Gone 'n' dunnit!

[John Candy]

After a few years of dithering, have ordered a 3D printer, in fact a Snapmaker 2.0 A350, which also can laser cut wood and plastics and CNC mill wood, plastic and aluminium.

The laser and milling functions will cut from common image file formats (JPG, PNG, etc.) as well as CAD files .... just as well since I have no CAD skills.
It will be able to work from images I previously prepared for the Cricut Maker (a heavy duty die cutter).

The 3D printing bit is still a total blank so far as my capabilities are concerned but that will now need to be mastered.

The plan is that the combination of the three functions will produce panelled carriages and horse boxes (principally GNR/GCR/LNER and LNWR/MR/LMS stock).

There are plenty of videos about using the Snapmaker on YouTube but has anybody here used a Snapmaker?

Regards,
John.

[cabbage]

John,
Examine the Wiki on Cura, LibreCAD, OpenSCAD and Laser Web. Have a play with some of the SCAD scripts. Hopefully I have made them easy to read and understand.

I hope you enjoy being as lazy and cheapskate as I am!!!

Regards

Ralph

[IanT]

It looks to be an interesting machine John.

I've had a 3D Printer (Sovol S01) for just over a year and have found it very useful for some things (all workshop related thus far). Ralph recommended Open SCAD for simple objects and I would agree with him that SCAD provides a low-effort route to designing for 3DP. I've used it for simple things and also downloaded useful objects from Thingiverse that can be 'adapted'.

For larger/more complex, especially multi-part objects, a good, modern 3D CAD system is required and I've been transitioning from TurboCAD 2D to Solid Edge 2020 since last year - partly prompted by now having the Sovol. I can highly recommend SE 2020 (Community Edition) as being both functional and very powerful. It's fully parametric and uses both ordered and synchronous design methods (hard to simply explain but it does make life easier). It's fully parametric and can generate dimensioned 2D drawings from 3D parts very simply. More importantly perhaps, it's also a free lifetime license (and is not Cloud based like Fusion).

I have thought about buying a small CNC machine but I do have a finite limit on the new things I can absorb within a given period and I've quite enough with 3DP and 3D CAD at the moment.

I will be very interested to hear how your machine handles the CNC side however.

Regards,

IanT

[IanT]

Noticed this comment on the G13D Circle John - and thought of you!  :-)

"I wanted something bigger so I bought a Snapmaker A250 3-in-1 machine from China.  This prints, laser cuts and etches.  So far I have only 'printed' but I am extremely satisfied.  I like some of the design features. Calibration has a 9 point probe of the bed and then a single point depth measurement.  Changing filaments is very easy with direct access to the head drive. If power is switched of the machine restarts where it left of.  Software is called 'Luban' and is based on Cura."

Sounds good.

Regards,

IanT

[John Candy]

Ian,

Mine arrived yesterday (from Manchester although it was made in China) and I have only had time to check the contents are all there.

It is very solidly made..... the box (it is the A350, the largest version) I was unable to lift!

Encouraging to hear positive reports and hopefully will find time to assemble over next few days.

Regards,
John.

[John Candy]

The contraption is still in its box (when assembled it weighs 29kgs.... 63lbs) so I still need to find a suitable base to stand it on, as well as clearing space in the garage.

The first items I wish to print are domes for the LNER (ex-GC) class A5 4-6-2T.
I have prepared OpenScad drawing (as below) but am uncertain about a few aspects.

1) How will the printer handle the "arc" where it sits on the boiler, to prevent the rest collapsing (will it automatically insert temporary supports)?

2) The extreme edges, where it fits onto the boiler, are very thin..... will they print or do I need to "beef 'em up" (not sure how best to do that) ? At present I have (you can just see in image) included a slight (cylindrical) central underhang to raise the edges from the boiler so Isopon filler can be used (if necessary) to replace the missing lip.

The boiler will be rolled n/s ..... I don't feel adventurous enough (yet) to try and print the boiler and dome as one item.....give it time though!!

John.

