3D Printing - A useful thread

[rwillett]

Have a look at this for a pretty exciting 8 mins or so.

 

 

[SpondonBassed]

Great timelapse, thanks.

 

What were you making?

[rwillett]

It's a set of test prints to check how PETG can be filled and sanded down for spraying.

 

PLA is horrible to sand as it clogs up paper or discs. So I am glueing two bits of PETG to deliberately create a join line, filling the join line, sanding down using a mesh sandpaper OR wet and dry, using a primer that is "supposed" to act as a filler (ha ha ha ha) and then spray painting a decent colour on top, so using gray as a neutral colour, and then putting a polyurethane coat (or two) on top of that.

 

I want to see how good I can make it. So am printing off a few test sets to use.

Rob

 

 

[rwillett]

Just in case anybody is still following this thread, Amazon are knocking out esun Fire Engine Red PLA+ at around £5 a kg if you buy a pack of four. 

 

Just brought sixteen rolls at that price. I suspect it's a glitch as every other roll is 2.5x higher. 

 

https://amzn.eu/d/4FvltQb

 

Rob

 

 

Edited October 7 by rwillett

[Dad3353]

48 minutes ago, rwillett said:

Just in case anybody is still following this thread ...

 

A splendid offer, but there's an extra 33€ for delivery to France, and it's not available on Amazon.fr, so I shan't be taking it up. Thanks for the 'heads up', though. 

[Stub Mandrel]

1 hour ago, rwillett said:

Just in case anybody is still following this thread, Amazon are knocking out esun Fire Engine Red PLA+ at around £5 a kg if you buy a pack of four. 

 

Just brought sixteen rolls at that price. I suspect it's a glitch as every other roll is 2.5x higher. 

 

https://amzn.eu/d/4FvltQb

 

Rob

 

 

 

Done for one batch of four. Thanks.

[tauzero]

2 hours ago, rwillett said:

Just in case anybody is still following this thread, Amazon are knocking out esun Fire Engine Red PLA+ at around £5 a kg if you buy a pack of four. 

 

Just brought sixteen rolls at that price. I suspect it's a glitch as every other roll is 2.5x higher. 

 

https://amzn.eu/d/4FvltQb

 

Appears to be if you join Prime, otherwise it's 3.5 times that.

[rwillett]

Ah! That might explain it. It's a very good deal if you do a lot of printing, however joining Amazon Prime isn't cheap. £5 a roll is excellent value. 

 

Sorry about that. 

[rwillett]

If anybody is coming to the Bass Bash this weekend and wants some rolls and doesn't have Prime, I can order some and bring them down with me. It's only available in Red but at £5 a roll, it's cheap as chips. I might order more today anyway. 

 

Rob

[rwillett]

I may have over-ordered on the filament....Thats eight boxes which is 32 rolls and there's another 16 rolls elsewhere.  I may have ordered twice by mistake.

 

That should see me for the next 6-8 months, so it's actually good I ordered it when it was cheap. I'll keep telling that to myself.

 

[Jackroadkill]

3 hours ago, rwillett said:

I may have over-ordered on the filament....Thats eight boxes which is 32 rolls and there's another 16 rolls elsewhere.  I may have ordered twice by mistake.

 

That should see me for the next 6-8 months, so it's actually good I ordered it when it was cheap. I'll keep telling that to myself.

 

 

Ha, thanks - you've just reminded me i need to order a reel of PLA and another of TPU....

[rwillett]

3 hours ago, Jackroadkill said:

 

Ha, thanks - you've just reminded me i need to order a reel of PLA and another of TPU....

 

I may have a spare roll of PLA+ but all the above is fire engine red.

[rwillett]

As with many people, I have a load of 'rolls of stuff' that are a pain to keep on. e.g. copper tape or foam adhesive tape.

 

Both comes on a cardboard roll but that has no sides and it falls out (or at least it does for me).

 

So I had a think about it and have come up with this parameterised solution in Fusion 360.

 

 

The nice bit is this reel comes apart and has a simple screw thread to screw together afterwards. 

 

As it's parameterised, everything is adjustable. 

 

 

 

 

So the above is 120mm for the reel size, the internal hub size is 75mm (which fits my copper tape rolls) and is 11mm between the reel sides. The copper tape is 10mm so a little bit of a gap.

 

The screw thread automatically adjusts as well, which is great. Here's a larger version that just has the parameters changed.

 

I'll try and upload the Fusion 360 file

Rob

 

 

 

Edited December 19 by rwillett

[rwillett]

I printed off four cylinder puzzles for Xmas and put various Xmas presents in.

 

 

I have managed to keep four people amused for two hours as they have had to crack their locks. I'm sure that constantly saying "Do you need any help?" was well received by one and all. 

