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Forum topic by Karda posted 01-08-2019 05:22 AM 664 views 0 times favorited 15 replies Add to Favorites Watch
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Karda

1640 posts in 1030 days


01-08-2019 05:22 AM

Hi, just changed sharpening from sander to grinder so my gouge is a little different, 70 degree angle and the nose is more blunt that before. I am using an elsworth jig in a one way V pocket. Heres the problem. I am turning a birch bowl and the out side surface the cut was not smooth but grooved. That happened with my small gouge as well and that one had not been changed in any way. Also the shaving were small and very dusty. The wood is dry. here is a pic off the out side the grooves are towards the bottom. I was able to cut clean on the rest of the bowl but not on the bottom. I finally got a smooth surface by shear scrapping and sanding. I know I can do better but I can’t figure out whats wrong. Thanks mike


15 replies so far

View Turns4wood's profile

Turns4wood

51 posts in 258 days


#1 posted 01-08-2019 06:36 AM

So help us out and show us the tool and tell what grind it is. I have been turning for some time and I think some of the angles that you are describing are might be to acute

-- Nothing better than sawdust on the floor

View Wildwood's profile

Wildwood

2711 posts in 2611 days


#2 posted 01-08-2019 01:25 PM

Are there woodturners using a 70 degree bevel angle successfuly? Yes!
Have posted this link before, but have listened to folks a turning synposiums saying they like 70 degree bevel. See Ellis Walentine’s explanation:

http://www.woodcentral.com/newforum/grinds.shtml

So not sure problem is with your bevel angle from looking at your picture. Don’t know if wood species a problem, but do think you are getting more of scraper action than cutting. Might have something to do with how you are hold and using the tool. Talkig about gripe and body movement while turning! If getting chips verus shavings something not right.

Could it be you design (flower pot bowl) think might have something to do with tool marks too! Ellsworth designs with his bowl gouge but you are not ready for that so might put little more thought to it!

-- Bill

View gwilki's profile

gwilki

318 posts in 1950 days


#3 posted 01-08-2019 01:27 PM

How is the bowl mounted when this happens? Is it still mounted with the recess toward the tailstock? In which direction are you cutting, from the tailstock to the headstock or vice-versa?

-- Grant Wilkinson, Ottawa ON

View LeeMills's profile

LeeMills

676 posts in 1777 days


#4 posted 01-08-2019 04:49 PM

I tend to agree with Wildwood. Looks like mostly body movement and the angle the tool meets the wood as you start around the bend.
Also, the closer you get to the flat bottom the more you are cutting directly into end grain so you will get more “dust” and fine “chips”

-- We cannot solve our problems with the same thinking we used when we created them. Albert Einstein

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Karda

1640 posts in 1030 days


#5 posted 01-08-2019 11:39 PM


So help us out and show us the tool and tell what grind it is. I have been turning for some time and I think some of the angles that you are describing are might be to acute

- Turns4wood


the top gouge in both pics is 5/8ths with 70 degree grind, bottom is 1/2 inch with 40 degree grind. The 5/8 was changed I changed sharpening from belt sander to grinder but essentially the same angle the 1/2 inch i still sharpen on the sander 120 grit on both sander and grinder

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Karda

1640 posts in 1030 days


#6 posted 01-08-2019 11:47 PM

ok I’ll try to change body movement, I have not had this problem in a very long time but even when I was doing better I still wasn’t using body movement. the bowl was mounted on a worm screw, I have had these problem with screws before but it has been with live edge bowls where the blank could rock on the screw. This is a flat stable attachment. I started on the inside and my 5/8 gouge cuts very smoot

View Knockonit's profile

Knockonit

601 posts in 678 days


#7 posted 01-09-2019 12:19 AM

i essentially was struggling with the tool marks also, and a experienced turner watched me and advised, i was holding the tool with a death grip, to lighten up and be alittle more fluid in my body movements, i’m working towards it, and figure i’m not sanding the rolling pins as much as the first half dozen, so think i’m getting the jist of it.
Rj in az

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Karda

1640 posts in 1030 days


#8 posted 01-09-2019 12:58 AM

I don’t do to much spidle work but I found recently that by using body motion I get a smoother cut. I just finished the bowl kinda, a lot of the dusty shavings is dry wood. What I am getting even with my scrappers is like when I turn a 2×4 or ply wood. just saying I know there is much badly sharpened tool as well. I still san’t grt the ridges out of the inside of the bowl

View Kirk650's profile

Kirk650

663 posts in 1225 days


#9 posted 01-09-2019 03:05 PM

I think more practice and sharp tools are the order of the day. And in difficult places on a bowl, I’ll usually reach for one of several big thick heavy scrapers and use a very light touch. Your tool rest matters too, particularly on the inside of the bowl, since cuts with the edge too far from the rest are tough to control.

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Karda

1640 posts in 1030 days


#10 posted 01-09-2019 06:31 PM

yes I need more practice but that in it self is a problem, is what I am practicing right or wrong. I am going back to my sander using a jig is supposed to be the best thing since sliced bread. I changed to a fixed Ellsworth jig on a one way arm and I can’ get a sharp bevel. T finish I am leaving is still to lumpy and ripply for a scrapper. I do use scrappers

View mrg's profile

mrg

860 posts in 3476 days


#11 posted 01-10-2019 01:40 AM

How are you setting the distance of the arm for the angle with the Elseworth jig? Are you using a spacer that sits in the vnoth and butts against the wheel. If thats the case the spacer block for the Elseworth grind may be off. Try this http://carlford.info/pages/jigs_tools/Sharpening_Templates/Sharpening_Templates.pdf

I took a class with David Elsworth and he pointed out that its a dance, and not to have a death grip. With the lathe off with one hand go at the area you need to fix (the dug in spot) and turn the lathe by hand. You will see where it is catching and be able to correct. Come in at a different angle see what happens. Are you cutting with the nose or the wing? Angle to high or low? Is the tool rolled over to far.

-- mrg

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Karda

1640 posts in 1030 days


#12 posted 01-10-2019 04:53 AM

Hi mrg I am setting the distance by moving the arm until the gouge bevel is in perfect contact with the wheel, i verify with marker on the bevel an then measure the distance. this is my jig

I try to use body movement when I do the out side but when I am on the inside I am leaning over the lathe and the only thing I can use to get forward motion on the bottom is my arm

View LeeMills's profile

LeeMills

676 posts in 1777 days


#13 posted 01-10-2019 05:29 AM

You are correct. On the inside of a bowl you move your arm instead of your body. You still want to start and stop in a comfortable position. With the Nova I have an advantage (IMO) over some because I rotate the head stock out at least 22.5° and the tail stock never interferes with the tool swing.

In Stuart Batty’s 2nd video on stance he shows stance on the outside for the area you are having a problem in your picture. I believe it is about half way through the video.

-- We cannot solve our problems with the same thinking we used when we created them. Albert Einstein

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Karda

1640 posts in 1030 days


#14 posted 01-10-2019 06:28 AM

which is his second video, I can’t understand how gouges cut, his 4o/4o video is good. I set up my sander for a 70 degree grind and I get a much better edge, I am sticking with the sander for my gouges

View LeeMills's profile

LeeMills

676 posts in 1777 days


#15 posted 01-10-2019 03:10 PM

Sorry ‘bout that…. I always think of Vimeo when I think of Stuart Batty.
It is his Stance Part 2 on the second page of his videos.
https://vimeo.com/woodturning/videos/sort:alphabetical/format:thumbnail

-- We cannot solve our problems with the same thinking we used when we created them. Albert Einstein

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