Questions by Delta newbie

Hi All,

I am waiting for my new Rostock Delta mini pro kit and to replace my Orca (that crashed the main board recently) in mean time I have some questions.

1) Who sells the circular blue tape build surface ?

2) What should be Repetier home positioning coordinates ? Does it home in the middle ? Seems logical to me ?
However, the config by the supplier says that after the print, the head should move to x0, y0, z0

I think this will crash the head in the object isn't that so ?

3) Has anybody upgraded such a printer to obtain a heated bed ? If so, by which parts ?

Thanks Thomas
www.3Daybreaker.blogspot.com

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

On that kit, swap in smaller belt pulleys for almost double the resolution, most people use 20t, those are 36t. I would also put the extruder up on top for a more direct bowden run. The longer and more bends in your bowden the more pressure it takes to push filament.

If you do add a heated bed, be absolutely sure to insulate it from the frame as the heat might cause the acrylic to craze and yellow sooner than normal. It will no matter what, it's just a matter of time.

As for the questions:
1. It's just blue painters tape on glass. Try both, but I would recommend getting an Elmer's Glue stick instead. Painters tape works well, sometimes too well, and it takes more effort than a glue stick, particularly if you want it to look like that all the time. Glue stick, you just rub it on the glass if it needs more, wait a few minutes to dry, and start printing. Cleans off with water. but usually you can just re-smear it with a damp towel. Blue tape, you put it on carefully, then end up tearing it off after a few prints, if you are lucky. I usually had to do it after almost every print.

2. Home on a delta is at the top center of the build volume, so 0,0,X, where X is your max height.
Z0 is actually .1mm above the glass, and yes, you WILL crash the head at some point. Not just once, but repeatedly, that's life with a delta. Usually it results in no serious damage, other than your ego.

3. There are plenty of deltas with heated beds, my Rostock had one, and my Mini Griffin has had one at times.
Check the Griffin website, particularly "Sizing your Griffin", we have links to manufacturers for Borosilicate glass (including Borosilicate) and heaters for almost every delta size.

Griffin 3d is also selling Gorilla Glass beds for 170mm (which the mini uses) and 300mm. Borosilicate is not only not as strong, it has been found to chip and flake as you use it. I've personally pulled up chunks of glass from it and I understand SeeMeCNC is seeing problems with it as well.


Full disclosure, I'm co-owner of Griffin3d.

Edited 2 time(s). Last edit at 08/10/2014 01:32AM by sheepdog43.

Hi, Thanks for this detailed response.

Maybe you have another kit in mind, but mine comes already with 36 teeth pulleys, as far as documentation states. (Or did I misunderstood the point ?)
(I ordered at 3dprinterczar)

I will have a close look at your site from now :-)


Thomas

Edited 1 time(s). Last edit at 08/10/2014 03:27AM by Replace.

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

I'm saying to replace the 36t pulleys it comes with, with 20t pulleys for better detail.

Ahh,

sorry for my mistake. I am not a native english ....... I WILL investigate this option.

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

I did find some 20T pulley sellers, so that is not the problem.


Can you point me in the right direction which firmware parameter has to be changed to reflect these smaller diameters ?

speaking of that, If I consider that the Gcode will ask revs to move x-mm, how do details improve by this upgrade ? It just has to make more rev for the same distance does it not ?

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

today I did order the 20T pulleys. I think the estimated arrival will be approx that of the Rostock, so I can start building it with the new teeth.

But please advice on firmware changes for the teeth number ?

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

I was confused at first about the pulleys too, you would think 36T is better than 20T. Was wondering how that improves the "resolution" though and if the belts would need to be changed also or if they could be reused.

Thanks for the tip on the heated bed burning the acrylic. I have been toying with the idea of a heated bed and never considered that.

When you say that the nozzle is actually 0.1mm above the bed surface, you are referring to the paper gap set when calibrating? Does it matter if the hotend is heated or not?

And I am also going to take a quick look at your site, thanks for the help.

[calculator.josefprusa.cz]

Use the first calculator on the page. 36T with "normal" motors and belts gives 44.44 steps/mm, which is an unusual number (to my mind), so I'd double check the belts and motors to make sure of their specs.

Typically for 200 steps/mm motors @ 1/16th microstep and a 2mm pitch GT2 belt, it's going to be 80 steps/mm for a 20T pulley, and 100 steps/mm for a 16T pulley.

As Grat said, In the configuration.h, you need to change steps per mm from 44(?) to 80 steps per mm.
The more steps per mm, the higher your print resolution.

Quote
Kurzaa
I was confused at first about the pulleys too, you would think 36T is better than 20T. Was wondering how that improves the "resolution" though and if the belts would need to be changed also or if they could be reused.

When you say that the nozzle is actually 0.1mm above the bed surface, you are referring to the paper gap set when calibrating? Does it matter if the hotend is heated or not?

36t will give you speed, not precision. A 20t is more than fast enough, but adds precision.
Belts will need to be shortened a tad (a few mm probably), but can be re-used, that's not a problem.

Yes, that is the paper gap. And while it should be done hot, it's not a huge deal. You do want the bed heated though. I recommend a sample print to do final calibration on head height regardless of how well you think you did the paper gap. Different surfaces often need more or less pressure and heat to stick.


You're welcome, and good luck guys.