Prusa I3 - Kit purchase and upgrade?

I have to say that buyers of FT kits are lucky there is such a great reprap community to help them because at under US $280 for a kit there cannot be any $$$ left for tech support.

Hi guys,

elkayem you're right, sometimes I probably uses words that are too rude.
That's what I can read on the parts of the messages you extracted.
To be honnest, I can't remember all the context when those was written.
I'm french and as italians we use to communicate with a lot of theatrality.
But be sure that's not meant to be arrogant or supperior. It's just the way we use to communicate.
Probably it sounds differently in other countries, and some words I used are maybe a much stronger translation than intended.
Through, reading is not the same than communication face to face in the real life.
Words can be strong but the way you pronounce them can be kind.
I have some experience to share, but I don't believe I'm a reprap guru.
Some people here are real reprap pioneers and can be considered as gurus, what I'm definitely not.

elkayem I used to say there's no perfect kit. It's not about the price tag,
just there is good and bad in any kit. Some kits have even nothing got to offer, except beeing a kit.
That's what I call cheap kits, or rubbish ones. (Is rubbish a too strong word ?).
I don't mean cheap like not expensive, I mean cheap like the oposite of smart.
That's why I believe you can get a pretty good printer sourcing parts by yourself,
because you will pay attention to get good components matching your needs.

When cheap kits resellers select components, they're just in search of the best profit.
You can see that. When a component is definitely too bad they need time to change it for a better one, because it reduces profit.
That's exactly what happens with folger's first extruder. I talked with Dan about this and he was blind !
His main argument was "we know some customer have issues because of irregular filaments, but for some people it works".
Actualy we know no filament can have a diameter as constant as you can drive it trhough a fixed gear system.
The truth was when the filament was too thin you get under extrusion, and when it was too fat it was grinded,
then when the gear was glogged by chips thiner filament gets loose too easily with a growing under extrusion,
then when the gear was full of chips, you just have a jam. And Dan cannot ignore that.

I believe the DIY and Open Source communities have a growing success because companies fail.
By the past, a company was working first for its reputation. Good reputation = good feedback = more sales=prosperity.
And people wanted to buy good things, knowing they wasn't rich enoyugh to buy cheap things.
Today most companies works only for profit, just selling what you can agree to buy, not too much, neither too little..
The price is just a hair under the maximum money you're ready to spend for that.
There's nothing in relation with the production cost. It's just about instant profit.
That's why if you want to get a good thing, you probably can't get it from a company, you need to DIY it.

I realy understand why people buy kits and why they buy at low cost.
First the overall quality won't be good enough anyways. And they're yet ready to change (throw or upgrade).
People buy a function and a price, and want it quick and easy.
Actualy for them, issues is an acceptable standard (they complains and ask for help here not to the seller) and average is considered like good.
I don't blame anyone, I start 3d printing with a cheap kits, like most of people !
But I learned hardly how much I was wrong : issues, costly upgrades, time consuming.
The time I spend here is all about to try to prevent newbies to don't fall into the same traps. Nothing more.

++JM

Guys! Stop Fighting!

Look at my Marvin!


Setting were:
Extruder temp 210
Bed temp 60
layer hight 0.1 mm
Print speed 50 mm/sec

Edited 1 time(s). Last edit at 11/28/2015 10:15AM by noogie.

Hi noogie,

I guess you used PLA. It's not that bad for a first time.
Maybe it's a bit too hot. Do you have a cooling fan on the part ?
Here's what you want to achieve :

Dutch PLA gold
Temp 195°C
Bed 65°C
Nozzle 0.3mm (E3D V6)
Layers 0.1mm
Printed @ 120mm.s

++JM

Edit : it's a M6 screw

Edited 3 time(s). Last edit at 11/28/2015 10:25AM by J-Max.

I remember you posted it, that's why I printed and posted mine.

Yes, the fan was on.

I'll try printing at 195°C @ 120mm.s

Hi,

Hmm. Maybe 120mm.s need a fully calibrated printer.
Not any printer can keep this print quality at this speed.
Stick to 40-60mm.s for your calibration time.
Then you will raise the speed gradualy until you notice print quality goes down.
What you want at this time is to increase print quality, not speed.

Did you calibrate your extruder ?

++JM

No, I didn't.



Edited 1 time(s). Last edit at 11/28/2015 12:45PM by noogie.

Hi,

This is a bit better !

You need at last two fans.
One to keep the heatsink of you hotend cold. The seccond (or the nexts) is for part cooling.
See under the "ears" of your marvin, this shows that your part (your marvin) is not cooled enough during the print.

