Tool Post Styles

Tim I have been doing some research on your lathe. Very, very interesting. Here is a link to a forum member who made one. He may be able to help you with your tool post. https://www.hobby-machinist.com/threads/gingery-lathe.70810/

I saw several online that had a 4 way. There seems to be more room than 3/8" from the top of the compound to center line. And looking at your pictures it looks like there is around 3/4" from the top of the compound to center line. You have a spacer that appears to be 1/4" to 3/8" and then what I call the rocker/shim and finally your tool bits. Assuming that you have the tip of the tool bit on center line what is the distance from the tip to the compound? Where are you measuring from?

gingery lathe 01.jpg
 
mickri said:
Tim I have been doing some research on your lathe. Very, very interesting. Here is a link to a forum member who made one. He may be able to help you with your tool post. https://www.hobby-machinist.com/threads/gingery-lathe.70810/

I saw several online that had a 4 way. There seems to be more room than 3/8" from the top of the compound to center line. And looking at your pictures it looks like there is around 3/4" from the top of the compound to center line. You have a spacer that appears to be 1/4" to 3/8" and then what I call the rocker/shim and finally your tool bits. Assuming that you have the tip of the tool bit on center line what is the distance from the tip to the compound? Where are you measuring from?

View attachment 318413
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Hi, looks are deceiving in my pic i believe, In the pic the arrow on the right is .375, if I lay a .375 tool bit on top in aligns about perfect with carbide center.
The spacer is alittle less than .250, it doesnt look right but thats what I measure.
Thanks
 
Well guys, all in all, I'm about up to my ears in tool bar information,,, can never know to much about tool bars.:)

Today I spent about 10 hours playing with my tool bars, :D and by the end of the day I was back to the old one that I always used.
Its similar to the new one, just shorter, and will take only .250 bits, but that's OK, I can always use the new one for bigger bits when I need to.
So, for the old one, it takes washer like shims to raise and lower the tool bit , I made up about 10 different thickness of washers that can be used to center the bit.. its fiddling, but its seems if you think about it, everybody does a fare share of fiddling and will just Live With It..
Its not so bad if I keep the shims in a handy place.
I am now kinda at peace about this tool bit excitment:cheer:
Thanks for all the help..
Tim
 
mickri said:
What I would do if I was in your situation is make a 3D model in Google Sketchup of each of the different types of tool holders scaled to fit your lathe. That will give you a visual. If you don't use Sketchup or any other 3D modeling software I would be glad to model them in Sketchup for you. Just let me know. Then you could make one of each in wood to see how it actually fits. Then make what you like best in steel.

You will find that you will use each of the different types of tool holders depending on what you are doing. I use my lantern to reach into tight places. If I am going to be using 2 or 3 different tool bits back and forth over and over I will set up my 4 way so I can just swivel between the different tool bits. I do use my Norman style QCTP most of the time. They are really easy to make and not complicated once you figure out the sizing and placement of the slot to fit your lathe. If you can make a lantern you can make a 4 way or a Norman.

I think that the reason you are having to tilt your tool bits up or down is the get tip of the tool bit on center. From looking at your pictures the 3/8 tool bit has to be tipped down to get the point on center. The 1/4 and 5/16 you are tipping up for the same reason. To get the tip of the tool bit on center. This requires a lot of fiddling. With either a 4 way or Norman style QCTP you would be limited to using tool bits no bigger than 1/4. You have to shim with the 4 way. Some people glue the shims to the tool bit or use a larger tool bit and grind it down so that the tip is on center. With any of the QCTP there is an adjustment screw that you use to raise or lower the tool holder to get the tip on center. In all of these situations the tool bit is level in the tool holder. Never angled. This makes grinding the tool bits a lot easier.

You will figure out what works best for you. Most of all have fun.
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That would be great when you have time, because I can always use several different styles for different jobs..
Thanks,
Tim
 
Dabbler said:
@horty I've read more about your lathe, and it seems to me that it might be best to make your own, that will fit your lathe properly.

Really nice work on your rocker tool post. Very professional looking!

