Thursday, 1 December 2016

CoreXY Build - update 11

Spent a few hours getting things ready for final wire up. I got some cable management and put it on the cables that I was happy I knew where they were being routed. If you enlarge the picture by clicking on it you can clearly see the drylin bearings I'm trying on the X carriage.

A short pice of filament to test the drive gears location etc. Anyone know if you can print tpu (Flexible filament) etc with a bowden setup?

I'll need some cable ties to hold everything to the frame later.

Started to test out tentative places to locate the LCD.
I understand Tech2c didn't have one, but I run my printers from octoprint and don't like to tether my laptop or hump it around from place to place. So having the convenience to do things on and to the printer without a laptop or even octoprint is indispensable to me.

I'm thinking of adapting the ramps holder to accomodate the raspberry pi that runs octopi so it can be mounted on top or near the ramps...................but I've backed the Re-ARM for RAMPS, simple 32-bit upgrade which has ethernet access and I'm not sure what kind of impact that will have on using octopi if the printer can be directly hooked up to my network It may mean I can just run everything from Simplify3d or any one of the other slicers out there.

I got some cork flooring tiles to insulate the bed

I used some small squares cut from offcuts of the 3M heat resistant double sided sheets I use to stick the PEI to the aluminium hot plate.

Click any picture to enlarge

Wednesday, 30 November 2016

CoreXY Build - update 10

I posted some of this on 3d printing Australia's Face book page but will include it here for posterity :-)

Another "Give yourself an uppercut" day lol spent the morning wiring up the proximity switch. Attached it to the ramps and soldered in some pins for power that weren't on my models board but had the attachment points to do so.....................nothing! Checked everything a dozen times, still nothing.
A frustrating hour later I'm going into kitchen to make coffee and I walk past my power supply!!!! just sitting where I'd left it.... hahahahahhaha needs power you idiot!! attached power supply and hey presto little light on the proximity switch comes on when a metal object is brought near.
I really need to lower the dose hahahaa reads 3.47v if I'm doing the test right. Good enough lol

What threw me was having the board plugged into the computer and the screen lit up, made me completely forget I wasn't providing power to the board where it was needed. So engrossed in getting the wiring correct and as a novice electronic guy distracted my thinking completely. Trying not to kill myself with 240v and not producing the "Magic smoke" on the board. 

Today the stepper motors arrived and I have been fitting them along with a few other bits and pieces.

It really is a rats nest of wires ;-)

It's Thursday the 1st of December and I'll be slowly get the printer ready to run over the next few days. The littlest of things need doing, like lining up the drive gear on the extruder so it meshes with the filament. I also need to reduce the length of the bowden tube as it seems way too long.

Friday, 25 November 2016

What paints stick to petg and the Cross Hatch Tape Test

Well first things first. The materials I will be using will be listed and the results that I get, will reflect them, not the materials you might be able to get, so do the same types of tests as this on your own substrates first, with the paints you can get.

I'm also not going to try other types of paint as I'm looking for a one product suits all approach so I don't have to stock multiple versions for different plastics and I know this type of paint works on pla already..........

Blueprinted White Petg

Plastic Primer Filler

This can claims to be specifically for plastics like bumper bars etc and the cynic in me, thinks that its probably just good old grey auto primer...........maybe with some additive to help with plastic bonding. Its good stuff though none the less and just to be safe worth getting something like this. I would be willing to bet that normal ordinary grey primer would work just as well though.

The reason I think this, is because I believe it is the solvents that help adhere to the substrates using chemical bonds and not just mechanical bonds. I could be wrong, it has happened before and I'd happy to concede given scientific rigour slightly better than my own mythbusters like methodology

Spray Putty Primer
This is a grey primer that is probably just has more pigment filler in it for it to be called Spray Putty. Again good stuff but with no claims of plastics adhesion.

Cross Hatch Tape Test
This is a link to a search engine result for this test. I first heard about it sometime in the early 80's from someone from the Australian National University and have used it thoughout my career to test different coatings on different substrates.

Basically you just score the coated surface after allowing the coating to cure/dry for the recommended time, you use some sticky tape rubbed onto the cuts and ripped off to see how well the coating sticks.

To have consistant results in all your tests you should use the same tape/products on all your tests.

So result No1 using the first can of spray meant for palstics.

edit: Absolutly no surface preperation was used prior to painting. No sanding, no wiping with solvents and no wiping to remove dust with a tack cloth...................What can I say, I'm both lazy and curious :-)

Click for a bigger version

So good! It has stuck like a champion and trying to scratch it off after the tape failed to damage it. was a big tick for its adhesion to petg.

