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[TheBoy]

I'm trying that ABS print .. so far I can say:

Bed adhesion with PLA? 1000%
Bed adhesion with ABS? Er.. not very.

100ºC bed temp but no treatments like glue stick/hair spray on hand, and now I see why they say that's basically mandatory!

[edit] BTW Jaime (I am not typing your current forum name every time ) what size are the ziplocks you use, roughly? "Large" tend to be 35x35cm roughly, or slightly larger, but that's 'flat' size.. hard to judge and I don't want to buy hundreds of ziplock bags to find ones that fit

PLA is currently in a box with a lid and 1Kg of silica gel.. overkill but I had those bags sitting around from the old garage - just had to dry one out in the oven for a bit.

Apologies, just seen this.

ABS is far more challenging to print with, and due to the higher shrinkage, the corners peel up whilst printing, causing at best a distorted print, and worse, the thing comes completely adrift from the bed.  Decent bed levelling, not the autowank, helps, but somethings you may need to design in break off round discs in each corner to assist with corner adhesion.

Bed levelling is critical, and auto levelling is shite. End of.

Adhesion wise, this is what is currently coming off my printer, and note no bed adhesion tricks like rafts of brims, because I have properly levelled the bed, manually.  I would say this is a reasonably challenging print, and if you can print something like this without adhesion problems in PLA, you bed levelling is at least adequate.



Ziplockwise, for 1kg reels I use the larger of the 2 "ziplock" branded ones that Costco sell, ir the ones that have around 150 per box, not the smaller over 200 per box.

[TheBoy]

And this is what I mean by round discs at corners with ABS




Such tricks should not be required with materials such as PLA or TPU.

[456lbft]

I did some playing with "magic numbers" based on the stepper and lead screw and the results have been quite pleasing printing at 0.12 and 0.16mm.. currently printing a set of exhaust manifold bends at 0.32 to see what they come out like.

Starting to get to grips with all the settings - one thing I noticed is that Cura was very optimistic on the timings; turns out that's because it is calculating (in part) based on the acceleration settings it has (1800mm/s2, I think .. units might be wrong) while the printer is locked down in the firmware to 350mm/s2 due to the mass of the bed that needs to be moved. Folks reported success in bumping the firmware numbers up (a bit, not to the 3500 of smaller models, though!) and then down in Cura to match, so I'm fiddling with that.

Also modeled a Ford FE header flange in Fusion 360 as I couldn't find a model to steal, and printed one of those - got it dead nuts right first time which I was rather pleased with! Now to make a header flange that will snap into the exhaust manifold sections (https://www.thingiverse.com/thing:2053049)

Incidentally - those manifold sections can be bought as a finished product .. £1500 per set!

This sounds like a conversation that I should be part of, regarding exhaust manifold modelling.  I have some ideas about it, we should chat sometime, especially as you aren't too far away.
I've been making manifolds the hard way for 36 years, so anything that makes it easier is music to my ears!

[aaronjb]

ABS is far more challenging to print with, and due to the higher shrinkage, the corners peel up whilst printing, causing at best a distorted print, and worse, the thing comes completely adrift from the bed.  Decent bed levelling, not the autowank, helps, but somethings you may need to design in break off round discs in each corner to assist with corner adhesion.

Bed levelling is critical, and auto levelling is shite. End of.

I got ABS printing in the end - well, I got the adhesion issues solved.. I couldn't get an acceptable print quality for 'small' features (like the snap fittings on the exhaust template sections), but I suspect that was crappy filament; lots of 'popping' while printing implies a lot of trapped moisture, coupled with a little under-extrusion of the ABS meant bits were basically missing  I suspect having experimented more since with both PLA and PETG, I could probably get acceptable quality now, though.

I manually level on the four corners (where the levelling jacks are) using the 'paper drag' method, but then I have to run an auto-level after that to tune the offsets; with a 400x400 bed it's never going to be perfectly flat and true all the way across so needs a little help in the middle (essentially it droops slightly toward the center). Down-side of having a giant print-volume on a low-cost printer, I suppose

I did cheat slightly on the last ABS print though - gluestick.

This sounds like a conversation that I should be part of, regarding exhaust manifold modelling.  I have some ideas about it, we should chat sometime, especially as you aren't too far away.
I've been making manifolds the hard way for 36 years, so anything that makes it easier is music to my ears!

