JD's Garage DIY CNC Plasma table build

[GG1]

After some people showed interest in this project on a couple of other threads, I thought I'd start a new one here to document the (hopefully to one day be actually finished) build.

Summary so far:

I purchased the plans after seeing JD's Garage many Youtube videos about the table they developed:

Plans available here (I have no afiliation):

GEN 2.0 CNC Plasma Cutter Plans, includes .stl files for printing

GENERATION 2.0 Plans include information for both imperial and metric builds. These are based on 2x2 inch tubing for imperial (USA and Canada) and...

jdsgarage.bigcartel.com

The plans are in both Imperial and Metric for a 28" x 32" table (can be scaled scale up) and include optional Z axis and rotary axis for pipe notching.

 

[GG1]

I have started printing some of the 3D parts on my trusty Ender 3 - selecting PETG for toughness and longevity rather than the usual PLA, which was a challenge for me but seem to have a slicer profile which works, albeit slowly - the biggest prints took well over 2 days each!

 

[GG1]

This was one of the two big ones, biggest by far I have ever printed, 100% infill.

Very happy how they eventually turned out, not quite surface plate flat, but easily good enough for the job - the adjustable bearing block for the Y axis.

 

[GG1]

I'm keeping the postman busy and it's starting to look like a project.

Bearings mounted in the blocks and so far everything going to plan. The instructions are comprehensive and pretty straightforward to follow.

I was a bit concerned that the metric version was just an afterthought, well it probably was, but it seems like they have done a proper job. There are even options for the size of the square hollow section to cater for local availability and the flanges in the photo were a nice sliding/push fit over the tube size I chose (70x3mm).

 

[GG1]

That's where I am up to so far.

Other things I've been thinking about (any suggestions/advice very welcome):

Z axis - I'll be building this from the start

Y axis length - I'll be going for longer than their design for sure, just not sure how long.

X axis length - ditto. I believe it's possible to squeeze a few more inches out of the design without major problems, but much longer would require either a) a bearing support at the other end or b) another Y axis drive system mirroring the other. The latter is JD's Garage's advice as the preferred option and they supplied me with a photo of one of their customer's builds for inspiration, attached.

Table height - their design is quite low with folding legs to stow away. I'm quite tall and that isn't going to work for me but I do want it to fold up.

Water table - I anticipate this being a once-in-a-while machine so the idea of filling up and draining every time really doesn't appeal. I guess the main functions of the water table are reducing/catching dust etc and cooling the workpiece to avoid distortion. I have been thinking that wheeling it outside could help with the mess and the Scottish weather will provide the cooling, with a back up of some kind of water spray/mist system in case of a break in the rain.

Plasma cutter selection - with much help from members of the board I have decided to just go with an HF start unit and mitigate for any electrical noise it may generate. The budget is not large and while I'd love to have another R-Tech machine or similar, I think Mr Bezos will be happy with my eventual decision.

Bed slats - these just sound like another pain to me. I can't help thinking that all these so called professional manufacturers of industrial machines who have been designing these for decades have got it all wrong and there's a much better way of doing it.

 

[indy4x]

As I mentioned in your other thread, I'm quite keen on building one of these as well, payday soon so will be buying a set of plans as well

Out of curiosity, do they recommend 100% infill on the 3D printed parts?

Its going to have to be a cheap plasma for me, but I'd like to find a 'CNC' compatible one just to save some grief

 

[iNf]

I think Mr Bezos will be happy with my eventual decision

Or pay a visit to your local Lidl ?

Review - Parkside PPSK 40 B2 plasma with compressor.

Unboxed and plugged in, worked like a gem straight out of the box. Tried it on some one foot long runs of 10mm, 6mm and 1mm. left the kerf on so you can see what you get. None too shabby for a cheap plasma and the inbuilt compressor kept up with the cut. Did notice that the 16amp lead...

www.mig-welding.co.uk

 

[GG1]

As I mentioned in your other thread, I'm quite keen on building one of these as well, payday soon so will be buying a set of plans as well

Out of curiosity, do they recommend 100% infill on the 3D printed parts?

Its going to have to be a cheap plasma for me, but I'd like to find a 'CNC' compatible one just to save some grief

Yes they suggested 100% for PETG, I think 80% for PLA. More important for strength they said was wall thickness >=3mm. The son of the father/son team is a 3D print manufacturer engineer so I just went with everything they suggested, I'm a 3D novice.

