My 2nd machine

[Sieg]

Hey guys,
Pretty much immediately after I finished my Jgro router I started designing and building my next machine :P
You learn a lot from building a machine! what its strengths and weaknesses are, and what can be done to make it better.

I started modifying the Jgro and it just kinda got out of hand Unfortunately, because I already took the Jgro apart, I could not use it to cut parts for the new machine. Hence, once again, I did everything by hand.
When it's operational I'll have it reproduce its own parts (some out of HDPE).

So here's the design:


It's a moving table with a fixed double gantry. Because of this it has a relatively large footprint, but it is ever so rigid



And here it is nearly completed:





This picture shows how I can swing the monitor out of the way:



The fixed double gantry:


The z-axis inbetween the two rails, no flex!




Four adjustment bolts holding the bearings tight against the rail:




This shows the custom made router mount. It's constructed out of 3mm thick stainless steel.


Backside:



This is the bottom of the moving table, showing the bearings it rides on:



All six home/limit switches are installed and working.

What's left to do is making the x-axis move, I have no proper leadscrew for it yet.

Hope you like it

[harryn]

It is easy to under estimate just how much better and more rigid a design like that really is. That is a really well thought out design. Much lower torque load on the gantry and it removes the wobble inherent in fixed table designs.

I completely agree with your idea of a double supported Y axis and moving table. This also lets you add a few more pieces and brushes to gain a semi - enclosed routing area.

The only location that I wonder about is the inside of your box structures on each side of the moving table. Since all of the Y motion is being transmitted through these boxes to the actual table, it might turn out that you can stiffen the design even more by putting some kind of cross brace diagonal inside the hollow box.

Of course, that is just MHO.

[19roomer68]

Hi,

very good design.

Is a video available ?

The moving Table is not fixed ? Only the bearings and rails on the picture ?

Really a good idea....

Bye

[Sieg]

Originally Posted by harryn The only location that I wonder about is the inside of your box structures on each side of the moving table. Since all of the Y motion is being transmitted through these boxes to the actual table, it might turn out that you can stiffen the design even more by putting some kind of cross brace diagonal inside the hollow box.

Good point, I will like into that! I could redo them as torsion boxes perhaps.

Is a video available ? The moving Table is not fixed ? Only the bearings and rails on the picture ?

No video cause it's not fully operational yet. I will make one as soon as I get it cutting.

Right now the moving table is being held down by it's own weight, but I was thinking about pushing it down with bearings at its sides.

[WayneHill]

The open rails at the bottom could pose some problems with wood chips resting on them. Are you planning on using a vacuum system?

[Sieg]

Originally Posted by WayneHill The open rails at the bottom could pose some problems with wood chips resting on them. Are you planning on using a vacuum system?

I will build a good dust-extractionsystem .

Meanwhile I've been trying to control the router 0/1 with mach3. But my relayboard doesn't seem to work



I took this schematic out of an old thread, and soldered it exactly like that. Mach3 is set up correctly cause it outputs 0 or 5v when I toggle spindle (I measured voltage at the pin to check).

What could be wrong?

[BobF]

Originally Posted by Sieg Good point, I will like into that! I could redo them as torsion boxes perhaps.

Looks like you could just cut triangles and slide them into place with some glue and screws.

[Sieg]

I took some measurements of the voltages in key places. Maybe this will help with troubleshooting. All measurements are relative to ground.



Who can help me?

[Sieg]

Ok nevermind, I got it working I can now turn my router on and off with mach3.

[aolshove]

Congrats. So, would you mind posting what you did to correct the problem so others (me) could build the circuit too? :-)

[Sieg]

Sure:

I replaced the 2N7000 transistor with a BC547B transistor, and used a 1N4002 diode. That did the trick.

Allthough the guys at the electronics forum still swear the original schematic should work aswell. I'm not sure what was wrong.

[Sieg]

BUMP

Wow it's been a while since I last posted here. I had sort of a winter-stop and the machine has been collecting dust in the shed.

The reason is have been trying to find a rack and pinion suplier in Europe, but there are NONE Unbelieveble!
I will have to order overseas again and pay the extra price.

Anyway, can someone tell me what type of rack and pinion I need?
- I will use it to drive the moving table with a Hobbycnc 305 oz-in stepper
- It must be 1m long
- What pitch or nr of teeth should the rack be?
- What diameter and pitch or nr of teeth should the pinion be?