New Toy
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Fantastic,
I have a Charter Oaks automation. Physically similar.
Also, I made the same decision: DRO, not full CNC. It's been VERY productive...
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@danal Thanks. Coming from you, I'm reassured that my decision not to eventually turn it into a full CNC machine is justified.
The only thing that I'm finding is a bit of a PITA, is that I need to produce some sort of dimensioned drawings to work from, and as up until now I've designed everything exclusively using OpenScad, this isn't as easy as it could be. I need to look into that. -
You can make cut in OpenSCAD, then export them as DXF, and load them in LibreCAD (very good software)...
Or switch to something much more powerfull, like Onshape/Fusion360 (not open).
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@fma Thanks, I'll give that a try. My current method is to import the OpenScad file into Freecad, then use an add on to make dimensioned drawings. It works reasonably well but I think what I need to do is just get to grips with some other Cad package and cut out the OpenScad step.
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If you don't mind the cloud part of Fusion360 its hard to beat the value to feature ratio of integrated CAD/CAM.
It is a bit tedious to export openscad -> freecad -> fusion just because there are no common formats between openscad and fusion though.
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@bearer Yes I've tried Fusion. It's a big learning curve for someone like me who has never used anything other than OpenScad. But then, so is FreeCad and probably all other CAD packages.
For the motor mounts, I just exported an image from OpenScad, printed it, looked though the OpenScad code to get the dimensions, then just scribbled them onto the printed image. Slightly better than the back of an envelope sketch, but not much........
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I think that when you learn the basics, Fusion workflow is much easier.
For those mounts, did you just use the same thickness as for plastic ones? -
I think that when you learn the basics, Fusion workflow is much easier.
For those mounts, did you just use the same thickness as for plastic ones?Ref, Fusion - you could be right but I've got a lot going on at the moment so finding the time the time even to learn the basics is not easy.
I did use the same thickness aluminium for those motor mounts as the plastic version. They are 5mm thick and I realise that I could have got away with using say 3mm thick aluminium, but then I'd have had to change many dimensions to get the motor position in exactly the same place in all 3 planes. And I'd likely have needed to get all new bolts because the current ones would bottom out, both in the motor and in the extrusion Tee nuts using a thinner plate. (Edit - and that's 8 bolts per mount x 6 = 48 new bolts).
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I was actually guessing that you kept the same thickness. Because of all of the reasons that you mentioned, that is the simplest way.
And I am curious about the stiffness gains. OK, on your printer it is going to matter, but on smaller ones? I have a feeling that plastic could be good enough. -
I was actually guessing that you kept the same thickness. Because of all of the reasons that you mentioned, that is the simplest way.
And I am curious about the stiffness gains. OK, on your printer it is going to matter, but on smaller ones? I have a feeling that plastic could be good enough.Oh plastic is fine as far as rigidity is concerned. Stiffness isn't an issue, nor is it the reason why I wanted to make metal mounts. Up until now, I've always tried to adhere the the RepRap philosophy and use as many printed parts as possible. Of course, that was partly driven by the fact that I had no means to make anything out of metal so I had no choice. All my carriages and idler pulley mounts are printed parts and I have to plans to change them, even though I could now do so.
The reason why I wanted metal motor mounts was purely to do with heat. I've had problems in the past with very long prints (30 hrs+) and motors getting hot (as is normal) but the heat was causing the plastic mounts to soften slightly. Then the tension of the belts acting on the motor shaft caused the mounts to deform. I re-made the mounts using PET-G and also fitted fans and heat sinks to the motors which was 90% successful but not 100%. I'm still getting some deformation after very long prints - nothing like as bad but it's still an issue. Hence the need to use metal mounts - no other reason than that.
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I wonder if vibration dampening mounts could have gotten you the last 10%? I removed mine when I got alu motor mounts to help dissipate heat from motors.
Moot point at this time though, but maybe someone else who stumble onto the thread will find it usefull.
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@bearer said in New Toy:
I wonder if vibration dampening mounts could have gotten you the last 10%? I removed mine when I got alu motor mounts to help dissipate heat from motors.
Moot point at this time though, but maybe someone else who stumble onto the thread will find it usefull.
Maybe. But I hate the thought of using them on a printer. How can one guarantee positional accuracy if the motor itself can float about? I know they are quite popular but using them where positional accuracy is important, just goes against all my gut instincts.
