New 8'x4' Router build

[belli]

Hi all,

I have been promising to put the build log up here so that people can see the machine as it progresses. All the parts were made and the gantry assembled here in my garage, we then transported it to a friends house who very kindly lent me his garage for the final assembly. This machine took about 40hrs to design and was made on little more than a Bridgeport mill and a small lathe.

The X axis uses 20mm HG guides, the Y and the Z use 15mm HG guides. I am running rack and pinion on the X, 20x10mm ball screw on the Y and 12x4mm on the Z. Stepper motors through out.

I will post pics of the control box when I fit it, running Mach through the LPT but purchased a Grex initially (until my friend really wanted it!) I will get another Grex for the next one which is about 80% done (need to find another garage first). The next will be fitted with servo's to see how quick we can really make them go, I will limit the speed on this machine to about 8m/min I think.

I will carry on posting over the next few days as time allows me to build on it.

Cheers,
Greg

www.cncdirect.co.za

[joecnc2006]

Very nice, I always like the look of the 80/20 industrial style.

Lookforward to seeing it come together, Can you also keep us updated on cost as well?

Thanks, Joe

[cut more]

belli,
The table looks great so far. Do you have any drawings for your design? I would like to see them if you would not mind. The gantry pictures are pretty dark and It is hard to see much detail, But thank you for posting the pictures.
Cutmore

[belli]

Hi All,

Well the X axis linears are on, all one hundred M5 cap screws and the rack for the X, another one hundred M5 cap screws, would you believe that there are almost 500 bolts holding this machine together???

Joe: This section is similar to the Rexroth section, 45 x 90mm and 90 x 90mm, the bigger section weighs about 7.5lb's/ft! Very nice and rigid. I don't know if 80-20 do sections this heavy. As you see the frame it is 10' long and 5.5' wide, about 3' high. I haven't done a good costing exercise but will do one still.

Cutmore: I have done the drawings with ACAD and have asked a friend to do a full 3D model with Solidworks, I have considered offering it as a booklet similar to some others but this is a serious build, no MDF here. I might still make the plans available for download from my website. The gantry has been anodised dark blue, I will take some better shots when we mount it to the frame, maybe tomorrow.

Today I started clocking up the rack to the linear guides, hopefully tomorrow I will be done and then the gantry goes on. The day after will see the electrics mounted and then I am practically done.

Cheers,
Greg

www.cncdirect.co.za

[cut more]

Belli,
This looks like a very rigid machine! I have a practicalcnc router and it moves around. Your design looks like something I would like to build to replace my table with.
What are you going to use for a table-top?
Keep up the great work, I can't wait to see your finished router!
Cutmore

[belli]

Hi All,

I am determined to get done by the end of the week, I clocked up one of the racks today, it is within 0.2mm over 3m which I think is acceptable, the teeth on the rack act like a cheese grater! My knuckles are raw! Tomorrow the other side, then the gantry gets hoisted on and that will be the mechanics about done. Electrics on Thursday hopefully.

Cutmore: I intend fitting a 32mm (1 1/4") MDF top to start with, I made up some vacuum pads that can be screwed to the table if I choose to use vacuum, I will post a photo of them. The aluminium is certainly very rigid and I don't really have facilities to use steel, besides it's really messy when the grinding starts!

Cheers,
Greg

[belli]

Hi All,

Today was a good day, got the other rack clocked up and the gantry on. I sheared one of the M5 capscrew and spent about 20mins removing the rack to get the stud out, these things will happen. I guess it was a bad screw.

Gantry is on and looking good, I will screw the Name plates onto the covers tomorrow. I have included some photos of the reduction units on the X axis R&P drives, I have a 15:80 tooth timing pulley arrangement.

The build has stalled at the moment as I have run out of Geckodrives! I have a shipment on the way, hopefully it's here soon.

Cheers,
Greg

[joecnc2006]

those are some big gantry uprights, but nice to have everything contained inside of them. How do you plan to apply tension to the spur gear against the rack & pinion, (possibly adding a spring to motor assembly to apply the upward force needed).

Joe

[belli]

Hi Joe,

Yes, you are correct. There is a threaded rod which screws into the base of the upright. This carries a nut which 'tightens' the pinion into the rack, it is adjusted up until the pinion runs smoothly across the entire travel and is to prevent the pinion 'climbing' out of the rack on a sudden reversal. Then a spring is tensioned over this which takes up just the last little bit of play, this spring is quite light and so shouldn't cause the pinion to wear out. I might add a third nut which forces the pinion away from the rack to prevent the constant pressure caused by the spring, it would only carry the load on the very lowest parts of the rack. The rack is within about 0.008" over its entire length and so I am not sure about this one.

Cheers,
Greg

[eloid]

what are u using for motor what is the troque rateing per zo/inch

[belli]

Hi Eloid,

I have two 640 oz.in on the X axis (long axis) driving through 5.3:1 reductions onto rack and pinion. The Y axis has a single 1200oz.in directly on a 10mm pitch ball screw and the Z is a 270oz.in directly driving a 4mm pitch ball screw.

I will easily achieve 15m/min on the X and Y axis, at the 45kHz setting on Mach, if I fit the GRex I am sure I would get 50% higher speeds.

Regards,
Greg

[zoltan]

Greg,

Could make public the Bill of Materials of your table? I am referring to profiles size and length by each, connector types and quantities, and linear rails size and length? I would like to build a similar table following your photos.

Thank you,

Zoltan