Bench grinder lathe

[Filip Winiewicz]

Greeting from Hong Kong, this will be my first post here.
I would like to ask some experience turners what do you think about making a small lathe from bench grinder. I have seen the youtube video in some post here with a guy who did something similar and the opinions were not so positive. My case is bit different. I need to turn some 4 inch diameter, one inch thick wooden discs for my project. I bought a 6' bench grinder with variable speed 2000-3000 rpm, I'm thinking to ad an external speed controller to lower the the rpm even more for detailing if needed and fix the work piece on small faceplate. I would use small set of Proxxon tools. Variable speed bench grinder seems a good solution to me. I'm wondering what could go wrong because I haven't seen much of similar DIY projects on English sites (there are some Russian though). I would really appreciate your feedback. Thanks

[John K Jordan]

Greeting from Hong Kong, this will be my first post here.
I would like to ask some experience turners what do you think about making a small lathe from bench grinder. I have seen the youtube video in some post here with a guy who did something similar and the opinions were not so positive. My case is bit different. I need to turn some 4 inch diameter, one inch thick wooden discs for my project. I bought a 6' bench grinder with variable speed 2000-3000 rpm, I'm thinking to ad an external speed controller to lower the the rpm even more for detailing if needed and fix the work piece on small faceplate. I would use small set of Proxxon tools. Variable speed bench grinder seems a good solution to me. I'm wondering what could go wrong because I haven't seen much of similar DIY projects on English sites (there are some Russian though). I would really appreciate your feedback. Thanks

You could certainly do it - people have made lathes from all kinds of motors. I met a guy in Venice, Italy who used a Dewalt electric drill to turn wood.

One problem would be to build something to hold the work securely. This might be easier in your case if you only plan to turn one type of thing.

I think it would be a lot easier to find a lathe, even a small one, new or used. It will already have a means to adjust the speed, an adjustable tool rest, a headstock and tailstock, and means to hold work between centers or mount on a faceplate or a chuck.

JKJ

[Wes Ramsey]

歡迎！

I was in HK just a few weeks ago for a few days at each end of a trip to Taiwan. By FAR the prettiest big city I've ever had the pleasure of visiting. Very much hope to go back again and see more of it.

I think the grinder idea could work if you can find a reverse-threaded faceplate with the correct threads. If you have access to a machine shop they could probably make one as cheap as you could buy one. Another option might be to make a wooden faceplate sandwiched between two nuts with the outside nut set into the wooden block. If you can get it close to flat and round you can true it up one the 'lathe' before mounting anything.

One thing I would consider is mounting the grinder and tool rest onto the same platform. And I would make it heavy or mount it to something heavy - if you get a catch I can imagine it sending the grinder (or you!) flying. You could probably come up with some ways to adjust the tool rest if needed, but just make sure that neither the tool rest or grinder will move once you start cutting.

Best of luck and let us know how it goes!

[Guy Belleman]

Save the grinder to sharpen the turning tools. Since most of our lathes are made in China, I would think you could find a great deal on a benchtop lathe that is ready to turn wood. Unless you are an Engineer and enjoy Rube Goldberg challenges.

[Filip Winiewicz]

Thank you all for advice. I got my grinder and tried once turning. Rpms are really fine, its very quiet and no need any extra speed control. I definitely need to fix it to the tables as it jumped time to time making pieces of wood flying. The existing tool support cant be used after opening the side of enclosure. I'm waiting now for pen turning tools that seem to have right scale for my project, it didn't go so well with beveled chisel. About Chinese lathes I've browsed their Taobao (like ebay) forth and back to see lathes. They have most of the models you can also see on Amazon. Right now I needed something really small that would fit in HK micro apartment to start turning. Chinese lathes are usually up to 280mm diameter and if I would buy one I would like to have possibility to turn stool seats so now I'm thinking to build a large scale lathe on my own as many of lathe components are available on taobao for cheap. I have found a small faceplate from 6in1 kind of tool, will see if the thread fits, for now the nuts and plates holding the grinding disk will have to do. I will post some bench grinder turning results soon to share with other interested in that option.

@Wes Ramsey: About Hong Kong, I'm not such a fan. Watch the new movie Ghost in the shell, Hong Kong is the main background. Hot, humid, loud and crowded. I'm lucky to live in a village in one of the outlying islands - Lamma. You should visit one day, its a good part of living here, staying in a village and in 25 min going by ferry to the center of huge city.

Regards

[Wes Ramsey]

Thank you all for advice. I got my grinder and tried once turning. Rpms are really fine, its very quiet and no need any extra speed control. I definitely need to fix it to the tables as it jumped time to time making pieces of wood flying. The existing tool support cant be used after opening the side of enclosure. I'm waiting now for pen turning tools that seem to have right scale for my project, it didn't go so well with beveled chisel. About Chinese lathes I've browsed their Taobao (like ebay) forth and back to see lathes. They have most of the models you can also see on Amazon. Right now I needed something really small that would fit in HK micro apartment to start turning. Chinese lathes are usually up to 280mm diameter and if I would buy one I would like to have possibility to turn stool seats so now I'm thinking to build a large scale lathe on my own as many of lathe components are available on taobao for cheap. I have found a small faceplate from 6in1 kind of tool, will see if the thread fits, for now the nuts and plates holding the grinding disk will have to do. I will post some bench grinder turning results soon to share with other interested in that option.

@Wes Ramsey: About Hong Kong, I'm not such a fan. Watch the new movie Ghost in the shell, Hong Kong is the main background. Hot, humid, loud and crowded. I'm lucky to live in a village in one of the outlying islands - Lamma. You should visit one day, its a good part of living here, staying in a village and in 25 min going by ferry to the center of huge city.

