CHIPS AHOY! need advice

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BeeAMaker

BeeAMaker

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Elkhart IN, USA
I posted about this once before but figured it was just a bad casting. However I now have 2 more blanks that just shred right into tiny chips. They are from a different vendor than the previous posting, but the 3 I talk about here are from the same vendor. I don't know the material as their web site doesn't say, 3/4" round.

It didn't matter what I did. I tried Low speed, High speed, medium speed, sharp tools, Carbide, tools, dull tools (in fact dull ones worked better but not much) I also notice that one color cut OK, but the other chipped more with the swirls.

I tried turning a blank for a friend and it right away came off in tiny tiny chips. Turned up the speed, helped a little bit but ultimately just made smaller chips. Stopping the lathe revealed a blank resembling the dark side of the moon, tiny little craters full length of the blank. The picture below shows the 3rd blank I tried. I barely touched it and chips-a-flying.

The first one did the same thing, I had two others of the same type (different color) so I thought I better see if I have the same problem with those, and I did. All 3 blanks chewed up like powder. And it seems to have "soft spots" the only way I can describe it is imagine turning a blank that was segmented with Desert Iron wood and white pine. I'll go as light as I can, barely shaving anything off and suddenly chips-a-flyin.

I can only think that it is me because I can't believe that people would continue to buy these types of blanks if you half to be so delicate with them. They just are not fun to turn, they are very, very brittle. Any advice?

This is about a half a second very light touch with a carbide
chips.jpg
 
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To me it looks like you are being too aggressive but that's only a guess since it is only a picture. It could be a number of things. You have said your tools are sharp, and you have tried different speeds and different tools. It could possibly your approach, such as angle of approach, above, below or on center, different for different tools.
Personally I would watch a few videos on turning acrylics like maybe some of the ones on the Exotic Blanks website or maybe something on youtube, and watch what they are doing. You can get specific like search for turning acrylic pen blanks with carbide tools or something like that.
It's probably something small you are doing and once you get it figured out you will be good to go.

Good Luck
 
CREID said:
To me it looks like you are being too aggressive but that's only a guess since it is only a picture. It could be a number of things. You have said your tools are sharp, and you have tried different speeds and different tools. It could possibly your approach, such as angle of approach, above, below or on center, different for different tools.
Personally I would watch a few videos on turning acrylics like maybe some of the ones on the Exotic Blanks website or maybe something on youtube, and watch what they are doing. You can get specific like search for turning acrylic pen blanks with carbide tools or something like that.
It's probably something small you are doing and once you get it figured out you will be good to go.

Good Luck
Click to expand...

Well, Ive watched plenty and not doing anything different. Other materials like Alumilite, and ones called "Acrylic" turn just fine. It seems to be the material that I have an issue with, I believe it is Acrylester. I had the same issue with one called Inlace Acrylester a while ago. I'll see if there are any specific videos on that type.
 
If you are chipping with carbide then I believe your angle of approach is underneath the blank. Your tool rest is too low. You would do best with a round cutter because it is the smallest area touching the blank. You have to treat the blank as if you are doing a bead on the end. You need to round over the edge to get started and then keep working your way toward the center. You do this on both ends and work toward the center. If your cutter drops below center now the blank will come down hard on the tool and if there is any chip in the blank it will explode. Best to be above than below. Always can work your way down but not up.

Now with that said. All these people putting out blanks have no quality control going on in their shops and it is possible the mix was too hot and brittle or who knows. If you can not figure it out it may pay to contact the vendor. But use the bad blanks to practice on. If you can correct things on a bad blank then you found your sweet spot in turning them. Good luck.
 
It looks like a polyester resin. And, yes, it takes more finesse than alumilite or acrylic acetate. However, it is not the material, it is your technique.

Best to find a local turner who knows how to turn acrylester, polyester and all the little esters--there is nothing like a hands on lesson. If you're going to the MPG, bring a few sticks and we'll find a corner and spend half an hour on a lathe--you will leave knowing what to do with those materials.

FWIW,
Ed
 
Listen to Ed. I have trouble with acrylester myself and what you may think of as light cuts may not me light enough. This material is finicky but makes a nice pen.
 
jttheclockman said:
If you are chipping with carbide then I believe your angle of approach is underneath the blank. Your tool rest is too low. You would do best with a round cutter because it is the smallest area touching the blank. You have to treat the blank as if you are doing a bead on the end. You need to round over the edge to get started and then keep working your way toward the center. You do this on both ends and work toward the center. If your cutter drops below center now the blank will come down hard on the tool and if there is any chip in the blank it will explode. Best to be above than below. Always can work your way down but not up.

Now with that said. All these people putting out blanks have no quality control going on in their shops and it is possible the mix was too hot and brittle or who knows. If you can not figure it out it may pay to contact the vendor. But use the bad blanks to practice on. If you can correct things on a bad blank then you found your sweet spot in turning them. Good luck.
Click to expand...

I did try the round Carbide, that is the tool that caused the image in the picture lol. I did find this,
http://mrwoodturner.co.za/pub/WorkingWithInlaceAcrylester_Instructions.pdf
Note that it suggest NOT using Carbide simply for the reasons you describe.

But you mention something else I had also thought about, the mix being too hot. If they are in a hurry to crank them out they may be mixing them hot, which also makes them too brittle.

I'll keep at it!
 
BeeAMaker said:
I posted about this once before but figured it was just a bad casting. However I now have 2 more blanks that just shred right into tiny chips. They are from a different vendor than the previous posting, but the 3 I talk about here are from the same vendor. I don't know the material as their web site doesn't say, 3/4" round.

It didn't matter what I did. I tried Low speed, High speed, medium speed, sharp tools, Carbide, tools, dull tools (in fact dull ones worked better but not much) I also notice that one color cut OK, but the other chipped more with the swirls.

I tried turning a blank for a friend and it right away came off in tiny tiny chips. Turned up the speed, helped a little bit but ultimately just made smaller chips. Stopping the lathe revealed a blank resembling the dark side of the moon, tiny little craters full length of the blank. The picture below shows the 3rd blank I tried. I barely touched it and chips-a-flying.

The first one did the same thing, I had two others of the same type (different color) so I thought I better see if I have the same problem with those, and I did. All 3 blanks chewed up like powder. And it seems to have "soft spots" the only way I can describe it is imagine turning a blank that was segmented with Desert Iron wood and white pine. I'll go as light as I can, barely shaving anything off and suddenly chips-a-flyin.

I can only think that it is me because I can't believe that people would continue to buy these types of blanks if you half to be so delicate with them. They just are not fun to turn, they are very, very brittle. Any advice?
Click to expand...

Well, I think that the answer to your problem has already been mentioned by other members, the only thing that I can add to it is that, if you have a fair number of those blanks that you would like to turn into pens, I would suggest you use the "Flap disc system"

Good luck,

Cheers
George
 
ed4copies said:
It looks like a polyester resin. And, yes, it takes more finesse than alumilite or acrylic acetate. However, it is not the material, it is your technique.

Best to find a local turner who knows how to turn acrylester, polyester and all the little esters--there is nothing like a hands on lesson. If you're going to the MPG, bring a few sticks and we'll find a corner and spend half an hour on a lathe--you will leave knowing what to do with those materials.

FWIW,
Ed
Click to expand...

MPG?

I know it is probably mostly me, but if this material is so finicky - why keep using it? It doesn't look any different than the other plastics that I have seen.
Is there things this material has over others?
 
I mentioned carbide round cutters because you mentioned. My go to tool to turn any pen blank is a skew. I will always finish a blank with a skew. I may rough a blank with carbide if I am too lazy to sharpen a roughing gouge. But I will always finish with a skew. That is a tool you really need to master. I always have recommended that tool any time people ask what tool to turn with. Every material has its does and don'ts. I have no idea what that material is that you are turning.
 
Thanks everyone for the advice. Bed time now, I'll put these chewed up blanks back on tomorrow and see if I can get it right. In the mean time I need to order some new blanks.
 
Have you tried a skew. You mention the carbide tools and most of those are used in a scraping technique. After the first chip out scraping will tend to continue the chipping.

Speed can also be your friend. Slow speed will tend to result in fewer bigger bites and high speed will give you a lot of small bits and more control. Imaging cutting down a tree with an axe or a chain saw.
 
Actually there are a couple reasons to continue turning it, for me number one is it makes me a better turner--put something on a lathe and I will make a pen. I don't much care what it is.

Now, if it is inlace and you do it often every day, it turns VERY quickly, polishes like glass, has colors that are very deep (lots of mica is possible) and colors stay separated since it is made "hot" and cures very rapidly. I know of no other blanks that are as "pearly" and "deep" as inlace acrylester.

We do NOT sell it at Exotics, because too many people will blame the material for their inability to make it into a pen.
 
