Is there anybody out there?

Greetings,
Just wondering if this site is still active?
Regards
daggs
Heathcote NSW

Yeah there hasn't been much activity on the aussie groups for a while but there are still some of us around.

Hello, I'm here!

I'm based in Glenwood.

I've done a Rostock build that took me 5 months to gradually build up and absorb all the open-source information out there:
was a fun, interesting, sometimes frustrating journey but all rewarding in the end.

Here's a picture:

[www.dropbox.com]

Sample cookie cutter print:

[www.dropbox.com]

Prusa i3 variant (Reprap Wilson) parts that I've done for a friend:

[www.dropbox.com]

And now onto my second printer, which is a Mini Kossel from locally sourced extrusions (8020):

[www.dropbox.com]

Happy to help anyone interested.

Edited 1 time(s). Last edit at 08/31/2015 07:39AM by DennyP.

Hi DennyP
Some great photos, thanks for sharing.
I really like the look of the first one and am wondering about its dimensions.
Do you have any other photos of it i.e. other sides?
I have been at a reprap prussia i3 for just over 6 weeks, fun 5%, Interesting 20%, frustrating 35%, nightmare 40%, there is soo much info on the web, that I am grabbing bits and pieces from different sources as nothing is ever the same.

I'm almost ready to try my first print (then again, I thought that would happen about 3 weeks, I can only live in hope).

Cheers
Daggs

Hello Dagg,

Yes I do have additional photos showing other angles:

1) Top and bottom plywood bases added:
www.dropbox.com

2) Top and bottom bases layed on the side:
www.dropbox.com

3) 1st side brace added:
www.dropbox.com

The side panels are 762mm x 90mm, but this isn't a strict requirement.

The dimensions of the base can be found here:
[www.thingiverse.com]

ForAfter building the Rostock and Kossel from the ground-up, I do recommend going Kossel for the aluminium extrusions that just makes it easier and modular like lego/Ikea where you can rout cables
using the extrusion slot. getting them pre-cut to size is also convenience galore.

I had to use marine plywood because the regular plywood from Bunnings (you can get better plywood deals elsewhere) is crap and MDF apparently absorbs moisture; marine plywood doesn't so the machine will hold calibration for a very long time. Cutting marine plywood is very hard and you need to be very very careful; I had to make a jig and use a circular saw. Overall it's a very big effort.

However I do agree that the wood ones do have a certain nice look to it with the grain. There's now heaps of wood models since the Rostock was released as shown:

[www.google.com.au]

If I had to do another wood delta, I would do this one provided I have the tools:

[www.appropedia.org]

Because:

1) Making a circular base with a constant diameter is intrinsically easier if you have the tools such as the router and the jig, compared to circular sawing very exact perpendicular lengths.
2) It has the vertical braces directly adjacent to the horizontal rails to give it extra strength.

Haha I know that feeling, one you go over the "peak of agony", you'll eventually approach the "period of enlightenment and accomplishment" I promise

What are you stuck on your Prusa i3?

Regards,
DennyP

Edited 1 time(s). Last edit at 09/02/2015 07:24AM by DennyP.

p.s Just added the image links on my last post as it was missing.

Edited 1 time(s). Last edit at 09/02/2015 08:05AM by DennyP.

Greetings Denny,

I've been away for a few days, just so I can prepare to torment myself some more tommorrow.

Thanks for the pics, it looks good.

What are your max XYZ dimensions?, when I get a chance I will try and find a video of how your system works as it looks (to me) like the XY&Z motors will all have to act in concert with each other at the same time

Tommorows agenda ~ Back to smacking my head again.

> levelling the bed, I would have thought this was simple excercise until I found out that one of the M5 nuts on my Y axis was unloosining itself during up / down movements, another crappy pla fitting supplied by Sintron, I think I have fixed it hopefully enough to print some new parts when I get it working.

> Where do you normally have your home position? I can see that via pronterface, I can set it to 0,0,0 or 100,100,0 (and adjust accordingly) but I have not yet stumbled across teling the machine where that physical starting / home point is is relation to the heat bed.

