Taper cutting attachment

[Bernd]

I needed to clean up a number 4 Morse taper on a drill arbor. Since my 9" X 19" Grizzley dosen't have a taper attachment I had to come up with a way to be able to clean it up. The compound slide only travels about 3" on this small lathe. I needed about 4.5" inches of travel. So I built one all out of aluminum to try out my concept. I hope to build a much better one latter when time permits. The following description and pics might give you an idea of your own.

First a bit of history as to why I would even attempt this. I make motor plates for a guy that builds drag race cars. The motor plate gets bolted between the motor and transmission so it can be tied soildly to the frame rail. With rubber mounts and the horsepower these engines produce, it would just rip the motor right out of the chassi. Here's what one of those plate looks like.

The holes are laid out to a master template, center punched and then 3/8" pilot holes are drilled. Two .500" dia dowel holes are drill one each side of the big hole. This lines up the engine, plate and transmission. There are six 3/8" holes for bolts to bolt the whole mess together. The 3" hole on the right is for the starter, the smaller one, lower and left of the starter hole, is for bolting the converter to the flywheel and the large hole is for clearnce when everything is bolted together. The two cutouts on the bottom corners is for the frame rails where the plate sets on. The plates are about 18" tall by 22" wide by 1/4" thick. All the holes are done on my Grizzly bench drill. The two smaller holes are done with a hole saw while the large center hole is done with a treepan tool I made. I had no problems making the plates with the equipment I have.

But... now an engineering change came along. The plates are to be 24" wide and 20" high and the large center hole is now to be 14.5" in dia. Fine and dandy, but I can't cut the center hole because I only have 7" from center of the drill chuck to the column on my drill press. So I'll do them on the Buffalo drill press since I have 10.5" from chuck center to column. Only thing is I don't have a #4 Morse taper of anything. A couple of freinds helped out by giving me some beat up old arbors. They needed some bad TLC and that's how the idea of making a taper attachment for the lathe came about. It's crude but proves that it will work. I hope to refine it later.

Here's two pics of one of the beat up arbors I started to turn.

I made a taper plate so I could line up the attachment on the lathe cross slide.

This model lathe has a nice flat table to mount things on so I made a flat plate to hold the movable slide. I first bolted an angle plate I made using a 5" sine plate set to the (what I had figured to be the proper height) proper height. In the picture of the angle plate and sine plate you can see the angle the way the holes are lined up.

I zeroed in the straight side of the angle plate and then pushed the attachment up next to the angled portion and bolted it down nice and tight. I was pretty close after taking a skim cut. I took one more heaveir cut and measured the angle. I was off by about .020" in the 4.5" length. After checking my figures I found I was off on those also. But I managed to save the second arbor and that will get used for making the next part of this adventure in motor plate manufacturing. ;D So stayed tuned. I'll make another fixture that will use this arbor in the Buffalo drill press with my Sherline headstock attached to it.

Bernd

 

[rake60]

Nicely done Bernd!

I've cut tapers on my own Grizzly G4000 by offsetting the tail stock.
To put it as politely as possible that is a PAIN IN THE A$$!

Then getting the tail stock set to cut straight again is another PAIN IN THE....
Well you know... LOL

Great project idea!
Thanks for sharing it!!!

Rick

 

[DICKEYBIRD]

Geez I must be stoopid. ??? 'Splane it to me Lucy!

Can someone describe what is moving in this setup?

Thanks

 

[Brass_Machine]

Geez I must be stoopid. ??? 'Splane it to me Lucy!

Can someone describe what is moving in this setup?

Thanks

Don't feel bad... I am scratching my head too. I understand the principals of taper cutting attachment, but I would like to know how this one works. Can we get more pictures? Maybe a video? Drawings?

Please it looks very well done... but I am lost.

Eric

 

[Rog02]

Don't feel bad... I am scratching my head too. I understand the principals of taper cutting attachment, but I would like to know how this one works. Can we get more pictures? Maybe a video? Drawings?