You didn't mention the 'size' of the aloris style tool holders you have. I still think you might get away with the '0xa' size of aloris style holder. Here are the dimensions of the smallest readily available aloris-style holder, the 0XA (bottom of the page):

www.shars.com

Quick Change Tool Post Set Wedge Type #000 OXA

www.shars.com www.shars.com

Another way to get more height is to attach a threaded steel insert below your cross slide. that .250 space will be critical in fitting a tool post.



@Boswell, that is mostly true. I sometimes have to police bad behavoir here from time to time, as people tend to get emotional about tool posts at times.
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Thanks for saying it looked professional, but really with age my OCD is lagging, but good enough, leaves me more time for an extra beer or 2
Tim
 
Tim
Based on the dimensions you have given here is a sketch of a 4 way that should fit you lathe. I made it 2" square by 7/8" high. The slot is 1/8" up from the bottom and is 3/8" high by 5/16 deep. If it was me I would make the slot not quite 5/16 deep so that a 5/16 tool bit would be just proud of the edge. This way when you need to square a tool bit to the chuck face the 4 way does not get in the way. I guessed that the center screw was 3/8. Drill the center hole to whatever size you need. I made the set screws 1/4". They could be smaller but I don't think that they could be any bigger. The set screws are 5/32" in from the edge. Depending on how you grind your tool bits you might not need any shims with 1/4" tool bits. 5/16 and 3/8 tool bits would have to be ground so that the tip would be at center line. Dabbler does this. I am sure that he would give some pointers on how to do it. I'll have a sketch of a Norman style QCTP for you sometime tomorrow.

4 way.jpg
 
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Here's the Norman. All I had to draw was the tool holder. It is basically just one side of the 4 way.

norman.jpg

Because you have a flat top on the compound you don't need a base. And because of the limited distance from the compound to center line you would only use the height adjustment screw for tool bits 1/4" and smaller. For a 5/16 or 3/8 tool bit the tool holder would sit on the compound and the tool bit would have to be ground to be on center line just like with the 4 way. You might be able to get away with using the screw that is on the compound as the post. I would certainly try that first. If you have to have a post you want it as large as possible to provide more clamping area.

The dimensions are the same as with the 4 way except for the width which I drew at 1 1/2". The height adjustment screw I drew in at 5/8" up and 5/8" from the side. You would have to check the location to make sure that the height adjustment screw is over the top of the compound and that there is sufficient room between the center post and the nut on the height adjustment screw for a wrench to fit on the nut . You will mostly likely have to change the location. The clamping bolt should be 3/8 if possible. Otherwise use a 5/16 grade 8 bolt. 1/4 bolts aren't strong enough. I tried a 1/4 bolt and twisted head off trying to get the tool holder clamped to the post. I cut the slot to the post with a hacksaw and that width has been sufficient to clamp the holder to the post.

I am sure that I have missed some detail.
 
Here is another style designed by a guy on another site. Very nice design, very rigid and will not twist.
1585508953502.png
 
@horty
Tim, you are getting some great help here with people posting all kinds of ideas!

Here's one more.....
Just today I saw an interesting tool-post version I'd never seen before; more like a mill-table hold-down or toe clamp.
It's the seventh picture in this post:
https://www.hobby-machinist.com/threads/new-small-lathe-owner-from-canada.83300/post-731768

I will try a direct link, but not certain that it will work:
https://www.hobby-machinist.com/attachments/20200329_102637-jpg.318584/

For you, I wondered if you could gain some vertical height by placing your cutting tool directly on to the cross slide (ie. without the rocker-shim and spacer as labelled by @mickri above).
Of course, you'd still need to shim it to centre height, but it might allow you to use larger tool bits without tilting them.

But sorry, my CAD skills are not as good as @mickri above, it would take me days to electronically capture what I mean.
If you need a hand-drawn sketch, let me know.

-brino
 
Here's what I did on my tool post , just one side is cut for larger toolsDSCN2512.JPGDSCN2509.JPGDSCN2509.JPG
 
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