Any thoughts would be appreciated.
Thanks
Daggs

Hello Daggs,

The Rostock utilizes the alternative kinematics called Delta, and it's exactly as you described: dependant vertical axes moving simultaneously together to move the hot-end to a definite 3D location using diagonal rods. it uses some trigonometric calculations to do it.

You can drive a delta printer faster more confidently because the hot-end is positioned on a light platform called the end-effector suspended by (usually) carbon rods. The extruder
motor is separated by using a teflon tube and this further reduces weight. All this weight reduction reduces any inertia effects that resists the change in acceleration, which in turn
theoretically increases print quality, but really the print quality doesn't differ between the two systems, it's more speed and maybe build height you want.

It's roughly 200mmx200mm and roughly 350mm in height, the printable area is reuleaux triangle that just misses the corners of the printed bed. The best image to show this is:
[forums.reprap.org]

I've used both cartesian and delta and it feels like a cartesian is an automatic car, while delta is a manual haha. The calibration of a delta is considerably more exhaustive (especially
without auto-bed levelling) and like with cars, manual to automatic is easy but automatic to a manual is probably a challenge. They ideally need a 32bit system too.

1) You could use a spirit level ($2.80 around from a Daiso store, amongst many useful reprap tools like a M3 Hand drill!) to see that your heated bed is flat everywhere, and use it to ensure
that your X and Y system are also levelled and perpendicular to one another. Good job with the Fix!

2) Don't quote me on this because I don't regularly own a cartesian:
It's defined usually X=0,Y=0,Z=0 for the bottom left hand corner; X becomes gradually positive to the right of the bed, Y becomes gradually positive to the back of the bed and Z becomes positive. You need to set this in Pronterface under Settings -> Printer Settings -> Build Dimensions, and your slicer settings (e.g. Machine -> Machine Settings for Cura). You need to make sure that when you home your printer, your hotend is positioned at X=0,Y=0 and 0.1mm above the heated bed for Z=0. If it's not, then you'll need to set endstop offsets in your firmware - however there is such a thing called hardware endstop offsets/adjustments but I would avoid them as they are way more tedious to implement.

Delta machines have their origins defined in the middle instead.

I'm assuming you've reached the following things:

* You know about firmware and have uploaded one into your (presumably) ramps board, I use Marlin because it's easier to read and has more EEPROM command support which you'll come to know and love definitely soon.
* Test that the X,Y,Z,E motors work, I use this test code, compile in Arduino IDE: [reprap.org]
* Test that the endstops work: X_Min, Y_Min and Z_Min, you really don't need maximum endstops. Use the M119 gcode command.
* Test that the thermistors work by just looking at the temperature graph in Pronterface. T0 is for the hotend and T1 is for the bed on the Ramps board.
* Set the initial steps_per_mill values for X Y Z, E isn't important for now. Use [prusaprinters.org], based on your pulley/belt system.

Do the endstops press onto solid printed plastic, or they touch an adjustable screw?
Where are your X_min, Y_min and Z_min endstops located? X_min at the left? Y_min at the front? and Z_min on the bottom beneath the bed?

Regards,
DennyP

Edited 1 time(s). Last edit at 09/04/2015 05:49AM by DennyP.

Hello Daggs,

How's your Prusa build going?

Hi Denny,

Greetings,

Still frustrated but the end is in sight.

Yet to actually do any more than extrude some abs, then that even stopped working.

As I was replying to your previous comments (and getting close to 3~4 pages), the more I read it the more clarification I was actually sorting this out my self as I went on and re-read it.

Things were looking good for a little while until a previous fix on the X axis (drive end) failed as I did not take out the m5 nut that was not sitting correctly and was stuffing up the Y axis movement (the nut was rotating bit by bit and thus causing jitters, throwing all my alignments out of whack).

I played with that for a while and thought I had it sorted out, but all was not to be.

Somehow or way, my next issue, there is a threaded rod that connects the hot end to the extruded, it snapped without me knowing it and after a few test runs (with no printed result), the hot end separated itself from the extruded, I screwed the hot end back into the extruder assembly (before I knew it was busted) and it effectively ground away the main extrusion gear.

