My FIRST lathe project!

[zetec7]

Well, after seeing some of the others' ball-turning attachments, I decided the I just HAD to do one myself!  It's a variation on Steve Bedair's design, modified to suit the materials I could get my hands on (or had "in stock"), and requiring the absolute minimum of milling (as I don't have a mill, a milling attachment, or access to a mill).

The main base and "puck" are made out of 6061 aluminum (because that's what I had), a Saab clutch throw-out bearing (also, because that's what I had) between the base and the puck, and a PTFE bearing under the head of the stainless socket-head bolt that holds the two parts together (I had some PTFE, so I turned a small bearing - worked great!). Underneath is the conical insert (also aluminum, and threaded so that it acts as a jam nut to keep the center bolt from turning out) that fits into the cross slide - it's an exact duplicate of the cone on the underside of the compound, and seems to hold the ball turner down solidly. The handle shaft is a piece of spring-tempered stainless steel (you guessed it - I had it in stock), and the handle itself was the first ball-turning job for the tool. It worked well, as you can see. The reason the knob is the shape it is is because I also wanted to try taper turning, internal threading, etc., and this shape required several different turning techniques. The whole thing needs cleaning up and polishing, but it's in working condition now.

One issue I had was how to attach a cutting tip to the thing. I've seen various techniques, many of which required milling. So, since I had a spare 3/8"-square-shank cutter with indexable carbide tip, I decided to use that. However, cutting a square hole for it to slide into wasn't in the cards, so I turned the square shank down to 1/4" round, and drilled & reamed a hole for it to slide into. The beauty of it is that I can reverse it for cutting concaves by just loosening the socket head bolt on top, removing the cutter, and sliding it back in from the other side.

Anyway, it's really not much of a project compared to the incredible work I've seen on this website, but as my very first machining build, I'm quite pleased. It looks okay, but most importantly it works!! Well, we all have to start somewhere!

[dsquire]

zetec7

Very nice ball turner for a first project. Nice to see that you were able to adapt some of the things that you had around the shop for the project. We will be watching for more like this when you do them. Thanks for sharing it with us. 

Cheers 

Don

[Stilldrillin]

Hi Ze,

That's a really nice, simple, effective ball turner you've made from what yer got! 

Well done, and thanks for showing! 

David D

[GordTopps]

Zetec7 very nice work.

Regards
Gordy

[AdeV]

Zetec - looks really nice, and you built it using only a lathe? Respect...

Q: How did you cut the cutout where the three cap-head screws go? Was that a milling cutter in the chuck & the ball turner clamped to the cross-slide, or some other technique? Enquiring minds want to know...

[tony ennis]

That's very nice.  I find it amusing - and fitting - that the first object made using the jig is the handle for the jig. 

[zetec7]

Zetec - looks really nice, and you built it using only a lathe? Respect...

Q: How did you cut the cutout where the three cap-head screws go? Was that a milling cutter in the chuck & the ball turner clamped to the cross-slide, or some other technique? Enquiring minds want to know...

Unfortunately, I had to go to a machine shop to get that done!  Thus, my desire for a milling attachment (I'm negotiating for one from one of the fellows on the Practical Machinist site who has one to spare).  That little bit of machining cost $86 +taxes   The most "involved" bit of machining is inside the turner, though - the profile of the Saab throwout bearing is tall and fairly complex, so about half of the relief went into the puck and half into the base.  That took me a while!  One day, I'll take it apart & photograph the innards...

[johnny123]

That is a fine looking turner you have there! I had to do some hmm's and hahh's because of the limited height there was to work with. Overall I am happy with mine other than setting the darn thing up so I am not making eggs...lol. Anyone have some advice on this detail?

[zetec7]

Thanks!

AS for making eggs, well, my second attempt was an egg as well!  I finally figured it out (it's pretty bad when you build your own tool from scratch, and THEN have to figure out how to use it!).  Find the center (left-to-right, not up & down) of where the ball is going to be (basically, the point nearest yourself on its circumference), and lock the carriage!  Then, just back out the cross slide until rotating the tool by its handle just causes the bit to start cutting at the left and right extremes of the ball, and slowly advance the cross slide in, but ONLY the cross slide.  Gradually, the cuts on the ends will move inward, towards each other, meeting at the equator of the ball.  If you move the carriage even a smidge after you start cutting, you'll make an egg, or at least an oval.  Ask me how I know...

