Anyone used online 3D printing services

[Onoff]

I remember years back a chap I knew invented a cable reeling system which tbh he should have patented but he wasn't interested. Various rip offs ensued but they tried cheapening the design substituting white nylon instead of Nylatron. The cheap copies nylon components all swelled up and seized! 

[Onoff]

Well, happy 21st!

 

 

@Temp, do you reckon the MOSFET upgrade as worthwhile? He (we ?) do intend printing ABS:

 

https://m.all3dp.com/1/anycubic-i3-mega-upgrades-mods/

 

 

[Temp]

I did the MOSFET upgrade on my Anet A8 because I'd read of problems with the control board connectors. Later I was told it wasn't strictly necessary because the connectors had been improved on the latest versions of the control boards.

 

The issue is that on a 12V system the bed heater draws quite a lot of current. This goes from the PSU to the control board then on to the bed heater. eg it runs through connectors on the main board. With the MOSFET mod you run two new power wires from the PSU to a new MOSFET board and then on to the bed heater. So the high current no longer goes through the mother board connectors.  You can do the same mod on the nozzle heater. It's less critical but explains why some people do two MOSFET mods.

 

I'd check on a forum for the anycube i3 to see what others think. If the connectors have been improved it may not be needed anymore.

 

I found this video on how to do it here for your printer https://www.youtube.com/watch?v=Ol6QecdYUw0  It shows how to do a MOSFET upgrade for both the bed heater and the nozzle heater. Although for some reason he uses the words "Table" and "Tip" instead of "Bed" and "Nozzle". Looks like you need to print some mounts to support the MOSFET boards first.

 

Be careful with the wiring polarity. I accidentally powered up after the mod with 12V and 0V swapped. Normally that would destroy the control board but somehow I got away with it.

 

PS: I think some control boards had/have push-on power connectors and others have screw terminals for spade connectors. The screw type are better.

Edited December 21, 2019 by Temp

[Onoff]

Thanks. Trying the test model, a "pair of owls" and he set it running and went off (to download Cura). I noticed that as it was printing the whole print was moving where it hadn't stuck to the bed I guess. This print was square to the bed then "slipped" like this. 

 

 

Just cleaned the bed with IPA and trying again but I reckon it's a bed level issue.

 

 

[Jeremy Harris]

Not sure if it's the same for FDM printers as it is for resin printers, but I've found that levelling the build platform (bed for an FDM printer) is hyper critical.  From what I've read, with FDM printers there are also other tricks to ensure that the base layer adheres well. 

[Onoff]

7 minutes ago, Jeremy Harris said:

Not sure if it's the same for FDM printers as it is for resin printers, but I've found that levelling the build platform (bed for an FDM printer) is hyper critical.  From what I've read, with FDM printers there are also other tricks to ensure that the base layer adheres well. 

 

I did read somewhere, maybe it was  @Temp mentioned it, that some put masking tape on the bed. Says in the book for this one not to do that.

 

He just tried printing that little switch bit you did for me but it looked dog rough ?

 

 

 

What fill percentage did you use?

 

At the moment the printer is sat on the dining room table and as it prints you can the vibration through the table. I wonder if that's an issue? 

 

Only took 1m25s though!

 

 

[Onoff]

First two times he used generic, A4, "matt" inkjet printing paper, 0.1mm thick to level the bed. The owl pair didn't stick and the switch piece came out naff.

 

Just used the glossy 0.1mm piece of A4 that came with the printer and looking much better. A little flash on the underside. Actually looks better than the photo.

 

 

 

[Jeremy Harris]

44 minutes ago, Onoff said:

 

What fill percentage did you use?

 

 

 

There's not really a fill percentage with resin printers, unless you design the part to be hollow.  Parts like this are always printed as 100% solid by default.

[Onoff]

4 minutes ago, Jeremy Harris said:

 

There's not really a fill percentage with resin printers, unless you design the part to be hollow.  Parts like this are always printed as 100% solid by default.

 

So far here using 25% infill and a print speed of 50mm/s with 0.2 layer height. Just done the keyboard foot and your resin one has much sharper edges and the infill is "complete" as in no discernible striations. It's just "sharper".

 

Trying now 50% infill, 50mm/s

 

Then 25% infill, 40mm/s

 

Just playing really!

[Onoff]

Just finished another keyboard foot at 100% infill, 50mm/s, 0.2mm layer in PLA. It's fine but not as sharp as the resin one Jeremy did imo still. 

 

Give my boy his due he's picked up Cura and Blender in an afternoon and is slicing and dicing 3D models as I write this. 