 

[rwillett]

I've wondered about doing this for a few months and never had the time to think this through.

 

Background

 

As part of the Basschat 8" speaker thread, I needed to attach a speaker grill to some risers. I wanted the speaker grill to be easily detachable without using any tools, such as an Allen key or a screw driver. I did look at quick release fasteners but they didn't quite work for me, so I thought I'd make some gnurled knobs using M3 bolts.

 

 I've made loads of these type of knobs before and have always followed the same pattern, design the knob, then insert a bolt after printing and use a little plug to fix the bolt in. Here's an example, the bolt goes through the hole and I simply glue a plug on top. Dead easy BUT it requires glue and a plug.

 

 

So I wondered if I could design a knob that has the bolt put in as part of the printing process and not afterwards and therefore no plug is needed? This technique might be useful to somebody else so I thought I'd document it so somebody else can benefit from it. This is a little advanced in the number of steps and it might well be partly Prusa specific and Octoprint specific.

 

Solution

 

And this is it.

 

This is a cut away of the knob and you can see where the head of the M3 bolt would sit. It looks like there is already the screw element of the bolt already in place, this is the long column underneath the knob head and this is actually never printed, thought it is exported to the slicer. The column is there to position the knob head correctly in the vertical axis in the printer slicer, in my case Prusaslicer. There is actually two different bodies in Fusion 360. The long column is 3.25mm in diameter and the hole in the knob head is 3.25mm as well. In this case it's a little under 16mm long as I will use an M3 16mm Hex headed bolt. Technically the knob head has zero overlap with the sacrificial column, this is important.

1. Both bodies are experted to Prusaslicer as a single component.
   
2. In Prusaslicer they are then converted to Parts, not Objects in the right hand mode pane. If you convert them to Objects, the head loses it's vertical position.
   
   
3. The bottom of the knob head is painted for manual supports, that's the blue bit below. I used a Smart fill and as the knob head base is flat, that works well.
   
4. Select the sacrificial column and in the Mode Window add in "Infill" and "Layers and Perimeters", using the right mouse click. This creates these options JUST for the sacrificial column.
   
5. This presents these two options at the bottom of the Mode window as well
   
6. Change the settings to 0 for everything in these two windows. 
   
7. This tells Prusaslicer not to print anything for this specific part, the sacrificial column. The column is still there holding the knob up, but doesn't exist for printing purposes.
8. Change the support options to "Generate support material" and turn off "Auto generated supports". This is really important.
   
9. Press the "Slice now" button and you get this. However your job isn't done yet.
   
10. Using the layer inspector, slide down the layers until you are one layer below where the head of the bolt would be
    
    
    This is one layer higher and you can see the blue indicating an "Overhang perimeter" in Prusaslicer. If you can see the blue, you need to go one layer lower.
    
    
11. Right click on the Layer Inspector  and select "Add Custom G-Code"
    
    
12. You need to add in specific G-Code here to tell the printer to pause. I use Octoprint and a pair of Prusa Mk4's (not the MK4S). The below works for me, but if you have a Bambu or an Creality this might not work,
    
    The gist of the code above is:
    a) Move the printer head to X=10 and Y=200, basically away from the part you are printing. Thats the G1 element.
    b) Make three 1.5sec beeps - Thats the M300's
    c) Disable the stepper motor timeouts - This is needed for Prusa's but I'm not 100% certain as to why I used this command as I wrote this a few years ago  I think that this was because if the stepper motors timeouts aren't disabled, then if I wait for too long, the stepper motors are disabled. and aren't fixed in position using a steady current and if you knock the the printer, the printing head won't go back to the exact same position.
    d) Enable the stepper motors - Put some current in the stepper motors to fix the position of the plate and the head.
    e) The @pause is an Octoprint command which displays pause on the Octoprint (and Octodash) display and then allows you to press "Resume". This is the bit where you then insert the bolt. Kinda important. An email is also generated in Octoprint and sent to me so I don't have to watch the printing. 
    d) The M105 returns the print head to the correct temperature after the pause (and the insertion) of the bolt. When the printing head temperature is back to the right temp, the printer carries on. I turn off the temperature as it might be an hour before I respond to the email.
13. You now have a knob with an M3 bolt embedded in it, no glue, no plugs, so it's a lot stronger and neater.

This looks like a lot of fuss and steps but it's probably 90 secs to go through to setup. Once you've set it up, you can then "Add Instance" and you can create four of them in a few seconds. 

 

Hope this helps somebody

 

Rob

 

 

 

 

 

[Stub Mandrel]

That's excellent Rob... I've sent you a message.