Please it looks very well done... but I am lost.

Eric

I'm just guessing here, but as I see it the length of allthread in the photo is the feed for the taper plate on which the tool post is mounted.

In other words he is moving the tool post rather than the compound.

Like I said it is a WAG, so don't flame me if it's wrong.

Actually it is a pretty elegant simple solution to a problem. I like elegant, simple solutions.

 

[tel]

I did that once, about 25 or so years ago, never again - as luck would have it, a short time later I 'aquired' a taper turning set up, minus the bits that connect it to the cross slide for almost no money - a couple of hours later and a few bits of offcut stock and it was a goer.

Nicely done Bernd!

I've cut tapers on my own Grizzly G4000 by offsetting the tail stock.
To put it as politely as possible that is a PAIN IN THE A$$!

Then getting the tail stock set to cut straight again is another PAIN IN THE....
Well you know... LOL

Great project idea!
Thanks for sharing it!!!

Rick

 

[DICKEYBIRD]

I'm just guessing here, but as I see it the length of allthread in the photo is the feed for the taper plate on which the tool post is mounted.

Yup, I saw that too and you're probably right but I don't see a handle on the end of the all-thread rod?

 

[Stan]

It just looks like a long compound to me. Set the plate at the desired angle and move the tool - just like cutting tapers with compound.
It seems to be universal on all lathes that the amount of travel on the compound is less than the length of the tailstock taper.

 

[BobWarfield]

Interesting solution Bernd. I like your hose clamp for the lathe dog too. I'd seen cylindrical grinders use that trick.

It seems to me that you're most of the way to having a classic taper attachment if you move that rig out and use it to control your original slide's position instead of as a replacement for the compound. It'll take a bit more work, but I'll bet you could work out a nice attachment there.

Cheers,

BW

 

[Bernd]

Sorry for not taking better picture guys. :-[ But I was in a hurry to see if this idea would work. As I said it is very crude but proves the principle.

Rog02 and Stan your both right.

I guess I shouldn't have called it a taper cutting attachment as used on machines that come with one. But it does cut a taper.

Baiscially what I've done is make a cross slide that moves a greater distance. The plate that is held down by the clamps was milled out to give a small step for the aluminum slide to ride on that holds the tool to ride on. Then I used a couple of aluminum pieces with the 3 screws in it to hold down the moving slide. The all thread rod was the only thing I could think of to use for such a setup. I just drilled a hole in the tool holder and used the threaded rod to push the cutter toward the head stock. No handle on the all-thread, although I could have used one. My fingers sure got tired.

My idea is to make a much better slide using some decent rails. I would also like to incorporate a sine plate that will allow easier and faster setup.

Tel,

I'd be happy to buy a lathe with a taper cutting attachment and if I did find one I'm still going to design one for a lathe that doesn't have one like I've shown. Just quickly checked the Grizzly catalog. I found one lathe with a taper attachment: 18" X 60" for $10,995US. A bit to big and a bit to much money for me. I'm not saying finding one with a taper attachment is impossible. I think they are far and few between.

I've taken a few mores pics. Hope they make it a bit clearer than mud now. :

Here's an over all picture showing how I clamped the "rig" down on the cross slide. Also shows the all thread rod I used.

This pic shows one of the clamp rails removed, plus the space under the slide that has the tool post mounted.

This one shows the hole in the tool holder for pushing the whole works toward the head. I used a piece of oil lite bronze for a pusher on the end of the threaded rod. The piece that the all thread goes though has clearence milled in the bottom to clear the slide.

Here's a view from the back side. Notice the angle I had to cut off to clear the tailstock center. The reason I used the tool post as a place to push the whole thing was I didn't have any room underneath this Rube Goldburg design. 8)

All I was interested in was if this procedure would work. As I was working on it I came up with the idea of integrating a sign bar into the next design to make setup easier and faster.

If any of you have more questions I'll try to explain. As I said above I hope I made it a bit clearer than mud. ;D

Bernd