Toolpost mount for Acorn lathe

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dmbgo
Posts: 547
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Re: Toolpost mount for Acorn lathe

Post by dmbgo »

20220905_163457.jpg
Today I finished of the block of steel that I had already started on, and mounted it onto the cross slide in a similar manner to Uwe. (See photo).
Since I had already used my dividing head to machine some indentations for ball bearings to fit into the bottom of my tool block, I'll keep those for the time being and just make a better toolpost. I wasn't very happy with my first attempt anyway.
I'm thinking about using larger balls. (Apparently, brave people use these).
dmbgo
Posts: 547
Joined: Sat Aug 15, 2020 9:21 pm
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Location: Bendigo Vic Australia
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Re: Toolpost mount for Acorn lathe

Post by dmbgo »

Another question; Is graduated indexing of the tool block really necessary?
I realise that with 2 tools in position, I need at least 90 degrees of index for my tool block, so that I can change tools, but what are the advantages of the angles in between?
The controller should and does, create any angle needed by simply varying X: and Z: feed rates.
In the past, when my lathe was manual, I used to change angles all the time, to achieve tapers etc, but with CNC, isn't that a thing of times gone by?

I have never had a need to do this, but for example, if you wanted to create a sphere, you could turn the first half of the sphere, away from the chuck, with a normal turning tool, then create the side of the sphere towards the chuck with a left handed tool, never changing the angle of the toolpost.
suntravel
Posts: 1967
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Re: Toolpost mount for Acorn lathe

Post by suntravel »

With CNC I use only 90° indexing 99° of the time.

Multifix was made for manual lathes to cur 30° chamfers ect.

With CNC you can use it with live tooling for boring at an angle or if you need tu turn 45° left side with DCMT...

Uwe
dmbgo
Posts: 547
Joined: Sat Aug 15, 2020 9:21 pm
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CNC Control System Serial Number: 0035FF8A7F34-0730203594
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CNC12: Yes
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Location: Bendigo Vic Australia
Contact:

Re: Toolpost mount for Acorn lathe

Post by dmbgo »

I have settled on a tool block mount for the time being. Thanks for all the examples, and answers to my questions.
I used a solid block of steel to mount the tool post onto, as per Uwe's system, which has an advantage that I didn't think of initially, it provides a good edge from which to use a square, in order to make sure the toolpost is at 90 degrees to the Z axis.
I made a new nut and post to mount the tool block to, and made it non-indexable. It is now permanently at 90 degrees to the Z axis travel. As I mentioned earlier, if I ever need to rotate it for some reason, I can remove the locking bolt, loosen the centre nut, and rotate the tool block temporarily.
Since I converted the lathe to CNC in the 1990s I don't think I've ever needed to rotate the tool block, so I think rotations will be infrequent to say the least.
Here's a photo of the finished block. *Note the 8mm bolt in the rear right hand corner of the tool block, locking it in place*.
Toolpost and mount 11-9-2022.jpg
vw_chuck
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Re: Toolpost mount for Acorn lathe

Post by vw_chuck »

How did this new toolpost help in rigidity? What was your deflection before hand and what is it now?
dmbgo
Posts: 547
Joined: Sat Aug 15, 2020 9:21 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 0035FF8A7F34-0730203594
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Bendigo Vic Australia
Contact:

Re: Toolpost mount for Acorn lathe

Post by dmbgo »

The new toolpost has helped a lot with rigidity, especially when parting off. The parting tool used to occasionally dig in and take a dive, resulting in a broken tool. I have had no issues in this area since changing to a solid block instead of the old compound slide.
I never measured the deflection before changing, but so far, so good.
suntravel
Posts: 1967
Joined: Thu Sep 23, 2021 3:49 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 6433DB0446C1-08115074
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Germany

Re: Toolpost mount for Acorn lathe

Post by suntravel »

Thanks for reporting back, yes cutting off should go much better now.

Uwe
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