# How do I prevent this kind of chipping?



## SDTurner (Jan 17, 2017)

Hi guys, I'm having some trouble with this kind of chipping. Can anyone tell me or steer me in direction that can help me avoid these kind of chipping. I use a round carbide cutter when turning. I doubt that could be the issue. Would it be easier if I tried turning with the traditional tools? These chip outs occurs when I try and take a little bit of a deeper cut to put that curve into the workpiece. Is it because I'm not supposed to cut deep into the PR blank with the carbide tool? I've seen videos of people cutting deep into wood with these cutters so I wasn't sure if that same technique applies to PR blanks. Now after taking very light cuts and a long time later I was able to make that deep curve and finish turning. Any tips and suggestions that I can use to improve my technique would be much appreciated.


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## keithbyrd (Jan 17, 2017)

That material is chip prone.  It is awesome material but sharp tools and light cuts.  Being too aggressive or dull blades..  Even carbide tools get dull!


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## lorbay (Jan 17, 2017)

Cut it and don't scrap it.
Lin


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## jttheclockman (Jan 17, 2017)

I would switch to HSS tools because with a round cutter you will go into the piece at the wrong angle because th cutter head is too big and there is a cutting edge all around the cutter. detailed gauge will work nice on that.


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## greggas (Jan 17, 2017)

Sharpen the tool...and use a skew


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## TonyL (Jan 17, 2017)

Until/if you decide to use a skew, try a fresh edge on your carbide cutter and take lighter cuts as Keith suggested. I would also move the cutter more slowly across the surface of the material. 

Much success as you discover what is right for you.


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## RKB (Jan 17, 2017)

Hi,  I use carbide too, i like it.  When this happens to me it's usually because I have presented the carbide cutting tool too low, below center.   Also you may want to check your screw holding the cutter on and make sure it is not too long and protruding out the bottom of the tool and interfering with its movement on the tool rest.

Rod


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## leehljp (Jan 17, 2017)

In addition to several above notes, it looks like the tool rest needs to be a tad closer too. Too much distance can cause chattering. Lower the tool rest a tad also and see what that does.


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## Rolandranch (Jan 18, 2017)

If you are using that round carbide cutter, make sure to hold it at an angle...not just flat. This usually fixes the problem.


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## Ted iin Michigan (Jan 18, 2017)

Not so sure I'd choose a skew. That inside curve seems a bit too tight. I'd choose a detail spindle gouge, sharpen it and take light cuts. 

But if you are using carbide almost exclusively it might be best to stick with it. Couple good suggestions here - get your tool rest at the optimal height, make sure you are sharp and try holding the tool at an angle. 

Regardless, the finished material looks super. You gotta be doing something right!


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## randyrls (Jan 18, 2017)

Also the carbide cutter bits on the market tend to be too aggressive for acrylics.
Take a look at these two cutters.  The top one will give you pits on acrylic, but the bottom one will shear off endless ribbons in the hardest acrylics.

Hone your cutter with a credit card diamond hone and a drop of water to keep the cutter sharp.

With the cutter you have, try to cut just below center.  The further below center you are, the more stress you put on the blank, but the less aggressive it is.


View in Gallery


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## eharri446 (Jan 18, 2017)

What kind of material is that? If it is Inlace Acrylester you have to apply everything that was mentioned above and then you may still have chip out occur. That is due to the nature of the material.


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## SDTurner (Jan 19, 2017)

jttheclockman said:


> I would switch to HSS tools because with a round cutter you will go into the piece at the wrong angle because th cutter head is too big and there is a cutting edge all around the cutter. detailed gauge will work nice on that.



The only reason why I haven't switched to HSS tools is because I didn't have the proper jig and also the sharpening slow speed bench grinder that is needed to sharpen them each time I turn a new brush. 



RKB said:


> Hi,  I use carbide too, i like it.  When this happens to me it's usually because I have presented the carbide cutting tool too low, below center.   Also you may want to check your screw holding the cutter on and make sure it is not too long and protruding out the bottom of the tool and interfering with its movement on the tool rest.
> 
> Rod



Yeah the screw is just the perfect size and it's not coming out the bottom at all. I do notice that depending on the height of my tool rest, the bottom edge of the cutter will touch the blank and not the carbide tip so I usually try and lower it so that doesn't happen. Still trying to figure out what is the exact height I need to put the tool rest at. The deeper the curve gets, I lower the tool rest even more as I feel like it cuts better and less chances of chipping. 



leehljp said:


> In addition to several above notes, it looks like the tool rest needs to be a tad closer too. Too much distance can cause chattering. Lower the tool rest a tad also and see what that does.



I have tried putting the tool rest very close but when it's too close, I can't angle the cutter down to cut and if I keep the tool flat on the tool rest, the bottom of the tool huts the blank and not the carbide tip at all. 



