Radius on the side/top of a round bar.

[ukracer]

I need to put a radius on a round bar to be welded to form a support for a fixed steady.

Seems like no one has done it like I plan to.
I chose round as I had some round stock from someone on here in a plastic paint container . ( need to find some more as I have very little left now).
I don't have any suitable square stock.

Anyway it would be nice to get it perfect but I am not sure how to machine it.

These photos show the type of thing I need but they used square stock.

The radius I need is 188mm as this is the steel ring I have.

 

[Chippie]

Put bar in chuck on a dividing head or rotary table so bar is horizontal to mill table, then with a large boring head with a suitable cutter, set your radius to suit (94 mm?)...move mill table up a bit at time to achieve the radius the full width of the bar...

 

[ukracer]

Put bar in chuck on a dividing head or rotary table so bar is horizontal to mill table, then with a large boring head with a suitable cutter, set your radius to suit (94 mm?)...move mill table up a bit at time to achieve the radius the full width of the bar...

Sadly I don't have a chuck on a dividing head or rotary table.

 

[Johnnybravo]

Not sure as to why you need to machine a radius of 188mm when that is the diameter of the ring you have? Clamp the bar onto a faceplate and bore the radius into the end of the round bar….that’s if i have got the gist of what you want to achieve correct…

 

[Agroshield]

File a flat onto the ring.

Sadly I don't have a chuck on a dividing head or rotary table.

You do not need a chuck or a rotary table. All that is needed is to hold the bar horizontal in a vise and then use the boring head to machine the radius.

Easy way to set boring head radius: centre spindle over corner of fixed vice jaw, move X-axis 94mm, adjust boring head until cutter just traps a rizla between itself and the vice jaw.

Move Y-axis to suit relative position of edge of bar and centre of radius to be machined (e.g. half the bar diameter if the bar centreline passes through the ring's centre point.

You would need to check the diameter your lathe will swing if you use the faceplate method. The inner end of the bar will be 94mm from the lathe centreline. The outer end will be 94mm + the length of the bar. Assume it is 50mm long - then your lathe would need to swing 144mm over the bed or over the gap (i.e. nominal 6" centre height).

 

[ranchero]

leave the end flat and fill the gap with weld

 

[ukracer]

leave the end flat and fill the gap with weld

Possibility. But I like to learn as I go to be honest. It's not like business that pays the mortgage etc.

 

[ukracer]

File a flat onto the ring.

Had not considered that idea.

You do not need a chuck or a rotary table. All that is needed is to hold the bar horizontal in a vise and then use the boring head to machine the radius.

I must be missing something because I can't visualise the boring bar cutting.
Don't suppose anyone knows of a YouTube video of someone doing the described actions?

 

[Chippie]

Had not considered that idea.


I must be missing something because I can't visualise the boring bar cutting.
Don't suppose anyone knows of a YouTube video of someone doing the described actions?

Imagine the round bar is a sheet of paper laying on a flat surface…,
Now take a set of compasses ( for drawing a circle….) open them up to say 1”….draw a circle on the paper…take a rubber and erase part of the circle….the end of the metal bar will have a radius just like the circle on the paper

 

[ukracer]

Imagine the round bar is a sheet of paper laying on a flat surface…,
Now take a set of compasses ( for drawing a circle….) open them up to say 1”….draw a circle on the paper…take a rubber and erase part of the circle….the end of the metal bar will have a radius just like the circle on the paper

Ok I think I get the idea.
The radius will then be on the top of the bar. So I will need to set the bar at an angle to be able to have it fit to the ring.

Or I will need to angle the bottom of the bar.
.
I was visualising the radius top to bottom. (Vertical) Your way is horizontal. I love how the brain sees what it thinks it wants to see. Lol

My brain was envisaging the bottom of the bar to be flat on the plate. And the top fitting on an angle.

Cheers..

 

[not done it yet]

I’m glad you can visualise it. I can’t.

What, precisely, are you trying to achieve? Is it broken?

My fixed steadies are the support!

