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Gallery, Projects and General => Project Logs => Topic started by: 1hand on January 16, 2011, 12:17:41 AM

Title: 1hand's CNC RT
Post by: 1hand on January 16, 2011, 12:17:41 AM

I'm going to build some sorta equivalent of this mount.
(http://i706.photobucket.com/albums/ww62/mrazink/A3/CNCkit.jpg)
(http://i706.photobucket.com/albums/ww62/mrazink/A3/08spiderinstall.jpg)
(http://i706.photobucket.com/albums/ww62/mrazink/A3/09mountinstall.jpg)
(http://i706.photobucket.com/albums/ww62/mrazink/A3/installed.jpg)

Here we go.
Before I started, I thought I would tram my mill.
(http://i706.photobucket.com/albums/ww62/mrazink/009-8.jpg)
...And it was off about .0015

I'm starting with a 2.25" square piece of 6061 for the mount.

First I squared 1 end.
(http://i706.photobucket.com/albums/ww62/mrazink/008-11.jpg)

Then flipped a found the edges and set the tool height.
(http://i706.photobucket.com/albums/ww62/mrazink/010-7.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/011-8.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/001-42.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/002-34.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/004-28.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/005-25.jpg)

Matt

Title: Re: 1hand's CNC RT
Post by: madjackghengis on January 16, 2011, 07:30:50 AM

Hi Matt, it looks like there's a rotary table bug going around, seems like everyone want's electronic controls on their rotary table.  I take it you are doing this job on a CNC mill?  Some pictures of your machine in action would be interesting.  I look at your milling out that round pocket with envy, I either put it on a rotary table and turn it by hand, or a four jaw, and turn it in the lathe.  That first piece looks pretty good, it's a nice start, you should tell us where you aim to go with this, or offer prizes for proper guessing.  Are you developing the electronics yourself, or are you using a package deal?  What size table is that, and what worm ratio?  Just asking questions as I will be doing my own when I get past the projects already on burners, and the more info there is, the easier it is to make choices.  It's good to see a new project starting up with a relatively new member, welcome from North Carolina,  :poke: mad jack

Title: Re: 1hand's CNC RT
Post by: John Stevenson on January 16, 2011, 08:12:37 AM

1hand,
I'd advise against using one of these Lovejoy type couplings. They are designed for axial misalignment and when doing these RT's if there is any misalignment it's always radial.

Look at Bog's post on his and use Oldham couplings, they are zero backlash and will handle both radial and axial misalignment. Plus feature is they are often shallower and save more space.

John S.

Title: Re: 1hand's CNC RT
Post by: 1hand on January 16, 2011, 07:26:48 PM

A few more.

(http://i706.photobucket.com/albums/ww62/mrazink/003-32.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/001-43.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/002-35.jpg)

Matt

Title: Re: 1hand's CNC RT
Post by: 1hand on January 17, 2011, 05:21:34 PM

(http://i706.photobucket.com/albums/ww62/mrazink/001-44.jpg)

(http://i706.photobucket.com/albums/ww62/mrazink/002-36.jpg)

Just wiring now!

Matt

Title: Re: 1hand's CNC RT
Post by: raynerd on January 17, 2011, 06:25:18 PM

Looks good, like John said though, I also used Oldham couplings for mine.

Title: Re: 1hand's CNC RT
Post by: John Stevenson on January 17, 2011, 06:31:03 PM

You can also fit bearings into this type of table as well, needle rollers and needle thrust, makes them a lot smoother.

(http://www.stevenson-engineers.co.uk/files/rotary%20table3.jpg)

One on the left is original, centre one has had the eccentric shortened down to get two thrusts in and bored for the needle rollers.
Far right is finished and assembles with the oldham coupling half doubling up as lock nut and adjuster.

(http://www.stevenson-engineers.co.uk/files/rotary%20table%205.jpg)

finished and tested.

John S.

Title: Re: 1hand's CNC RT
Post by: raynerd on January 17, 2011, 06:33:31 PM

I only use my one occasionally, 4 is just greedy!  :clap:

Title: Re: 1hand's CNC RT
Post by: 1hand on January 17, 2011, 06:41:50 PM

Boy them are nice!

Down the road, I may have to redo!

Matt

Title: Re: 1hand's CNC RT
Post by: Spurry on January 17, 2011, 07:05:23 PM

John S
It looks like you have turned about 8mm off the rear of the eccentric for the thrust washers. That would seem to move the worm outwards by about 4mm from it's original position. I thought it would be a good idea to remove 4.00mm and to counterbore the front thrust bearing by about 3.50mm, so the worm was only out of position by 0.50mm. Apart from more work, is there likely to be any other adverse result?
Thanks
Pete

Title: Re: 1hand's CNC RT
Post by: John Stevenson on January 17, 2011, 07:21:10 PM

The worm position isn't critical as it only uses about three teeth anyway and as long as you are somewhere along the worm thread with full engagement , that's all that matters.

John S.

