Protype machine - My first CNC Part

[mikie]

Hi All,

I finally churned out my first CNC part last night with my protype CNC.
WOW - I think it would have been cheaper to buy the part at the local hardware store for $20 bucks!

For those of you interested, I have a few pictures of the unit.
It's 1000mm(X) X 600 mm(Y) X 150mm(Z)

The slides are 1/2" pillow blocks for the X and Y Axis.
I obtained the Y-screw in my travels and is 4mm metric.
The x-axis is a belt drive system, which utilises the cam belt and pulley from a Daihatsu van.
The z-axis is a Acme thread.

The stepper motors are driven by Gecko's and I am running Mach3 to drive the system.

Issues:

I have found that the 1/2" rails on the X-axis are not adequate. There is flex present which needs addressing.

The x-axis requires some sort of gearing as i am having trouble driving the unit in the x-direction. I am finding that as the tool drives into the material, some skipping of the stepper occurs, or the entire gantry starts porposing due to the tool biting.

I would also like looking at putting the Gecko's away from the unit. There is far too much wiring on the machine.

A dust extraction system will need to be deployed as it just gets everywhere.

The effective cutting envelope is reduced due to the Z-axis unit width.Effectivly, you loose about half the width of the Z-axis

The x-axis is reduced by half the width of the Y-axis. I would like to re-engineer this for my next machine.

I had to add a third rail to the Y-axis as I had the initial 2 rails which guide the Y-axis too close together. The weight of the router itself then caused the entire Z-mechanism to sway forward and at times sway when i tried to cut. I added a third rail up as high as possible and this added a large amount of rigidity to the whole gantry.

Hope this helps some one who builds a machine in the future

/Mikie

[dighsx]

Hey congratulations Mikie. I just finished my first machine and I know that feeling of shock when the thing actually does something.

[WarrenW]

Does the X axis only have trouble moving when your cutting? Does it move okay when its not cutting? I was thinking maybe the linear shafts are not aligned and could cause some binding. I plan to use some mounting blocks for mine so I can adjust it anytime.

Too bad your not using open end bearings because then you could add a support for the X shafts to keep them from flexing. I have 1" drill rod I plan to use but I'm going with the ole rollerskate bearings method for now and will be adding supports on the shaft to prevent any flexing.

Nice work though! I can't wait to get mine together...

Warren

[DennisCNC]

BUT, you can't buy the fun factor for $20

[Jason Marsha]

Originally Posted by DennisCNC BUT, you can't buy the fun factor for $20

DITTO.

Jason

[mikie]

Hey warren,

Yeer it moves great without load, so it is defintly the direct drive system from the stepper motors. I always figured it would give me grief, but i will use this machine to build the reducton gear which i will retrofit to this unit.

I also have a 300oz/in stepper available to use, so i will make everything up with this unit and then drop it in to the unit.


True - about the fun factor, plus the satisfaction of producing something from nothing.

[Evodyne]

Mikey,

Congratulations!