# Radius turning fixture



## Lindo (Dec 2, 2013)

Thought the site would be interested in a radius turning fixture I made
and the expanding balls.
used for taking dents out of saxophones

see link < https://plus.google.com/photos/112848589944601328801/albums/5678442248754209393 >

Regards
John
Spain


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## Tinkerer58 (Dec 2, 2013)

Very nice you have drawings, looks like it does a great job too. Very nice work, thx for sharing.


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## Lindo (Dec 2, 2013)

Gday Bruce.
I have drawings based on mounting to a typical Real Bull mini lathe.
I use Mastercam as a CAD although it is intended for CAD/CAM.
I can convert to DXF if you would like me to.Not sure if the 3D aspect of the 
drawing would work,depends on your converter.


John
Spain.


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## Omnimill (Dec 2, 2013)

Looks quite similar to mine except I put a large bearing race in it.


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## Niceonetidy (Dec 2, 2013)

Why do we have to sign in to google plus to view.  Can't we do anything anymore without having another account?


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## Lindo (Dec 2, 2013)

There is bearing/bushing on the underside,also the top part revolves in the inner 
bore with 2 ball bearings used as a thrusts in the vee rail.
These balls can be adjusted by 2 set (grub) screws for tension.

As regards the google + photos,its a good way to send photo links.
I tried photobucket and it wanted (a) to backup all my photos in my computer
including the holiday snaps (yawn) and (b) it crashed with Picasa which
I like to down load pictures from my camera.So I had to restore my computer to an earlier date and remove Photobucket.
I am not an IT guy and I know enough computer knowledge to be dangerous.
maybe I did something wrong.
If you just send a request through Google + I will let you in to the files that
are for public display.
Thanks
John


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## Omnimill (Dec 2, 2013)

Not had any problems with Photobucket, I just upload photos as required. This is my unit.


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## John Rus (Dec 2, 2013)

Very neat! I am learning soprano saxophone and wondered how they pulled the dents out (mine doesn't have any). I really like the tick marks on yours.

Thanks for sharing!
John.


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## Lindo (Dec 3, 2013)

Thanks Guys.

Nice looking tool,and thanks for the comments about the dent balls.
just for your info,to take out dents and there is more to it,but basically
you select a ball that just slips past the dent,then slowly expand the ball and 
push and pull,expand and push and pull.
One end of the ball has a rod,the other a cable to go round the bends.I use a 
Triumph motorbike speedo cable connected to the one end of the ball.
if you note one of the pictures shows a special expanding ball where I can
adjust the diameter whilst in the sax.
Best regards
John.
PS how do I reply to one person only if I receive several posts on the same subject.I am not savvy yet on this web site.


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## Lawijt (Dec 3, 2013)

Very nice. I have also a ball turner. If you use it , Are you turning under the center or on the center. I have Always very much shatter & I turn on the center.

 Barry


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## Lindo (Dec 3, 2013)

Barry.
With carbide, I like to be just below center.by .002"/.003" (0.06/0.09 mm)
It's just my personal choice.
For the chatter problem,check your cross slide gibs and the saddle strips for
excessive movement.
Regards
John
Spain


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## gus (Dec 3, 2013)

I use a DIY Rotary Table and cut brass balls with no chatter.


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## kvom (Dec 4, 2013)

The picture of the balls is very neat.  My daughter is a music major in college (clarinet) but her b/f is a trombone major.  I assume the same technique can be used with any brass instrument.


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## Lawijt (Dec 4, 2013)

Thanks for that info John.

 Barry


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## Lindo (Dec 5, 2013)

For anybody's interest in engineering excellence I have 
posted a link  Ferress US.

< http://www.ferreestools.com/Cover-page54.pdf >

There tooling is first class and innovative.
I in the past have bought a few pieces from them,but the substantial increase in
the cost of postage from the US and the customs bureaucracy has stopped me.

Taking dents out of trombone slides and keeping parallel
is very difficult.

John


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## gus (Dec 5, 2013)

Hi John,
The repair tool cataloque was very educational. Friend of mine once told me about very expensive maintainance cost to keep a brass band going and that was 55 years ago when I was a 15 year old kid trying to make some music of a badly dented bugle.:wall: And all I got was some very sour notes and an out of breath giddy kid.:hDe:


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## kd0afk (Dec 8, 2013)

I would like to make one of these but I don't have a mill. I have a design though but I would still need to machine the end of a piece of round bar to accept a diamond shaped carbide insert.


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## Lindo (Dec 8, 2013)

Could be a little tricky without a mill.
Send a drawing of what you need,maybe we could help you.