I use my R2 carbide and (like everything else) spin it at maximum speed. Be gentle 'til it's round, then you can (gently) be a little more aggressive. If you start to get chipping, back off and be really careful as you approach final diameter. If at that point you have pits, switch to sand paper. Oh, and never, ever even consider starting your cut at the end of the blank--you will get a catch and bad things will happen. Once I get the diameter down a bit, I like to start taking the ends down close to the bushings, always going "down hill". Then you can more safely take the center of the blank down w/o the danger of catching an end.

Is it worth the hassle? That's up to you, but there are unique colors and patters of IA and it does finish up beautifully.

Regards,
Michael
 
If you're having problems with your chisel and skew techniques, don't be afraid to just sand it all the way down to proper diameter .... grab some old 80 grit belt sander material, cut off a strip, and sand away wet or dry (prefer dry ... less mess!)

As you get close, switch to 120 or 180 .... the only important thing is to make it look right in the end.

As to WHY we'ld subject ourselves to such insane hair-pulling agony? Because the pen can be worth it in the end ... this material is beautiful, when done right. Many people don't like to take the time and frustration to do it right, though ... try it for yourself before you make your final decision on whether to keep this stuff in your shop.
 
I like to turn it because of the beautiful colors and patterns that are in the blanks.

Having said that, you are correct that it is difficult to turn. I normally will use a file to knock off the corner and then use a Sorby SpindleMaster and my round carbide to turn it down.

I also, stop proud of my bushings and use AbraNet sanding mesh starting at 100 grit and going to 600 grit.

Once I am down to where I want to be with the AbraNet, I switch to MM and wet sand from 1500 to 12000.

I have spent over an hour just turning on tube for a Sierra style pen, when I can turn wood or other resin type material in 20 minutes.
 
mecompco said:
I use my R2 carbide and (like everything else) spin it at maximum speed. Be gentle 'til it's round, then you can (gently) be a little more aggressive. If you start to get chipping, back off and be really careful as you approach final diameter. If at that point you have pits, switch to sand paper. Oh, and never, ever even consider starting your cut at the end of the blank--you will get a catch and bad things will happen. Once I get the diameter down a bit, I like to start taking the ends down close to the bushings, always going "down hill". Then you can more safely take the center of the blank down w/o the danger of catching an end.

Is it worth the hassle? That's up to you, but there are unique colors and patters of IA and it does finish up beautifully.

Regards,
Michael
Click to expand...

If I go any lighter I won't be touching the blank! LOL.
I won't give up, I'm a trouble shooter so when something doesn't work right it bugs me until I figure it out. Then I'll decide if it is worth it or not to keep using this type of material.

Thanks!
 
Here is a photo of the first time I used IA, it chipped all the heck too and I THOUGHT I had figured it out and it polished up nicely (although there is a chip at the nib all the way to the brass, so unusable) The same techniques I used on this didn't work on the other 3 blanks I am describing earlier.

But what I want to point out with this particulate blank is the lines in the blank. I zoom the photo so you can see them - and yes you can feel them. I think it is just nature of that particular casting process, but I'm not a fan. I don't like the feel of it.

IAzoom.jpg


Here you can see the thin black lines in the casting
IA2.jpg
 
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Mike8850 said:
When I have had this problem I found my tool rest was either too low or too far away from the blank. Might be something to check.
Mike
Click to expand...

Great point! I find that with my R2 carbide there is a definite "sweet spot" where it will cut smoothly and not be prone to catches. Even a mm off, and it doesn't work as well. I'm finding that leaving the tool a bit further away from the blank that I would with my other tools. Since I'm using the Magical Skew carbide tool, I tend to switch between using it an angle and straight scraping.
 
Mike8850 said:
When I have had this problem I found my tool rest was either too low or too far away from the blank. Might be something to check.
Mike
Click to expand...

Yep, was thinking that this morning - I'll check that, speed, tools, and aggressiveness, although I felt I was pretty light. The tool rest might have been a little low, but it was within an 1/8 from the blank after getting it round. I had the speed way up, but not at max, so I'll try that too. I'll re-sharpen everything and try again!
 
This statement is counter to everything I have ever read or heard at demonstrations, so consider it as only MY OPINION and MY OBSERVATION--subject to being wrong for YOU>

FOR ME!!!! I don't think razor sharp is good for acrylester. Immediately after sharpening, I am more likely to take a chip out. 4 or 5 passes later, the tool is less sharp and more cooperative.
 
ed4copies said:
This statement is counter to everything I have ever read or heard at demonstrations, so consider it as only MY OPINION and MY OBSERVATION--subject to being wrong for YOU>

FOR ME!!!! I don't think razor sharp is good for acrylester. Immediately after sharpening, I am more likely to take a chip out. 4 or 5 passes later, the tool is less sharp and more cooperative.
Click to expand...