Will be interesting to see how your plasma choice goes in comparison.

 

[GG1]

Or pay a visit to your local Lidl ?

Review - Parkside PPSK 40 B2 plasma with compressor.

Unboxed and plugged in, worked like a gem straight out of the box. Tried it on some one foot long runs of 10mm, 6mm and 1mm. left the kerf on so you can see what you get. None too shabby for a cheap plasma and the inbuilt compressor kept up with the cut. Did notice that the 16amp lead...

www.mig-welding.co.uk

Yes, I have been keeping an eye on that...very tempting.

 

[GG1]

3D printing brought to you by Fairtrade.

I thought it was going far too well. 14 hours worth, oh well.

 

[GG1]

This morning's effort brought to you by Brillo.

Interesting failure, the first flat section printed fine, but the upright part of the L section curled up. It has been colder and windy here - I don't trust the printer running overnight so have it in the back corner of an outbuilding on the concrete floor, but I think there is a cool breeze getting to it.

 

[Ged93]

Want to see it in action asap

 

[ukracer]

This morning's effort brought to you by Brillo.

Interesting failure, the first flat section printed fine, but the upright part of the L section curled up. It has been colder and windy here - I don't trust the printer running overnight so have it in the back corner of an outbuilding on the concrete floor, but I think there is a cool breeze getting to it.

View attachment 418576 View attachment 418577

What filament are you using?

 

[GG1]

It's PETG, branded eSUN from Amazon.

 

[m_c]

What temperature are you printing at ?
Going by that failure, it looks like it's printing a bit too cool and not fusing as well as it could.

You'll also need to address the draft to avoid the corners lifting.
It's probably worth creating a temporary enclosure.

 

[GG1]

It's printing at 245 with bed at 80. I think you're right, the upper part of the print is matt rather than shiny which I understand is a cool print. Perhaps as it's thinner and above the thermal mass of the bed and print it does end up too cool, plus the draft as you say.

I'll try what you suggest with the enclosure, thank you. Otherwise do you know if Cura can change the temperature half way through a print, or would I have to delve into the GCode?

 

[GG1]

In other news, I have made a little progress with the Y axis assembly.

Instructions were again straightforward and apart from the gantry top plate warping a little in the heat - I did only stitch it, but tickled back in line with a hammer - I'm happy how it turned out and nice to get part of it finished.

 

[iNf]

My printer is in my workshop/garage and a couple of times when I opened the main garage door the draught/temperature drop caused a print to lift. I've built a simple enclosure out of scraps of hardboard/thin ply and it results in the temperature being approx 10°C above ambient without any extra heating. Also as your prints seem to be taking a long time have you tried a larger nozzle? A 0.8mm nozzle makes printing a fair bit quicker.

 

[ukracer]

It's printing at 245 with bed at 80. I think you're right, the upper part of the print is matt rather than shiny which I understand is a cool print. Perhaps as it's thinner and above the thermal mass of the bed and print it does end up too cool, plus the draft as you say.

I'll try what you suggest with the enclosure, thank you. Otherwise do you know if Cura can change the temperature half way through a print, or would I have to delve into the GCode?

II have not done this personally. I just copied this of a forum as it might help you...


"I have done this with Cura a few times. Take a look at the plugins that come with Cura (I’m looking at version 19.12). It comes with two plugins: Pause at height and Tweak at Z. Tweak lets you change speed, temperature, flow rate and fan speed. Pause lets you move the head to a location (so you can change filament) and then will resume where it left off.

Very handy."

 

[m_c]

It's printing at 245 with bed at 80. I think you're right, the upper part of the print is matt rather than shiny which I understand is a cool print. Perhaps as it's thinner and above the thermal mass of the bed and print it does end up too cool, plus the draft as you say.

I'll try what you suggest with the enclosure, thank you. Otherwise do you know if Cura can change the temperature half way through a print, or would I have to delve into the GCode?

I normally print PETG at 250, but exact temp depends on the printer.
Given the size of prints, it's probably worth printing some temperature towers to find what gives the best finish.

It might also be worth turning off part cooling, as on large parts it's not as critical.