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Nov 24, 2015, 03:44 AM
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Mini-Review

Print-Rite 3D Printer


I finally bought a 3D printer, after a long time of humming and harring over the cost and the uses for it. For sure it would have uses, but they need to be cost effective too!

When HobbyKing had the Print-Rite 3D printer on special for almost $100 off, which was AUD$383, I quickly read up on it and with all reviews etc sounding good I decided to get one!

I am no 3D Printer Expert!! Not yet anyway. But this was easy to assemble and set up - with a bit of added DIY usefully added. And then the first two test prints went PERFECT right away! That was a surprise bonus, after reading so much about setting up importance and issues etc. you can run into.
Well, they are a quite simple device really....

I also ordered a heated bed from ebay for AUD$19, but on the 6 prints I have done so far the stock bed and tape setup has been totally fine really! I had read how good it is - better - to have a heated bed.... hmmm.

It IS important to align it all! The two main things are leveling the 'cross beam' and setting the home Z Axis nozzle height. It seems best to do that every time you get the printer out to print again, as they can move/change.

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Nov 24, 2015, 04:06 AM
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Mods


The first thing I did was cut out a piece of MDF to mount the Printer onto.
500mm x 480mm of 16mm thick MDF.
Just two self tappers needed to hold it in place.

Next I separated the filament spool holder and made it into 'two' holders. That way I could mount them on the top beam and have two colours at the ready - and save space.

The Wiring Loom more or less just "lies around" as it comes! They give you some cable ties, but they are pretty useless for routing the wiring in a truly decent manner! So I made up a wire guide for the Print Head end of the loom, and some alloy plates to hold the loom rigid elsewhere. Then a few cables ties, and it was all locked nicely in place and with enough flexibility to follow the Print Head wherever that could go.

I put some velcro onto the MDF board and AC Adaptor so that it could mount into one corner of the board.

I drilled some air holes into the processor/power board cover, seeing some people had mentioned it can get a bit hot in there.
With a heat bed to be added (soon) you need a bigger power supply because that uses a LOT more power than the stock unit as it comes, so I will use a PC ATX power supply then.

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Nov 24, 2015, 04:21 AM
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First tests


As mentioned, the two test prints went perfectly - I stopped the big 'teardrop' early so it came out just a 'bowl'.

The first real project was to make custom servo mount units, so that you glue that into the plane (wing, tailplane, fin etc) and then can just push a servo into that and put on a 'cover' plate to hold it locked in.
I used Tinkercad - the online 3D editor - to design them. Tinkercad is limited but does do everything you could need for more simplistic 'geometric' shapes. Editing is FAST in Tinkercad, versus 3DSMax etc.

I found issues with the supplied SLIC3R program included with the Print-Rite Repetier software. So I changed that to the latest version.
I also changed the Repetier software to the latest version, but then I had issue printing at all ! So for now I have the stock supplied older Repetier, with the new SLIC3R version in that. (SLIC3R can be used on its own too).

You basically design a 3D model in some program (Tinkercad, 3DSMax) and save it out as STL format preferably.
Then you feed that into the SLIC3R program so it creates a 3D Printing file (GCO). Then you are ready to go and print it out!

You need to use some 'thought' about the design and printing limitations, but I didn't find that hard to do. You envisage the printers output ability... a 0.4mm flow of plastic(!)... and make sure your design CAN be built up using that!
Of course the first print are pretty simple - though of reasonable complexity in angles and corners - so I will find out... learn... other issues later on I am sure!

But so far.... AUD$383.... this 3D printer has done exactly what it is supposed to right away!!
So first I am making a HEAP of servo 'boxes' for two main sizes, and then a set of landing gear for my Dynam DC-3. To make them retractable, and in the same manner as per the full scale uses.

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Jun 02, 2016, 07:53 AM
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Heatbed added


The Blue Painters Tape actually worked quite well to hold the prints down - at least for the smaller ones. I didn't really do anything large on the stock print bed. But I did note that the Tape 'wears out' and then prints do NOT stick down as well... to the point where eventually they will just break free of the Tape at some stage during a print.
All you need to do is replace the Tape....

But what good is replacing the Tape AFTER you find something broke free? And that wasted your time and filament....
I decided I needed a heated bed so that I can just print 'forever' without any Tape changing or prints breaking free part way through the printing.
But I probably should have READ a lot more about it all first!!!

