[beluga282]

Hi everyone !!!

I'm pleased to show you a new CNC birth, named B2CNC :



This machine is built with Baltic Birch and MDF. There is still lot to do, like permanent wiring, a new aluminum Z axis, locate and install all the limit switchs, and finally, design and built the base.

Some specs :
- Cutting area of 30" by 60" by 7.5"
- Moving gantry
- Rack and pinions for all axis, including the Z
- THK linear rails, from Ebay
- Four stepper motors, Nema 23, 425 oz/in
- ...

I began the design few months ago, and read a lots of forum, french and english, to determine the spec of my machine.

Few weeks ago, the "Z prototype" was mounted to the gantry, so I made a little milling test with aluminum. The result was better than expected, so I decided to finish the machine with the actual Z (prototype made with baltic birch) and use it to mill the real Z axis parts in aluminum.

So, the real fun will begin soon !!!

Bye !!

[DonFrambach]

Very cool!! Please post more pictures!!

[beluga282]

Few pictures :

[beluga282]

The fun began today !!!

I've made temporary connection, draw a little thing on the computer, generate the G-Code, and did the first cut !!!

B2CNC - First cut !! - YouTube

I used a piece of pine, and a 2-Flute end-mill. The speed was 150 ipm for the rough cut, an 100 ipm for the final cut.

Works great !!!

Bye !!

[ger21]

How did you attach the rails to the wood? What type of fasteners?

[beluga282]

I forgot to take a picture of that during the assembly...

To install the rail in the good place, and minimize the misaligment possibility, I made a slot in the baltic birch, just large enough for the rail, and 1/8" deep. So, the rail is perfectly aligned with this process.

To maintain the rail, I just use wood screws from my "pocket hole" kit. These screws have a flat head and fit perfectly in the rail holes.

Edit : Picture from the drawing


Bye !!

[ger21]

Thanks.

[beluga282]

Hi !!

I've made a second milling test toning, with a sample file from 3dMachinist.

My "ball nose" cutter used for the finishing pass is really cheap ... But the result is not too bad !!!

Except for one thing ... You can see a drift on the picture, so the router height drift during the finishing process by around 0.25" ... I don't know is there was a drift during the rough pass ... But for sure, I've made a good "zero" juste before the finishing pass ...

Everything seem to be be tight on the Z mechanism ...

Anyone has an idea ??

[ger21]

Try reducing the Z axis acceleration.

[PaulRowntree]

Perhaps too tight or too heavy, and it was missing Z steps on the way up? Does it drift when doing air cuts as well?

An appropriate project from La Belle Province today !:cheers:

Cheers!

[beluga282]

I've just made an other test, and I am in a good way !!!

I dont know why I've made this, but I've set the kernel frequency to 100kz ... I decrease to 35kz, and this is now definitly better !!! And the max speed is absolutly enough !!

Tomorrow, I will test the Z acceleration, and that will surely fix the little remaining drift.

Thanks for the tips !!!


Bye !!

[beluga282]

Perhaps too tight or too heavy, and it was missing Z steps on the way up? Does it drift when doing air cuts as well?

An appropriate project from La Belle Province today !:cheers:

Cheers!

Yes, I've made the next tests "on air", without wood. And the drift was there.

My last, with the lower kernel frequency, was also on air, and the drift was almost gone. A little more tuning to do tomorrow with the z accel ...

Salut !!

[beluga282]

New test tonight ...

No more drift !!! :banana::banana:


Thanks to everyone !!

[PaulRowntree]

Great! What were the original and final Z acc values?

[beluga282]

The final accel value is 15. The Z movement is very smooth.

Bye !!

[ger21]

Got any pictures of your Z axis r&p?

[beluga282]

Picture from the actual prototype (built with baltic birch plywood), or from the drawing of the real aluminum version ??

Bye !!

[ger21]

Both??

[beluga282]

Hi Gerry,

Few pictures of the actual prototype, and 2 from the actual design of the final Z.

If need to modify the design to add dust collection.


Bye !!

[ger21]

Thanks