Steel Gantry Machine 1500x750x200

[toomast]

For Compensation Type I use In Computer.

I will try other options today - will try changing tool offsets in Mach3.
Although I have been using my machine for a year now, I am quite clueless about G-code :( If I need something to change I always go back to CAM and repost...
For faster/better workflow I should compensate in Mach3 I guess.
For roughing passes I leave 0,5mm stock which is default by F360.

[Nr1madman]

Im not good at this stuff, but just a thought..
Do you get the same error in the rough cut?

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[toomast]

I will measure in the evening. I use adaptive cuts for roughing out - little circular cuts with 2,4mm load. But I guess I should be able to measure 0,3mm. Will try.

[Richard]

Very nice build! Is this really your first one??? Can I ask a couple of questions?

Did you use epoxy on the gantry as well or did you get it machined flat?

Did you have any problems getting everything square?

I see you have the z rails on the moving z plate, which is the better method. Is the z plate rigid enough with just the rails bolted to it? I wondered if C channel steel or a box made from ali plate would be better? (the rest of the machine looks super rigid)

(that's 3 questions! Sorry!)

[toomast]

Very nice build! Is this really your first one??? Can I ask a couple of questions?

Did you use epoxy on the gantry as well or did you get it machined flat?

Did you have any problems getting everything square?

I see you have the z rails on the moving z plate, which is the better method. Is the z plate rigid enough with just the rails bolted to it? I wondered if C channel steel or a box made from ali plate would be better? (the rest of the machine looks super rigid)

(that's 3 questions! Sorry!)

1. Yes, its my first CNC machine build.
2. I used epoxy on the gantry too.
3. Squareing is time consuming. Have to use creativity and long machinist squares.
4. I can measure quite a lot of deflection on my Z. For sure you can design it stronger. Steel is more rigid. It all depends on your requirements and budget. It is nice to have a super strong machine, but it all comes with a cost. Also I like to point out that good machinist can produce superb parts with mediocre machine. There is no black and white, only gray :D

[Richard]

There is no black and white, only gray :D

Ha! very true!

Your design is very similar to one I started to draw up, with the deep sides to avoid the bendy gantry sides many people have...

I wanted to as long Z travel as possible, so I used steel channel for the Z plate. The fusion360 sim showed that a flat plate would flex a lot.

Your build is very impressive and it looks really nicely finished.

Do you make any mistakes at all???

Would have done anything differently?

So how did you do the epoxy on the gantry? I can see you have rails on the top and underside of the gantry (good design to keep Z close to the gantry!), so the top epoxy would be easy! The bottom????