RazzMaTAZZ - my KITTAZ Build

A forum dedicated to those intrepid few, that have built their own TAZ 3D printers using our KITTAZ.
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mhackney
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Re: RazzMaTAZZ - my KITTAZ Build

Post by mhackney » Thu Nov 05, 2015 10:45 am

I'm getting up to speed on the nuances of Repetier for cartesian printers with mixing extruders and bed leveling! So much for methodically working on 1 thing at a time.

Firstly, bed leveling...

In Repetier the G32 S0 leveling command saves the transformation matrix to EEPROM and enables auto leveling. After running it you do not need to run it again before each print (unless your printer is really rickety!).

To set it up I first heat the bed and nozzle and then home with G28. One thing I don't get and want to figure out is G28 leaves the nozzle touching the bed (Z=0). With a PEI or other plastic surface, that could leave a small melt divot. I want to raise the head 5-10 mm after homing. Ideally this would be a firmware config but I can't find it. It is easy enough to insert a G0 Z10 into the gcode header in the slicer but that will not work when issuing G28 from the command line or the LCD display. I have to be quick and raise Z in those cases.

Once I've homed (and raised Z off the bed) I run a G32 S0 to probe, calculate the transformation matrix and store it to EEPROM (which you must have enabled in firmware). After that, a simple G28 home in my gcode sets Z=0 and the print starts. It's interesting to watch the Z axis move up and down ever so slightly to "level" the bed. The first layer goes on nice and even in thickness.

One nice thing about the FSRs and probing is since I have a sensor in the front 2 corners of the bed I can probe those 2 spots and adjust one of the Z screws to get the <-X-> movement parallel to the bed. It takes a few seconds and should only need to be done once. This cuts down the amount of Z movement needed during auto level. Now seeing how easy doing a manual leveling is with the FSRs, I think an adjustable rear (center back edge) FSR holder would allow leveling manually in Y too. Then the auto level would be the "last mile" and tweak out any minor issues due to environmental changes in the machine.

Dual mixing extrusion

The E3D Cyclops is a mixing extruder - it has 2 filament feeds in and 1 nozzle. Repetier has explicit support for it. By default, no matter how you setup your gcode, the firmware advances both extruders together so you get a 50-50 mix of color. Interesting! There is a table in EEPROM that defines 16 virtual extruders. Each virtual extruder is configured to be a mix of the physical extruders and are give tool numbers like T0, T1, etc that slicers understand how to use. By default, all of these are set up to give a 50-50 mix. To create T0 that has 100% from extruder 0 and 0% from extruder 1, you simply use M163 to set the % and M164 to store the weights to a specific virtual extruder. It sounds complicated but it's actually an elegant solution during the dark days of insufficient slicer support.

I still have work to do to really calibrate the extruders, get perfect first layers (they are perfect from a thickness perspective but they show signs of nozzle drag that can be fixed with polishing as per my guides in my signature), calibrate temperature and all the normal commissioning stuff needed to really fine tune a printer.
Sublime Layers - my blog on Musings and Experiments in 3D Printing Technology and Art

Start here:
A Strategy for Obtaining Great Prints

Strategies for Resolving Print Artifacts

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nbmoretto
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Re: RazzMaTAZZ - my KITTAZ Build

Post by nbmoretto » Sun Nov 15, 2015 11:14 am

So I installed the hardened steel rods along with the linear ball bearings and dampeners. The machine is SOOOOOOOO quite compared to before. You can see my machine in the image below. Also you will notice the thin bed fingers I made out of aluminum
123.jpg

nbmoretto
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Re: RazzMaTAZZ - my KITTAZ Build

Post by nbmoretto » Mon Nov 16, 2015 12:45 pm

I was talking to someone I work with about my recent upgrade to linear ball bearings and he asked why didn't I just use an oil impregnated bronze bushing. He stated that at slower speed they should be more accurate along with making less noise. What is your take on this?

This is one that I found:
http://www.bronzebushings.com/am-1015-2 ... m-oal.html

Also did a search on thingiverse:
http://www.thingiverse.com/thing:526660

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mirage335
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Re: RazzMaTAZZ - my KITTAZ Build

Post by mirage335 » Mon Nov 16, 2015 12:57 pm

If the ID of the bushing is even slightly greater than the OD of the smooth rod, the clearance will allow some motion. Whereas bearings can be preloaded. Also, metal on metal may wear faster - always consider applying high-quality grease with any linear bearing system (eg. PTFE SuperLube).