If you look closely at the photo you can see a smear in the middle of the cross hatches on the right hand side of the test piece where I tried my thumb nail to try and remove the paint.

I have another piece sprayed up with the other can of spray putty and will post its results in 48 hrs.


The second piece which was once a part of the first piece that I'd cut in half was sprayed and left to dry for 48 hours.

I cut a cross hatches into the piece and tried the adhesive tape to see if anything would be removed and nothing was. I then tried my thumb nail and finally managed to remove some paint and plastic with the exacto knife. The fact that to remove paint I had to remove plastic as well bodes well for this type of paint.

I'd like to try some ordinary grey acrylic laquer primer in the future but my cynicism and belief that these are just essentually the same products with different labels for marketing still holds sway in my mind...... my wallet is also a contributing factor but should I find myself in the position to try it I'll post the results here :-D
Naturally I'd be happy to be proven wrong, but I've been in advertising for so long now, everything looks like a marketing maneuver to me lol

So my belief is that any automotive grey primer will adhere to petg really well and I'd be willing to bet that the Arcylic Lacquer topcoat would stick as well even without the undercoat. I'm not recommending you go without a good primer that will help fill gaps etc I'm just saying you probably could, in a pinch.

I need to stress that I only tested one brand of petg and will test others if and when they become available.

I will test different base colours of petg as well just to be thorough.

Thursday, 24 November 2016

White as a filament!?

White filament has been a horrible colour for me to print regardless of the type of plastic.
It hasnt mattered if its abs, pla or petg the results I've been getting are "fugly" at best.

I've heard that the titanium oxide pigment is the problem as it requires more pressure and or heat to force it though the hot end, but it is more than this for me.

I temperature test all my filament even if I order two rolls of the same colour, I will still do the same set of tests.

I've been a convert to petg since I first heard about it in this video Published on 19 Sep 2015 so its been my go to filament for a lot of applications. This video, was the one I shared with a lot of popular and or famous YouTubers.

None of them credited back to me for sharing I might add, Bastards! lol

When I first started 3d printing it was with abs and with an open framed i3 clone, with which I had some good luck printing with, until I tried............white!

I've then tried pla white and it was a little better but still suffered from a form of banding that had me questioning everything, except the very thing I should have been looking at, the filament itself!

This is white pla in the picture below, (edit: Sorry, I think, it could be abs), and you can see where I've dirtied it up for photography, the terrible banding that I was blaming on lead screws and temperature fluctuations, I've redone the pid settings so many times to be sure. I printed this about a year ago.

This partly printed box modeled "procrasination pig" had some serious problems with temperature and cooling issues in petg.

Pitting and layer missalignment prevalent everywhere.

Sorry phone wouldn't focus but just more layer misalignment and pitting.

You can see more examples in this blog post I did a while ago 
The same exact file was printed with the same settings in both GITD Blue and white.

I guess the reason for this blog post, is as a warning on printing with white for those new to 3d printing.

I realise I could probably, and I stress probably, improve my white prints a little more, with a lot more testing, but if I used a blue or green from the same suppliers I get fantastic results (For my i3 of course, it has its limitations) and don't need to spend so much time on testing that I could spend on printing instead. I love Blueprinted and The3dprinters and 3dfillies blue petg.

These great results don't require me to do much more than one test to find its preferred temperature and that's real point of this post.

"How much effort should you need to put into a filament to get a decent print that you'd gladly be seen out in public with?"

So, as much as this pisses me off, I'm no longer going bother to use white anymore. I'm going to spend that time and effort in painting instead, to the white colour I want. NB there might be exceptions lol

I've already sprayed a piece of white petg with some automotive grey primer and will be doing a cross hatch tape test on it soon. My version is just with an exacto knife and whatever tape I have on hand :-)

For comparrison here is a temp tower in blue petg.

Like a boss!

So Smooth

Here is some pla I printed not long ago and it was ok and without much of the banding I was getting so my rant really should convey the difference between the abs petg and pla I've been getting.

Some pitting was showing up and something that could be tested for and probably removed but really don't like the idea of farting around trying to get something to work when another colour would "just work."

