Ball or Radius cutter

[ksor]

--> MadNeck

It's too cold around here to do something in the workshop, the last knop I did on my ball-tools was steenless steel and it was going well - no fooling around because of the balls - I think my biggest problem is, that I tried to implement a "diamond-cutting"-arrangement, and I did not get the right angle in the first place, so now I have to make a new "tower" for mounting the bit.

If you do a ball in alu or brass it should be no problem I think.

I will not at all cancel my "ball-bearing"-arrangement in my tools, but try to make a better arrangement for placing the cutting bit enabling adjustment up/down for better performance ... but it's too cold these days, so I'm doing "in-door-hot-coffee"-thinking  ..... and driving my wife mad !

[MadNick]

Thanks Fellas,

Time for a rethink, I mean, whats the point of reinventing the wheel?

Nick

[Fergus OMore]

Following our E-mail discussion last evening, you have a boring head but with an unknown taper shank.
In other words, you have most of the tool which will kake balls and whatever- if only you could get rid or find a solution for the spiindle/shank.

All that you need now is three things
1. a decent tool to do the cutting
2. a spindle
3. a holder of sorts which takes the new spindle but at lathe centre height

[75Plus]

There is a member on Hobby-Machinist that used a flycutter as part of his ball turner. It does allow some adjustment and tool possibilities. You may have to be a member to see the photos though.

http://www.hobby-machinist.com/showthread.php/4570-Another-version-of-a-ball-turner?highlight=ball

Joe

[Divided he ad]

Nick,

Sorry to hear it's not performing to expectations.... I know you may be thinking of the boring head version but I can assure you that this version will work if you take a direct copy of Steve Bedairs design (turret mounting etc) and my tip adaptations. 
No bearings to have play in and you can make the turret to fit the recess in the base. So no need to panic over accuracy of dials etc. (I know that my dials are no where near as good as they should/could be according to the books!)

Scream all you like carbide bashers of the world....(I'm getting fed up of people telling Newbies that carbide is useless!)  I have many photo's and videos that prove that these things work perfectly well with carbide tips!

Feel free to check my videos on youtube.   

eature=mhee  Every single thing on the lathe created with mainly carbide tooling... My only HSS tools are a micro parting tool (used for grooving only) and a small boring bar.

I've no issue with HSS in general.... I just don't use it on my lathe that much.
The issue with HSS tips for these tools is re-creating the exact tip when it needs sharpening/changing..... you have to re-calibrate the tool (lapping and setting to exact length etc) and could possibly lose hours trying to get it accurate again!



Apologies for the micro rant Nick.... I just think you have more than enough talent to make a working tool the way you are going. 





Ralph.

[MadNick]

Thanks Chaps,

I need to come up with something - need to make these handbar clamps!

Nick

[Stilldrillin]

Scream all you like carbide bashers of the world....(I'm getting fed up of people telling Newbies that carbide is useless!)  I have many photo's and videos that prove that these things work perfectly well with carbide tips!

I've no issue with HSS in general.... I just don't use it on my lathe that much.
Ralph.

Ralph.

Me too! 

But, I don't recommend setting up with expensive throw away tooling for a mini lathe.
Too many sweeping statements........

David D

[MadNick]

Just like The Bionic Man, they can rebuild him...

Ive taken the bearing out the equation and turned down the turret to fit the step the bearing used to sit in.

I then lapped the turret into place with coarse and then smooth grinding paste and it turns nicely - no slop.

Ill have to start on a new toolpost and the height of the tool is now lower. Ive got some small HSS tips I use in my boring bar that could be adapted.

You cannot keep a good man down!

Edit - I have machined two L shaped toolposts out of the old base. I did this on the vertical mill using a slitting saw in a 1" arbor. It made a bit of noise but did a half decent job (better than hacksawing my way through this lot).



Next job will be to clean up the toolposts and make them fit the turret.

Nick

[Rob.Wilson]

Hi Nick

Good to see your still plugging away at the build ,,,,,,,,,,, i am sure you will get it sorted 


Rob

[Divided he ad]

Nicely done Nick    Good metal recovery from the old base 


David, I don't recommend expensive throwaway tooling either... As I recall my tools cost me £125 (6 various angled tools and a boring bar) and ten tips were about the £20 mark.
Sounds expensive....?  For £25 per year I don't think so.
I've had them now for nearly five years Still on the same ten tips. There are 4 cutting edges on each tip.

