Advice sought for wood lathe compound sliding tool rest (numerous pics)

[Eric Patterson]

Dave and other machinist friends, you out there?

I bought an old Delta wood lathe compund sliding tool rest off ebay and have a few questions. The reason for buying it is I am going to use it to turn the tenons on duck call inserts to 5/8". Doing it by hand and calipers is slooooooooow and undershooting results in a wasted insert. So my thoughts are to use the compound slide and with accuracy and repeatability turn the stock to 5/8".

Pics 1-5 are of the one I bought. Pics 6-9 are of another one that recently sold on ebay. Pics 10-12 are of a restored one from owwm.com.

I have a few questions concerning the one I bought and getting it mounted on my lathe for making cuts.

Question group 1. The tool post on mine is missing the rocker (little skinny radiused wedge seen in pic 9). Any idea where to get one or come up with a substitute? I guess I could buy a whole new tool post, assuming I can find one that will fit, but is that necessary? Should I look for another type of tool post for my application?

Question group 2. The compound slide I bought came off an 11" lathe. There is a 1/2" sub base spacer (casting cbl 405 in pics 9-12) that is needed for a 12" lathe. Without the spacer I suspect the cutter will be too low. On the 12" lathe the sub base spacer is machined so that it fits in the lathe gap so that the whole works will slide along the lathe and stay aligned. My 11" lathe has a metal bar (see pic 5) that bolts to the bottom to keep the slide aligned by riding up against the front side of the lathe bed. I need to come up with a replacement for the base and I think the way they keep the slide aligned with the sub base spacer is superior to the metal bar on the 11" lathe. Any ideas on how I might make a replacement sub base? One thought is to take a piece of 3/4" steel, have it gound flat, and then mill all but the part that fits in the gap to 1/2". That might be expensive route. Any suggestions?

Question group 3. The arm that holds the cutter is for 1/4" cutters. It looks to be bent for a left hand cut. Any suggestion for a cutter that would work well with wood? Maybe one of the ones in Pic 13?

Any other thoughts or observations? Thanks for entertaining these somewhat technical questions.

Pic 1

Pic 2

Pic 3

Pic 4

Pic 5
These are pictures from a similar one that sold on ebay recently.

Pic 6

Pic 7

Pic 8

Pic 9


The pics below are of a restored on from owwm.com.

Pic 10

Pic 11

Pic 12

Pic 13

 

[Dave E]

Question group 1. The tool post on mine is missing the rocker (little skinny radiused wedge seen in pic 9). Any idea where to get one or come up with a substitute? ---------------------------------- The tool rest has a rounded bottom so that one can adjust the cutting tool for various angles. I am sure you can buy one at any store that sells metal lathes. They are all pretty much the same. You can make one out of 1/4 inch bar stock and a belt sander. Shape it, then heat it to red-orange hot, then cool it in oil (not water) do this twice. This will harden the outside. --------------------------
Question group 2. The compound slide I bought came off an 11" lathe. There is a 1/2" sub base spacer (casting cbl 405 in pics 9-12) that is needed for a 12" lathe. (snip) Any suggestions? ------------------ Just take a stack of anything hard- 3 1/4 inch pieces of flat stock and make your base(s). The end result is that you want your cutter just below the center line (about 2 to 10 thousands of an inch to prevent chatter on the cutter.) The tool rest should adjust several different ways to accommodate many different types of cutters. --------------------------

Question group 3. The arm that holds the cutter is for 1/4" cutters. It looks to be bent for a left hand cut. Any suggestion for a cutter that would work well with wood? Maybe one of the ones in Pic 13? ------------------------- The tool holder is bent to clear the head stock while cutting threads with a 90 degree tool. Yours looks like a 30 deg one. They make straight ones (and others) as well. Again, any place that sells metal lathes will have them. They are made of case steel. ------------------------

Don't get too hung up on having it to be just like the original. You want your tool rest solid. That is all you need to worry about. As a rule wood lathes turn much faster than metal lathes. Do you do any metal work at all? Dave

 

[Eric Patterson]

Dave

Thanks for the input. To answer your question, no, I've never done any metal maching, other than grinding things to an edge

You brought up chatter. Getting a good clean cut is what the ultimate goal. Any suggestion on that. You mention the cutter tip should be a few thou below the centerline. What other advice? I suspect cutter geometry and grind has a large impact on quality of cut as does lathe speed. It will be a trial and error process to figure it out so getting advice before I start down a bad path is really useful.

