EWT and Acrylic

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jgerman

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I'm having a really hard time with acrylics and easy wood tools. Specifically I'm turning bottle stoppers atm but it applies across the board.

I frequently get catches and chunks shattering out of the acrylics, I think it's when I am doing inside curves exclusively. Gentle curves seem doable but whenever I go for something tight it's an exercise in frustration. I'm assuming it's a mismatch between the concavity of the curve and the radius of the cutter.

My question is: would I be better served by a narrow spindle gouge in this case? If so, any recommendations?

I prefer the EWT for most turning since I'm not primarily a turner (though seeing what some of you guys put out definitely puts the urge in me), but I'm glad to buy more appropriate tools if it will lessen the frustration.
 
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jttheclockman

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Your catches are probably coming from sharp points of the cutter. Switch to a round cutter. No edges to catch. If you still get catches then you need practice of presenting the tool to the work piece. :)
 

low_48

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Is the end of the handle of the EWT higher than the cutter when you use it? That's proper scraper technique. You really need to take light cuts with some acrylics. I prefer a gouge for that type of turning.
 

Edgar

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You didn't say which EWT tool you are using.

I use an R2 "square" cutter for pens and for making gentle shapes on other things, but I mostly use a round cutter for bottle stoppers. You do have to be careful to not cut a steeper or deeper curve than what the cutter size & shape allows. As mentioned earlier, you also have to watch the angle of your approach.

I used my R2 cutter to put the bottom slope on the stopper in the photo below and I used my round cutter for the rest of the stopper shape. The top concave is essentially a plunge cut and the lower one is a sweeping cut.

Acrylic is a bit more touchy than wood, but the key is to stay within the limits of what the cutter size allows.
 

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jgerman

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I use my easy finisher for the most part on the acrylics, after I bring them round with the rougher I find the finisher does a better job on them for all of the shaping.

I didn't realize I was supposed to have the end of the handle higher, I thought the carbides approach was straight on.

I just went out and tried to be very delicate with my cuts and I was able to 'erase' the tearouts. But switching to the finishing pads I noticed a few tiny dots of chip out.... and tore out worse trying to fix it....

I think there's wobble in my piece when I don't have the tailstock there. I'm starting to think the wobble is what's causing the issue. It's why I've had such a hard time turning the top of the piece. So much so that I've had to leave the indentation from the live center alone on the top of my first stopper.
 

Sappheiros

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I use the rougher primarily and touch up with the pen finisher. One problem I've had is if the tool dips too low, it easily catches and shatters the blank. I do believe you should be approaching it on a straight line? I could definitely be mistaken.

What's the proper way to hold the EWT or any carbide-tipped tool for that manner in relation to the lathe?
 

Edgar

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I use the rougher primarily and touch up with the pen finisher. One problem I've had is if the tool dips too low, it easily catches and shatters the blank. I do believe you should be approaching it on a straight line? I could definitely be mistaken.

What's the proper way to hold the EWT or any carbide-tipped tool for that manner in relation to the lathe?


As close to straight on as possible and as close to the center line of the blank as possible. It's ok if the end of the handle is slightly lower than the blade (uphill), but you don't want the tool pointing down.

I really like the Rick Herrell flat top tool rests. They help me keep the carbide tools level and I like to use them for all other tools as well.
 

Sappheiros

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Thanks, Edgar! That's exactly what I thought. I have a couple of those level gauges to stick onto my tools, but just haven't yet. I always compare the level of the tool to the blank and mandrel before starting a new turning project. I haven't invested in any additional tool rests as of yet. I feel like I probably should...
 

Terredax

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I haven't used a EWT tool, but it sounds like it has a carbide insert.
I used a tool that had a small round carbide cutter and stood it on edge (perpendicular to the spindle) and eased it in to start a groove. Then slightly rotating the handle began to widen the groove and shaping it into a half round. I continued this while also moving to the side and pulling it out. By flipping the cutter 180 degrees, I repeated the process the opposite direction and I ended up with a nice concave shape.

This probably makes no sense and I'm sure it wasn't the correct method or use of the tool, but it worked for a concave shape that was smaller than the tool diameter.

Please be gentle when scalding me for improper use of a tool.
 

Edgar

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I haven't used a EWT tool, but it sounds like it has a carbide insert.
I used a tool that had a small round carbide cutter and stood it on edge (perpendicular to the spindle) and eased it in to start a groove. Then slightly rotating the handle began to widen the groove and shaping it into a half round. I continued this while also moving to the side and pulling it out. By flipping the cutter 180 degrees, I repeated the process the opposite direction and I ended up with a nice concave shape.

This probably makes no sense and I'm sure it wasn't the correct method or use of the tool, but it worked for a concave shape that was smaller than the tool diameter.

Please be gentle when scalding me for improper use of a tool.

No scolding here - if it works, it works. :)

I haven't tried going completely vertical with a round cutter, but I do sometimes cant the tool to one side or the other, which is similar to what you are doing there.
 

Edgar

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Thanks, Edgar! That's exactly what I thought. I have a couple of those level gauges to stick onto my tools, but just haven't yet. I always compare the level of the tool to the blank and mandrel before starting a new turning project. I haven't invested in any additional tool rests as of yet. I feel like I probably should...