[Jeremy Harris]

In general, resin printers give a finer surface finish (layer height is ~25µ to 100µ) but only have a small print volume, or more specifically a small print base area (mine's limited to 115mm x 65mm for the base and up to 155mm high).  FDM printers can generally print bigger things, but the layer height is usually around 50µ to 300µ, plus, in practice, the diameter of the nozzle has an effect on surface finish, as the smallest is often around 400µ.

 

There have been a few times when I've wanted a bigger print volume, though, as having to print multiple smaller parts and then bond them together is a bit of a pain.  I could also do without the smell of the resin.  It's unpleasant enough that my printer lives out in the workshop, as it's both too smelly and too messy when washing prints to remove excess resin after printing, cleaning up the printer with IPA etc.  I also have to wear gloves when using it, as the uncured resin isn't good for your skin.

[Onoff]

Another test piece. The fuzziness is the camera not focusing too well.

 

[Onoff]

 

Pity they don't actually screw together! ?

 

 

[Temp]

Failure to adhere to the bed is a common problem and everyone seems to have their own favourite solution.

 

The nozzle gap is critical and should be uniform across the bed. This is to ensure the first layer is squished down just the right amount. Feeler gauge recommended. 

 

Heating the bed seems to help, presumably by stopping the bottom layers shrinking as it cools and cracking off the bed. My printer automatically turns off the bed heater after completing a print and you can sometimes hear it crack off and come loose as it cools. 

 

Turning off the cooling fan for first layer or two in the slicer/cura can help adhesion.

 

Many people (including me) put a toughened glass plate on the bed as this is flatter than the aluminium plate supplied. Helps maintain the nozzle gap constant as the nozzle moves across the bed. These are available on Amazon.

 

Treating the glass bed can also help. Some people use Pritstick. You rub it on and then wipe the surface with a bit of wet kitchen towel lightly. This dissolves the Pritstick and when it dries it forms a uniform coating on the glass. The coating lasts many prints. I tried that and found it worked but it's time consuming and messy. Blue painters masking tape is what I'm currently using. It's much quicker than the Pritstick method and seems to work as well.

 

Even when you get PLA to stick you can have issues with other materials. Sometimes the first few inches of filament get dragged all around the bed. To fix that I add a brim or similar  which not only helps adhesion but also gives the extruder  time to settle down before printing the real part. Sometimesine of holes fails to stick. I find slowing the print speed for the first few layers  helps with that - sometimes go as slow as 20mm/second for first layer. 

 

 

 

[Temp]

That nut and bolt look pretty clean. Not tried printing a nut but I found an ordinary metal nut would fit onto a bolt I printed. Cura allows you to scale prints so adding a few % and reprinting the nut might work or run a tap through it if you have one.

[Temp]

Forgot to mention that there are automatic bed leveling systems out there. They work by measuring the height of the table in many places then moving the nozzle slightly in the z (vertical) axis as it moves in the x or y direction so the gap is maintained even if the bed isn't level. 

 

I haven't gone down this route as you need to do a firmware update to the Marlin software in the control board of my printer to support auto levelling.

Edited December 22, 2019 by Temp

[Onoff]

31 minutes ago, Temp said:

That nut and bolt look pretty clean. Not tried printing a nut but I found an ordinary metal nut would fit onto a bolt I printed. Cura allows you to scale prints so adding a few % and reprinting the nut might work or run a tap through it if you have one.

 

It's adhering fine to the bed now.

 

This one looks the part but it's M? ? Think he was messing with the scale. Doesn't screw together either, in fact I think the helix angle is different on each bit. Never mind he's having fun. The knurling's pretty good:

 

 

 

[PeterW]

@Temp I’m tempted to go the Marlin route with an A2 and upgrade to a new nozzle and a tempered glass plate. Any reason why you’ve steered clear of Marlin..?

[Temp]

Somewhere I read that the A8 control board is short of memory. Someone even said the loader had been left out of some versions to get it to fit? Been too busy to investigate really.

[Onoff]

Thought I'd copy the thermostat housing I've just taken off the wife's car...as you do:

 

[Onoff]

Not bad. Printed with speed in mind rather than anything else. Absolutely useless on the car as it would melt! ?

 

[Onoff]

With the car in pieces thought we'd print some new trim clips for the wheel arch liners. CAD done by me then handed over for printing. Original 2 piece part:

 

 

 

Trying the "pin" first.

 

 

Not too good, any ideas? Seems as it increases in height it's still too "fluid" to resist the lateral force of the hot end as it extrudes the filament. Been experimenting with slowing things down. 

 

[PeterW]

Print a wedge up each side 

[Temp]

Cooling fan enabled?

 

Try printing it horizontally with supports. Should be stronger that way as well.

[Onoff]

It doesn't seem to like the recess halfway up the shaft for some reason. Throws it off all wobbly: