Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Fred_evans on January 06, 2015, 12:22:08 PM
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Hello Hood - long time no speak
I picked up a thread from 2012 in which you showed a 12 tool tool changer you were going to manufacture
Did you get it going??
regards
fred evans
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Yes and have just finished making an 8 pos VDI one to replace the 12 position one.
Pic below of new one.
One day I may ( or most likely may not) get round to painting the cover ;D
Hood
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You've attached the wrong pic Hood; that's no turret. SWMBO & I Netflix'ed 'Star Trek Into The Darkness' last night and your pic is of the Warp Drive® core module. ;D
(Got any videos of it working?)
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LOL
Vid of it indexing here.
https://www.youtube.com/watch?v=35p74Bf51u4
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Hood,
VERY cool, but looks like you've got a pretty massive coolant leak! :-)
Regards,
Ray L.
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Hood, why replace the 12 w/an 8 ?
Curious,
Thanks
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thanks hood-- very impressive
All running on Mach3??
excuse my ignorance but what is VDI ??
Is this your workshop??
are there any pictures nof your shop??
regards fred
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Ray,
thats the washdown ;)
Russ,
12 Pos was just too crowded, originally I wanted 10 pos but the curvic was 48 teeth so only allowed me to have 8 or 12 . I could have made an offset plate for 10 positions but it would have been awkward. Eight positions on the standard clamp type turret was a pain as I regularly use more than 8 tools so would be constantly swapping and setting. The VDI allows me to swap out with pre-set tools repeatably.
I have also made up a jig so that I can set tools up and they will be close on the X so only a slight tweak to get dialed correctly in. Was going to mount it somewhere in the workshop but space is a premium so found the perfect spot, on the lathe itself where the front post used to be :D.
Fred
Yes from Mach using a PLC and an Indexing servo drive.
Yes it is my workshop but no pics, too cluttered to stand back far enough to take any :D
VDI is a type of holder that is clamped into the turret with a kind of teeth and wedge system, see pic. Means tools can be swapped in and out and are repeatable. The tollerances are fairly tight, for example the holders have the centre tooth at 29.7mm and the hole for the wedge needs to be at 30mm, this means when the wedge is screwed in it will push the tool holder tight against the face of the plate.
Hood
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again--what is a curvic ?
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It is a high precision ground toothed coupling which allows repeatability when rotated and clamped in any position. Pic below showing one that I had on the previous turret, also a pic of the coupling used on this one. It is a Hirth coupling, similar but different idea but does the same thing and is just as accurate..
Hood
Edit, I only show one half of each, there are two that mesh with each other.
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Russ, the original Curvic was actually 24 teeth, its the Hirth that is 48. Same thing applies though, no way of getting 10 positions from the curvic without making an offset tool plate.
Hood
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Thanks hood .
So i suppose you let a piston move the one away fron the other- then let the servo index and then
reclamp to the new position?
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Yes Fred, hydraulic cylinder pushes the whole plate with half coupling forward to disengage then rotates and clamps once there.
You obviously need some means of having the shaft move without the motor or pulley or whatever also moving. On my first turret I had a splined section in the middle of the shaft and the pulley was splined. On this one I have a splined section of shaft bolted onto the end of the shaft and use a splined bush on the end of the gearbox.
The gearbox is planetary box, so inline, with a 25:1 reduction. That way I can use a smallish servo to rotate it.
Hood
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Scots engineering at its most innovative
regards
fred
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Ha ha Fred, I think all these ideas were worked out long before I did them :)
Hood
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I recently got a lathe almost the same as the one Hood made the turret for. I would sure like to copy hoods design, its the best I have seen yet for a DIY.
Are any further details on the turret available? I wonder about what was used for main shaft bearings that allowed the shaft to both rotate and slide for unlocking. Details on how the coolant passages were done is also a mystery.
Hood, any chance you still have some of this info? I would sure like to make my own !
Thanks much!
George
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The VDI info/specs are available online, I just did a google for it.
I think most of the other info you asked is in this thread,
http://www.machsupport.com/forum/index.php/topic,22080.msg201728.html#msg201728
Hood
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Thanks Hood. I thought I had read everything related to your turret but I never found all that info in the BT30 thread.