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Is it possible to take someone else's design for say a battery adapter off of thingiverse etc and reverse the process converting it back to the .dwg or whatever model so you can alter it? Suspecting AutoCAD will throw a hissy fit. 

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2 hours ago, Onoff said:

Is it possible to take someone else's design for say a battery adapter off of thingiverse etc and reverse the process converting it back to the .dwg or whatever model so you can alter it? Suspecting AutoCAD will throw a hissy fit. 

I don't see how it would be possible because the .stl file contains only the triangulated surfaces of the final object not details of all the components that make it up.

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Apparently you can import simple .stl files  into Fusion360 or AutoCAd but I've not tried. I imagine it would be difficult to do anything more than simple changes on it.

 

https://toglefritz.com/convert-a-simple-stl-into-a-body-in-fusion-360/

 

This lists some other programs it says can "easily" turn the surfaces back into solids...

https://all3dp.com/1/7-free-stl-editors-edit-repair-stl-files/

 

No idea how good the results are.  Better to persuade the author of the .stl to give you their source.

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3 minutes ago, Temp said:

Apparently you can import simple .stl files  into Fusion360 or AutoCAd but I've not tried. I imagine it would be difficult to do anything more than simple changes on it.

 

https://toglefritz.com/convert-a-simple-stl-into-a-body-in-fusion-360/

 

This lists some other programs it says can "easily" turn the surfaces back into solids...

https://all3dp.com/1/7-free-stl-editors-edit-repair-stl-files/

 

No idea how good the results are.  Better to persuade the author of the .stl to give you their source.

 

I've created some very simple solids in Draftsight then tried to work on then in AutoCAD. YOU CAN'T! 

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On 30/01/2019 at 08:04, Onoff said:

Can I ask what program you model in? In fact what are the stages in all this. Never heard of Cura or the "slicer".

Ta. 

 

Who me? Right now I've not designed anything and printed it. I've just printed other people's  designs. I've used Sketchup in the past but intend to get Fusion360 as that's what a lot on Thingiverse seem to use and it's free.

 

So far I've been printing out parts to upgrade my A8 to an metal framed AM8. I've  printed about 15 parts taking 28 hours of print time and 140 meters of filament. Still some quite big parts to do.

 

The sequence for me will be:

1) Design objects in Fusion360 and export in an .stl file

2) Import the .stl into Cura and generate a .gcode file.

3) Send .gcode to the printer.

4) Print it.

 

Cura is the slicer recommended by ANet. It turns an .stl files into the gcode file the printer needs. The printer prints the object by building up layers of plastic. Each layer is drawn using a small nozzle to extrude plastic onto the bed or layer below. Cura works out the path the nozzle has to take in 3D to print the object. Cura starts by allowing you to drag and drop one or more objects/.stl files onto a grid representing the printer bed. Then you can rotate, move or scale them. Typically I've had to rotate some parts to get the grain/layers in the right plane as this is the weakest plane in the finished part. Most parts are printed "hollow" to save time and plastic. In Cura you can specify the thickness of the outer shell and fill the inside with a grid that improves strength and stops (for example) the top surface sagging. When it's configured I usually check I haven't accidentally lifted a part off the bed (Z displacement must be zero) and click  "Prepare". In a few seconds it generates the gcode file and tells you how long it will take to print. If that's too long you can either remove parts from the bed or tweek the settings to try and improve it. After that it's just a matter of getting the gcode file into the printer and setting it going.

 

Edited by Temp
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As an update, I had 54 hooks printed in white nylon by 3DPRINTUK,  mentioned by @Temp . I am very pleased with the result. The whole process was completely painless as they keep you informed about your order and the price was reasonable.

 

146640892_VBHooks.thumb.JPG.7dd84959a22be655fdf97a63012054c3.JPG

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  • 2 weeks later...