Saturday, 12 November 2016

Remaining Filament Calculator

Remaining Filament Calculator


Have you ever run out of filament during a print? This calculator will estimate the length of the remaining filament, based on 3 measurements of your spool.
Works for 1.75mm and 3mm filaments. All measurements are in mm. The resulting length is in m.
D - The outer diameter of remaining filament
d - The diameter of inner coil
W - Inner width of spool

Wednesday, 9 November 2016

CoreXY Build - update 9

I added the other belt after having to reprint the carriage because I broke it trying to cram some m3 nuts into their slots that were a little too small :-)

I added the proximity do-hicky as well and apart from the fan I now have everything attached to the carriage. I'll need to trim the belts but will wait until the end to do it.

I'm still waiting on stepper motors and the ramps board, pei sheet and will have to order the power supply next friday, so things are still a ways off being ready for printing.

As the Hypercube "BOM" on thingiverse said, order the short v6, it turned out to be the wrong one and it has since changed to the correct, long one, so I'm also waiting on the new one to arrive.

I printed the Ramps holder and it seemed to print with some issues on the bottom of the tabs where they didnt print properly. I've been noticing a lot of small issues like this with the latest update to S3D recently!? ok edit: it seems I should have looked at the file in S3D a bit closer it was designed that way so I take it back :-)

I'm posting a lot of these pictures so if you are also making this and find your way here then you'll have a series of reference photos you can use if you, like me, get stuck sometimes wondering which is the best orientation for a part. I'm not saying this is the best way to do it, just consider it a starting point.

Monday, 7 November 2016

CoreXY Build - update 8

Some small progress on the printer, I got one of the belts on the printer temporarily, to make sure things lined up and I'm happy to say the top belt does at least.

I also fitted the spool holder with some 8mm threaded rod and my over designed spool holder which screws together and spins on a couple of bearings.

Maybe red isnt the colour for this but it wasnt made for this printer and it will do until my ocd can't take it any more lol.

Made this spool holder in Fusion 360 for some fun and I got carried away and took it all too seriously. Also the reason I went into our local Hardware store Bunnings for some 8mm wing nuts.

Some Led self adhesive lighting strips now fitted. It costs way too much, but getting some cheap ones from China would have taken too long and I need lighting to see what I'm doing while building the printer and I will need it later so I bit the bullet while at Bunnings buying some wing nuts.

Saturday, 5 November 2016

CoreXY Build - update 7

I redesigned the end of the bed support at the front as the original one had only one bolt hole.
I also had to shorten the Z axis bearing / bed frame holder by 25.4 mm as the bed plate holder at the rear had no where to bolt on to.
STL for the front of the bed.
STL for the rear Z Axis

The photo wouldnt focus but I'm trying to show the new M3 pan head bolts stting lower than the stupid ones I ordered, some allan keyed ones that sit way too high above the build plate.
I wanted some counter sunk ones but when conglomerates that run shopping centres buy up hardware stores you end up with huge stores that no longer sell hardware like they used to, and you no longer get much of a choice. 

And then they all whine that we are spending all our money overseas, via the internet!

Final build size is 220 mm x 220 mm x 230 mm the same as my i3. 
Which is 8.6 inches x 8.6 inches x 9.05 inches
I was hoping the Z axis was going to be a bit bigger but in reality I've only ever got close to using the full Z height a couple of times...........and all I have to do is to buy longer 2020 to make it larger, so not really a problem.

The lengths of 2020 that were cut for this build were:-

Z Axis = 4 x 500 mm
X Axis = 4 x 380 mm
Y Axis = 4 x 320 mm

Were I to rebuild or buy some more 2020 in the future, I'd add 10 or 20 mm to the Y Axis, so it was 330/340 mm for some additional clearance from the Z axis holders at the rear as well as some peace of mind. In hindsight I would consider adding another 10/20mm to the X as well. 

Suggestions in the comments if you know.
I need to find out about how to set it up so it knows home will be a set distance away from the bed, so to be clear, when the extruder is at its home position it will be about 25mm away from the bed in X. Where do I enter this information in firmware so it knows this?

The X Axis gives me room at "home position" so the hot end sits off the bed at rest and allows room to clear the nozzle.

I havent yet fitted the end stops so I'm still not certain of anything until that is done.

edit: The end stops showed up today and for reasons not yet clear 9 of them showed up lol Bangood said they were out of stock on some items so I cancelled that order and ordered some more, then they turned around and said they were ready to send the same items a few days later, so who knows what going on with them.

I could have assembled the printer in the lounge room on my little coffee table or on my kitchen table but both are covered in stuff that I didnt want to move just yet ;-D