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SteelRat

3D Printing

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I also recently purchased an Ender 3 (standard model) but have had it sitting for a number of months. Over the last few days I finally was able to print my first parts and am impressed. I have a few thoughts that hopefully will be useful:

1) Before buying and attempting to use "higher strength" filaments, it may be worthwhile to look at the YouTube or webpage version of CNC Kitchen. He goes over actual strength tests for common materials and the results are somewhat surprising. PLA is actually a very strong material. It's lack of ductility and low melt point make it appear to be a poor substitute for ABS, PC, or nylon, but used correctly PLA parts should survive many of the rigors of RC driving if the parts are designed and printed well. If you crash as much as I do though, maybe nylon or the like is better, though :).

2) Before getting the higher-end filaments, I would look up all the requirements for printing. The Ender 3 comes out of the box with a PTFE tube and a stock hotend, which for PLA should be fine. Elevated temperatures with ABS or nylon cause the PTFE tube to break down, emitting caustic chemicals. I wanted to print with these materials so I went ahead and bought an all metal hotend ahead of time (microswiss), and made an enclosure to print outside. If all the research I've done is correct, none of these materials are something you'd want to breathe in or have vent directly indoors. The all metal hotend prevents the PTFE tube from breaking down due to a dramatic temp difference in the heat break, and an enclosed helps prevent warping for ABS, etc. In my case it also helps keep out the elements. 

3) I foolishly thought that my research and my job background would help with my first prints and I would be ahead of the game, but these printers are a hobby and as such need fiddling and work to print really well. I still have tweaking to do before I'll be satisfied with the results. As such, I'd prepare to use a moderate amount of filament tuning your printer and verifying the optimal bed and nozzle temperature, z-offset, extrusion percentage, bed leveling, etc. This will likely change with each filament also, but I can't for certain speak to that. 

4) Watching build videos really helped me to understand how to get the printer setup properly. There are plenty out there and all the ones I've seen are really good. 

5) I use Cura and it's a great slicer for my application and has a lot of adjustability. It also has sock settings for the Ender 3 (not sure about the pro). 

I hope this helps and isn't too much information lol. Best of luck with your printer and please keep us posted on your progress!

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9 hours ago, SteelRat said:

Love that Vette Mark.. love creative thinking and ideas like that.. just brilliant and the blower looks superb!

Thanks, glad you like it! I have a couple other similarly-themed ideas kicking around. I need to buy more drag tires and wheels, I think...

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I hope you'll have loads of fun with the Pro :)

As other have said, it has PTFE tube going into hotend, so you'll need modifications if you want to go beyond 250C (no matter what sellers or manufacturers say, it is not safe to use PTFE beyond that point) A new heatbreak (part that divides hot and cool part of print head) should be enough - bimetal heatbreak seems like the best option, it should work with Bowden extruder even with PLA, which is usually problematic with all metal hotends - however, I didn't get to test it yet, so I might be wrong with this one.

I also recommend to print a filament guide - ender feeds filament from top through horizontal extruder hole, which means, that filament rubs and wears through top of it - filament guide reduces that considerably.

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Thanks guys.. I've been looking at 3D printing videos more or less non stop for the last couple of days.  Couple of take aways:

* Ender3 Pro seems to have a very large community of people providing 3D printed mods as well as third party manufacturers, so the tweak / upgrade path is immense and flexible (YouTuber Scott Yu-Jan did a superb series of E3 Pro mods)
* Fusion360 / Ultimaker Cura seem to be the best in terms of 3D modelling / slicing applications
* Bed levelling and getting it right will be the first thing I do after the initial build!
* A replacement hotend is not only an essential mod for printing in other materials, but also a generally good upgrade from the point of view of longevity and reliability
* 3D printed Christmas presents generally aren't received very well, with a few small exceptions :D

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Bit of an update: Printer arrived yesterday and after a bit of a play with Fusion 360 and a whole lot of trial and error, which mostly surrounded bed levelling, I've got my first 3D printed A Arm for my Bitsa Beetle.  Essentially (and really what started this whole thing off), I wanted to narrow the track of the rear end so that it lined up with the front and looked a wee bit more scale.  This initial print is just pretty much default settings on the PLA filament that came with the machine.  You can already see splits and weak points, but it's a fantastic place to work from and I'm delighted with the fact I've got this far in a relatively short period of time.

Mocked up the fitting so that you can see the "before" and "after" in terms of the track narrowing.  That is a standard 45mm dog bone from a TL01 / TA03.

Next job is to tweak the hole positions, round off the edges of the "U" piece, make the top arm and try a full 100% infill, PLA+ print edge on.

IMG_20211204_144436.jpg.88020e0a2177fc6ba4291dfc8d19f49c.jpgIMG_20211204_144502.jpg.e7bcc52f4c49ffef07bffb52bcf30473.jpg

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Make round, no 90° corners. try to make more meat around the pins. Great you already have your first useable result!

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3 minutes ago, Collin said:

Make round, no 90° corners. try to make more meat around the pins. Great you already have your first useable result!

Yup.. v1.1 is already done with those rounded edges.  I've moved the holes in a notch as well as the first prototype of the top arm, both printed edge on with an 80% infill.  The top arm is a little long (giving some serious negative camber on the wheel!), so will need a redesign, but I've bought a set of digital callipers so that I can make more accurate measurements for the design phase.

In the process of designing the shock tower, which will mean moving the holes further in to allow for the reduced track width.  I'm in two minds whether I'll need shorter shocks as well, but we'll see how that goes.  All of this is getting to the point where it's going to warrant a build thread!

Pretty impressed with PLA+ too.. it's REALLY strong.  At least, I think it'll be strong enough for the level that I run / will be running this particular car (i.e.  not that hard, and not that often!)