Happy to have a chat anytime - I can't claim credit for the template sections, they're freely available on Thingiverse and they are essentially a clone of a commercial product.. I'm kinda hoping they might make it possible to get manifolds manufactured for the kit car without needing the car to be at the exhaust place.. because that will reduce cost and headaches for all involved!

I'll PM you my number anyway, because either way the car is going to need a set of manifolds .. and you're local 

[TheBoy]

A 400x400 bed should be flat enough (if its any good, so might be worth skipping the autolevel routing if you can.  If its not flat enough, you need a new bed that is, as autolevelling is a software attempt to fix a hardware problem, and just doesn't work.

Prittstick, hairspray, a 20% PVA/Water mix, whatever works.  Though its most likely its not its adhesive abilities, but more its closing the gap between the bed and the first layer.  I cannot stress enough that you need to get a good first layer.


The print I showed above shows that you should be able to get a small, thin, minimal bed contact, item to print without become detached with a good level bed.  Worth experimenting.  Also, a cube, for example, should have a very smooth finish on the bottom, not one that looks blotchy or stringy.

[Kevin Wood]

Oops! I think I've just pressed the button on a 3D printer.

[Doctor Gollum]

Oops! I think I've just pressed the button on a 3D printer.

You'll be buying a drone next

[Kevin Wood]

Oops! I think I've just pressed the button on a 3D printer.

You'll be buying a drone next

Well, it'd be nice to be able to fly something.

[Doctor Gollum]

There's that should get some in before too long

[MikeDundee]

I think all you guys are behind a little bit with the times...….you need to get a 3D printer that does this...…………..

https://www.engineering.com/3DPrinting/3DPrintingArticles/ArticleID/17038/Additive-Construction-From-the-3D-Printed-House-to-the-3D-Printed-High-Rise.aspx

[LC0112G]

It's been suggested that we buy a 3D printer for work. Apparantly there is some 50% price matching scheme from the government. Anyway muggins here has some input to the decision (I've been asked what I would like!) but I know SFA about any of it.

So far my input has been that to be useable we probably need something that has an A4 size print bed, and can do stuff the size of a milk bottle or bag of sugar. We'd probably use it for making prototype hand held electronic enclosures and front panels. No idea what that means in reality.

Does anyone have any suggestions in terms of hardware? I don't know the funding, but I expect something in the high hundreds or low thousands. A quick look at eBay shows many DIY kits for £100-£200, but I think we're talking about the next level up from that.


 

[TheBoy]

Oops! I think I've just pressed the button on a 3D printer.

You know it makes sense

What did you go for?

[TheBoy]

It's been suggested that we buy a 3D printer for work. Apparantly there is some 50% price matching scheme from the government. Anyway muggins here has some input to the decision (I've been asked what I would like!) but I know SFA about any of it.

So far my input has been that to be useable we probably need something that has an A4 size print bed, and can do stuff the size of a milk bottle or bag of sugar. We'd probably use it for making prototype hand held electronic enclosures and front panels. No idea what that means in reality.

Does anyone have any suggestions in terms of hardware? I don't know the funding, but I expect something in the high hundreds or low thousands. A quick look at eBay shows many DIY kits for £100-£200, but I think we're talking about the next level up from that.

You're in a awkward price bracket and size. You're not in the budget for a industrialised printer, and hobbywise, a £200 FDM will perform similarly to a £1500 FDM, though possibly needing a bit more faffing.

I think this is why the big boys haven't really entered this segment, because the end result will easily be matched by a far cheaper printer, and they would never be able to compete on price.  Which is a shame, as once they do, I think they could be more consumerised rather than the geeky thing they stubbornly remain.


Even the cheapest on the market, a form of Anet A8 (a Prusa i3 clone) but with a plywood frame, which can be bought for £60 before customs charges, can achieve nearly the same results as a £1k FDM, if you can find a way to brace the frame.  Not that that meets your requirements, as not quite A4, and I reckon it would need a bit too constant adjustment for your needs.

[STEMO]

The one wifey has in school cost around £200 and was recommended to them the AMRC in Sheffield.
https://www.amrc.co.uk/
She tells me the kids love it and are very proficient. No mention of it being unsteady.

[STEMO]

She tells me it's a Colido compact and cost £180.