I am picking up a new extruder assembly today (and then I will go looking for spare parts) to fix the 1st one.

I needed to get back in touch with you so you did not think that I have been ignoring your valuable input and still want to chat about your current project as it looks very interesting.

I'll be back
Cheers
Daggs

Hi Denny,

After more mucking around and a weekend of dissappointing sports (I am an ardent sharks and swans fan) and printer results I am finally back (with the printer) to where I was before the extruder last time i.e. It will not print anything......

I should rephrase that, it wants to print i.e. it goes through the motions but nothing sticks to the bed!, the material just tends to curl itself into a spidery ball underneath the nozel
??DN?? bed heat? extrusion speed?

I am going to make some notes for myself below, I found last time it helps, please feel free to comment if there is something blindingly obvious that i am missing

> new extruder installed, supplied in reverse configuration by Sintron to the unit it is replacing, reconfigured the carriage and end stops to suit - rehomed to bed / sorted.
[ business card (0.58mm) used for clearance between hot end tip and bed]
[ firmware settings for home
// Travel limits after homing
// #define X_MAX_POS 190
#define X_MAX_POS 200
#define X_MIN_POS 0
// #define Y_MAX_POS 190
#define Y_MAX_POS 200
#define Y_MIN_POS 0
// #define Z_MAX_POS 600
#define Z_MAX_POS 185
// #define Z_MIN_POS 0
#define Z_MIN_POS 0.1]

??DN?? 0.58 + 0.1 should mean the clearance for print start = 0.68 above print bed - need to check, perhaps this is too high

> Extruder tested - temp OK for PLA 185 Deg, 230 for ABS, new extruder now fitted backwards, reversed electrical connections on Ramps 1.4 board to correct extrude / reverse directions - OK

??DN?? In pronterface, the extrusion is at 125mm / min, too fast? too slow?

> Bed temperature tested - ok for PLA 60 Deg, Not OK for ABS 110 Deg (struggles to get to 910 Deg), Heater bed is coveref in kaptan tape, thermistor is taped towards the underside side as advised by Sintron
??DN?? Check output voltage of pwr Supply and adjust accordingly

Denny,
Is there anything that you think I may have missed or should focus my attention on?

Regards
Daggs

Hey Daggs,

I was also cut that the Sharks didn't make it, but atleast the Bulldogs didn't go through! (Parra supporter here).
Ah never thought you were ignorning my advice, just keen to try to assist you. I know the pains of starting with a open-source printer, especially when
there seems to be not many of us in Sydney to refer to.

The hotend seems definitely too high above the glass plate if it's truly 0.68 mm above the heated bed, and the "spiderballing" is a classic symptom.

The hotend tip should be ~0.1mm above the glass surface when the machine is homed. I really do recommend getting a feeler gauge (~$5 from Bunnings is where I got mine) because it's such
a critical measurement that having +-.05mm can make a noticeable difference. A 0.58mm business card definitely won't do wonders.

Check out the "Getting your first layer to stick - " section in the following link for reference.
[richrap.blogspot.com.au]

If you find that your extruder is extruding in the wrong direction, yes you can swap the extruder stepper-motor coils connection over, but if you can't be bothered navigating through the cables (like myself) then you can change it in the marlin firmware by altering the following code:

#define INVERT_E0_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false
#define INVERT_E1_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false
#define INVERT_E2_DIR false // for direct drive extruder v9 set to true, for geared extruder set to false

Change E0 to true. E1 and E2 corresponds to a second and third hotend if you have that capability.

Don't rely on setting extrusion rates in the host software; this really must be set in the firmware.
You must alter it here:

#define DEFAULT_AXIS_STEPS_PER_UNIT {79.8802, 80, 80.0334, 620}

The last number relates to how many steps the extruder motor needs to undertake to extrude 1mm of filament.
You must modify this number so that when you extrude 100mm of filament, it does actually extrude 100mm!

