Welding Tips and Tricks

I designed a couple chip guards for my 7x12 mini lathe that you can print out if you've got a 3d printer or know someone that does. We've got a local community hacker shop that lets anyone that walks in use their 3d printers so even if I didn't have one I could get it printed locally.

My understanding is there's really only one company that makes these Mini-Lathes which is SIEG if I recall correctly. Littlemachineshop.com, Grizzly, Harbor Freight, Central Machinery all use the same model from what I hear but Littlemachineshop.com will tell you the true story. SO these chip guards should work for all of them, but at least you can resize and edit to your hearts content since I include the original .blend files for blender.

This chip guard covers either side of your apron to brush chips away from your apron and keep them out of the rail ways and gibs. Less cleaning, more turning! You just need two 12mm neodyium magnets and I recommend a sponge brush but you can fill the holes with bristles if you'd like.
http://www.thingiverse.com/thing:1905502

This chip guard covers the gears for the handwheel that drive the apron left & right so chips don't fall down into this which they do especially as you clean things up. I used black RTV Silicone after cleaning the backside with alochol and it's on there solid now. You can do screws but with RTV you don't need to dis-assemble or drill anything. If you need to remove it one day, it's RTV so you can just peel it off.
http://www.thingiverse.com/thing:1905460

Hey, another Blender using brother! I used to teach compositing and rendering on blenderartists a lot. You can find me on that site under this same user name. Just recently started throwing my 2 cents back into the ring over there.

3D printers will print from a .blend file? I thought it had to be from a .dwg or whatever it is that autocad spits out.

Nice! I've been working with various CAD programs over the years with many hours spent trying to pirate AutoCad across the years and their version lines. Blender really is the ticket if you wanna be legit n legal without the uber-expensive licensing! I think I've been to that site a few times as I look up random tips on getting a job done so maybe I'll have to subscribe there. I really think I'm gonna need to join a forum for a machining site too but we'll get there...

Good call on .blend files though. No 3d printers won't print them so I export from Blender to .STL to load into Cura or whatever I'm using to print with since STL is the universal standard then I can convert it to G-Code since G-code is all a 3d printer understands. Just like CNC

The only issue I have with blender is it sometimes thoroughly destroys my geometries but I've learned from many other design experiences, save your design changes in incremental files so when things go to hell, and they usually will eventually, you can pick back up at a good point

I designed my folding welding table in Blender too. I've since decided I'll be doing something different but Blender was the way to see it all come together so you can virtually fold it and figure out what you're gonna clash with before you spend $800 on material and 12 hours of TIG'in only to find out at the end you botched it The new welding table is going to be using parts from two different garage doors that I now have. Without divulging anything else, that might perk some visual thoughts on how I'm going to build it

I've never had blender screw with any of my geometry. I've had to fight like hell to get the mesh to work with me on several occasions though. Subsurfed goemetry can be a bit of a bitch to work with sometimes. Especially on cars.
Blender used to have an autosave option that would spit out a new instance every five minutes or so with a new instance number so that you could comb through the files to find the file before things went wrong. Bad part about it was it stuffed a ton of files in there. I just save em as I go too in order to avoid that schmoz.
Is it blender that's misconfiguring the geometry or the STL export script? Whichever is the case, you should report it to the bug tracker. I believe Campbel Barton writes most of those python scripts. There's also an http://www.blenderartists.org forum dedicated to scripting where a lot of those issues get resolved.

It's likely the models I'm using. They are highly complex geometries I'm mixing with simpler ones.

The worst was my motorcycle because I did a 3d scan of it. Trying to polish up a 1.3GB true to life scale size model like that that was piece parted together using 3d stitches was a PITA. Had to do multiple camera shoots and figure out the right amount of light to the right amount of pix to get it to build decently.
That TIG Monster Claw I build had it's fair share of complications too which was originally from my Halloween Monster Claw/Glove I designed. I don't blame blender necessarily, it's likely just bad geometry that doesn't show it's "face" until I dink around too much.
Perhaps I'll send them what I can some time though since perhaps there's more to the story since I can cut these models up just fine, it's just at a certain point it doesn't like it anymore. I can even do the same cuts that fail far along in my edits, in the early or original models and all goes well. So yeah, next time I get into that maybe I'll be a good user and help out my fellow engineers...

If you're using the knife tool, don't. That thing hacks the hell out of your mesh. Boolean modifier is also a no no with all but the most simplistic of meshes, plus you really need to match up vertices with it to avoid a shit ton of triangles. Triangles mostly SUCK in blender unless youre in a corner.
1.3 GB? Holy crap bro! You know blender has memory issues, right? I bet it crashes a lot on you with files like that. Memory issues are different between operating systems and blender distributions. Linux Ubuntu will handle more in memory than any windoze build......but not a whole lot more. Always save before attempting to render. I'm not sure why the developers still refuse to make memory management a high priority because that can and does drive professional users away from the program unless they want to unwrap a model or use cycles render for something.
I'm not sure whether or not they ever got the Decimate Modifier working properly but it may be something to look into for reducing vertex count. I haven't cracked blender open in a couple of years so I'm not up to date on a lot of what's current.
See here:
https://www.blender.org/manual/en/model ... imate.html

And there we go! Yep mine are boolean cuts on complex shapes. It usually works out up until a certain point. Thanks for that tip and it really makes sense

I've got 16GB of DDR4 and a GeForce GTX960 which handles that model well. Most edits and renders occur in real time for me. The RAID array, and 3.3Ghz Intel I have really help out a lot too. That said I really haven't had memory issues but have thought about booting to my Linux distro (true install not VM) to see if it helps but all in all haven't had a dire need to do it.