I've Made hundreds of things with them and not spent hours grinding and lapping tools... To my detriment I hear them say?  Not in my book. I'm still making things that make me happy.

Somewhere on here (maybe HMEM?) there is a thread about diamond lapping carbide tips to create alternative cutting edges.... Can't recall where or by who though?

I do grind HSS tooling BTW... Flycutters for my mill' (taught by Bogs)  and occasional drill bits.


Anywho, I'm Boring myself now.....

Sounds like Nick's happy with his progress today so going to make an effort to add a little less of this  stuff and carry on with the positive.

Nick,
Looking forward to seeing This tool in action and how these handle bar clamps develop. But I bet no where near as much as you are? 






Ralph.

[MadNick]

Evening.

Good progress made today. Carried on with the toolpost - trimmed it down to size and made use of the radius on the inside corner.



Its also got a nice shoulder on the upper part of the 'L' which fits nicely onto the turret.

Heres the thing assembled so far -



Just need to work on the tool height and deciding what tooling to use. I have some nice HSS 8x8 which would work well on this.

Best.

Nick

[saw]

Looking good MadNick, soon you can make your own balls 

[MadNick]

Ah the international language speaks again...

Will get more done tomorrow.

Nick

[Pete49]

jiihoo you trouble maker.....here I was happily minding my own business trying to manage the time I have left reading my forums and you point out another one. Now I have to ask for another 10 years to be added to my life
Thanks for the link 
Pete

[MadNick]

Evening,

I was busy last night and managed to take a few pictures this afternoon -

First off was another try at the toolpost. The old one would have worked with a carbide tip but I couldnt quickly figure out how to cut the 80 degree pocket for the tool. I started again and I had in mind holding an 8x8 HSS tool. The script was the same, machine the bottom part of the L to fit the slot in the turret and mill out a slot to hold the HSS  -



and



I was pleased with this and really just needed to make the leverage bar. Fitted -



Looks like the first ball I will make is going to go on the end of the bar.

A few jobs yet to do before I can try a few test cuts. The retaining bolt needs to be glued in and its clearance checked against the cross slide as it feels like its undoing itself. Also the mounting bolts need to be turned down a bit or made shorter so I can get a full swing with the toolpost moved back. I also need to grind the tip to cut balls.

All in all it feels like im getting somewhere.

Nick

[ksor]

  really nice with that extra wide "foot" you have !

But height isn't very easy to adjust - OK, it's only ones you have to do it so ...

Nice peace og tool - now make a video of Ball turning 

[MadNick]

Evening

Well I have had a good afternoon , perserverance paid off and my inaugural ball has been cut!

I made a couple of blanks pre-drilled and tapped to 10mm and an arbor with a 10mm thread.

My first effort is on the end of the leverage arm, here -



Its a bit of an olive shape I know.

The second one here, more of a ball shape as I started to work out how to get the best cut -



A couple of things need to be sorted out. I think the slightly olive shape is where the arbor flexes due to being a bit too thin at 10mm diameter. Also the tool sounds like it is rubbing when moving from 6 o'clock to 9 o'clock.

Will investigate tomorrow but for tonight I am feeling triumphant!

Nick

[rleete]

See?  Told ya it was fun to cut spheres.  Nearly as entertaining as getting an engine to fire up.

[ksor]

No - the olive shape is because the turner is NOT placed exactly vertically under the center of the chuck (maybe wrong spelling of 'chuck') !

Exactly this placing differently you can use for making different decorations - convex and concave - but to make a ball you have to place your tool very accurately under the center of the chuck.

[DaveH]

Good stuff Nick

Well done
 
DaveH

[Divided he ad]

Nice balls Nick     



Seriously though, Congrat's on the results 

The first one on the handle is almost an exact replica of my first attempt.... Still got it rolling round in the tool box draw, couldn't bring myself to throw it away.

The slight ogive you are getting is most probably due to the tool setting from the centre of the "turret" not the centre of the chuck.

If I may to refer to one of my own posts again (just to save me writing it all out again)  http://www.homemodelenginemachinist.com/index.php?topic=1721.45  About half way down I explain how I learned to set this type of tool for consistent results.  No need for pins and other things.


I hope that will help you and you can get them spot on.


You'll have fun making shapes with this.... Roll on handle bar clamps   





Ralph.

[MadNick]

Thanks fellas,

Its only a simple thing but I do find it immensely satisfying.

Woking on those handlebar clamp designs as we speak...

Nick