Desktop 1000 mm x 600 mm Gantry Router

[Soyb]

Hi Jazzcnc, thanks for the detailed reply

More things to consider!

I keep thinking of different ways of doing things and then over complicate the design trying to do everything, I keep having to pull myself back to the original concepts and need. The machine will be for cutting mainly wood accurately with the occasional plastic, CF and aluminium. I have based the design on what I currently use which is a Stepcraft D600, its a nice little machine but definitely for the hobbyist, leadscrews and rollers on extrusion. This has been a great tool to get in to CNC / machining but its maintenance and lack of accuracy is now an issue.This machine is the next step and instead of just buying a new machine I thought it would be more interesting to design and make my own. (and cheaper).

I am using my Stepcraft to make the parts so I am limited in what I can do hence the design attempts to use as many off the shelf components and the use of a Kress and KK01 BOB as I already have a UCCNC UC100 controller and license.

I will upgrade to 15 mm gantry sides and z axis and look at the spindle / controller options / closed loop steppers although these might be a version 2 upgrade once I can sell the Stepcraft.

Thanks for the feedback

Ian

[pippin88]

I have proximity switches mounted inline - can confirm crunching....

Definitely mount the switches at 90 degrees / not in the path so a crash / run away cannot damage them.

Use physical stops to prevent running off the end of axis.

[Soyb]

I have the option of using mechanical switches that have enough travel to react in time to a crash / runaway so I will use them but have a play with the proximity switches to learn how they work, every day is a school day!

[JAZZCNC]

I have the option of using mechanical switches that have enough travel to react in time to a crash / runaway so I will use them but have a play with the proximity switches to learn how they work, every day is a school day!

Proximity switches are much better, even the cheap ones, than mechanical switches unless you buy expensive high-quality mechanical switches.
They react faster and are more reliable, a long time ago I did a test showing the repeatability of the cheap proximity switches to show how repeatable they are, it's on youtube and this forum somewhere. But since that time I have literally fit 1000's to machines I build and I have very few issues, probably 2-3 in every 100 will arrive faulty and I rarely have any fail when in use on the machine, I can't remember the last time I had one fail on a machine.
However, everyone I've fit slides by the target rather than face on. They sense and repeat just fine when sliding past the target and you don't risk crunching them if crashing the machine at high feeds where inertia will cause overtravel even though the switch reacted quick enough.

[Soyb]

First stage finished. nice and solid using standard C beam extrusion and 4 end plates.


I decided to go with 1605 ball screws for accuracy as speed it less important for a small machine, next stage is to fit the 2 y axis stepper motors and test connect the electronics, limits etc

[Kitwn]

Very kind of you to show all the pictures upside-down for the benefit of us Australian readers

All you need to do now is take a hacksaw and a drill to those lovely end brackets and modify them to take the proxy sensors the right way on.

Kit

[Soyb]

Cross Beams finished, starting on feet. Once I have the base frame assembled I will start on a test setup of the electronics so I can drive the twin Y axis and limit switches

[Soyb]

I put some temporary plates on the Y carriages and used the cross beam to check the difference between each end, using some feeler gauges the gap is virtually identical at ~ 0.4 mm, the gap seems to be with the edges of the extrusion and the T slot plate so I am happy that the rails are square. I am going to put 1 mm pockets in the gantry side plates for the ball screw nuts, carriages and cross beams, so I can accommodate .2 mm either side for the X axis cross beams. Phew, first issue wasn't.

[Soyb]

Started to 'play' with electronics, all axis working, slaved C to Y axis, tested proximity sensors and they will work with the feeds I have setup without crashing. Relays setup.
Having a play with steps/ feeds etc Realistically the machine does not need to be super accurate so I am going to set it up to have a resolution of 0.01 mm with an expected tolerance of +/- 0.05 mm ?

Pleased with the results so far, I am using Stepperonline 2Nm Nema 23 Closed Loop Stepper Motor 5A 76mm & Servo Driver CL57Y, the movement is nice and smooth



Waiting for some electrical components, once they arrive I will assemble the electronics properly

[Soyb]

Latest update, started cutting the plate for the , spindle, z axis. I have subcontracted the top and bottom of the z axis as I cannot get the squareness required and these are critical for the smooth running. My Stepcraft is good enough for plate Y/X but isn't square on the Z, anything over 10 mm thick and you can see a noticeable slant.



Also start finalising the design for the dust shoe



And doing test layouts for the electronics, I am mounting them upside down under the machine on rubber shock mounts