Steel frame cnc router design/build

[JAZZCNC]

I wouldn't go running full welds round the edges if they are only for decoration and capping purposes. There will be a lot of heat generated for those welds and you want to keep heat to minimum.

Just chamfer the 4 corners and tack weld into place they will be more than stronger enough.

If you must fully weld then just chamfer the edges. If your on your own with no one to hold then buy some cheap magnet clamps to help.

Edit: Gytis . . if your still reading this then go check your email ASAP please.!!

[CraftyGeek]

Thanks Jazz - that kind of backs up my first thought.

Another quick Q on the welding front - how much cleaning do you do before welding new mild steel?
I've been searching & keep seeing hugely conflicting opinions - just a quick wire brush & then good to go?

[JAZZCNC]

Another quick Q on the welding front - how much cleaning do you do before welding new mild steel?
I've been searching & keep seeing hugely conflicting opinions - just a quick wire brush & then good to go?

Well with stick welder then not critical has other forms like Mig-tig etc but still the better you clean the easier it will be to strike up and get good weld.
Just a quick whip over grind or flat wheel is enough just to remove any rust spots etc.

[CraftyGeek]

So it turns out that welding is quite tricky to master...who'd a thunk?...more practice & video watching required!

At least pillar drill tests with 10mm steel went smoothly - very happy drilling the stuff, but need some new taps.

[JAZZCNC]

So it turns out that welding is quite tricky to master...who'd a thunk?...more practice & video watching required

Keep trying and it will click and don't get too stressed if your welds don't match those you see on the videos. Even pigeon shity looking will hold more than you realise. Weld 2 pieces together and then try to break the joint you'll be surprised how much effort it takes even with crap looking welds.!!

[CraftyGeek]

Keep trying and it will click and don't get too stressed if your welds don't match those you see on the videos.

I'm not stressing over it at all - i'll get it...not convinced i've got the current setting nailed yet. Welding lines & dots on a flat surface are coming out nicely - 'T' joins are a bit of a mess but solid. I think i've only used 3 rods so far...another 10 & I might get the hang of it.
Overall though, I like it - very relaxing to do.

[JoeHarris]

I'm not stressing over it at all - i'll get it...not convinced i've got the current setting nailed yet. Welding lines & dots on a flat surface are coming out nicely - 'T' joins are a bit of a mess but solid. I think i've only used 3 rods so far...another 10 & I might get the hang of it.
Overall though, I like it - very relaxing to do.

Relaxing until you blow your nose after burning a few rods and realise you are coating your insides with filth!

[JoeHarris]

If you can get over the annoying accent there is a guy on YouTube called chucke2009 I think who does some handy trouble shooting videos on stick welding. I found them useful anyhow. Practice is key though I think...

[CraftyGeek]

If you can get over the annoying accent there is a guy on YouTube called chucke2009 I think who does some handy trouble shooting videos on stick welding. I found them useful anyhow. Practice is key though I think...

I found his trouble shooting vid at the weekend - that has helped me loads...need to have another quick go, I think I should be sorted after the next practice.
For anyone needing welding help have a look at this...
How To Weld: Stick Weld Troubleshooting - YouTube

I've got a fan set up blowing 'most' of the black crap away from my nose - still got a bit of filth working its way through :-p

Progress report...
Design is still progressing, well on the way now - I should have a more advanced version to show soon.
As the design for the main base frame is finalized, I've bought the steel for the sides & rear brace so at least I can start making some progress on the build. First pieces were cut & drilled over the weekend.

[CraftyGeek]

Ok - design progress time

The overall machine...base frame is mostly the same as before except for a few minor tweaks - I'll probably add more cross bracing when its built if I feel it needs it (there's plenty of room)


Moving on to the gantry - i've lost count of how many times i've altered the way this fits together...i'm now pretty happy with it - there's nothing offending me there now
The upper & lower front plates are 5mm aluminium...all other plates/braces are either 15mm or 20mm (ecocast where appropriate).


Back of the gantry is also skinned with 5mm aluminium - 2 sections to allow easier removal around the Y-axis motor mount block. I did try to fit the motor inside the gantry, but there just wasn't quite enough space...by the time limit/home switches are in place I really don't think it'd fit.


Back of the gantry with the rear plates removed for a peek internally. There are a couple of 5mm aluminium plates at either end on the rear of the front faces to help tie them in at the sides (they will bolt to the back of the vertical piece between the main gantry side braces).
The main gantry frame as such is now 75 x 50 x 3 steel box (top, bottom & vertical side blocks)


Z-axis - 20mm plate with rails & leadscrew mounted on the back.


An attempt at a cutaway to show how the whole of the gantry/Y/Z fits together - its tight in there, but everything has at least 2mm clearance except for the Z anti-backlash nut housing which only has 1mm clearance on the back of the Z plate.


X-axis:
2x 1610 leadscrew (1400mm thread length)
SB20 rails - 1500mm
linear bearing spacing - 200mm (outer faces)

Y-axis:
1610 leadscrew (800mm thread length)
SB20 rails - 900mm
linear bearing spacing - 170mm (outer faces)

Z-axis:
1605 leadscrew (350mm thread length)
SB20 rails - 400mm
linear bearing spacing - 170mm (outer faces)

X-axis movement is roughly 1200mm - a smidge under what I was originally aiming for, but acceptable
Y-axis movement is roughly 750mm - a little more than I was aiming for, happy
Z-axis movement is roughly 180mm - could probably tweak this to gain another 10-20mm.

How does all this look/sound?

Looking for some sort of approval (hopefully :-p) before covering all the parts in holes etc