Yes, I found the duller tools seemed to work better, lowers the aggressiveness I assume.
 
What is happening is you are finding a challenge and to me that is good. The reason it is good is because it gets you to stretch yourself and find ways to overcome these situations. So boring putting blanks on a rod and spinning and then taking off and putting pieces in it.

Find out what it is you are doing wrong as you try different things.

The blank with the black lines is typical casting. People do not realize some of the things they cast just does not work together. The material to cast the majority of the blank is a certain hardness. The thin black lines is a vinyl or other plastic material with a different hardness. Thus when you turn this the tool will dig in further in the softer material than the thin lines. You are judging your feeding pressure of the tool to cut the ribbons. Now you go to sand this and the same thing occurs. To combat this it is important to sand with a sanding block behind the sand paper. It will force the sandpaper to cover a larger area at an even pressure. This will result in a smoother feel.

This effect is more drastic in wood blanks that use plastics and metals for segmenting. It is very possible that after some time the wood may shrink or swell and the other solid material will not change or change very little. This can create ridges and you maybe able to feel them. Or you use different woods and they move differently the same results. You may do everything the right way but this problem will still occur. Top coating with CA may counteract the movement or it may just crack. Just the nature of what we do.

Dull tools is never good in any shop work. Sharpen those tools up and have at it. If you are finding tools that are dull more easily controlable your technique needs work.
 
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Blank problems

Just to add another two cents worth.
You did not mention how you are holding and turning the blank. If you are not turning between centers (TBC) are you sure that everything is square and true? Are the bearings good in your mandrel system.
I have found over time that if your mandrel system is off only a little bit it will cause lots of problems with the blank, no matter the material. If you have a dial indicator you could take some readings on your system.
Just a thought.
 
Gunnarkouper said:
Just to add another two cents worth.
You did not mention how you are holding and turning the blank. If you are not turning between centers (TBC) are you sure that everything is square and true? Are the bearings good in your mandrel system.
I have found over time that if your mandrel system is off only a little bit it will cause lots of problems with the blank, no matter the material. If you have a dial indicator you could take some readings on your system.
Just a thought.
Click to expand...

I used a Mandrel twice when I first started then I tried TBC, that was the end of the Mandrel. :smile: So, yes I was turning these between centers.
A Dial indicator is next on my tool list to get. I need it for our Mill also - so I will be getting one soon.
 
I turn a lot of acryluster, as my icon shows one of my favorites.

With that, there is soemthing you can use for training wheels. A negative rake scraper, Robert Sorby makes 2, I have the small one and I use it when the material is super chippy, otherwise I use the small round carbide cutter.

For the carbide: You must, get the tool rest as close as possible and as the diameter gets smaller, you have to keep adjusting its location. The further away you are the more likely you will catch an edge-forcing an angle change causing a chip. I'm sorry, I wish I could show you but I'm not set up for it.

For the negative rake scrapper, it is much more forgiving and I have been able to be significantly aggressive with it. However, I have the small one, and it appears to lose the edge faster. I might buy the larger scrapper soon.
 
Negative Rake scrapper by Robert Sorbey or others = Training wheels for acryluster.

I primarily use my small round cutter for acryluster, but the negative rake scraper works great for super chippy materials.

Make sure you are constantly bringing the tool rest as close as possible. If you are not and there is a gap, that leave room for you to catch and edge, knock the tool, then re-engage and create a chip. So keep moving the tool rest as you keep turning down.
 
All of these posts are very good advice.
I had a problem with blanks chipping apart a couple of winters ago. It turned out that my shop was too cold. Below 40 degrees or so the blanks become brittle. I notice the original poster is in Indiana. We're having a very mild winter here in Austin but the current temp in Elkhart is 32 degrees.
BeeAMaker, is your shop heated at all?
 
That first blank (the inlace acrylester) with the black material lines ....


The way to fix that is to add a CA finish over top. I know, it's counter-intuitive ... to put a CA finish on an acrylic blank, but that's how you fill in and stabilize the alternate material that was put into that blank for it's color and texture detail.

As for the chip-out ... if you can FIND the chip and CA glue it back in, the match can be good enough to pretty much be undetectable .... but another way around that is to put an "oops band" there, and possibly a matching one on the opposite end, making it look more like a planned design element.
 
