Author Topic: governors  (Read 31202 times)

Offline Jo

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Re: governors
« Reply #30 on: October 22, 2012, 03:33:23 PM »
The task for today is to machine the weights ;). I have two spherical  turning attachments, today I am looking to use my up and over one. To use this I need to first machine the following profile:



It is worth keeping the diameter of the rod for the weight slightly over sized at this point because these spherical turning attachments need to be set up otherwise it results in odd shaped turnings :mischief:. So here is the blank for machining:



So I have now set up ( :noidea:) the spherical turning tool and start by making a first cut to confirm that it is central:



As it shapes up if the tool is incorrectly set you will find that the outcome is a weight that is either squat or oval :naughty:. So this is what we end up with:



It is a good point now to get your emery out and give it a polish. We now machine the collar at the top of the weight.



Use a small safety file to merge any turning lines around the collar and then part off.



The smaller weights were also done the same way: So at the end of the day four weights :LittleDevil:. There is little point in polishing them further as they are due to be painted.



Jo
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Offline smfr

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Re: governors
« Reply #31 on: October 22, 2012, 04:37:46 PM »
Nice, Jo! Could you give us a shot of the "up and over" ball-turning tool?

Simon

Offline steamer

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Re: governors
« Reply #32 on: October 22, 2012, 04:50:44 PM »
Nice, Jo! Could you give us a shot of the "up and over" ball-turning tool?

Simon

Simon beat me to it! :ThumbsUp:
Dave
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Offline Jo

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Re: governors
« Reply #33 on: October 23, 2012, 11:47:29 AM »
This is my spherical turning tool I used for this job:




I built it using the Hemming way drawings. It is fairly simple just a tapered boss running in a head that is on a rotating mount.  The only important measurement is that the tool holder holds the piece of tool steel at 7 degrees.  Looking at the drawings I also need to make the internal tool holder.

Jo
Usus est optimum magister

Bogstandard

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Re: governors
« Reply #34 on: October 23, 2012, 01:18:52 PM »
Just as an aside, if you don't have a ball turning tool, and even though I have an up and over one that uses my boring head off the mill for the end part, I find it easier to just hot up a couple of the correct sized ball bearings to soften them, then drill and tap to the size I want.

One of the main problems with me though is that I have a ball bearing fetish, and use them whenever I can, having almost every size from real tiny ones up to 1" diameter.


John

Offline Jo

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Re: governors
« Reply #35 on: October 23, 2012, 04:16:33 PM »
I find it easier to just hot up a couple of the correct sized ball bearings to soften them, then drill and tap to the size I want.

That had been my original plan but I did not have any 16mm balls, hence being forced to turn them.

---------------------
Today I started on the drop links, this is the design:



These are both going to be machined out of square, so the starting point was to  mount the four jaw SC chuck and face the ends. Over to the mill and the pivot holes were coordinate drilled. That gave us these two bars as starting points:



You can see that I have marked up the material with permanent markers, I have also coated the end of the stock that these came off with the same marker pen. It gives a slight protection from the rust bug.

Off to the mill, I chose to do the smaller one first, so first job square everything up. As there will only be 0.5mm on either side of the slot on the smaller arm I chose to check the set up with a bit of scrap 3.2mm before starting on the main arm:



There is no rush, I took 16 cuts to cut these slots using a 2mm slot drill running at 3000rpm, if you rush all that happens is you break a very expensive slot drill.



So I have slotted for the first arm :whoohoo:, I will do the other tomorrow.



Jo

Usus est optimum magister

Offline smfr

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Re: governors
« Reply #36 on: October 23, 2012, 04:48:51 PM »
Good progress, Jo. I like the toolpost-mounted ball turner. I have a carriage-mounted one and it doesn't get close enough to the chuck for most things.

Simon

Online sco

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Re: governors
« Reply #37 on: October 23, 2012, 09:37:07 PM »
This is my spherical turning tool I used for this job:




I built it using the Hemming way drawings. It is fairly simple just a tapered boss running in a head that is on a rotating mount.  The only important measurement is that the tool holder holds the piece of tool steel at 7 degrees.  Looking at the drawings I also need to make the internal tool holder.

Jo

Snap!  Here's mine in action;

<a href="http://www.youtube.com/watch?v=UVc0ZbVQVoE" target="_blank">http://www.youtube.com/watch?v=UVc0ZbVQVoE</a>
Ars longa, vita brevis.

Offline Jo

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Re: governors
« Reply #38 on: October 23, 2012, 10:09:12 PM »
Thanks Simon, A video explains how these spherical turning tools work so much easier than trying to describe it in words :ThumbsUp:

Jo
Usus est optimum magister

Offline NickG

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Re: governors
« Reply #39 on: October 24, 2012, 05:19:14 AM »
are there any advantages of doing it that way?

Offline Jo

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Re: governors
« Reply #40 on: October 24, 2012, 07:17:57 AM »
Other means of making spheres include form tools, which I use for making the smaller ones the 8mm was the limit to what I would look to use this tool for. Softening ball bearings to use can be hit and miss, I find I have to try to soften 4 to hope to get two that my drills can touch.

You can also get spherical turners that mount on the cross slide and go around the work rather than over. To use these you have to take the top slide off. But where the up and over tool only needs about an 1 1/2" clearance to the chuck, these need a lot more.

Jo
Usus est optimum magister

Offline AussieJimG

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Re: governors
« Reply #41 on: October 24, 2012, 07:45:43 AM »
This is a great thread  Jo, I am enjoying it immensely and learning heaps. Thank you for posting the detail and the sage advice.

Jim

Offline Jasonb

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Re: governors
« Reply #42 on: October 24, 2012, 07:58:26 AM »
Jo if you are buying the balls then get stainless steel ones they are not as hard as steel so you can drill them with care and no need to polish them back up afterwards.

J

Online sco

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Re: governors
« Reply #43 on: October 24, 2012, 09:04:10 AM »
Other means of making spheres include form tools, which I use for making the smaller ones the 8mm was the limit to what I would look to use this tool for. Softening ball bearings to use can be hit and miss, I find I have to try to soften 4 to hope to get two that my drills can touch.

You can also get spherical turners that mount on the cross slide and go around the work rather than over. To use these you have to take the top slide off. But where the up and over tool only needs about an 1 1/2" clearance to the chuck, these need a lot more.

Jo

For really small stuff I use my collet chuck to hold the workpiece - then the head of the spherical turning tool doesn't clash with the chuck so no clearance problem at all!
Ars longa, vita brevis.

Offline jonesie

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Re: governors
« Reply #44 on: October 24, 2012, 04:23:13 PM »
 :ThumbsUp:  jo i like up and over radius turner. do you have plans to build this or are they a copy right. if so do you have a site to buy the plans, been holding off building one , but i like this one and would like to build. thanks jonesie