C-Axis for lathe (construction in progress)

[Black Forest]

Very nice job.

[Scary]

That looks awesome. How are you programming the live tooling? Are you using cnct or cncm

[suntravel]

That looks awesome. How are you programming the live tooling? Are you using cnct or cncm

cnct since it is a lathe

I have made an easy to use program that can be used with live tooling or fixed tools for broaching or milling linear grooves...



Uwe

[Reedfirst]

Wow! Great work!

[suntravel]

Same G-Code works for Keyways also....



Uwe

[Muzzer]

Now it works for first testing, but still waiting for the clutch....

Got this running today, but I will make some more complex things with it like shown here

Uwe

Nice work, Uwe. Perhaps one day I might tackle the PLC code like you but so far I have avoided it!

It's a tiny quibble but when testing the repeatability (video, 4:15), ideally you would approach the same set point alternately from each direction, as this will show you the backlash.

[suntravel]

Now it works for first testing, but still waiting for the clutch....

Got this running today, but I will make some more complex things with it like shown here

Uwe

Nice work, Uwe. Perhaps one day I might tackle the PLC code like you but so far I have avoided it!

It's a tiny quibble but when testing the repeatability (video, 4:15), ideally you would approach the same set point alternately from each direction, as this will show you the backlash.

yes you are right.

Resolution with 4.5:1 gearing and 4000 Steps is anyway limited to 0.2°. That is also the max. allowed backlash of the planetary gearbox I am using.

For a higher precision you must use a harmonic drive with higher ratio and no backlash, but this is also a lot more expensive.

The direct servo driven C-axes on my production machines have an 90000 line encoder for C, that gives 0.01° resolution, but they use a 7.5 kw servo for max. 30mm turning diameter on the small ones.....

This here is only a hobby project on a tight budget ( ~700 bucks for everything needed )

Uwe

[cnckeith]

sweet! nice work, thanks for posting.

[suntravel]

Some engraving with the C-axis....



Uwe

[Muzzer]

For a higher precision you must use a harmonic drive with higher ratio and no backlash, but this is also a lot more expensive.

I have a 50:1 harmonic drive on my 4th axis which is pretty much backlash free. You can get used ones from the Korean machine breakers for a reasonable price. If there is any backlash it will likely be due to the toothed belt drive, reduced by the 50:1 ratio. certainly I can't measure it with my test indicators.

If only my linear axes had such little backlash - there is a special disappointment that follows when you install Swissi's probe app and it tells you in cold hard numbers what is actually happening!