The common Mk3 heatbed is a good heatbed, so that part of the plan was fine! It comes as a 3mm alloy plate with the heating 'plate' built onto that. The Printrite control board does not really have the Current ability to Power a heatbed properly or safely! This means you really want to add a RELAY that takes the Printrite control board heatbed Voltage and use that to switch the Relay, which passes Voltage from an adequate power source.
I used a 600W ATX computer power supply that can do 25Amps of 12V.
Ideally I will set it up to also power the Printrite printer and get rid of the stock power supply unit. I have not set that up yet.

So now I had a heatbed. What do you do with that? Well you set it to heat up to some temperature to help make PLA stick to it, and thus no need for Blue Painters Tape..... except that does not work at all....
All in all the heatbed was useless for PLA.... in getting it to stick... and in getting it to cool down slower, and thus make a better print.

Doing some READING NOW I worked out some things....
You STILL need a way to stick down the Prints! Thus the heatbed does NOTHING to help that aspect! Boo!
Many people suggest HAIRSPRAY - spray a good coating of that onto the heatbed BUT do not use more than about 30degC of temperature - if not even less, or NONE!
That makes the heatbed useless..... you may as well not even have one! (except for other ABS printing needs - if you use ABS).
It also means you need to CLEAN the heatbed quite often, to get the many layers of hairspray off! Plus, it does not even stick prints down that well anyway!

Next was to add Blue Painters Tape and try that with some heat.... but heat just makes the Tape work WORSE! Hmmm....

The next idea suggested in one Forum, and rarely suggested(!!), was to use PVA Glue!! Spread a thin layer of that onto the heatbed and run the heatbed to 30degC or so. That WORKED, but it is very messy. So then I added some Tape again, and 'glued' prints to that with the PVA. Now the prints stuck like glue!! 100% solid and reliable! AND hard to get off too!!!
So that worked.... but it was still a bit short of a 'perfect system'.

More READING and then a GLASS piece on the heatbed was supposed to be great for sticking prints down solidly with NO other material needed.. not Tape... not Glue... not hairspray!!
So I bought a piece and added that - you just put it onto the heatbed and hold it in place with small 'bulldog' clips.
IT WORKED!!! The prints stick as solid as with PVA, except there is no mess! And they release from the glass once they cool down!

Oh.... "cool down'. So that means you cannot get it off, unless you make a fair effort, until it is cool enough - and that takes TIME!
So the next Forum suggestion was to have TWO glass plates, and change them between prints. That way the just completed print can cool down ELSEWHERE, and you can print right away again on the next glass piece!
But I only bought ONE, so that I could use it and PROVE it all works as suggested. And it DOES!!!

The Mk3 heatbed is larger than the Printrite stock bed, so I had to make brackets to allow the heatbed to be sat raised on bolts. You need that HOT thing to be above and away from the perspex stock heatbed!
That was easy enough to do, so then it was all complete and NOW it is a 3D Printer that operates how you would HOPE to have a 3D printer operate!
Prints that stay in place solidly and assured!!
And NO TAPE.... NO MESS... NO CLEANING.... Just PRINT!!!!

The heatbed was AUD$25 delivered (approx).
The glass plate was AUD$16 delivered.
Both from eBay.
The Relay was about AUD$8 from Jaycar Electronics. It is rated for 30Amps.

Note that most 'cheap' 3D Printers are not going to be set up this way - and even if they have a heatbed, maybe even glass, they still pretty well alwyas need something done/improved to that anyway!
So in cost terms the Printrite 3D Printer, with these add ons and their costs, is still a bargain price!

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Last edited by PeterVRC; Jun 02, 2016 at 08:00 AM.
Jun 04, 2016, 07:30 PM
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Final PLA printing perfection!


I thought I was 100% home and hosed with the glass bed addition! But it was not quite 100%!!
When I did a large print, its edges curled up and thus distorted it a little bit for quite a number of layers. You don't want the prints ALMOST perfect!!! You want them ALWAYS 100% perfect!!

I had already done the "PVA glue" method in earlier tests, so I did that on the glass surface. I used about 1 part PVA to 20 parts water - to really weaken it, and see what happens.
It held rock solid!! So solid that after printing the print is like it is part of the glass!!! That is not a good thing.... you would think... but it ends up that it actually is a good thing!