Update: I've now almost finished printing all the parts needed to upgrade my cheap Anet A8 to a metal frame. The log on the printer says it's taken about 65 hours of printing time!! Not sure I believe it. That might be the total time I've had the printer on? Still it wont be much different as I don't leave it ON when not actually being used. I've gradually learnt how to speed up the printing process but this is clearly the big issue for 3D printing. If you are "time poor" then a faster printer would definitely be a better purchase.

 

The box on the left for the control electronics was meant to be printed in two parts, a 5 sided box and the lid with hole for a fan. The main part should have taken 9 hours to print. In an attempt to print it faster (6 hours) I turned up the speed too much and had issues with the stepper motor skipping after about 2 hours. Second attempt also failed at a slightly slower speed. In the end I decided to salvaged the back from one failed print and broke the rest of the box down into 4 separate sides in Fusion 360 and printed each separately, then super glued them together.

 

Most of the parts are from this design https://www.thingiverse.com/thing:2263216 but I took parts from several other designs (the belt tensioners, electronics case, LCD mounting brackets, PSU cover) as people have improved these elements since the original was published.  

 

Think I have one more part to print before I tear down the original printer and transfer over all the rest of the stuff.

 

1635258827_Kitofparts.thumb.jpg.6a01d270f12eeaa25d738a33180ada1e.jpg

 

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Not sure if it will make it more accurate. It should help remove some artifacts like ripples from some surfaces and make bed levelling easier.

 

Already managed to print this "impossible dovetail" which most woodworkers will be familiar with. I drew it up in fusion 360 and the clearance between the two parts is 0.2mm (as drawn). The two parts were printed separately (change of filament between) and slide together easily but not too easily.  

 

Sorry my photos are a bit out of focus it's my cheap phone.

 

IMG_20190221_194140839.thumb.jpg.07a7544da4f391f5441f31e62a9351c7.jpgIMG_20190221_194205653.thumb.jpg.64335d36cc106f85c27a875e14f73384.jpg

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26 minutes ago, Temp said:

to upgrade my cheap Anet A8 to a metal frame.

 

Does that use printed connectors between off-the-shelf metal parts? Standard extrusions cut to length? Anything else done to the metal, like drilling a few holes?

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I got a metal work kit from here  http://www.ratrig.com/ . It included standard "2040" (20mm x 40mm) extrusions (cut to length), some metal L shape corner brackets, and a bag of allen key head bolts and "T" nuts. The two vertical extrusions came with the holes at the bottom end already tapped M5 (which I was expecting I would have to do myself). No other holes or processing is needed anywhere. Each joint between extrusions has at least one L shape metal bracket and one printed plastic bracket. You might be able to omit some of the plastic corner brackets but they have alignment ridges that help keep everything square even if the metal bracket is probably providing 90% of the strength.

 

It seems there is a whole sub culture out there of people rolling their own 3D printer and CNC machines. If you know what you are doing you can buy partial kits containing a controller and stepper motors from Amazon and roll your own frame, rails and linear bearings etc. Most 3D printers seem to use the same standard heater block and nozzle also available on Amazon. Have a browse around that Ratrig site and you can find several different frame styles, some of which are intended as upgrades or to roll your own.  

 

I'm still exploring Fusion 360 but I'm amazed how powerful this software is and its free for home use.  

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38 minutes ago, PeterW said:

They are less than £100 now ...

 

decent size platten too 

 

3D Printer

 

That one looks similar to my Anet A8 except I think the frame on the CTC is wood (MDF?) rather than acrylic. Mine was around £104. I think they are all essentially copies/clones/variants/derivatives of the Prusa i3.

 

I note CTC claim a print speed of 100mm/s. My A8 is specified at 60mm/s and I've run it at that and had no issues. I tried it at 120mm/s and had failures after 2-3 hours. Very annoying to get that far into a 5 hour print only to have it fail. I think 100mm/s might be ok but I haven't really run mine at that speed for long enough to be sure. It can depend on what you are printing. 