Rolandranch said:


> If you are using that round carbide cutter, make sure to hold it at an angle...not just flat. This usually fixes the problem.



any suggestion on what angle should it be? Like angle it downwards or upwards? usually I try and cut straight while keeping it flat and slowly angel it a little downwards as the curve gets deeper. I'm afraid to put too much angel because I would hate to catch and make a giant chip. I will post up some pictures of my other work when I get home tonight with some bad chipping trying to make a sharp curve.  ruined two casting blocks this way at the every end lol. 



Ted iin Michigan said:


> Not so sure I'd choose a skew. That inside curve seems a bit too tight. I'd choose a detail spindle gouge, sharpen it and take light cuts.
> 
> But if you are using carbide almost exclusively it might be best to stick with it. Couple good suggestions here - get your tool rest at the optimal height, make sure you are sharp and try holding the tool at an angle.
> 
> Regardless, the finished material looks super. You gotta be doing something right!



I will try and experiment with the angles on my next brush and see how that turns out. Thanks for the complement, it was the first time I tried making that shape as I knew it was going to be a challenge for my limited tools/skills. 



eharri446 said:


> What kind of material is that? If it is Inlace Acrylester you have to apply everything that was mentioned above and then you may still have chip out occur. That is due to the nature of the material.



It is the Castin' Craft Polyester Resin. Michales had 60% off coupon over the weekend so I got 2 32oz cans for like 15-16/each. Cheaper than Silmar 41.


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## Magicbob (Jan 19, 2017)

This is the exact problem that prompted the development of my Magical Skew.

Notes about using carbide on plastics:
1. use VERY light cuts and go slow
2. make sure your tool is firm against the tool rest before you begin the cut
3. use a very sharp cutter
4. I find it better to be slightly above center when cutting
5. be sure to tighten the fixing screw
6. I use a medium speed for this, everything else I turn as fast as my lathe will go


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## SDTurner (Jan 19, 2017)

Hum.. medium speed you say? I always turned at full speed at 3200rpm on my 5 speed HF cheapo lathe. the only time I turn it down (750 rpm) is when I'm drilling the blank or sanding. All other times I just change the belts back up to 3200 rpm for turning and buffing the acrylic. 

the speeds this late has are 750, 1100, 1600, 2200 and 3200 RPM. 

When I pour my next blank I will try a lower sleep, probably 1600 and see if that works better. 

I do not have any of this chipping issues when I make a pen. I have made two pens so far and about 4 Razors and they all turned out perfect w/out any chipping issues at max speed. It's just the brushes that give me the problem.


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## Rolandranch (Jan 19, 2017)

> any suggestion on what angle should it be? Like angle it downwards or upwards? usually I try and cut straight while keeping it flat and slowly angel it a little downwards as the curve gets deeper. I'm afraid to put too much angel because I would hate to catch and make a giant chip. I will post up some pictures of my other work when I get home tonight with some bad chipping trying to make a sharp curve. ruined two casting blocks this way at the every end lol.



Sorry for not clarifying. I meant at an angle to the side, not up or down. Usually, a downward angle has more chances of chipping and an upward angle will hit the tool instead of the carbide cutter. When you hold the tool at a sideward angle, it usually cuts the material better, whereas holding it flat has more chance of ripping into the material. I attached some photos of how I hold the tool at an angle. Hope this helps.

Seth Roland


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## wood-of-1kind (Jan 19, 2017)

Carbide needs 'speed' and you approach your piece aiming at the center. Slow speed and carbide are NOT a good mix. Get your tool rest as close to your work piece as possible. And keep advancing your tool rest as you are removing material from your piece. Man there are variations of approaches with carbide tools but some of the comments that I read are just not correct. Folks mean well with advice but I still find that there is so much misinformation when it comes to understanding carbide tools. Sermon is over.


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## Rockytime (Jan 19, 2017)

All my carbide tools have round shanks. Eliminates a lot of problems.


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## SDTurner (Jan 19, 2017)

Rolandranch said:


> > any suggestion on what angle should it be? Like angle it downwards or upwards? usually I try and cut straight while keeping it flat and slowly angel it a little downwards as the curve gets deeper. I'm afraid to put too much angel because I would hate to catch and make a giant chip. I will post up some pictures of my other work when I get home tonight with some bad chipping trying to make a sharp curve. ruined two casting blocks this way at the every end lol.
> 
> 
> 
> ...




Oh I can definitely try that angel when I make my next pen or a razor. But i'm not sure if that angle would work making a sharp deep curve. I will give it a shot and try to go slow and hopefully the edge or back of the tool doesn't hit the work piece. 


As promised here is my first attempt at trying to get a sharp curve. Definitely shows my inexperience with turning.


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## jttheclockman (Jan 19, 2017)

I still say HSS tools and a detailed gouge or even a spindle gouge would work wonders on that. You can ride the bevel into those curves and shape with detail. Carbide anything is going to give you fits going into a curve like that because as I said you can not control the cutter from so many angles. At one time you are hitting 3/4 of that curve with a round cutter. Been there done that. Others maybe able to pull it off but save yourself the agony if you are going to make those kind of shapes. Just an opinion. 