The print sticks so solidly that it is NEVER going to move during a print, not is any part going to warp and lift off... even the slightest fraction at an edge! So that is GREAT... but how are you going to get it OFF when you want it off!!??

That turns out to be EASY!
Firstly, once the bed/glass and print cool right down it just 'falls off' by itself anyway! Thus it is off....
In some cases it does stay stuck down, so for those I just took the glass plate off and when it was cool enough I ran cold water over it and again, the print just 'falls off'!!
Doing it this way means you can also clean the glass in that same process - wiping the PVA glue off.

This need to wait for cool down etc means you want to have TWO glass plates, so that you can remove one glass plate and put it aside and put on the other glass plate to get another print going - then go and remove the first print, as mentioned above, when it has cooled enough.

I bought another glass plate.....
I saw that I really only paid AUD$$15 for the first one, and the next one was AUD$14 due to a better exchange rate at the moment.

So now everything is 100% PERFECT!!! It is so great!!
Perfect printing..... perfect print item bonding to the print bed.... easy item removal... and the ability to print the next item right away!

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Jun 04, 2016, 07:38 PM
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Temperature settings


For PLA, so far, I have found that I set the heatbed for 70degC, for the entire print.
For the PLA Filament I use 206degC extrusion temperature for the first layer - this makes sure it is very flowing and bonds to the glass plate optimally.
For all further layers I use 201degC.
I have altered the extrusion temp in real-time to test and found that even down at 198degC it still did the printing perfectly fine. I think it works best to have the lowest temperature possible - without going too far(!) - so that it forms a really 'clean' flow and 'bridge' to the prior laid down PLA. But the tolerance range for that, on my printer, seems to cover that 198degC to 201degC range.... even a bit wider really. (195 to 203).

Heat sensors, per machine, COULD have variations, so anyone else might need to test these values and fine tune it to suit what THEIR machine really does. eg Mine might show 198degC but it is really 200degC, and someone else's shows 196degC when ti is really 200degC.

PLA filaments, and where they come from - quality, real material constitution etc - probably also come into this, but so far with my various 'no name from China' filaments they are all quite similar results.
Who knows, maybe expensive filament makes a notably better print!!?? One day I might try some....
Jun 04, 2016, 07:42 PM
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Heatbed, glass, PVA for ALL printers


Note that this printing bed setup is applicable to ALL 3D printer types!

You want a heated print bed
You want a borosilcate glass plate for on top of that
You want TWO glass plates - if you want to be able to print without delays in between
You want to use watered down PVA glue as an extra bonding 'glue'

No other tape, 'glue' etc method works 100% properly.... you need to buy costly tape... get it off.... or use some other glue idea, which almost none are water based and thus messy to get off.....
Many ways work OK, but none do the 100% job AND the ease, of watered down PVA glue on glass!
Jun 04, 2016, 07:49 PM
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Printrite 3D Printer - would be 10/10 but....


So, the Printrite 3D printer is VERY GOOD, as far as printers go. And it is very cheap too!
But I found a better one....

Geeetech I3 Pro B....
It is the same base design, but it comes WITH the heated bed and glass plate AND a 240v switching power supply to power that ALL from the one unit (which mounts onto the printer frame too).... and also an LCD control panel that supports SD card printing too!
For AUD$329 !!!

CHEAPER than the Printrite, and it is a newer generation of mechanics WITH all the extra stuff I mentioned too!
So it wins hands down over the printrite!!

They also have a dual extrusion FEED version - not two nozzles but ONE nozzle fed by two filament feeds! This allows colour switching on the fly, BUT it also allows colour MIXING on the fly! Not only in a fixed ratio, but a realtime alterable mix ratio too! That means you can create SHADING too.!
But that version costs AUD$640.... pretty well double the cost of the single extruder version! Though if you want, or need, dual colour and SHADING, then it is worth that.

This Geeetech AUD$329 version thus means the printrite cannot be 10/10....
It can be 10/10 after mods and in how it works, but not in TOTAL COST.
The Geeetech does all the same stuff, as it comes, and at a notably cheaper price!!
Note the printrite cost AND mods costs is about AUD$450 - over 100$ more, to end up with a bit LESS!! No LCD control panel and SD card printing.....
Jun 22, 2016, 08:17 PM
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Printrite..... DOES end up as 10/10 !! After required mods....


I bought a Geeetech I3 ProB printer also.....

