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Author Topic: Mill or Turn?  (Read 26059 times)

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Offline TPS

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Re: Mill or Turn?
« Reply #150 on: May 20, 2019, 04:30:01 AM »
i assume you have checked accurate x-axis moves via gauge and mdi moves.
so what is left? all your cut's are to small so IMHO only two things are left:

-spindle rack get's pulled up by cutting force
-tool get's pulled down by cutting force

just trying to think loud. ;)
anything is possible, just try to do it.
if you find some mistakes, in my bad bavarian english,they are yours.

Offline Davek0974

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Re: Mill or Turn?
« Reply #151 on: May 20, 2019, 06:08:23 AM »
Hi

yes the axes moves have all been checked and were all ok, all done with MDI moves, any backlash accounted for, but is minimal

I will do more tests when my cutters arrive, i do not like these cheap triangle tool holders, the bits are not located well and the fact i get different errors between two tools tells me not to trust the tool holders i think.

I have some SCLCR/CCMT and other shapes coming so will redo my tests when they are fitted.

Offline Davek0974

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Re: Mill or Turn?
« Reply #152 on: May 21, 2019, 06:40:55 AM »
Tried a lump of HSS and diameters came out as requested - best not to use cheap triangle insert tooling i guess :)

Offline RICH

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Re: Mill or Turn?
« Reply #153 on: May 22, 2019, 08:45:39 AM »
best not to use cheap triangle insert tooling

I sharpen mine first  before using them on a universal grinder and they work fine.
Let me state that they don't seem to hold up under some conditions.
Carbide inserts grades and quality vary even between the best manufactures.
One problem with cheap carbide tooling is the grade of carbide and how made .....whatever it could possibly be..... even if stated!

Have a magnified comparison of the HSS and carbide tooling that you used and probably the nose radius is
smaller and cutting edges are sharper. Not surprised that they machined to spec.

Like I said before, the tool table can be right on as far as offsets but a lot of things affect machining to spec.
I sum it all up with the catch words  " ones  machines system" which is all inclusive!

RICH
« Last Edit: May 22, 2019, 08:48:04 AM by RICH »

Offline Davek0974

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Re: Mill or Turn?
« Reply #154 on: May 22, 2019, 10:39:55 AM »
Finally got some results i like.  :) :)

Pic attached of a little test part, diameters requested were 11,14,17,20mm results i got were 10.97, 14, 17, 20 so it seems accurate enough i think.

Short video...
https://youtu.be/AlcihBYrKIA

After the facing cuts, the first few passes are blank because the stock was 1mm under size (running out of junk metal)  ;)

Birds nest at the end as well, lots to learn.

Next up is the multi-grooving/turning tool, see if it can part-off without snapping my tool.....

Offline TPS

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Re: Mill or Turn?
« Reply #155 on: May 22, 2019, 01:29:20 PM »
happy to see you got it figured out.
so some cover's, some fixtures to get it off and on reproducable and a lot of learning about CNC turning (i think).
good Job  :) :)
anything is possible, just try to do it.
if you find some mistakes, in my bad bavarian english,they are yours.

Offline Davek0974

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Re: Mill or Turn?
« Reply #156 on: May 22, 2019, 02:23:45 PM »
Yeah, pretty much.

Covers next but need to sort out why the bearings get so hot first.

Maybe too much preload, not sure.

Using deep groove balls which i know is not ideal but they do have a rating for axial loads and the radial load rating is off the chart for a spindle.


Fixtures not so important as it only takes a minute or two to tram-in.

Offline Davek0974

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Re: Mill or Turn?
« Reply #157 on: May 22, 2019, 03:30:24 PM »
A short video of some tool paths to create the part shown in my original post.

Does it look like it might work or i need to change something ?

The tool is only 1.5mm wide.

https://youtu.be/J3ZCPnOwcrs

Offline Hood

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Re: Mill or Turn?
« Reply #158 on: May 23, 2019, 07:17:19 AM »
Certainly not the way I would do things and may be prone to deflection depending on the actual tool used and the material being cut.

Offline Davek0974

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Re: Mill or Turn?
« Reply #159 on: May 23, 2019, 07:24:32 AM »
Hmm, ok.

Material is 6060 aluminium

You would groove the body away maybe, then just a final finish cut?

Was trying to go with just one tool :)