Also, the thingiverse page specifically mentions "you may have to ream out diameter with 5/16" drill bit to fit rods". So, getting good results may require carefully machining these to closely match your smooth rods.

nbmoretto
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Re: RazzMaTAZZ - my KITTAZ Build

Post by nbmoretto » Mon Nov 16, 2015 1:44 pm

mirage335 wrote:If the ID of the bushing is even slightly greater than the OD of the smooth rod, the clearance will allow some motion. Whereas bearings can be preloaded. Also, metal on metal may wear faster - always consider applying high-quality grease with any linear bearing system (eg. PTFE SuperLube).

Also, the thingiverse page specifically mentions "you may have to ream out diameter with 5/16" drill bit to fit rods". So, getting good results may require carefully machining these to closely match your smooth rods.
I currently use 3-in-1 oil for my linear bearing system: http://www.3inone.com/products/multi-purpose/

Do you think that is fine or should I use PTFE SuperLube?

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mirage335
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Re: RazzMaTAZZ - my KITTAZ Build

Post by mirage335 » Mon Nov 16, 2015 2:13 pm

In my experience, oils are not thick or persistent enough to prevent wear. SuperLube PTFE grease is great because it is thick enough to persist, yet sufficiently low-friction to use with ball-bearings.

That said, either may work, and I haven't studied the options scientifically. As particularly extreme examples though, I have managed to get the SuperLube PTFE grease embedded in circular ball bearings used on a tractor mowing mowing deck, as well as LM8UU linear bearings on HacDC's Prusa Mendel. In both cases, friction went down by an order of magnitude or two.

For the tractor bearings, this was done after catastrophic failure of two bearings, since which, no failures have occurred. The remaining bearings ceased to sound gritty when spun, and could spin freely for tens of seconds. Checking these bearings after several weeks of use, showed they were still slick. Other lubricants would not last. Obviously, this is a high power application, far beyond 3D printing requirements.

For the Prusa Mendel, the LM8UU's and smooth rods were reaching unacceptable clearances in ~6 months. After applying the grease, this wear ceased to be noticable for another 1.5 years.

Personally, I think just grease is cheap and quick to apply, bearings are expensive and time consuming to replace. Also, I've found this grease useful and trustworthy for a wide range of applications, including corrosion prevention.

nbmoretto
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Re: RazzMaTAZZ - my KITTAZ Build

Post by nbmoretto » Mon Nov 16, 2015 8:08 pm

mirage335 wrote:In my experience, oils are not thick or persistent enough to prevent wear. SuperLube PTFE grease is great because it is thick enough to persist, yet sufficiently low-friction to use with ball-bearings.

That said, either may work, and I haven't studied the options scientifically. As particularly extreme examples though, I have managed to get the SuperLube PTFE grease embedded in circular ball bearings used on a tractor mowing mowing deck, as well as LM8UU linear bearings on HacDC's Prusa Mendel. In both cases, friction went down by an order of magnitude or two.

For the tractor bearings, this was done after catastrophic failure of two bearings, since which, no failures have occurred. The remaining bearings ceased to sound gritty when spun, and could spin freely for tens of seconds. Checking these bearings after several weeks of use, showed they were still slick. Other lubricants would not last. Obviously, this is a high power application, far beyond 3D printing requirements.

For the Prusa Mendel, the LM8UU's and smooth rods were reaching unacceptable clearances in ~6 months. After applying the grease, this wear ceased to be noticable for another 1.5 years.

Personally, I think just grease is cheap and quick to apply, bearings are expensive and time consuming to replace. Also, I've found this grease useful and trustworthy for a wide range of applications, including corrosion prevention.

Thanks for the info. I might give it a try, any tips for applying it?

Kevinhipfner
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Re: RazzMaTAZZ - my KITTAZ Build

Post by Kevinhipfner » Mon Feb 22, 2016 1:21 pm

I would love to get my hands on a Kittaz ! They said they are not available anymore

Kevinhipfner
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Re: RazzMaTAZZ - my KITTAZ Build

Post by Kevinhipfner » Thu Mar 03, 2016 12:11 pm

Where can I buy a Kittaz please ?

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piercet
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Re: RazzMaTAZZ - my KITTAZ Build

Post by piercet » Thu Mar 03, 2016 2:44 pm

Kevinhipfner wrote:Where can I buy a Kittaz please ?
You can't anymore, there are no additional kits being sold. Your closest and least expensive alternative will be to buy a used Taz 3 and upgrade it to 5 spec by using parts at http://i-t-w.com/parts/

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