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I enjoy to read your progress! You also should get some reamer in the size you need most (M3 for shure...) to make all holes really nice.
9aaa557ce6854be54c60dc8519fefcbf

 

Also you already noticed now, why I sayed prototypes from FDM printer and final piece (of art) from industrial printer. On ssuspension arms I always failed with delaminating arount the shafts, simply because the 2 or 3mm material arount the hole is not enough.

 

Keep on man!

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welcome in 3D printing world :)

You are at the discovery step... You will discover the limits of what you can do with the FDM printer progressively. It's a journey...

Limits you will have to handle is the Z resistance, and the precision when you have to include supports in your prints. That is exactly where the industrial printing using SLS or MJF and a powder based material is going to be of help...

Good luck and good fun :)

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1 hour ago, Collin said:

I enjoy to read your progress! You also should get some reamer in the size you need most (M3 for shure...) to make all holes really nice.
9aaa557ce6854be54c60dc8519fefcbf

 

Also you already noticed now, why I sayed prototypes from FDM printer and final piece (of art) from industrial printer. On ssuspension arms I always failed with delaminating arount the shafts, simply because the 2 or 3mm material arount the hole is not enough.

 

Keep on man!

Thanks @Collin.. those reamers are a definitely a good idea.  Yeah I can see that..  however that initial print was just a protoype to test fit etc.. didn't take very long to print or use much material.  The updated version was printed in a different axis (so that the weakness lines aren't in the same direction as the majority of acting forces), with a higher proportion of infill and I moved the inner hole further in the piece just by a single millimetre so as not to greatly affect the geometry, or cause any functional issues with the half shaft..  There was an immediate difference just in doing that.  I was able to fit the self tapping metal pivot axles without any splitting and the overall piece is noticeably, considerably stronger.  Proof will be in the pudding though, so we'll see how it holds up.  I have some black PVA+ coming, so the parts will at least be in the right colour for the final print!

 

 

10 minutes ago, silvertriple said:

welcome in 3D printing world :)

You are at the discovery step... You will discover the limits of what you can do with the FDM printer progressively. It's a journey...

Limits you will have to handle is the Z resistance, and the precision when you have to include supports in your prints. That is exactly where the industrial printing using SLS or MJF and a powder based material is going to be of help...

Good luck and good fun :)

Thanks @silvertriple the discovery stage, finding the limits and see if I can think my way around some of them is definitely part of the fun!  I've spent the weekend getting to grips with the software, tweaking settings here and there to get as good results as I can (at least for now; there's definitely room for improvement in that area) and whilst there is a lot to learn, it's good that you can get a good way in relatively quickly so long as you're prepared to persevere with it.  I've also had a really good look around Thingiverse and various YT creators to get inspiration and have been blown away by the sheer range and ingenuity of the things that people have created both inside and outside of the RC sphere.  I've already seen some applications that I know would lend themselves very well to 3D printed pieces (the little plastic hooks on my wallmounted tool storage rack for example) and that's without the endless scale accessories I could make for my crawlers.

I do think it's rather funny that just a week ago I was sat at "I wonder if" and here I am now with "Lets GO!"

I'm just waiting for the first prototype of the shock tower to finish printing, so once that's done, I'll get everything assembled as it is currently and start a build thread.  I've got a lot of ideas for the direction I want to go with this Beetle and I think the 3D Printer will be a big part of some of that - although most of the stuff it'll make won't be load bearing, but just detail.

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Congrats on getting a printer :)

I recommend to take a look on CNC kitchen YouTube/webpage for interesting videos about print, materials and post-production methods. He often tests how different settings can change behaviour of prints, for different materials, especially strength in-between layers.

One advice - don't waste time and material on 100% infill - in most cases, it's not necessary, as most load is taken by shell anyway (you can see that on lot of Tamiya's designs), also, it makes prints more sensitive to over/underextrusion. I usually just increase perimeters count and play around with modifiers (I use Průša Slicer) to increase layer area with full infill, where needed (there's also setting that does that automatically).

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1 hour ago, Honza said:

Congrats on getting a printer :)

I recommend to take a look on CNC kitchen YouTube/webpage for interesting videos about print, materials and post-production methods. He often tests how different settings can change behaviour of prints, for different materials, especially strength in-between layers.

One advice - don't waste time and material on 100% infill - in most cases, it's not necessary, as most load is taken by shell anyway (you can see that on lot of Tamiya's designs), also, it makes prints more sensitive to over/underextrusion. I usually just increase perimeters count and play around with modifiers (I use Průša Slicer) to increase layer area with full infill, where needed (there's also setting that does that automatically).

Good advice, thank you.. will definitely look at that page.  The only tweak to the default settings to PLA+ I've made is the slightly higher temperature (210 C)..  When you're setting the infill do you change the type.. lines / grid / triangles etc - is there a preferred one for strength?  I can also see what you mean about the 100% infil not being needed.. I think I did that lower arm at 80% and it's more than strong enough!

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5 hours ago, SteelRat said:

When you're setting the infill do you change the type.. lines / grid / triangles etc - is there a preferred one for strength? 

https://m.youtube.com/watch?v=AmEaNAwFSfI&t=0s

I think it's well explained in this video. It doesn't cover all use cases, but I think that for arms and similar parts, 2-3mm wall thickness and minimal infill is best balance between strength and weight/print time.

Ofcourse, there are instances where larger area of higher infill will help - especially for compressing/tensional force.

Infill pattern will change how it behaves under compression and tension - 3D shapes like cubic or gyroid will have more uniform properties in different directions

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Oh man, that video is superb!  When he bent the foam to show where on the object the real stresses are, that's what made all the sense!  Brilliant, recommendation, thank you.

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