All in all you get what you paid for!
Whilst they list all the 'upgraded' better parts it has, they are not as good as it would sound to be!
At AUD$329 delivered, it is still a great value printer but it still needs some 'fixing' and upgrading. And the main mechanics - the slide rods etc - are not as high quality and 'perfect' like the Printrite has!

I decided that whilst the Printrite needs additions/upgrades to make it truly fantastic, which means spending about AUD$60 more on it - for a grand total of about AUD$460 or so - THEN you end up with a 10/10 3D printer!!
The Geeetech is still very good, once fixed up, maybe totalling AUD$360 then, but to get it up to the Printrite quality (rails etc) would add another AUD$50 or so. I guess then it would be as good, and have cost a bit less.... but it is a real KIT and takes 10 hours or so to build it all up too!!
Jun 22, 2016, 08:31 PM
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PLA print bed 'sticking' method - Use 1:20 thinned PVA/Water


The previous mentioned PVA 'glue' method, on heated glass, remains the ultimate way to assure 3D Prints remain stuck to the bed 100% assured - thus no warping etc.
BUT, it is 'too good'....
Once the glass bed cools down the item will come loose BUT during the cooling process you hear 'glass cracking' type noises as the glue bond releases. That would be fine and not matter at all, except one time the glass DID beak a thin jagged chunk out of it!
This then occurred on another occasion to another glass bed too! So both had one surface damaged and unusable then! (just turn it over....)

So then I thinned down the PVA/Water mix to be more like 1:20 or even less. It only needs the slightest amount of glue/bond really.
No more 'cracking' noises as it cools down.... and so far no more glass damage!

For small3D print items you can use NO PVA glue. Say up to about 40mm square. But not using glue means you RISK finding out you should have used it!

One coating seems to work over quite a lot of prints too, so I only wipe a bit more on if it is going to be a big print that I want to be 100% assured it isn't going to fail (fall off, or lift edges etc).

Oh..... now one glass bed has CRACKED, with an arc running from about 1/3 in from the edge, to the edge. That one was on the Geeetech printer and is because of another flaw/issue THEY have on theirs. It would/should not ever happen on the Printrite.....
Jun 25, 2016, 08:13 AM
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Heatbed mounting and calibrating


I didn't think that much... enough... about the printing bed until after doing improvements on the Geeetech I3 ProB. Seeing that printer needs bed calibration almost every print!

When I looked at the PrintriteDIY bed setup, plus the fact that I added a MK3 heated bed, I realised I had not checked enough about it and calibrating it.
It was not really level from corner to corner, across the four corners.
I removed my mounting spacers and put in Springs, like the Geeetech has, but that setup had a flaw...... just as the Geeetech does too I realised!

On the MK3 heatbed there is a bonded-on 3mm Alloy plate also and this means it cannot 'twist' really. It is very rigid. Maybe under heat it could warp a bit, but in general not at all. This means you can't use Springs because when you have Springs you rely on each corner being able to be 'pressured' by the spring, otherwise they all just push up to the screw head heights and ONE spring will always be a loose compression. This is what happens if you have a rigid plate(!) like the MK3, so there is just no point in using Springs at all.

So, back to the spacer idea - but now with additional factors accounted for!

You need the extruder nozzle to be equal height from the bed in all four corners of the print bed. Because the extruder carriage Y Axis runs from two stepper motors to allow Z (height) movement, it means you can actually adjust for a 'leaning' print bed in that Y direction by adjusting one of the stepper motors.
But you can't in the X direction - the axis that runs from the base rails below the bed. So THAT X Axis direction must be aligned accurately using the bed mounts - the spacers holding the MK3 heatbed above the stock print bed.
The first thing to do is use a ruler to measure the two Y Axis carriage mount ends and set them to be equal - by manually rotating ONE stepper motor (either) as required to achieve that equal height.
Drive the Z axis down yourself (PC controls - not using Z Home) until the Extruder Nozzle touchs the print bed in one corner. Now Disable Steppers so you can move the Extruder around to find the HIGHEST bed corner of them all and that will be the one you leave as the reference to set all others by. Set the extruder nozzle down to touch that corner area.
Then move the bed/extruder to the other three corners to check their heights - how much lower they each are. You must get the corner that is in line with the reference corner, on the X axis (the one parallel to the rails) adjusted to match the reference. You can see in the pics below how I used fiber washers to bring that corner up higher.

