Denford Software & Machines

Hello,

I've got access to a very well equipped workshop for the next few weeks and I've decided to take advantage of it to build an automatic tool changer for my Orac. Since the existing design obviously works perfectly well I thought I'd keep things simple and try and copy it as much as possible. With this in mind I'd be very grateful if someone with an original tool changer could measure the dimensions A-E on the drawing attached for me. I'm not looking for micron accuracy or anything - whatever's easily achievable with a calliper.

One thing I'm curious about is that in the pictures I've seen, cutters are held against the upper surface of the slot by grub screws from underneath (orientation from the perspective of the currently selected tool). What do you do if say you've got an HSS tool with the cutting tip ground down a significant amount - how do you get the tool tip coincident with the centre of the work? I had assumed the idea was to shim the tool as required, but in the pictures I've seen this doesn't seem to be the case.

Also does anyone know the height of the spindle axis above the cross slide top surface? I make it about 58mm, but I saw a tool changer someone else had made which seemed to use 59mm. I don't have a way to accurately make the measurement myself unfortunately.

Any help/suggestions gratefully received.

Thanks,

Luke

Hi Luke

Go to the link below and find all the dimensions you request,
https://www.homemodelenginemachinist.com ... ndex2.html

Here also some pictures of a 8 tool turret unit made for use on an Orac.
https://www.flickr.com//photos/xpylonrac ... 5602/show/

Rgds, Emgee

Hi Emgee,

Thanks for the post. Actually I've seen your toolchanger - I posted some questions in the thread you linked to a few months ago. I noticed that you said you had issues with tool clearance with that tool plate, hence I'm trying to get the original Orac tool plate dimensions. I think the design you used was for another Emco lathe (not a compact , correct?

-Luke

Hi Luke

Thought you may be the same person, only issue with tool clearance is when forward facing tools like the boring bar fitted are indexed next to the side cutting tool in use, care needed that when close to the chuck work takes place the boring bar doesn't collide with the chuck or jaws.
The toolplate dimensions I used were from a lathe using a 3" chuck, my Orac has a 4" chuck fitted which increases the risk of collision. If the work does not need the boring tool it is a simple 2 screws to undo and remove, no clearance issues then.
The same problem will be present with the original toolplate with a 4" chuck fitted, the tools need to be at a greater PCD to improve the design, you can see in one of my pictures it is possible to increase the tool PCD without issues with the cross slide.

Rgds, Emgee

Thanks for those insights Emgee.

I've finally got a bit of time to work at this and I've been playing around with various ideas for a toolplate with the hope of minimising the boring bar crashing into the chuck issue.

It'd still be useful to have the original Orac toolplate dimensions though, if for no other reason than to give me some bar against which to see if I've come up with an improved design. If anyone could give me the dimensions I requested in my original post I'd be very grateful.

Cheers,
Luke

I've got an original tool changer, i'll try to get the dimensions for you.

angel-tech wrote:I've got an original tool changer, i'll try to get the dimensions for you.

That would be great, thanks

angel-tech wrote:I've got an original tool changer, i'll try to get the dimensions for you.

Hi Angel-tech, any luck with those dimensions?

Thanks!

I've not had a chance to remove it yet, i'll get on it this week.