 

[Agroshield]

I was visualising the radius top to bottom

Could you make us a fag packet sketch? Or scribble on the fixed steady pictures you show indicating the round bar and where on it you want the radius.

I think we have all assumed you want the radius where the round bar touches the big ring, but that does not sound quite correct for your application.

 

[Hood]

Use Fusion to draw things up to give you the X and Y offset for your boring head, like so. It could be calculated but easier in CAD

BTW sizes of dia of circle/Angles/Bar Dia are just what I punched in and may not match your material

 

[addjunkie]

Id be lazy and find a man with a cnc to whizz you one up in billet ali, or plasma cut one for you!

While I apreciate what your trying to do, you could just file it and weld it on, as any inaccuracies will be taken up by the 3 point support in use.

 

[ukracer]

Id be lazy and find a man with a cnc to whizz you one up in billet ali, or plasma cut one for you!

While I apreciate what your trying to do, you could just file it and weld it on, as any inaccuracies will be taken up by the 3 point support in use.

I do agree. But I identify as a woman and once I have made up my mind....lol

 

[ukracer]

Bit of a mare tonight as the only boring bars that fit my boring head require anti clockwise rotation.
This resulted in the head spinning off (good learning point)
So I tried a fly cutter.
That did the job but needs holder grinding to clear the work piece.
So a job for tomorrow I hope......but at least it will do what I needed.

Oh and I had to setup a smaller vice to be able to get the angle to do what I wanted.

 

[Agroshield]

...as the only boring bars that fit my boring head require anti clockwise rotation.

...smaller vice to be able to get the angle to do what I wanted...

As an emergency, get-you-out-of-trouble, you can mount the boring bar so the tip is facing upwards and cut from the bottom up to keep the clockwise rotation.

I am not understanding the angle bit. As Hood's drawing shows, you change the X-Y position of the spindle relative to the part being cut to get any 'angle' you need. If the spindle is due east of the stock, you cut the RH end of the metal. If the spindle is south of the stock, you cut the side of the stock nearest to you. Looking at the photo, you could have the stock in the big vise parallel to the X-axis and the spindle roughly SE of it to achieve the same thing.

 

[addjunkie]

As an emergency, get-you-out-of-trouble, you can mount the boring bar so the tip is facing upwards and cut from the bottom up to keep the clockwise rotation.

I am not understanding the angle bit. As Hood's drawing shows, you change the X-Y position of the spindle relative to the part being cut to get any 'angle' you need. If the spindle is due east of the stock, you cut the RH end of the metal. If the spindle is south of the stock, you cut the side of the stock nearest to you. Looking at the photo, you could have the stock in the big vise parallel to the X-axis and the spindle roughly SE of it to achieve the same thing.

95% of any milling job is the set up, the rest is just wiggling handles

 

[ukracer]

As an emergency, get-you-out-of-trouble, you can mount the boring bar so the tip is facing upwards and cut from the bottom up to keep the clockwise rotation.

I am not understanding the angle bit. As Hood's drawing shows, you change the X-Y position of the spindle relative to the part being cut to get any 'angle' you need. If the spindle is due east of the stock, you cut the RH end of the metal. If the spindle is south of the stock, you cut the side of the stock nearest to you. Looking at the photo, you could have the stock in the big vise parallel to the X-axis and the spindle roughly SE of it to achieve the same thing.

I can see that now. my Brain could not visualise that prior to see it in operation.. Its weird as that used to be one of my strengths in achieving tasks.
Now though I seem to get dragged in to the way I first thought or assimilated what was being suggested.

 

[ukracer]

I can't do a lot yet today. Getting frustrated as I usually get a few hours on a Wednesday but I know thats not happening this week.
I found a large (think it's called a shell mill.
But it will remove most of the material I need to shift.

Ironically an angle grinder will possibly be quicker but I need a vice in a clean area and currently I am moving stuff around and where the vice is needs a hour or more to clean and tidy up.

I can then use the fly cutter to get a.more accurate radius.

I have confirmed my idea for you tube has merits for the future but I need more time to try that idea.
Number 2 Grandson has 30 hours Nursery after Xmas so I am looking forward to that. ,)