What killed me was building the mesh from the stitched pix. That took about 1.5 to 2 days and really put my system to the test. ALMOST as bad as cracking passwords with CudaHashCat

I did decimate my models a couple times but it seemed to start creating more problems with geometry but I haven't really played with it too much. It failed for me a couple times and I gave up since I found other ways around it

Still seriously thanks for the thoughts and tips! I'm sure they're going to come in handy as my 3d printing years progress which I'm over 2 years into now.

Your graphics card won't handle blender's internal memory issues. Besides, I don't believe that memory is shared with system memory anyway. I'm not sure where the upper limit is in blender but you can have 16 gigs of system ram on tap but blender can only address a portion of that. Last I remember it would crash on Ubuntu at just a hair over 3 gigs of memory allocation. It's probably a bit higher these days. I never crashed it with vertex count during mesh edit but I have seen it bog down to a crawl with a .blend that I helped another user correct. He had four mushrooms in his scene. Each shroom had four levels of multires modifier and six levels of subsurf modifier in line after the multires. You could hardly navigate through the 3D viewport because he had every one of those modifiers set to be fully displayed in 3D view. It would take about three minutes just for blender to select any one of those meshes.
You can negate a lot of that kind of crap by selecting vertices in edit mode that you don't want to see and ctrl+hkey to hide them and alt+hkey to unhide. You can do this with faces and edges as well. It makes for much easier editing on high poly models.

Meanwhile, back at the ranch...


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Sorry Coldman,
Didn't mean to give you a geek check.

It's cool man, you go right ahead. I welcome the opportunity to learn from the knowledgeable on any subject. I just can't resist the opportunity to take the piss when it arises. It's a character flaw of mine.


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Coldman wrote:Meanwhile, back at the ranch...

...the ugly duckling's learned to dance...

Is Blender an open source version of cad? I just rebuilt my pc around an intel i7 6700 with 32 gig of ram and a evga 1070 ftw. (I game a bit.) Would that run it?

No. Not by a long shot. Blender is a 3D modeleng and rendering suite that statred life as a character animation program. It is open source. It has some curve functionality, however crude. It's definitely nothing like autocad but can import and export autocad files (and many others) through built in python scripts. It has a video sequence editor, node based compositing and texturing system, heavily integrated python scripting capability, worlds premier uv mesh unwrapping system, bullet physics simulation, game engine, camera and object tracking system, etc...
http://www.blender.org

Blender demo reels will give you a feel for it's capabilities:
https://www.blender.org/features/reels/

Before we go anywhere.... I am just a really smart guy with computers and have a knack for figuring things out. I have never been trained in CAD. I use CAD for my 3D printing and I've worked with my friend at his motorcycle shop to come up with a way to cut custom gaskets using a basic scanner and CAD with his Gasket Cutter which is basically a vinyl cutter with a branding for gaskets and a flat table vs. a rolled catcher.

That said, the blatant difference I see with Blender and AutoCAD is making a radius line. In G-Code for the AutoCAD export to a printer, you get true radius lines vs. steps/coordinates since it's a special command. HP Plotters have the radius command (almost all plotters are built on HP's CAD commands) however I can't find a freeware CAD program that does this. That said, 3D printers don't even use true radi, they use steps/coordinates hence no true perfect circles. I also notice AutoCAD has better tools for navigation in relation to schematic building and overall design especially when it comes to using 2D schematics packages with/out annotations. Still, 3D dimensional shapes seem to be simpler to build in Blender than AutoCAD.
Beyond that, Blender is a perfect replacement for AutoCAD in many situations and I'm quite sure will get the job done on most CNC systems and CAD drafting. I even find it compliments AutoCAD in many ways.

P.S. your system is more than capable of running any 3D design/rendering software.

And I see Rambo replied with some more relativity for you

So autocad produces real, rather than segmented curves?
Does that make that much difference to a stepper motor or just the software that controls it?

I think I may have to do some more research. It's been 10 years since I built my last CPU so I'm just getting back into it. But I understand a little about what you said about the rendering of the curves compared to cad.

AutoCAD can interpret ARC (G02 and G03) G-Code commands unlike every other CAD/3D design program out there. When you're working with vinyl and/or gasket cutters, ARC is very important since you're almost dealing with an x-acto knife. The reason is because it's not uncommon you need 2-3 passes for a 1/16 sheet of vinyl/gasket. If you want a perfect cut without having to bust out your x-acto knife, then this is the ticket. When you're working in CNC and metal you're going deeper than 1-2 cuts so it's even more useful especially since an X-acto will not clean that one up.