The level gauge is a good thing to use if you are using carbide tools on standard tool rests. They aren't really needed if you use a flat top tool rest because the rest itself will help you keep the tool level without having to look at a gauge.
 

rholiday

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Keeping the tool level is important. Also, depending on which version of the finisher you are using, you may only be able to be 2 inches off the tool rest - any farther and you can get chatter. As to the diameter of the cutter versus the 'concavity' of the cut, I try not to get that too close because then too much of the cutter is in contact at the same time. For me, that can cause a problem. So, the cut I'm making with the finisher will generally be wider than the radius of the cutter unless I'm making a shallow cove. Deep coves, I want some extra width to the cove.

Bob
 

Edgar

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Keeping the tool level is important. Also, depending on which version of the finisher you are using, you may only be able to be 2 inches off the tool rest - any farther and you can get chatter. As to the diameter of the cutter versus the 'concavity' of the cut, I try not to get that too close because then too much of the cutter is in contact at the same time. For me, that can cause a problem. So, the cut I'm making with the finisher will generally be wider than the radius of the cutter unless I'm making a shallow cove. Deep coves, I want some extra width to the cove.

Bob

Good point about the closeness of the tool, Bob. I try to put the tool rest as close to the work as possible, leaving only about a 1/4" or so clearance between the blank and the tool rest. As I turn the blank down and the gap gets to be more than 1/2" or so, I stop the lathe and move the tool rest in a little closer.

I use the mini easy tools for small projects like pens and stoppers. For larger projects where more reach is needed, a tool with a much longer handle is needed to maintain good control.
 

Terredax

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No scolding here - if it works, it works. :)

I haven't tried going completely vertical with a round cutter, but I do sometimes cant the tool to one side or the other, which is similar to what you are doing there.

I guess it isn't really vertical, but more like you said... slightly tipped so it's cutting just below the center of the radius. I'm not sure if it would do any cutting if it was vertical, but I don't know.
 

DLGunn

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I see chatter in regards to tool rest distance to the piece was mentioned a couple of posts above.

Are you using a bottle stopper mandrel to turn these? If so, with no tailstock support I would guess. I don't turn bottle stoppers, but I do turn duck calls. I use a roughing gouge to get the majority of the material off, then switch to an easy wood type carbide tool to finish.

I do notice the tool cuts much better with the tailstock up. I realize with a bottle stopper, this might not be ideal or possible. Without tailstock support, I take very light cuts with the carbide tool. It takes a little longer, but I get very clean, smooth cuts.
 

Edgar

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I see chatter in regards to tool rest distance to the piece was mentioned a couple of posts above.

Are you using a bottle stopper mandrel to turn these? If so, with no tailstock support I would guess. I don't turn bottle stoppers, but I do turn duck calls. I use a roughing gouge to get the majority of the material off, then switch to an easy wood type carbide tool to finish.

I do notice the tool cuts much better with the tailstock up. I realize with a bottle stopper, this might not be ideal or possible. Without tailstock support, I take very light cuts with the carbide tool. It takes a little longer, but I get very clean, smooth cuts.

Good points, David - and your idea does actually work well with stoppers also.

I do use a stopper mandrel & I put a mandrel saver in the tailstock and put it up against the stopper blank to give it some support while turning the blank round and while turning the general shape that I want. Then I move it back out of the way to turn the top of the stopper and put final finishing touches on the profile (if needed). Only that last little bit is done without tailstock support and I use lighter cuts for that part.

In addition to having the tool rest very close, the tailstock support further helps minimize chatter. I use a mandrel saver rather than a live spur center so there's just a little marking on the top end rather than an indentation that needs to be removed.
 

MTViper

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In addition to having the tool rest very close, the tailstock support further helps minimize chatter. I use a mandrel saver rather than a live spur center so there's just a little marking on the top end rather than an indentation that needs to be removed.

I haven't tried a mandrel saver in the tail stock for bottle stoppers, may have to do that. At the Ft Worth turning club, a guess demonstrator pulled out his live center (cone with point in the middle) and screwed on a golf ball. He'd drilled a 3/4" hole in the golf ball so it fit tightly. Went home and flattered him (imitation is the sincerest form of ...). It works great with the bottle stopper mandrel. No divot to turn out, polishes the end. If you hit it, it cuts into the golf ball without damaging your tool.

Steve
 

flyitfast

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Everything most have said above. However, I haven't seen one thought.
How long have you been cutting with that cutter. If you don't rotate it, it can get dull and that will cause chatter and digs/catches.
Take the cutter off the tool and turn it upside down on a diamond sharpener and draw figure 8's to re-hone the cutter.
After you put it back on, keep track of how much you have used in all the positions around the cutter and rotate it every so often.
Gordon
 

Fish30114

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About a year ago, I was building some Italian themed pens for a customer--after a lengthy search I found some blanks at PSI that were flag themed and they had the Italian flag model. These were hard acrylic blanks--I had several of them explode on me--upon close examination they had small bubbles inside the blank--which I suspected caused then to blow--when I called PSI about the issue, the first question the tech person I spoke to asked was what kind of tool I was using to turn them--I was in fact using the round tipped cutter from easy wood tools--he told me immediately that carbide was the wrong thing to be using on blanks like this--his opinion was that carbide was so hard and had absolutely no flex to it, that it would cause a blank to explode (fail) easier than a steel tool which had a albeit minute, little flex to it. I can tell you this, I turned the rest of these blanks with my Sorby HSS Skew, and had no more blank failures, and oh yeah regardless of the actual cause of the exploding blanks, PSI replaced them. I use carbide tools a lot and like them--but when I get to a chippy blank of whatever type I go to HSS tools only--it has helped me IMO

Just a little FYI for perhaps a different perspective.


Regards--Don
 
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