Ken works acrylics very well, but then, so does my skew. When using the carbide tool, as Keith stated, I use the corner of the tool to round the blank. Also, as per Ed, take the ends off first. Gentle lite cuts and high RPMs. Spin the blank as fast as you feel safe. Wear a face shield and take lite cuts. All the Old Hats (read that as Ed:wink:) tell us those techniques. Thank you Ed for all your educational endeavors.

Charles

 

[wood-of-1kind]

You may also wish to try the completely ROUND solid carbide cutters on acrylics and any more brittle material. Because of its round shape you are less likely to get a 'catch'. The key to getting good results and avoiding destroying your acrylic blank is to have as little space between your tool (carbide) and the material that you are spinning. Keep adjusting your tool rest as your blank is being turned to the actual finished size.

Some turners give up far too early on getting good results with carbide tools and go back to what they have been using previously (HSS). Guess that is OK, but if they spend a little time with their carbide tool and 'practice', good results will be achieved. YMMV

 

[Dalecamino]

I recently started using a carbide bit for turning pens. I have no problem turning a wood blank and can find the sweet spot quickly and easily. But when I try an acrylic blank I have problems. I can't seem to find a good angle for optimum removal, let alone a decent removal of material. Any tips or suggestions that anyone might have uncovered would be appreciated.

thanks,
EuroChris

I'm pretty sure Ken (bitshird) had a video demonstrating how to use his Woodchuck Pen Pro. I could be wrong about this. I am not able to tell you exactly how to use it, because I'm not able to explain it in text. You basically have to experiment with it. But, search for his video. May be on his website.

 

[chevyguy65]

We turn round with a HSS gouge then finish with a round carbide. It takes a lot of practice to get an even smooth finish. I think that you need to have some heat build up to help cut nice ribbons instead of chips. If im not on the lathe for awhile then it takes a few minute to get the right feel again. keep trying im sure you'll find the carbide is a great tool. But watch out for the ends. a lot of our blanks blew at the last few cutswhen trying to get close to the bushings!!

 

[Rodnall]

I set the speed medium fast and use the round bit just like a scraper. Set the rest back and engage the tip just below center with the handle higher than the tip. Once the blank is round, I switch to the radiused tip, still using like a scraper to final shape the blank.

 

[kooster]

Easy Wood Tools . . . straight in, parallel. No problem. Check out their site www.easywoodtools.com and/or the PSI site for a lesser expensive versions. With these guys, you don't need that "sweet spot" . . . it' basically successful each time. they even sell small bubble levels to attach to the shaft to ensure it's level. Give it a shot. Good luck !

 

[EuroChris]

Hey thanks everyone for the tips and advice. There was some really good things there and the next chance I have to get to the lathe I will be putting them to good use. If things are succesful, I'd like to say thanks again. If not I will just take note of the next set of problems I run into and come see you guys here on the forums.

EuroChris