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## kd0afk (Dec 8, 2013)

Here is a photo. The part will be press fitted onto a bar. The slot it rides in will be two pieces of bar stock bolted to the base. But for this piece imagine taking a vnmg insert and pressing it into the end of a bar of clay. That's what I want, but in steel and not so mushy looking cause you know how clay can get when you press things into it. But I digress.


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## kd0afk (Dec 8, 2013)

I think if the piece was made the same diameter as the longest dimension it would be best. I can then grind and file it and turn it on the lathe so that the insert is supported but will have clearance. Anyway, if someone wants to tackle this thing pm me. I have tools with crappy plastic knobs and brass stock just waiting to replace them.


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## Lindo (Dec 8, 2013)

Not sure where you live.
I am in Spain.
maybe some member could help out who lives locally to you.
But a simple project for as mill owner.

John


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## kd0afk (Dec 8, 2013)

Thanks for the offer. I live California


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## Noitoen (Dec 9, 2013)

Looking at the different radius cutter designs, couldn't the tangential tool design be adapted to this type of tool?


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## Omnimill (Dec 9, 2013)

Noitoen said:


> Looking at the different radius cutter designs, couldn't the tangential tool design be adapted to this type of tool?



Yes, should work fine. I would take the sharp corner off it though to give a smoother cut.


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## Lindo (Dec 9, 2013)

Exactly,I use the largest radius tip DCMT available,as the radius is swung manually the sharper the tool point,the more unforgiving it can be to avoid leaving miniscule grooves.

John
Spain


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## kd0afk (Dec 14, 2013)

Would an insert holder be sturdy enough if instead of having a cavity that the insert sits in, you would have four hardened pins holding the insert in place with a screw in the middle?


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## Lindo (Dec 14, 2013)

I cannot see why it would not work.
provided they cleared the workpiece the tip is machining.
You could possibly get away with only 2 pins.
I believe you are taking this route as you have no milling machine.

Regards
John


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## Omnimill (Dec 15, 2013)

Probably easier would be to use two triangular inserts back to back supporting each other? Accurate drilling of the two holes would be essential.


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## Lindo (Dec 15, 2013)

Couple of points to consider,if I understand you correctly.

(a) Stacking inserts on top of one another could amount to several problems
of cracking,they can be quite brittle,and also it may be difficult to find the correct length TORX screw.The head of the screw and the tip counterbore are critical in retaining the tip in the correct place and rigidity.
(b) The DCMT (diamond shape) I have found to be better for sweeping into 
a corner if you have a spigot on the end of the ball,chuck side.

John
Spain


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## Omnimill (Dec 15, 2013)

Back to back, not one on top of another. Like this one but without material between them.

http://email.villagepress.com/pub/HSM/20101001/Images/3.jpg

http://www.projectsinmetal.com/wp-content/uploads/2009/01/radiusturner3.jpg

Agree about the clearance, that's why I chose the slim rhomboid shape insert for mine. I do intend to make another arm for mine though to use HSS tools.


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## kd0afk (Dec 15, 2013)

Lindo said:


> I believe you are taking this route as you have no milling machine.
> 
> Regards
> John


Yes, I've no milling machine and it sucks. Wish I could afford a Taig.


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## Omnimill (Dec 15, 2013)

It does make life a little difficult not having a mill, especially if you have a small lathe. You don't need to worry about specialist Torx screws for the insert if you have difficulty sourcing them, standard countersunk socket screws work just fine with a little "modification" on the lathe!


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## kd0afk (Dec 15, 2013)

What's screwed up is I can't find a job. I'm on disability but I'm allowed to earn $1100 more per month over my current income. If I could find work I could have a CNC Tormach in a few months. Without extra work, it'll take me a few years to save for one. 
I can't even get a job washing dishes or cooking here in Fort Bragg, Ca. I'm really starting to hate the US immigration policy.


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## Lindo (Dec 15, 2013)

Fully understand now.
The rear tip is only a support.Not sure why it's done,as I think it's impractical to cut anything from the operator side
of the machine.Again possibly to avoid milling the correct pocket shape.
If you check out Iscar,they have download PDF files of the tip geometry.
Also i do not like the cap head screws,buts that's me being politically correct.they look "Chinsy"
I like the TORX as it does not interfere with the swarf flow that a cap head could interrupt.
also how the screw acts like a glove,fitting nicely into the tip counterbores.
I have no friends in Sandvik to ask why they originally chose these screws.Somebody may answer this.
I believe the normal TORX thread is 2.5mm x .45mm pitch.Beware if tapping into steel,you will need lead,2nd and plug taps.
LMS may sell the screws,I will track down in my files where I purchased mine.
John
Spain.