First of all, you need to calibrate your extruder. Follow these two guides :

Tom's how to calibrate your extruder
Tom's Calibration and why you might be doing it wrong

++JM

From a scratch built Prusa i3 rework. Hexagon hot-end .4mm nozzle, wades extruder. 200 micron layer height. PLA at 190. Heated bed

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My updated Instructable on our Prusa i3 Build
[www.instructables.com]

Here's mine [goo.gl]

It's PETG because that's what I have in there and I don't have a print cooling fan so I know PLA would just droop.

Now I have to get back to making Braq [goo.gl]

Edited 1 time(s). Last edit at 11/28/2015 11:31PM by msaeger.

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Newbie with Folgertech 2020 i3.

Hi guys

@SteveRoy, it's not bad for a printer from scratch.
Your extruder seems well calibrated, that's a good point.
But you seems to have some play beween X and Y axis.
Maybe you can set your rods a bit away to minimize play.
If you use LM8UU bearings, you can fill them generously with lithium grease.
Or you can replace them with low cost bronze bushings.
Maybe you can improve your cooling part fan too.

@msaeger, your extruder is not so bad calibrated.
But it have the same issue than most of direct drive extruders, especialy @ 1.8°.
Definition of feeding is not perfect because the number of steps per millimeter is low. That's why a 0.9° motor is much better for direct drives.
The quality of the driving gear is also important, you want a small toothed one, like MK7/MK8.
The play of your machine is reduced compares at Steve's, that's a good point probably because of the aluminium frame.
Of course, because you have no part fan, overangs and sharp ends are not good.
The Marvin's eyes and handle makes that defaults particulary visible.
May I suggest a turbine fan with a fan duct who cool both sides of the nozzle deposit ?

++JM

Quote
J-Max

@msaeger, your extruder is not so bad calibrated.
But it have the same issue than most of direct drive extruders, especialy @ 1.8°.
Definition of feeding is not perfect because the number of steps per millimeter is low. That's why a 0.9° motor is much better for direct drives.
The quality of the driving gear is also important, you want a small toothed one, like MK7/MK8.
The play of your machine is reduced compares at Steve's, that's a good point probably because of the aluminium frame.
Of course, because you have no part fan, overangs and sharp ends are not good.
The Marvin's eyes and handle makes that defaults particulary visible.
May I suggest a turbine fan with a fan duct who cool both sides of the nozzle deposit ?



++JM

I ordered a geared extruder kit to see if that would help with getting the extrusion smoother I didn't know I could get a smaller degree pitch motor maybe I will order one of those and try it. Would I need to do anything besides swapping the motor? Some day I will get to the fan I am pretty happy with the overhangs on stuff I normally print if I use ABS or PETG it's the PLA that I really want the fan for.

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Newbie with Folgertech 2020 i3.

Hi guys,

Well the fan can help with any material, even ABS, but you must set it to the proper speed.
try the Atom overhang test
0.9° motors are 400 steps per revolution. So, if you swap for that kind of motor,
you must set your firmware's Steps per millimeter value according to that number.
And probably do again a proper extruder calibration procedure.

For direct drive extruer = (MotorStepsPerRevolution*DriverMicrosteping)/(HobDiameter*Pi())
For geared extruer = [(MotorStepsPerRevolution*DriverMicrosteping)*(SmallGearTeeth/BigGearTeeth]/(HobDiameter*Pi())

++JM

[goo.gl]

I think the biggest issue was the whole piece sagging because when I was watching it at the 70 part when it would do the shell of the overhanging part it would print it in the air so there would be a gap between the shell and the piece until it did the infill. Setting it to do the infill first may have been better or just getting it to the the outer most shell last. With something like this I am just amazed it finishes!

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Newbie with Folgertech 2020 i3.

Hi guys,

This print could have been worst. Usualy you setup with PLA, i believe PETG helps a lot here.
Yes, this par is all about printing in the air. This is a real benchmark part.
This part is meant to be printed right with a perfectly calibrated printer with efficient fans.

The down side of the part can't be perfect without a part cooling fan anyways.
But look at the imperfections on the up side of the part.
We can see the perimeters are not as straight as it should be.
The upperside of the part is not printed realy sharp too.
Probably there's something you can do to improve.

++JM

Quote
J-Max
Hi guys,

This print could have been worst. Usualy you setup with PLA, i believe PETG helps a lot here.
Yes, this par is all about printing in the air. This is a real benchmark part.
This part is meant to be printed right with a perfectly calibrated printer with efficient fans.

The down side of the part can't be perfect without a part cooling fan anyways.
But look at the imperfections on the up side of the part.
We can see the perimeters are not as straight as it should be.
The upperside of the part is not printed realy sharp too.
Probably there's something you can do to improve.

++JM

When it got into the higher parts it was definitely more sloppy looking as it printed that's what makes me think the whole print was sagging. Fan probably would have helped with that.

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Newbie with Folgertech 2020 i3.