 

[Huntindave McCann]

Eric,

I am at work right now on my short break. Not enough time for a solid reply. I'd rather just discuss your options in a phone call as my typing skills just plain suck. Email me a good time to call you. I won't get home till after 6:30pm as I am on a 12 hour shift right now. Any time after that as long as it's not too late. (have to be back at work at 5:30 am tomorrow) Overtime is great , especially following two 30 hour weeks but it sure doesn't leave time for much of anything else.

 

[Dave E]

Any suggestion on that. You mention the cutter tip should be a few thou below the centerline. What other advice? Wood is more forgiving on the chatter part. Some of this is due to the surface speed of the work on the cutting edge. Chatter is a product of harmonics (a whole 'nuther story) at a resonate frequency. The shape and angle the cutter is held is somewhat critical. In wood shop (Jr High---- back in the '50's...) we had to grind our tools on a whet stone then strop them on leather. The edge had to cut hair on the teachers arm or we had to do it again. What you want here is for your work to engage the cutting edge cleanly. Thw work will cause heat, whichwill be removed (in the wood chips) if done properly. If not enough work is removed, your very thing cutting edge will heat up and dull. Too much and you will tear your work. It's a balance. With a pit of practice you will be an expert. By the way there are specific angles your tools should be ground to. See: http://www.sherline.com/grinding.htm and http://serioustoolworks.com/woodturning-gouges.php You might pick up a tip here and there. Roll your shirt sleeves up first......

 

[Dan VanDeWoestyne]

The cutting tools in picture 13 are carbide tipped which I wouldnt use on wood, plus you will have a hard time sharpening them with diamond files. I would buy some High speed tool blanks so that you can grind the cutter into the shape you want on a pedistal grinder and then hone a sharp edge. With wood I think a positive raked and very sharp edge will work best for you.

As for your rocker... its been a long time since I have used one like that but you might be able to just shim the tool holder to the height that you need. If you decide to make one as suggested try to find a piece of 4140 steel and use the method described to hardened it but put it your oven for 1 hour at 400deg to temper it and make it less brittle.

If you need steel to make parts look on Ebay for a company called Speedy Metals.

 

[Geoff Pike]

Maybe I'm not seeing things right here Eric. If I am understanding you correctly you need to move the cutter up 1/2" to fit you lathe.
From the photos it looks like you have at least that much adjustment in the slot for the hold down bolt.
How about a stack of hardened steel washers ,and some shim stock for fine tuning, to get that height? Once you have the
height it wouldnt take much to have a one piece washer made so you dont have to worry about shims falling out!

 

[Eric Patterson]

Geoff

It's hard to say how much vertical room is there until I mount it on the lathe and decide on the cutter. I spoke to Dave last night on the phone and getting it on the lathe and sizing things up is going to be the first step. So you may very well be correct. I'm also thinking about taking a gouge I currently have and mounting it directly in the tool post, no tool holder. That will change the height as well. In my mind I think I have a a good idea on how to get things set up (thanks to everyone's help and Dave's chat last night) the one thing that I haven't resolved yet is if I use a HSS cutter in the tool holder and not a gouge, what is a good grind to give it for a clean cut.

Eric

 

[Shawn Hollis]

Eric,
Have you seen the carbide tools being used by bowl turners?
http://www.easywoodtools.com/
Watch the video!

I bought some inserts off ebay and my machinist friend made me a "copy" of one of these tools. Some one mentioned that the carbide "tears" more than cuts, and while that is true the end product is fine. Just throwing up another idea for you to think over.

 

[Ray]

what is a good grind to give it for a clean cut.

Eric

it has been a while since I turned anything, but I liked the way my skew rounded and smoothed the wood once it had already been worked with the gouge. Maybe a HSS mini skew tool would work to get you your final 5/8" size.