Here's a good reference (Step 1), it will essentially be an iterative process:
[richrap.blogspot.com.au]

Do you have insulation under the heated bed? It took me ages to reach 90 degrees without it like you, I use styrofoam which is one of the best insulators you can get, so do that first.

Do you have a endstop adjustment screw for the Z_min endstop?

Regards,
DennyP

Greetings Denny,

Mmmm Bulldogs or Manly, not quite sure I hate more....

I had no delusions that the Sharks would win the comp from the spoon holders last year, but note that the Eels have done so in the past.

Reading your previous notes:

Starting from (almost the end), I have put some styofoam under the aluminium bed, after about 15 mins it has reached 97 deg and is very slowly rising.

I have some "Polyair unicell" and will have a chat with a tech at bradfords / csr and get their thoughts on using this as an alternative.
< did that, less than responsive to the application >

The printer is in a very well ventillated area with a current ambient temp of 24 degrees

RE endstop adjustment screw: don't have but I can sure see how advantageous that would be, that being the case, I am considering getting the tip to bed as close as I can, setting the stop in position with some hot glue and then use the spring loaded bed mounting screws to adjust at all extremes (my head is screaming at me that this is a bad idea, but I cannot see that it will not work and in the worse case is reversible).

RE: feeler guages: I have some, just need to find them, could actually be easier and quicker to go to bunnings and buy some more.... the point has been taken.

RE: Calibration, going through the process now

cheers

Daggs

Hello Daggs,

What is the wattage of your power supply? it could be underpowered.
What is the resistance of your heated bed, it might be too high of a resistance.
Here are some resistances for reference, if you have a multimeter it would be a worthwhile check:
[reprap.org]

It's strange that an aluminium bed would take that long? Unless the aluminium heated bed in theory would have a higher thermal conductivity than a PCB heated bed, which could explain why even with a insulated aluminium bed, it
takes longer to heat to 100degrees compared to a insulated PCB bed because the conductivity actually dissipates heat better? For comparison, it takes roughly 8 minutes to heat up to 100 with a glass plate on, for my printer.

Is the Z min endstop held on a clamp on the Z threaded rod? such that you can slide it up and down as a "rough" endstop adjustment (not suggesting this is the solution).

Regards,
DennyP

I have a 3mm Mk2B Aluminium as well as a standard PCB heated bed. The Alu one is approx the same wattage (120W) as the pcb one, but it does take longer at 15min to reach 110deg as compared to about 7min for the PCB one. My Alu bed cant get past about 85 deg unless there is insulation underneath, and for that i just use some plain corrugated cardboard.

If you are using Marlin with a LCD, you can also try the BabyStepping feature for fine Z adjustment while the first layer is going down if its a bit too high. Setup the slicer to add a skirt/brim around the part, that way you can adjust it while its printing that before the main part gets printed.

It may all be for nought.

I fitted the polystyrene sheet and must have a) knocked the Y end stop out of whack in the process.
Not noticing this, I then proceeded to b) level the bed at each corner and noticed that the bed was not square and stupidly adjusted one of the Y travel rod pairs (not both at the same time).

Do you see where this is going?

One of my mates has my multi meter at the moment so figuring I should be right to go with some PLA as I had no problems with those temps and will check the pwr supply when it is returned and then sort out the heater bed....

I moved the tip to about the middle of the bed, extruded some pla to get some measurements, made some changes to the firmware to adjust the extruder steps, hit the home button and welcome to hell.

The printer bed attempted to be a 4 wheel drive, missing the Y stop and tried to climb out of the printer frame.

As I had not moved my Y axis rods / runners (both sides) equally to align them to the bed / frame properly, when the bed assembly hit the first speed hump, It managed to break 2 of the 3 Y axis bearing carriages.

So how was your day?

On the upside, I did manage to send out a few switchboards this afternoon,
I also managed to dodgy up the broken brackets a tad and did get bits and pieces of some brackets to print / stick to the bed just to see how bad the damage
was.

It's bad, however, still a small victory / milestone of sorts.

My next plan is to order some more pla, try and hot glue / weld (with the assistance of a soldering iron and staples) the broken brackets, see if I can get the STL files for the brackets, draw and try to print them, or buy another set, I will reassess on the morrow.