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Pretty sure they would have less flex than toasty plastic, they're surprisingly rigid. Anyways, relics from an era before silky smooth interpolated microstepping from Trinamic
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To block heat transfert, you could use a square sheet of cork between motor and mount (you can use a decent thickness). And use stainless steel screws. I'm pretty sure it's enough.
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@fma Again, a bit too spongy for my liking.
Also, metal mounts make it bit easier to earth the motors which I'm told is what we should all be doing to prevent static build up. Plastic mounts mean you have to run a separate cable.
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No doubt metal mounts is the good stuff, but not everyone will have a £1200(?) mill to make them?
Anyways, to get off the off topic off topic, just published a (parametric) fusion sketch as a template for making bellows to protect ways and rails.
Used to be a nice site that generated similar templates, but looks to be offline, so fired up fusion and poked it a bit.
Lazy mode is on, so won't try it until I can laser it. However the sketch does line up so can't see why it shouldn't work as a template.
If of interest: https://www.thingiverse.com/thing:3629856
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@bearer said in New Toy:
No doubt metal mounts is the good stuff, but not everyone will have a £1200(?) mill to make them?
Do I sense a hint of jealousy or is that just bitterness?
Oh, you can add on another £600 or so for tooling, then I guess you could add on another £1,200 for what I spent on an insulated door for the garage to put it all in. That makes about £3k or about £500 per mount. Cheap at half the price as they say
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I sure hope it doesn't come across as bitterness!
But would I like to have a real mill instead of a 300x400x80 CNC router? Sure. But I've gotten the CNC to do some light aluminium milling, so I'll get by, sort of:)
Bellows template is one of many steps to beef up the little CNC, but it'll never cut steel.
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@bearer I used a wood working router to make a groove in the underside of my aluminium bed plate when I first got it. In fact, if I had to do it again, I'd likely have to use the same method because the bed plate would be too big for the mill. So your CNC router wins of my milling machine.
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Ok, so you guys didn't REALLY ask... but...
I despise fusion 360. Really hate it. Also use it a lot because it is powerful and free.
Why the hate? I've used MANY MANY CAD packages for way too many years to admit. Each of them had quirks in their UI, and a learning curve associated with those quirks (once you got past basic CAD learning curve). OK, no problem, that's just the nature of human-created software where authors think differently than each other.
However... I'd swear that Fusion employs a huge team of people who's sole objective is to make the UI as non-intuitive as possible. Really, there's no other explanation. It can't be an accident and it can't be ignorance. It is just too pervasive to be anything but intentional.
Tons of examples, here's one that comes to mind off the top of my head:
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Draw a "sketch" (that is, 2d objects) with the intent to turn it into 3D later, probably via extrusion.
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Great, draw some lines, use snap or similar to get some good shapes, life is great. Lines and vertex points are draggable, you can specify line lengths as parameters, this is really intuitive and cool.
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Now, extrude part of the sketch to 3D.
Wait, the rest of the sketch disappeared!! Well, no problem, select the sketch in the browser and it re-appears.
Click on the next part you want to extrude. DANG, it disappears again!
Counter-intuitively, there is NO left mouse click sequence (i.e. "selection") that will actually select the sketch. You must RIGHT click the sketch (in the browser, because the sketch itself disappeared) and select "edit sketch" from the context menu... and then... Fusion hides the prior extruded 3D object, re-orients the drawing space completely and presents you with the re-scaled, re-oriented sketch. Icky poo.
Continuing the above example:
- Edit the sketch (via all that non-intuitive stuff) and extrude a different area.
Suddenly the sketch will stop disappearing, and is perfectly selectable (although still not editable except through the context menu).
More examples:
- There are many ways to get an object "high-lighted", yet that object is really not selected and can't be moved/changed, etc.
- In the "manufacture" workspace (i.e. CAM), everything is nicely arranged in a tree browser where double clicking on an entry opens nice tabbed dialogs that organize the hundreds of settings involved in generating a toolpath. Very powerful and still easy to use. Except... Ah yes, that little "exception" that drives you crazy with the inconsistency. It seems that "inside v outside" on contours couldn't be put in a setting (which all other CAM packages do...); instead, it is non-intuitively controlled by clicking on a little arrow on the drawing itself.
OK, this post is already too long. You get the drift. I use it because it is very, VERY, capable. At the same time, I find it extremely challenging in areas that it would seem quite simple for the developers to fix.
P.S. Disclaimer: Part of my day job is "User Centric Design" of UIs.
Delta / Kossel printer fanatic
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