RobS said:
I turn a lot of acryluster, as my icon shows one of my favorites.

With that, there is soemthing you can use for training wheels. A negative rake scraper, Robert Sorby makes 2, I have the small one and I use it when the material is super chippy, otherwise I use the small round carbide cutter.

For the carbide: You must, get the tool rest as close as possible and as the diameter gets smaller, you have to keep adjusting its location. The further away you are the more likely you will catch an edge-forcing an angle change causing a chip. I'm sorry, I wish I could show you but I'm not set up for it.

For the negative rake scrapper, it is much more forgiving and I have been able to be significantly aggressive with it. However, I have the small one, and it appears to lose the edge faster. I might buy the larger scrapper soon.
Click to expand...

Interesting, thanks. I have a lot of things to test.
Makes sense too,
 
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Martin G said:
All of these posts are very good advice.
I had a problem with blanks chipping apart a couple of winters ago. It turned out that my shop was too cold. Below 40 degrees or so the blanks become brittle. I notice the original poster is in Indiana. We're having a very mild winter here in Austin but the current temp in Elkhart is 32 degrees.
BeeAMaker, is your shop heated at all?
Click to expand...

I considered that actually. Tuesday, the temperature was 56, Wednesday morning the temp was around 50, but dropped all day and by the time i turned it was 22 out and snowing.

My shop is heated but you can still feel the temp difference, i.e. you know it's cold out side. It is a 16,000 sq foot building.

Temperature has an effect on my 3D printing so that made me consider temp might have an effect on turning plastic as well.
 
I've turned similar materials on my metal lathe using the tool holder that would eliminate many of the issues that could cause chipping with a very rigid tool holder and light consistent cuts. I still had chipping. Sharpening the tool didn't really help. I found that the tool was below center of the turning. After moving the tool to cut at the center of the blank, the inlaced acrylester cut smoothly. Same behavior with TruStone. It also cuts better with a smaller contact area with the tool, almost a point like what I use for machining metals. When turning by hand I use the corner of my carbide tool allowing to take a more aggressive cut when roughing.

Danny
 
More4dan said:
I've turned similar materials on my metal lathe using the tool holder that would eliminate many of the issues that could cause chipping with a very rigid tool holder and light consistent cuts. I still had chipping. Sharpening the tool didn't really help. I found that the tool was below center of the turning. After moving the tool to cut at the center of the blank, the inlaced acrylester cut smoothly. Same behavior with TruStone. It also cuts better with a smaller contact area with the tool, almost a point like what I use for machining metals. When turning by hand I use the corner of my carbide tool allowing to take a more aggressive cut when roughing.

Danny
Click to expand...


Yep,
On softer woods and Acrylics like Alumilite I found that going slightly below center eliminates a lot of chatter and give a good clean cut, nice ribbons too, However doing that on Acrylester seem to be a definite no no. One little catch and that carbide is going in for the kill, so to speak.

Once I master this I will be making a video of everything I learned. I have watched a lot of them and although they are informative, they don't really get into the mechanics of it all. knowledge is power and I like it share!
 
Well...
Last night at our meeting we played a bit with the Skew. Will take some practice to get the hang of it, and need a better skew.

But I started using my round carbide like a skew and it cut the blanks much nicer. So I will be back into in the morning and see what I can come up with.

Thanks for all the good advice!
 
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SUCCESS!

smooth.jpg


Thanks to everyone advice and tips I think I got it. I didn't sand or polish that blank yet, I used my round carbide as a skew chisel then went over it with some #0000 steel whole, very smooth and way less chipping. (I think temp might have something to do with it also, see below)

I want to give a big shout out to Ed from Exotic Blanks for taking the time to look at my technique. I will be taking what I learned to the next maker meetings in the upcoming weeks. With my new found confidence, I believe I can save at least 2 of the 3 blanks.

Now to change the subject, but I think it is related as I believe this has something to do with Temperature.

I noticed the brass tube is proud of the blank, but only on one end. This is true with all my plastic blanks I have glued up and squared. I square them on a disk sander so the ends should be flush. Here are a couple pics.

proud1.jpg


proud2.jpg


And like I said, this is only on one end, so I am thinking maybe I don't have enough adhesive at this end, allowing the brass to expand - or the plastic to shrink beyond each other. Thoughts? These are all "esters" material as well I had one allumilite one that had been turned and one wood blank that i had turned that were OK. I think it is a temp issue, but if they are glued properly, (and the glue holds) they should expand and contract together.

Thoughts?
 
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