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Emco V13 Taper attachment build

Darren

Ultra Member
Premium Member
My V13 didn't come with a taper attachment, and they are impossible to find, so i'm building my own. Here's what they look like:

taper cutting attachment1.jpg
Taper Attachment In Use.jpg

I'm going to loosely base mine on the Emco design. I found an old brake lathe at the dump a while back, and took it home knowing that someday i'd do something with it. Today is that day.

more in the next post.....
 

Attachments

  • Emco_Taper_Attachment.pdf
    1.6 MB · Views: 21

Darren

Ultra Member
Premium Member
51133207089_1d6554a307_c.jpg


51133540880_3a057ec4d3_c.jpg


51133206489_c696e27125_c.jpg


That there is a taper attachment.

To the bandsaw!

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51131773492_2c27d54ea9_c.jpg

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51131774977_217e0bf800_c.jpg
 
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Darren

Ultra Member
Premium Member
So i wasn't real sure how it was going to look once cut apart, so i left plenty of meat, which meant i had some material to hog off.

51132450466_7dc76f364e_c.jpg

51133230389_0c73e4b251_c.jpg

I left a bit for the surface grinder


51132450521_79e4603f1e_c.jpg


Since my lathe is an Emco, not an Ammco, this had to go

51132454341_157c8d7d24_c.jpg


Couple hard spots there

51131780312_2bb15de2e7_c.jpg


Fits the cross slide good, both are 5.5" wide

51132664668_f52046fa07_c.jpg


The new rear toolpost slide. The tee slot will make mounting and positioning a tool pretty easy.

And thats where im at right now. More to come.
 

DavidR8

Scrap maker
Administrator
Moderator
Premium Member
Awesome work!
Just cut/mill away everything that isn't a taper attachment, I love it!
 

Darren

Ultra Member
Premium Member
Awesome work!
Just cut/mill away everything that isn't a taper attachment, I love it!

Thanks!

LOL thats pretty much the idea. I could have made that dovetail, but it saved me a bunch of time. I'll be making the other dovetail slide and the guidebar though. Theres also a bunch of nice 3/4ish thick cast iron in that old brake lathe that i'll be using. The bandsaw slices right through it like butter. Should be an interesting build. It may even get built twice.
 

PeterT

Ultra Member
Premium Member
Nice work, following along. Always nice to see a piece of unloved metal turn into something nice & useful.
When this Emco was sold with taper attachment, did they have a different, cross slide lead screw attachment that disengaged during taper turning mode or what is your game plan in that regard?
 

Darren

Ultra Member
Premium Member
Nice work, following along. Always nice to see a piece of unloved metal turn into something nice & useful.
When this Emco was sold with taper attachment, did they have a different, cross slide lead screw attachment that disengaged during taper turning mode or what is your game plan in that regard?

Thanks Peter. The way Emco did it is fairly unique. The unit does not move the cross slide at all during taper cutting. It has its own toolpost on a slide block and is designed to cut from the rear, with the lathe in reverse. I'm doing it the same way. I will attach a few exploded view pics from the parts manual.


51133429239_3a4e3f937f_c.jpg

51133429254_48ee97ed6c_c.jpg
51132866373_07a9cbec9e_c.jpg

part number 1 is what i started on tonight. I'm going to cut the excess dovetail length off and mount it to a plate, and the cutoffs, which will now be 2 pieces will be run perpendicular to form a dovetail slide for the guide bar
 

Attachments

  • Maximat_V13_Serviceteile.pdf
    2.7 MB · Views: 8

Darren

Ultra Member
Premium Member
I believe most taper attachments top out at 8-10 degrees, i'm hoping to do around 12 degrees, with a bit more than 12" of taper length. I can't see needing much more. If i'm guessing correctly, i'll need a bit more than 3" of tool travel (x axis travel) over that 12". Anyone good with trig?
 

PeterT

Ultra Member
Premium Member
Veeeery interesting. That is unique. Cant wait to see this come to life.

Not quite sure I have a clear picture of where the slide action will be relative to the taper bar but 12" of base and 12 deg yields max 2.551" (of rise) displacement. If its acting at some other reduced position (just chose 9" for example) you get these kind of numbers

1619154564799.png
 

Darren

Ultra Member
Premium Member
Thank you for that. That make me feel a bit better. I can definitely get 3" of x travel, so i should be able to achieve 14-15 degrees. I'm good with that. Without a dimensioned drawing of the original, it makes it harder to visualize the outcome for me.

Yes, i think you have it right, you can set an angle of 12 deg, but only travel a 1/2 of the 12" max travel distance and the tool is only going to move 1.25" relative to the work.
 

RobinHood

Ultra Member
Premium Member
Excellent work and for sure a unique concept.

Your taper angle is per side; so you will actually have double that as an included angle. In your case it will be up to 24*. That is a substantial amount on any lathe.