Title: Re: 1hand's CNC RT
Post by: AndreasL on January 18, 2011, 05:05:28 AM

Quote from: 1hand on January 16, 2011, 12:17:41 AM

(http://i706.photobucket.com/albums/ww62/mrazink/011-8.jpg)

Your hight setter looks interesting.
Made it your self by modding the edge finder maybe?

Love to see the design if so...and othervise as well to be honest.  :beer:

/AL

Title: Re: 1hand's CNC RT
Post by: 1hand on January 18, 2011, 11:15:18 AM

Video

(http://i706.photobucket.com/albums/ww62/mrazink/th_001-45.jpg) (http://s706.photobucket.com/albums/ww62/mrazink/?action=view&current=001-45.mp4)

Matt

Title: Re: 1hand's CNC RT
Post by: 1hand on January 18, 2011, 11:18:24 AM

Quote from: AndreasL on January 18, 2011, 05:05:28 AM

Quote from: 1hand on January 16, 2011, 12:17:41 AM

(http://i706.photobucket.com/albums/ww62/mrazink/011-8.jpg)

Your hight setter looks interesting.
Made it your self by modding the edge finder maybe?

Love to see the design if so...and othervise as well to be honest.  :beer:

/AL

No, an ebay purchase

http://cgi.ebay.com/Z-MASTER-EDGE-FINDER-Z-HEIGHT-SETTER-CNC-MILL-/280612183872?pt=LH_DefaultDomain_0&hash=item4155ca1f40

Title: Re: 1hand's CNC RT
Post by: HS93 on January 18, 2011, 11:31:45 AM

is this the same one

 http://cgi.ebay.com/PRECISION-ELECTRONIC-X-Y-EDGE-FINDER-CNC-MILL-USA_W0QQitemZ270688430163QQcategoryZ58239QQcmdZViewItemQQ_trksidZp4340.m444QQ_trkparmsZalgo%3DCRX%26its%3DC%252BS%26itu%3DSI%252BUA%252BLM%252BLA%26otn%3D10%26ps%3D63%26clkid%3D6457999442746848815

     :ddb: Peter  :ddb:

Title: Re: 1hand's CNC RT
Post by: andyf on January 18, 2011, 12:10:42 PM

I think it's the same unit plus a block it plugs into, Peter.  Same eller also shows this:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280615997099&ru=http%3A%2F%2Fshop.ebay.com%3A80%2F%3F_from%3DR40%26_trksid%3Dp5197.m570.l1313%26_nkw%3D280615997099%26_sacat%3DSee-All-Categories%26_fvi%3D1&_rdc=1

For Z-axis setting, couldn't you do much the same with a block of known height, a battery, led, croc clips and a bit of wire?

Andy

Title: Re: 1hand's CNC RT
Post by: HS93 on January 18, 2011, 12:41:29 PM

as I am realy stupid , how does the block work ?

Peter

Title: Re: 1hand's CNC RT
Post by: andyf on January 18, 2011, 12:47:56 PM

No doubt Matt will enlighten us, but I imagine it contains insulation between the top and bottom surfaces, so that when the cutter is lowered to touch the top, it completes an electrical circuit via the metalwork of the mill, and lights up a led.

Andy

Title: Re: 1hand's CNC RT
Post by: 1hand on January 18, 2011, 03:51:05 PM

Quote from: andyf on January 18, 2011, 12:47:56 PM

No doubt Matt will enlighten us, but I imagine it contains insulation between the top and bottom surfaces, so that when the cutter is lowered to touch the top, it completes an electrical circuit via the metalwork of the mill, and lights up a led.

Andy

Yup, your right. works the same way when you take it out of the block and use as an edge finder.

Matt

Title: Re: 1hand's CNC RT
Post by: AndreasL on January 18, 2011, 07:09:34 PM

Thanks!

Cost less then expected.  :thumbup:

Title: Re: 1hand's CNC RT
Post by: cfellows on January 18, 2011, 07:13:15 PM

Hey, Matt, what size stepper did you use (voltage and current).

Chuck

Title: Re: 1hand's CNC RT
Post by: 1hand on January 18, 2011, 08:06:31 PM

nema 23 381oz/in 3.5amp 48v

I used the same as my mill and lathe to keep it all the same, but could of got by with a smaller one.

Matt

Title: Re: 1hand's CNC RT
Post by: 1hand on January 27, 2011, 11:59:37 PM

Got the 6" RT fixed up today also. Ended up getting a second 5C, to end the hassle of switching between the lathe and RT.
(http://i706.photobucket.com/albums/ww62/mrazink/002-37.jpg)
Matt

Title: Re: 1hand's CNC RT
Post by: Bogstandard on January 28, 2011, 02:23:50 AM

Nice neat job you have done there Matt.

It all makes making machining a little easier and allowing you to do more than you could before.


John

Title: Re: 1hand's CNC RT
Post by: 1hand on January 31, 2011, 06:29:38 PM

It was a real life saver today!!!!
(http://i706.photobucket.com/albums/ww62/mrazink/001-46.jpg)
Matt