ARCs vs. steps/coordinates keeps your tool sharp otherwise you're fighting pixels. It sounds weird but if you know about digital vs. true photography this should make a bit more sense. Still for the non-photographer, imagine a grid, then imagine cutting an ARC along that grid. There is never a true constant angle between grid points but that's how coordinate cutting works since it uses points vs. angles. You also need less code because it is one command to create a 90 degree 1" arc with arcing between degrees vs about 90 coordinates and the linear steps between. This is why AutoCAD will always prevail in any CNC world but you can certainly get away without it if you don't do this for production and/or don't care about your cutting tools.

I think some of this logic may be incorporated with the DXF/DWF AutoCAD formats but in general most applications that "convert" to this format never use ARC commands. This is why Blender does great for odd shapes, box shapes, and everything that does not need a perfect logical ARC. That covers most of your designs however to CNC machining, you'll still find your ARCs are better than anything else when required.

Oh yeah, you also need something to convert your whatever exported format to G-Code. STL is pretty universal but regardless your program that runs your CNC must interpret logically whatever format you can export.

So I don't sound like an idiot here's a technical explanation of the G02 and G03 commands:

http://www.cnccookbook.com/CCCNCGCodeArcsG02G03.htm

You can see the anatomy of beziers very well if you zoom in on them in Photoshop. Seems like someone clever would be able to tell the program to skip every inside corner so that it doesn't cut like this:
I can imagine that would be taxing on a cutting tool.

I can say Adobe products are not capable of this because I was using Illustrator CS6 which is 100% vector and can print directly to a plotter using HP proprietary G-Code. Adobe does interpret correct ARC paths but it will not export them no matter what format you use. I learned this the hard way and I think it resulted in the demise of the gasket cutter despite the fact it was already on it's last leg.

Adobe Illustrator resulted in a pixel cut every time because it does not interpret those ARC commands in it's plotter export even when using the HP drivers. This resulted in erratic cuts that were damn near on point for an arc but you could tell an ARC was not used. With a CNC mill, I can see you getting away with this since the force is greater and the material removed is much less than vinyl/gasket material. You also have a constant rotating cutting surface vs. a static blade. Still you'd never get that perfect ARC much like 3D printing software.

Think of it like stop and go in city driving vs. highway driving. You get better gas mileage and longevity of your engine on the highway using constant speeds. Coordinate cutting is like in-city driving so you're always at a persistent stop and go which any motor/engine does not cope well with over time. As Rambo said, this is taxing on your cutting tool.

The simple story is there is no freeware utility that will offer you the ARC commands that I know of but it's not the end of your machining hobby/career especially if you know how to write/edit proper G-Code

I worked in a sign shop several years back and the owner used illustrator with his plotter a lot. The only thing that he used more than illustrator was flexi sign.
He just exported extended post script files (.eps) and it was go-cat-go. I never saw that plotter hiccup. It just didn't care. Of course it was a $30,000 plotter/software package that he had on lease so that may have something to do with it.

Another thought... Blender does great at axial and rotational validations. This means you can setup a part virtually to ensure they do not collide with others. From there the exported formats can go to AutoCAD formats so you can do your pre-checks and then export with AutoCAD. Considering the versatility of Blender, this is why it is complimentary to AutoCAD and a great starting platform. Still the 2D planar travel of your tool is very important to consider. If it's a rotary tool, life is good. If it's a static tool with one cutting plane, then life could suck.

Rambo! We're both tearin up this thread

His Gasket Cutter never had issues for the longest time but it finally started not liking life so much. It was a 90s HP plotter with 15 years of service in the end despite the re-branding. It required more cutting force than vinyl due to material and thickness. So all was well in general but you could tell the performance difference between ARC cutting and coordinate cutting. The poor thing was already about to die and I had to repair several components but in the end it seemed like the linear cuts vs. ARCs were the final salts in the wound.

I'm curious about your buddy's exported format and/or printer drivers he used because who knows, maybe there's a useful difference when using the Adobe software suite.

Hey Josh! Going around Thingiverse I find a lot of people use OpenSCAD and OpenSCAD just came out with Customizer which has really revolutionized CAD. I've seen it floating around for a few years now but it's really taken off the last three years in the user space. It's also Free!
I've done mostly modeling and things that work well for what Blender can do but I do believe I'm going to switch to this since pirating software doesn't always come with good benefits and can come with more headache than satisfaction, plus the occassional PC equivalent of VD.
I've seen some amazing projects and the documentation/drafting output it gives seems up to par with AutoCAD.

I've got some more stuff to design up soon so I might remember to post back here and tell you just how easy or PITA it is but in your research time, check it out!

I have used Libre CAD which is another very well known popular setup but I found it had limitations with exporting to G-Code and did not offer the arc commands. This may have changed in the last 4 years though.