You could clean it up with a round nose scraper if you had that. That does not need the sharpening like other tools. Just honing.

I tried to find you a video for using the carbide round cutter for cutting coves like that but had no luck. Maybe someone else can.


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## rholiday (Jan 20, 2017)

The tool rest height is set so that the tip (cutting edge) of the carbide tool is at the center line of the lathe. The tool is held level (parallel to the floor).
The tool rest height is not adjusted for the depth of the cut. The tool rest is positioned closer to the work as more material is removed.  The bottom of the tool will not contact the work before the cutting edge.


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## raar25 (Jan 20, 2017)

Along with the suggestions above, when you are down to the last  0.050-.100" I would use a rounded skew and take advantage of the negative rake it provides when you use it in the scraper positions. This is a lot more forgiving just make sure you take very light cuts and hold the tool firm against the rest.

The problem is the cast material does not have a grain structure and the aggressive carbide point tends to dig into the random grain structure.


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## SDTurner (Jan 20, 2017)

jttheclockman said:


> I still say HSS tools and a detailed gouge or even a spindle gouge would work wonders on that. You can ride the bevel into those curves and shape with detail. Carbide anything is going to give you fits going into a curve like that because as I said you can not control the cutter from so many angles. At one time you are hitting 3/4 of that curve with a round cutter. Been there done that. Others maybe able to pull it off but save yourself the agony if you are going to make those kind of shapes. Just an opinion.
> 
> You could clean it up with a round nose scraper if you had that. That does not need the sharpening like other tools. Just honing.
> 
> I tried to find you a video for using the carbide round cutter for cutting coves like that but had no luck. Maybe someone else can.



got ya, I think I might just have to get different tools than carbide to work on the brush shapes. Do you have any suggestions on the budget ones? I was thinking of getting the HF Professional HSS Wood Lathe Chisel 8PC set. I know they might not be sharp but since they already have a pre made edge on them, to sharpen them can I just use a diamond credit card or rock and hone them and keep them sharp all the time and not have to get a grinder? 



rholiday said:


> The tool rest height is set so that the tip (cutting edge) of the carbide tool is at the center line of the lathe. The tool is held level (parallel to the floor).
> The tool rest height is not adjusted for the depth of the cut. The tool rest is positioned closer to the work as more material is removed.  The bottom of the tool will not contact the work before the cutting edge.



Got ya, on the next one I will not try and move the tool rest down as I cut deeper into the work piece and see if that helps. 

kind of disappointed at the carbide tools. The round cutter works great at turning a pen but just isn't working out for me at shave brushes.


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## jttheclockman (Jan 20, 2017)

Many people here have used HF turning tools and done well with so I will not debate them. But will say this honing will not get you there. It can help for a few turns but sharpening will be needed. A slow speed grinder is about $100 with some white wheels on it. As far as jig to sharpen. It is possible to free hand but there are ton of videos on utube that show home made jigs for sharpening tools. But again a good turning jig is not all that expensive. You have to remember these are investments in your hobby to further your product line. In business this needs to be done no matter what business. Makes for ease of making and you can turn them out faster plus the bottom line product looks a lot better. The one you shown can not be sold for any money in my opinion but it can be saved so it can be sold. Good luck. Again these are just my opinions.


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## TellicoTurning (Jan 21, 2017)

I do very little plastic now, and no pens,  so my comments may be irrelevant...  when I was doing a lot of the plastic for pens, some years back, after watching Ed Brown's demo at the first Mid West Pen Turners Gathering, I learned that the skew was the best tool for turning plastic... I was getting a lot of chip out using the scrapers and gouges but after switching to the skew, I got nice smooth surfaces... it did take a little bit of a learning curve, but not so much as to deter me.... my recommendation would be to get a skew, learn to sharpen it well, and learn to use it on the plastics.


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## oldtoolsniper (Jan 21, 2017)

I hated my skew and could not get the hang of it no matter what I tried. Bought a lot of woodturning stuff at an auction this was in the lot. 

This DVD helped me overcome the skew struggles I was having. It's about how to use the skew, more importantly it shows you catches and why they happen. No real projects in the DVD, just sharpening, using, with some pretty easy to follow practice using cut up 2x4's. 

He explains the stebcentre, (his is home made) and why you should use it with the skew. 

He states that the only way he knows how to never get a catch with a skew is to never use a skew.


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## oldtoolsniper (Jan 21, 2017)

Walnut crotch. Plain old carbon steel Great Neck skew. Every tool except the skew rips chunks from this wood. Carbide is horrible on this wood. 

I have the wolverine jig for lathe tools but I prefer to sharpen skews by hand. I hone a lot but the cuts when you get them right are worth it. 






Sent from my iPad using Penturners.org mobile app


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