[cabbage]

John,
One of the options that you will find on the control program be ot Cura or similar - is build support structure. This will produce a printed "froth" to fill in the gaps and produce an armature for the main piece to be built on. You then have to remove the froth with a knife or your fingers.

Note : PLA is the strongest and PETG has the best surface finish.

Regards

Ralph

[John Candy]

Thank you, Ralph.

Have found the settings.

The reel of filament supplied with the machine is 1.75mm black PLA.
There are suggestions in the support forum that the Snapmaker PLA is of variable quality and can crumble or break without much encouragement.

Will order some PETG to try out.
Where do you buy yours?

Regards,
John.

[cabbage]

Like steel PLA is strong but brittle. PETG is softer but rubbery compared to PLA. Think of them as steel and aluminium. I get both off eBay

Regards

Ralph

[IanT]

There has been some debate about using PLA in models that will be used outside John - mainly because there is concern that if left in direct sunlight there can be warpage. This has centred mainly around the printing of wagon and carriage body sides (e.g. relatively thin parts) and may be less of a concern for something more solid like a dome. Most of the G13D Circle seem to use ABS for these parts, although other filaments are mentioned too.

https://gaugeone3dcircle.groups.io/g/home

Thus far, I've only used PLA+ for my various prints but I have recently purchased some PLA+Carbon filament to trial (but this needs a 'hardened' nozzle). ABS is also more difficult to print than PLA - see:

https://3dprintergeeks.com/abs-vs-pla/

Regards,

IanT

[cabbage]

I live "fairly high up" and wind impact damage is more of a problem than solar heated distortion. The "tiles" I print are 9mm thick and are stuck to exterior grade plywood. I don't use dark colours suchnas slate but mimic the local "Bunter" sandstones and millstone grits. The tiles are printed at 20% fill so there must be little in the way of potential distortive energy. The bulk of my printing is for building work rather than Carriage and Wagon work. The last Brassica station was destroyed by a flying fencing panel on an 80mph gale.

Other than that and squirrel knawing I have had no problems with pieces left outdoors.

Regards

Ralph

[John Candy]

Having carried out a bit more research (in the light of Ralph's and Ian's comments) the main problems with PLA seems to be that it is not waterproof and is prone to "compost" if subjected to moisture and is prone to warp if it gets to temp. of 60C . It absorbs moisture in storage (hygroscopic) and can "foam" if water content too great (there are heated boxes available to dry out and contain the reel prior to and during processing). 
By comparison, PET-G is waterproof (it is the stuff used to make the drinks bottles for mineral water, fizzy drinks, etc.) and is more stable than PLA at higher temperatures (80C+ without significant warping).

The machine came with 1kg. of black PLA which I shall use to experiment but I have ordered 5kgs of PET-G for the loco and rolling stock parts.

How does one make a thin circular object (e.g an inspection manhole on a tank wagon) wrap around and lay flush on a cylinder....which instruction/command(s) can achieve this?

Latest OpenSCAD creation is a GCR/Robinson loco chimney for the A5 (still needs a few tweaks)

Regards,
John.

[cabbage]

Matter Antimatter... Consider the band as a cylinder the centre of which you antimatter another cylinder to make a tube. You then antimatter a horizontal cylinder underneath it . Then you antimatter a tube through the vertical tube at the same radius co-ords as the previous antimatter tube.

This will leave a curved part of the original matter tube remaining. OpenScad is very easy but you do have work some parts backwards!!!

Regards

Ralph

[John Candy]

Ralph,
Thank you.
I had a suspicion that would be the solution, not having found any commands which would produce a z-axis arched curve in a 2D/flat object.
One feature which would be nice in OpenSCAD (I cannot see that it is there to be switched on) is a co-ordinate tracker for the cursor, to display the x,y,z position at any point (useful in producing the co-ordinates for smooth curves with the polygon command).
Regards,
John.

[cabbage]

Can't think of anything like that in OpenScad unless you can import and convert a 2D drawing into 3D scad(?)

Too late in the day....

Regards

Ralph