For example NPT taper is 1/16 (or 3/4” per foot) => 1.7899* per side, not a whole lot all, things considered. R8 is only around 7*/side. CAT 40/50 is 7/24 (just over 8* per side).

You’ll be able to make all the common taper tooling holders with your new TA.
 

Darren

Ultra Member
Premium Member
Excellent work and for sure a unique concept.

Your taper angle is per side; so you will actually have double that as an included angle. In your case it will be up to 24*. That is a substantial amount on any lathe.

For example NPT taper is 1/16 (or 3/4” per foot) => 1.7899* per side, not a whole lot all, things considered. R8 is only around 7*/side. CAT 40/50 is 7/24 (just over 8* per side).

You’ll be able to make all the common taper tooling holders with your new TA.

Making my own tooling is the prime reason for building it. I know and have used all the other methods for tapers, but with this one, i'm adding a feature to pin it for specific tapers, then i just have to verify and tweak a small amount and i'm good to go. Turning NPT tapers is the other reason. Home Depot is 30 mins from my house, so i could make a fitting quicker...
 

Darren

Ultra Member
Premium Member
I managed to get a few hours in the shop tonight. A whole bunch of drilling and tapping and figuring. Here's some pics

51139001701_d598cfc765_c.jpg

I cut the tool slide piece down to a more reasonable size

51138325442_7c201c737c_c.jpg

I will have to cut the gib down and drill and tap for the adjuster screws

51139777104_8229911570_c.jpg

it'll have some sort of a tool holder like this spare that i have.


51139219478_7c0163b16e_c.jpg

All the dovetails get mounted to this plate, and it is what mounts everything to the cross slide. Had to drill some holes for countersink screws.

51139777259_d8711f9b74_c.jpg


51139219798_43b44aa61c_c.jpg

51139220053_c6a9f3398f_c.jpg

I put some extra bolts in to stiffen it up. These join the perpendicular dovetail pieces to each other.

51138326482_538c7780ae_c.jpg

These slotted holes allow adjustment of the rear dovetail like a gib. There will be a block behind the gib with adjustment screws to tighten the dovetail against the slide bar.

51140107810_97bf81c13a_c.jpg

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thats all for now
 
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Darren

Ultra Member
Premium Member
Thanks. Its coming together but i could have carved it out of a solid block by now. But this is free and fun
 

PeterT

Ultra Member
Premium Member
Very nice. This is obviously not your first rodeo. Just wondering, with the inverted tool on the original. Can you still accommodate insert type tooling shanks or you need to stay with (what looks like) HSS blanks?
 

Darren

Ultra Member
Premium Member
Very nice. This is obviously not your first rodeo. Just wondering, with the inverted tool on the original. Can you still accommodate insert type tooling shanks or you need to stay with (what looks like) HSS blanks?

Thanks! The dro on the mill makes it pretty easy. Edge find off of one corner and go from there. All the holes lined up perfectly. I was surprised.

I'm going to make it pretty universal, and I don't plan to run the tool inverted. I want the force to be downward on the tool, although its not going to be taking heavy cuts. Guess i'll figure that out once i get to the tool block part.
 

Darren

Ultra Member
Premium Member
Tonights progress

51141083711_9467ff8b9d_c.jpg

1x3" CRS for the sliding bar. I never like machining CRS, it has so much stress in it that everytime you make a cut, it moves. It took a while to square it up and straighten it out, And thats only the beginning.

51141292913_2740e1d8e1_c.jpg

Looks purdy though.....

51141855454_785def44c1_c.jpg

Starting on the first dovetail.

51141855624_43935ee3c2_c.jpg

About halfway through the first dovetail. I stopped for some measurements, and it was starting to move as the stresses changed. Some minor adjustments and kept on cutting.

51140407867_4020a21413_c.jpg

went in 0.575" total on the y axis, 0.0650 LR, and 0.0350 RL (climb milling) per pass. 600ish rpms, but it tried 400 (too slow, lotsa vibes) to 900 (too much heat). Had to flip it around several times to chase some warp out of it.

51141607058_1734dbd15c_c.jpg


It fits very good, but in the pic above it doesn't look like it because its slid all the way over and it was actually lifting at the end that the pic shows. The right side female dovetail is the adjustable "gib". No, I am not scraping anything in.

51141396766_8f43b923e1_c.jpg

The bar on top is a 1.5x1 slice of the same CRS and will get machined down to become the adjustable angle bar that will make all the magic happen.
 

PeterT

Ultra Member
Premium Member
Coming along nicely. Do you happen to know the alloy? I haven't done many long-ish parts like that, but I have also experienced CRS wanting to stress relieve. Worse if the part is non-symmetrical. I've done a little bit with hot rolled (A36 maybe?) but not enough to know if it would be significantly better. Some people say 4140 is better but I thought it was also (usually) cold rolled but maybe comes in different flavors. Any thoughts? I wish there were bars of cast iron somewhere local but seems to be unobtanium. It isn't even horribly expensive with some suppliers but shipping is a killer.
 
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