Regards

Filip,

Glad you took a shot at it! I know you'll get it to work, just be safe about it and attach the grinder and tool rest to the same base. One thing that can be said about the Chinese is that they are truly industrious. I've been to many parts of China and a common theme is that they can make anything out of anything and make anything work.

I thought the islands looked beautiful from the plane and hopefully I'll have a chance to visit Lamma next time.

[Filip Winiewicz]

1968439373.jpg1449024933.jpg246939887.jpg693015038.jpg2099726751.jpg1847877823.jpg

Greetings form the Hong Kong jungle. Not much time so my bench grinder lathe project is moving very slow. I couldn't find M12 faceplate so following my friends advice I decided to make it on my own with long screw nut and 5mm steel plate. After welding them together and cutting out rough circle I grinded it with angle grinder stone plate while turning the plate mounted on bench grinder at the same time. I was bit nervous about that power metal turning but it turned out ok. The home made faceplate is not bad, the other side is smooth but I think I need to make a smaller one.

So I'm now practicing turning. Need to work more on the tool rest, sharpening and turning skills. I bought a pen turning gouge set. I think the whole idea might work out for a while although the bench grinder might not live too long.

I have a question. As you see on the photos during the turning process there are big material rip offs that give me heart attack each time. Usually when I get to the edge. What might be the reason? I'm thinking that tool rest is too far. Or maybe there is some other rule when u get to the edge while turning bowls?
Thanks, Filip
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[Frederick Skelly]

Filip,

Your lathe is very clever! Well done!

Cut your wood into a round shape before turning it. (Make the wood a circle instead of a square before turning it.) I think that will reduce tear offs. I do not think it has be a perfect circle. But at least cut off those corners. I think that will help you. It will also let you move the tool rest closer.

Moving the tool rest closer to the wood will be safer for you. It will also give you better control of your tools while cutting.

Please wear safety glasses or a face shield. That will protect your eyes.

Good luck!
Fred

[Don Frank]

If you wanted to take your design up to the next level you can always buy some kind of cheap or old lathe on craigslist for $100 or less. Buy one with the idea of just using the bed (to attach your grinder) , the tailstock and the tool rest. You would have to make sure you could attach the grinder so the shaft height matched your tailstock height. Most of the time people throw in whatever tools they have as well.

[Grant Wilkinson]

As Fred said, try to cut your blocks somewhat round before putting them on your "lathe".

Your tool rest needs to be much closer to the piece. At the distance you are now, you are no doubt getting tool chatter which is contributing to your tear out and poor quality edge. Keep moving the tool rest in as the piece gets smaller.

It looks like your tool rest is too low, too. When you hold your gouge on the tool rest parallel to the ground, the tip of the tool should be at or very slightly above center.

Finally, since you are cutting into end grain if you go straight into the piece, try coming at it taking small cuts starting at the face and working towards the grinder. Nibble away at it. Don't try to take big cuts.

Good luck. It's a fun idea.

[John K Jordan]

Finally, since you are cutting into end grain if you go straight into the piece, try coming at it taking small cuts starting at the face and working towards the grinder. Nibble away at it. Don't try to take big cuts.

Filip, Excellent progress!

This might be the biggest thing. If you start on the outside circumference and cut across the wood can easily split when you get to the edge. If you start on the flat part as Grant mentioned, either on the right or the left, twist the gouge slightly towards the cut and make slow and make shallow cuts into the wood there should be no chipping (unless the wood is extremely fragile or full of cracks!)

The tool needs to be sharp. A "fingernail" grind helps with this type of cut. This can be done by hand on the grinding wheel but most people use a jig. A Oneway Wolverine base with a Vari-Grind jig makes this very simple, but you can easily make a jig that does the same thing. A friend of mine built one from wood for almost nothing and we made a document if you are interested. It costs almost nothing to make. Let me know if you want it and I'll find a link to the PDF file. Here are some illustrations I did (no dimensions are critical):

sharpA_system_small.jpg sharpD4_arm_small.jpg sharpE_jig_dim_small.jpg

JKJ

[Filip Winiewicz]

Hey, thank you for great response and all advice.
@Frederick Skelly: I will cut it round next time to see the difference. I saw many videos with guys beginning with square block. I thought it might be a way to get more turning practice. About the tool rest now I'm thinking to try something like the Japanese guy in this video: https://youtu.be/1F12qUyIACM?t=1m17s He has kind of movable tool rest. Might work better in my case.

@Don Frank: I'm in Hong Kong and wood turning doesn't really exist here so no options for used equipment. I could order something cheap from China but for now I don't have any space, this one I have to take outside every time I want to use it. I bought a spindle for a circular saw and I'm thinking to build a big column mounted lathe like this one but its a slow process. I have started a thread about it here: http://www.sawmillcreek.org/showthre...-for-diy-lathe
wtl.jpg

@Grant Wilkinson: "Finally, since you are cutting into end grain if you go straight into the piece, try coming at it taking small cuts starting at the face and working towards the grinder. " Thats a great advice. I will definitely try to do it that way. I thought there is probably a way to do it.

@ John K Jordan: thank you for the drawings. I tried to sharpen the tool on the bench grinder, I dont remember the grit of the stone but its some standard and it felt too rought to sharpen the roughing chisel. Even if I slightly touch it it leaves kind of teethes on the edge. Or maybe its just the chisel quality is so low. So eventually I decided to sharpen it manualy on the stone following Paul Sellers video and it seems to work for me much better. I don't turn so much so doing it by hand is no big deal.