Another day, another challenge...

cheers
Daggs

Greetings,

Please find attached stl as discussed, I'm not quite sure why 1 of the 3 brackets looks to me to be below the base line....
cheers
Daggs

Is it just me or do you get "bad gateway" messages when contacting this forum as well?, I have had issues on & off since about 4:30 AM this morning....

Hello Daggs,

I've completed the bushings last night:

[www.dropbox.com]

PM me your postal address and I can send it today,

I also had bad gateway messages too recently!

Regards,
DennyP

Hello Daggs,

I've done a search on Thingiverse and found this popular retrofit adjustable z-endstop for Prusa i3:
[www.thingiverse.com]

Worth taking a look

It looks almost perfect.

I can see how it would work but wonder if it may be better with a 3mm internal thread for the adjusting screw with a lcking nut.

Before my little 4WD adventure, I did notice there is a certain level of mechanical hysteresis involved with the limit switches / end stop travel. I don't think I can change it but will need to work out how it effects things.

I do have some more questions and will put them to the forum later today.

Cheers
Daggs

There are probably ones out there using a 3mm thread.

You could use a compression spring + washers to stabilise the M3 screw with a washer and a M3 nut or better, a locknut to hold it onto the
printed part like shown here:
[www.thingiverse.com]

Another idea is to actually cut a hole in the stl between the screwhole in the part and slide an M3 nut that's secure in the part itself to act as a lock.
Threadlocker will also help.

Haven't experenced mechanical hystersis, from googling though it seems that if you have those endstops with the metal tab, you should
remove it as that would be a contribution to it.
Other alternatives it seems is to get a different brand of mech endstop, put a filter, or go to optical or hall effect sensors.

mmm
Interesting comments,
I like the way you think.

I prefer option 2 at the moment as I tend to try and use bits that I have and in this case it will be an M4 screw and a M4 nylock nut in the middle.

RE the STL files, their weird, I opened up the file that I sent you and it defaulted to Autodesk Meshmiker and it showed one of the bushings underneath the X plane which I could not quite understand (and still don't), Mesh Mixer appeared to be an essential component after I installed Autocad 123D Design which is new to me. When I opened it this morning in 123D, all where on the same plane but one of them was on the negative X axis so I guess that it explains the inversion.

I also opened the file in pronterface it appeared to be normal as it centred the actual parts (to print) and slic3r did not seem to have an issue with it....

Whilst in 123D with the same file, I could not separate the 3 bushings to delete one if required, the other thing I find strange is it does not seem to have the ability to copy & paste individual parts (I am guessing that I can save the file and them import the saved copy to produce a duplicate in the same workspace but I have not tried that yet.

I am quite comfortable using autocad 2005 (I think I have 2006 somewhere, tried it and didn't like the interface) and it is great for 2D drawings which is what i have in the past primarily used it for. (I started with V10 which needed a dongle connected to the parallel port for it to work).

I digress, moving on, woking with the STL file seems to be a tad harder than working with an original file (it may be that I still not used to working with these files yet, time will tell).

RE: mechanical hysteresis, I did not think that such a term existed, I am an electrician by trade and relate hysteresis most commonly to thermostats which (as you probably know) switch on at one point and off at another point even though the setting remains the same.., which is exactly the same result I get using the
metal endstops as you mentioned below.

gotta love a challenge (until you hate it)

Regards

Daggs

Hello again Daggs,

Great minds think alike!

That's strange, about how all the different software deals with the same .stl, but nothing suprising. I think with open source software, esp two different brands doing the same thing, will do things differently
as there isn't really a set standard to do things out there in my opinion. We've both experenced that!

I had the same experence with slic3r as you with the 3 bushings; they were all dead flat on the base frame, and you can easily select one, delete the rest, rotate, multiply, etc.

My preference software for editing Reprap .stls is Tinkercad, I find it easy to cut holes with that software if you need to modify the .stl.
I don't particulary like 123D.

Worth a try, alternatively I can do it for you.