 

All these cheap Prusa i3 printer clones are quite crude. For example if the steppers start skipping they can crash the bed into the frame as there are no end stops only limit switches on one side to zero the bed. I don't know about the CTC version but some are known to be a fire risk unless you made upgrades by adding MOSFET boards to drive the heated bed and keep an eye on a few connectors. The heated bed draws a fair current.

 

Another 3D worth looking at is the Creality Ender 3 which is around the £160-£180 mark. It's still a kit or partly assembled kit but already has a metal frame.

 

 

 

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Just for info, here is a side view of my A8 showing the electronics. The red PCB is the Arduino based controller, two little boards at the bottom left are the MOSFET upgrade boards to drive the bed and nozzle heaters. Click to enlarge.

 

IMG_20190222_211421441.thumb.jpg.cc4e3cf756882cc73df66e5314b65677.jpg

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  • 2 weeks later...
  • 1 month later...
On 22/02/2019 at 21:06, Temp said:

Another 3D worth looking at is the Creality Ender 3 which is around the £160-£180 mark. It's still a kit or partly assembled kit but already has a metal frame.

 

 

I'm seriously thinking of buying a 3D printer now, and looking around it seems that you're right, the Creality Ender 3 does look to be good value.  Having been reading up as much as I can on these things over the past few weeks, it seems that there is a pretty large user base for the Ender 3, and consequently the few issues that seem to crop up have what look to be fairly easy workarounds or fixes.

 

I have a couple of jobs for it that will, if they work OK, pretty much cover the cost of the printer.  The first one will probably be a couple of ABS holsters for my car charge point cables.  These are around £25 - £30 just for a pretty simple bit of plastic: https://www.amazon.co.uk/Remote-mount-IEC62196-charging-holster/dp/B078HMRFLN

 

Be interesting to see how the printer copes with ABS.  From what I've read it should be able to print with it OK.  I'l start off with PLA, though, just to get a feel for how the thing works.  I need to make up a couple of custom project box enclosures, too.  With luck it will be easier to 3D print boxes with display apertures than mess about milling out holes in a standard plastic enclosure.

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1 hour ago, JSHarris said:

couple of ABS holsters

 

Thought for a minute we were going to have Dorset's answer to Rooster Cogburn on our hands...

 

This subject is beginning to get interesting.

Edited by Ferdinand
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I've not tried to print ABS but I've heard it's difficult. Some people say you need to put the printer in a temperature controlled cabinet but not sure how essential that is. 

 

I've printed PLA, PLA+ and some samples of metal filled PLA. Don't like PLA+ as it seems to warp a lot. Any overhangs can curl up higher than the nozzle which can hit it later. The Antique Bronze filled PLA printed ok but straight off the printer it looks like brown plastic. Sanding it exposes the metal but the effect isn't as good as I had hoped. Apparently putting prints in a rock tumbler with brass nuts improves the finish so I'm going to try that. The iron filled PLA isn't very impressive either straight off the printer. It's rather grey. It does stick to a magnet though. I plan to try rusting it to get an aged look.

 

Be prepared for a steep learning curve. I still struggle to get some things to print. The first layer is frequently the problem. I've got a glass plate to make the bed dead flat and have tried hairspray, prittstick and blue painters tape on the bed. These are the three main things people recommend to improve adhesion. Blue tape seems to work best for me.

 

One thing I had to learn was how to design parts so you don't need supports. Sometimes it's just faster or necessary to cut something in two in CAD, print both parts and super glue them together.

 

Will try to post some photos when I get home.

 

 

Edited by Temp
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Thanks @Temp.

 

The snag with PLA seems to be that it's biodegradable, and as the holsters I'd like to be able to make will live outside, that might present a problem!

 

From what I've been reading so far, ABS seems to need a hot bed and a higher extruder temperature, and also some form of fume extraction, perhaps, as it can apparently be a bit smelly when it gets hot.

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