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Hey guys.

I have been reading up on 3d printers because I came about one at about $300 and it surprised me you could get them this cheap, which means I could potentially afford one! Yay!

The thing is, I would want it with the highest precision, as previous extrusion-based prints i have seen have kind of disappointed me.

My use would be for making molds for food and candy and small figurines (I’m a 3D modeler by profession)

I like tinkering around, but if I get a 3d printer it is mostly to get results.

So I am not sure how this goes, I guess minimum thickness is determined by nozzle diameter, minimum precision is a question of how well calibrated mechanics are (more than what motors are in) and minimum layer thickness mostly comes down to material control, amount of overhang on subject and most importantly, how well the bed has been leveled.

For the Prusa models I have been looking at it seems to be something like:

XY precision is not much of a problem.

Wall thickness comes down to nozzle used where the agreed upon standard is 0.4mm.

Layer thickness is usually rated at 0.1mm as pretty standard, while 0.05mm is the “premium”.

The last one I have really only seen on the Original Prusa i3 mk2.

So the question is, if I want precision, should I opt for the expensive new Prusa, or can I also achieve it with a cheap half-the-price prusa “clone” and a bit of tweaking and tinkering?

Also, definitely feel free to send me to some article on this matter.

I just have not found anything that really explained it to me.

Thanks!

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Hi @Martin_Baadsgaa like most things in life, the old adage “you get what you pay for” applies and $300 is way down at the bottom of the scale so if you’re expecting high quality prints, you’re very likely to be disappointed.

Layer height is a key factor in the quality of the overall print, but it’s not the only factor. A printer that can achieve a layer height of 50 microns, which is very fine indeed at a budget level, could produce terrible looking prints if the XY stability is not good - it’s useless having a very fine layer height if the layers are not put down on top of each other in precisely the right place. Then there’s the quality of the hot end, the feed mechanism, vibration in the structure, the heated bed, and so on. The cheaper models are cheaper for a reason, but that reason is unlikely to be just one aspect, it’ll be compromises in lots of different areas which may build up to a quite noticeable difference in quality.

The importance of layer height really depends upon the model itself. If you’re printing a cube, for example, the layer height is (almost) irrelevant for the top and bottom surfaces and if the XY precision is high, may have little visible impact on the sides as well. On the other hand, if you’re printing a sphere the layer height is going to have a very big impact on the finished print (as will the control XY - printing curves precisely is a lot harder than printing straight lines).

Personally, I’d aim somewhere in the middle. If you go for the very cheapest printer you can buy you’ll almost certainly be disappointed and it’s unlikely you’ll get much of your money back if you try to sell it, even very new. If you spend too much, you might be paying for things you don’t really need with your first printer and, to be frank, there are printers out there that I think are overpriced, having been overtaken by improvements in other brands. The Prusa i3 Mk2 looks like a good machine for the money, especially the kit version (I have one on back order) and certainly should be able to produce molds for you at a high quality. I’m sure others here will have their own recommendations.

Depending upon what you’re modelling, and the casting process itself, you might also want to think about using ABS and solvents to produce a smooth finish. Just Google “smoothing 3d prints” and you’ll find all sorts of ideas and processes.

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Thank you for the quick answer!

I get the whole cross-section build-up principle with how a strong slope is harder than a straight drop, and that a thinner layer will make slopes look better. I will probably print ALOT of curves and stuff.

I thought I deleted that line again about $300 because yea that was more meant as “And that is why I got this idea”

This was for the monoprice version of the Wanhau I think, but we don’t get them that cheap here in Europe.

I have been looking at:

A p3steel model

Wanhau Replicator i3 v2.1

and the Original Prusa i3 Mk2.

(In that increasing order of pricing)

But I don’t know if I can do the same quality with the p3steel for example, but it will just be more fiddly. I am looking to maximize capability over ease of use, but of course not to the point where each model will take 3x the time to get right.

I mean I can get the p3steel with an extra nozzle for 2/3 the price of the Mk2, which I guess can be used for support material, so that is also an increase in capability…

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I hate to say it @Martin_Baadsgaa but only you can make that final decision. The P3Steel looks like a reasonable machine, and it’s got pretty good reviews here on 3DHubs (FDM 3D Printing Service | Instant Quotes, Online Ordering | Hubs ) but the price is so close to the original i3, I’d personally be inclined to go for the original rather than a clone. Check the prices as well, on the site I looked at, the price quoted didn’t include a heated bed and it’s not the latest i3 with all the new stuff Prusa have built in…

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I thought the original Prusa was plastic frame which is why I looked at the steel version, to make sure it was sturdy enough.

https://kitprinter3d.com/en/home/124-kit-impresora-3d-prusa-i3-steel-pro-easy-build.html#/extrusor-single

No it’s not with the latest details…

Comes with Heated Bed MK2b though.

So that’s 450 euros vs. 740 and I still don’t get what I get for the money, except autocalibration :confused:

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At a guess, that extra 190 euros is, just off the top of my head…

1) The Mk42 heated bed, with cold corner compensation

2) The PEI surface (that could be 30 euros alone - I just paid £36 for a 300x300 sheet)

3) The autocalibration (I’d pay 190 euros for that on its own)

4) The full metal E3D v6 full hotend - the hotend linked to on that page could be anything, it doesn’t look like any major known brand and it certainly isn’t going to be full metal… Again, I paid £35 (40 euros?) for a full metal upgrade to my FF Pro. This is the bit that actually controls and delivers the melted filament, so it’s quite important to get it right…

5) Original controllers, not clones

The steel frame might be a plus, but the frame isn’t the whole printer. If there are other materials used in the parts bearing a load, then it might be irrelevant. Perhaps more to the point, I’ve not seen any comments anywhere that suggest the original i3 has a problem with rigidity/build quality. You could be paying quite a lot of that 450 euros for the steel frame that, in reality, does little if anything to improve the printer.

As I said, it’s got to be your choice. The P3 could be a great printer that does all you need, or you might end up wishing you’d paid that 190 euros more. It’s almost impossible to make any reasonable prediction.

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That is a lot of great insight to go by. Thankyou for the input. I think I will do the safe bet and save up so I can get the Mk2 and be sure I get something reliable. Thanks.

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Well, hopefully my mk2 will be arriving in the next couple of weeks and another member here @wirlybird also has one on order so I hope it’s a good choice!