Anyway, when I followed my own advice ( ) it worked like a charm.  Here's a little part I made for a friend's motorcycle (it's a helmet hanger - threads into a disused mirror mount on his handlebar - you just hang the helmet by its D-ring on the strap, and it doesn't fall off).  It's made of T6061 aluminum, so it's easy to turn - a good practice piece, I figure...

The ball on the end is concentric within .0005", although it may not look like it in the pic (darned flash!)...

[Divided he ad]

Nice looking tooling there Zetec  

Same as myself, the first tooling I made, I made all the turned parts then tried to use my vertical slide (milling attachment) and scared the hell out of myself when I shattered a cutter (my fault entirely) but I waited for a couple of months then got a second hand milling machine off e-blag and finished it with that.... Expensive, yes. Worth it, oh yes!

if it wasn't for the postage you could have my vertical slide for next to naff all!



Johnny and anyone else wishing to stop turning eggs, the set up is quite simple and I explained it in a thread over on the HMEM site a while back...

http://www.homemodelenginemachinist.com/index.php?topic=1721.45


Hopefully this will shed some light on it for you?



Zetec, you're  going to find a never ending stream of things that can have balls concaves and all manner of somewhat spherical things added to them..... Enjoy  




Ralph.

[zetec7]

Thanks, Divided he ad!!

After looking at your previous thread, the following occurs to me...with this type of ball turner (basically, Steve Bedair's design & clones), it doesn't matter whether you work with the cross slide or the carriage...as long as you use ONLY ONE of these!  Divided's method (if I may paraphrase!) is to set the cutting bit up at the center of the end of the shaft, then back the carriage up  to where the cutter tip just touches the end of the shaft the ball is to be cut on, and slowly work your way along with JUST the carriage until you have a ball.  My method (so far...I may adopt Divided's method!) is the opposite, working from the center (of the intended ball) outward toward the ends using JUST the cross slide.  Both should work - well, mine has so far, and Divided's obviously works great!

If you move the carriage (in my method) or the cross slide (in Divided's method) you're going to end up with something...uh...lozenge shaped?...flat-knob shaped?...well, not what you were looking for .  And if you DO move the wrong one, it's very difficult to accurately get back to where you were before.  If this happens, and hopefully, the exact size of the ball isn't crucial, you could lock things down again after moving the cutting bit for a slightly smaller ball, and cut it down to a slightly smaller size to fix the lack of concentricity (is that a word?).

Have fun!  I've reached the point where I look forward to chucking up a piece of work & attaching the "Zetec7 Ball Cutting Attachment, Mod. 1" to my lathe.

[Divided he ad]

Zetec,

I think there is a little confusion over the carriage (saddle) and the cross slide usage?

The saddle is used to touch the tip to the end of the workpiece and then locked in position. The cross slide is used to draw the tool back towards yourself clear of the workpiece.  Then the lathe is started and the cross slide is advanced slowly as the ball turner is swung in an arc thus cutting the desired shape.

There is a video of me turning a ball on youtube. Posted in a thread on here -  http://madmodder.net/index.php?topic=282.0  - it shows the saddle locked and the advancement on the cross slide only.
(until I start playing with the collar, then it looks wild and odd till you understand the camera is attached to the saddle)


I'm saying this just in case we're going to confuse Johnny or anyone else?


Does your carriage/saddle lock? as this will help avoid being able to turn the wrong wheel.




Mine is still the best tooling I ever made and own 


Happy that you're enjoying the machining    Now for some 







Ralph.

[zetec7]

Okay, I WAS confused!  As it turns out, I guess we were using the same method after all.  I just didn't express it as well as you did - hope I didn't confuse Johnny!

[Divided he ad]

Glad we figured that out   




Ralph.

[zetec7]

Ralph -

I just watched your Youtube video again - interesting comment from one viewer on what to use it for!  I'm not sure if he meant to be serious or just silly.  I thought your response was very thoughtful, and good-spirited.  Well done Ralph!

I've watched your video probably a dozen times.  It's what prompted me to build a ball turner in the first place...

- Mike

[Divided he ad]

I thought your response was very thoughtful, and good-spirited.

   I think I know the comment you mean Mike.

I've erased such in the past, but I thought I'd have a bit of fun with this one, glad you liked it  He hasn't replied though    


Always happy to know the video has done it's job too. To aid and inspire. It was originally done for a member of HMEM who was having difficulties using the tool he had made.





Hope you have as many hours of fun making all sorts of shapes as I have





Ralph.

[johnny123]

All is good here!  I am guilty of moving the carriage a lil  during the process and not getting back to where I started.