Then move to the other corner that is 'adjacent' to the reference one - across the Y Axis - and get that one to the right height. Then do the last corner that is on that same X axis side.
The most important ones to get accurate are the pairs of X Axis aligned ones - the pair that are parallel to the lower slide rails.
This is because even if the bed it slanted a BIT in the Y axis direction, you can adjust for that by adjusting the Z axis stepper motor and the end that is NOT the Home side of that. The Home one is the reference end of that Y axis, seeing it has the micro switch that sets where Home height is. The opposite end can be adjusted to raise, or lower, that other end a bit so you get the extruder nozzle to be the correct height off the bed at that end too.
The aim is to do it via adjusting the bed mounts/spacers, but adding a washer might be too much, so a slight turn of the non-Home Z axis stepper motor gives you the ability to fine tune it accurately. Just turn the threaded rod to make the stepper motor move one 'step' and raise, or lower, the Y Axis carriage a fraction at that end.... to whatever is required.

DO NOT bother ever again doing the stock alignment process of using the "card' they give you to get the two Y Axis ends equal - it is unimportant, and even detrimental, once you have set up the print bed level as outlined above! The truly important thing is that the EXTRUDER NOZZLE is equal heights above the bed at all four corners! Their idea of measuring the Y Axis carriage heights is a bit flawed, because it relies on a number of other things being accurate - such as the BED being dead level across that Y Axis direction. It should be, but might not be! So adjusting the carriage to SUIT THE BED is the real aim of most use! And use the outer stepper motor positioning to achieve that if needed.

So doing all this I got my Print bed to be highly accurate and level - with all four corners pretty much dead right!
And seeing it is a RIGID alloy plate bed, once it is all aligned it will STAY aligned forever really.
This is another reason that upgrading to a MK3 heatbed is of great value and use!
The Geeetech with its MK2 'flexible' and 'warping under heat' bed, using springs to try to equalise all that, is just a very poor solution to something that is highly critical to producing good 3D prints! Unacceptable really - though it still works.... in its poor accuracy manner. I advise ANY 3D printer (of these types) really needs a RIGID heatbed.... thus the MK3 Heatbed is what you want and need!

The next things I had always known was the stock screw/bolt for triggering the Z Axis micro switch for Home, is sloppy and very inconsistent! It can alter its position just due to vibrations as you print! It is a terrible, inadequate, solution!
To fix that I used the PrintriteDIY printer to make its OWN improvement piece.... a block/plate to house a 5mm Nylock, so that the Bolt now goes through that Nylock as well as the stock threaded hole in the Y axis carriage.
The pair of threads that gives, plus the Nylock 'grip', means it is solid and true now! The extra height meant I needed to change the bolt to a 60mm long one, but now it is rock solid and 100% reliable accuracy!

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Last edited by PeterVRC; Jun 25, 2016 at 08:28 AM.
Jul 14, 2016, 11:50 PM
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Printing update and tips


I have printed a lot of things now.... many with issues... many great....
One by one "issues" and fixes/adjustments have been uncovered!

1) The extruder fan speed.
I do not really know WHAT this fans aim is! But printing programs generally have it OFF for layer 1, then on to 100% from layer 2 onwards.
I found that you want it OFF if the layer is a solid layer in those first few. eg the base is two or three layers of 100% fill (being a "wall"), then have it OFF for all three of those layers! Then back to about 80% for all others... not 100%.

2) PLA extruder Temps.
I was doing White at 204degC first layer and 200degC from then on. This worked totally fine.
BUT in GREY.... I had to come down to 194DegC for layer 1 and 192degC from then onwards. See the pics below to see how great that made the printing.
This shows how important it is to get the temperature right PER FILAMENT COLOR!!
A good test is to print something very small, but with some height (10mm) to see how it does the base and all layers above. Fine tune the temps as required....

3) "Rafts".
Many items will need a Raft used, to increase the footprint of the print so it sticks reliably to the bed. See the raft on the pics below.
But if the area of the Raft that is under the part is quite large (even as per those in the picture) then use a LOW percentage of Raft Infill. Like 20%. Otherwise it will be made too 'good' and bond to the part too well. On these parts below the Raft is impossible to remove! It will need to be sanded/grinded back!

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Last edited by PeterVRC; Jul 16, 2016 at 06:05 AM.


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