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## kd0afk (Dec 15, 2013)

I've asked Santa for a mill. I don't have any family left and all of my friends are homeless so I'm counting of the fat man to make Christmas not suck for a change.


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## Omnimill (Dec 15, 2013)

I believe they place two tips on the tool to make both convex and concave cuts, at least that my understanding - sure I've seen a video somewhere. Agree about the cap head. I used a stainless steel countersunk socket screw on mine.


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## kd0afk (Dec 15, 2013)

Yes, the two tips are for concave and convex cuts. I figured mounting the insert in the end of a piece of round bar and mounting the round bar in a piece of square stock at 90 degrees and the square stock would fit in the slot of the base. The slot on the base would be made with two pieces of square stock bolted onto the base.  
The only problem is the socket for the insert.


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## Omnimill (Dec 15, 2013)

Maybe you could hold the insert in place with a couple of pins and the screw?


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## Lindo (Dec 16, 2013)

Understand now about the 2 tips.External/internal spheres.
basically you are emulating a DCMT type tip with 2 triangular tips.
As you know I use the DCMT type and if I need to do an internal sphere,just turn the dog leg tool holder 180 degrees.
As long as the end result works,thats great.IE the tip is the far side of spindle centerline.
Ref Milling machines check out Amadeal (Hugh),he sometimes has trade in's.
I have a Weiss 16,use it most days,it's 6 years old,never a problem.
Solid base,the head rotates up to 90 degrees each way,feed screw Z axis,DRO on the quill.
In my opinion,some of the mills are just drill presses with X and Y tables.
they seem to be not sturdy enough.
Just a thought,I know Santa may miss you out this year,maybe the little elves are working at Hugh's premises.
John http://cdn.homemodelenginemachinist.com/images/editor/smilie.gif


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## Omnimill (Dec 16, 2013)

kd0afk said:


> Yes, I've no milling machine and it sucks. Wish I could afford a Taig.



I'm really sorry I can't help you with this, it would not take very long on a mill. I moved house a few months ago and sadly I haven't been able to set up a workshop yet and my milling machine is in three pieces in the garage. I don't expect to have a usable workshop until at least next summer ...


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## kd0afk (Dec 16, 2013)

Omnimill said:


> I'm really sorry I can't help you with this, it would not take very long on a mill. I moved house a few months ago and sadly I haven't been able to set up a workshop yet and my milling machine is in three pieces in the garage. I don't expect to have a usable workshop until at least next summer ...


I understand but if I owned a mill it would be the first thing that I unpack and set up. And you have a garage, holy cow how nice would that be. My shop is 3'x8'
Good luck getting moved in.


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## Lindo (Dec 16, 2013)

Just for interest,by coincidence appeared on my emails.
It does not initially look supportive enough.
< https://mail.google.com/mail/u/0/?tab=wm#inbox/142fcea781581ee6 >

John
Spain


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## Omnimill (Dec 16, 2013)

This one?


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## kd0afk (Dec 16, 2013)

Omnimill said:


> This one?



Yes like that.


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## kd0afk (Dec 24, 2013)

I could also make the cutter with a piece of round bar that has a hole cross drilled and a piece of sharpened drill rod for the cutter. D'OH!


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## Omnimill (Dec 25, 2013)

kd0afk said:


> I could also make the cutter with a piece of round bar that has a hole cross drilled and a piece of sharpened drill rod for the cutter. D'OH!



Or you can just clamp a piece of HSS in there.


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## kd0afk (Dec 25, 2013)

Omnimill said:


> Or you can just clamp a piece of HSS in there.



Please expound?


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## Omnimill (Dec 25, 2013)

Just use a piece of round (or even square section) HSS clamped in the cross hole.

Pretty sure this is HSS in this one, just clamped somehow in the hole.






In your case you just drill a cross hole in the post as you mentioned and use a clamp screw in the top.

Update: found another picture that might give you some ideas.


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## kd0afk (Dec 25, 2013)

Deleted. Deleted.


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## kd0afk (Dec 25, 2013)

Deleted deleted


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## gbritnell (Dec 25, 2013)

I replied to this thread, directed at one poster in particular and then when I looked at what I wrote it became more of a political thing than a machining thing so I deleted my original posting and wrote this. 
 I find it a shame when there are so many people wanting to help and it turns into a rant. 
 gbritnell


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