Wally's Electronics

Re: Wally's Electronics

Postby Nicholas Seward » Fri Dec 20, 2013 4:52 am

I use an Azteeg X1 with Repetier firmware. (Any firmware will do.)

Set the xy steps/mm in such a way that the firmware thinks one rotation is 400mm.


For Wally the angle is important not any lengths. Therefore I had to pick what virtual distance would represent 1 rotation. I thought about 360mm as the virtual distance so that 1mm is really 1 degree. I opted for 400mm instead for the distance so that it would divide evenly into 6400 or 3200 or however many steps/rotation your setup has. There is one added benefit of using 400. In this case every 1 virtual mm is really a gradian. (Really. Why do we use degrees?)

I am guess you are using 1.8 degree steppers with 1/16 microstepper setup. In that case set your x and y steps/unit or steps/mm to 8. 8 steps/gradian.

The z is going to be weird but for now just get an approximate setting. Move it from the bottom to the top while you record how far the computer thinks you actually went. Use the virtual distance and the measured distance to adjust the steps/mm to make the two values match when you repeat this process. (Again, this is going to have to get more complicated to account for the triangulation errors but for now this is good enough to get some prints and verify your setup. Working on a better preprocessor. One that is hobbled together in a hotel room.)
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Re: Wally's Electronics

Postby Cozmicray » Sat Dec 21, 2013 7:02 pm

It moves!!!

Got my Wally moving - still waiting for hotend to arrive
Airtripper extruder which seems really great.

Marlin
Repetier-Host
Mac (still can't get it to run on PC Win XP 64)

Settings X Y Z E 8.8, 8.8, 166, 100

Seems to react OK (bed falls -stepper no longer holds - after 30 sec)
That maybe these crappy electronics?

Can you give me repetier settings?
Where is HOME?
How is home set without endstop switches

So I load stl into Python program
G-code output --- load to repetier-host
and it should work?

Thanks

One of these days I'll hack out of jungle and say "Dr Wally I presume?"

:o
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Re: Wally's Electronics

Postby Nicholas Seward » Sun Dec 22, 2013 12:13 am

Why 8.8 instead of 8? Also you Z looks about twice as big as I would expect. (Check this calibration. To calibrate move the bed up 150mm (d) and then see what virtual distance (D) was. Multiply your step/mm by D/d. Repeat to verify. Also do this with your filament.)

There is a setting in firmware that will keep the steppers from turning off in 30 seconds. You can extend the time or turn it off. At least in Repetier firmware you can.

Zero is when the bed is at the bottom but the string is still in tension and the arms are touching their pulley stops. Make sure that positive not negative moves will move you away from the stops for all 3 axes. You can flip directions in firmware.

Assuming you have done all the above you are now ready to see what z height lets a piece of paper barely slip between the nozzle and the bed at both the front and the back of the bed. Put these values into the python program. You also need to measure the z height where the arms are at 90 degrees. Change the values below in the program.

Code: Select all
front_z=152.0
back_z=151.5
square_z=75
...
mechanical_advantage=9.5


The mechanical advantage is approximately (big_pulley_diameter+string_diameter)/(small_pulley_diameter+string_diameter).

Assume you have done all the above. No you can use slic3r or CURA to make some gcode for your setup with 0,0 in the middle of the print. You can then take that gcode and pipe it through the python program. You can then run the outputted gcode. If you are using something like Repetier as your host software then put it in dry run mode so you can just see if you are close before you commit filament.

Good luck.

Notes: The z is not correctly handled in the python program. There needs to be a better mechanical advantage calibration routine. The speed scaling from the python program is way off.
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Re: Wally's Electronics

Postby Cozmicray » Sun Dec 22, 2013 1:25 am

You gave me 8.8
"In that case set your x and y steps/unit or steps/mm to 8. 8 steps/gradian."

"Zero is when the bed is at the bottom but the string is still in tension and the arms are touching their pulley stops"

What are pulley stops?

Big pulleys locked to forearms by bolts with stops against arms
( well what I think are stops?)
Z axis Pulley stop, where is it?

What is "code" for? What software does it get inserted in to?

Hope the Beta builders have a better plan?

Anybody else out there got a Wally built and workin?


:?:
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Re: Wally's Electronics

Postby Nicholas Seward » Sun Dec 22, 2013 1:34 am

Whoops.

"In that case set your x and y steps/unit or steps/mm to 8[period] (for clarification) 8 steps/gradian."

That is confusing. 8 steps/gradian is what you need.

The big pulleys should have a raised portion that will stop the arms at 180 degrees.

The Z is zeroed when the bed is as low as it can go. No need for a pulley stop.

The code is a snippet from the preprocessor. I just wanted to show you the variables you need to adjust.

Hope the Beta builders have a better plan?


What are you referring too? There is quite a bit that needs improvement.
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Re: Wally's Electronics

Postby Cozmicray » Sun Dec 22, 2013 2:32 am

"Hope the Beta builders have a better plan?
What are you referring too? There is quite a bit that needs improvement.
Nicholas Seward"


Well this build is not intuitive.
I have built just about everything from log cabin to micro machine.
This is my first 3D printer build without hint of assembly drawing, wiki or anything.
Many a time --- wanted to put it out in dumpster

I hope to help out with instructions and build.
Hate asking you a million questions.

Hope Beta builders are Master tinkerers!
and have wiki, instructions, assembly drawing

I realize you are a designer and LISA is your project now.

But don't become like Trinitylabs (aluminatus A1)

Hope someone will write a firmware module for Marlin / Repetier-host to handle Wally

:?:
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Re: Wally's Electronics

Postby Nicholas Seward » Sun Dec 22, 2013 2:44 am

No. LISA isn't my focus. The order of importance is wife, job, GUS/WALLY, etc.

Assembly instructions are in the works. Don't feel bad about the questions. I am glad to answer and help. Especially since I haven't documented everything to a point it is intuitive.

Remember that Wally was only born a few months ago.
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Re: Wally's Electronics

Postby see3d » Sun Dec 22, 2013 2:51 am

Cozmicray wrote:
Well this build is not intuitive.
I have built just about everything from log cabin to micro machine.
This is my first 3D printer build without hint of assembly drawing, wiki or anything.
Many a time --- wanted to put it out in dumpster
I hope to help out with instructions and build.
Hate asking you a million questions.
Hope Beta builders are Master tinkerers!
and have wiki, instructions, assembly drawing
I realize you are a designer and LISA is your project now.
But don't become like Trinitylabs (aluminatus A1)
Hope someone will write a firmware module for Marlin / Repetier-host to handle Wally
:?:


Cozmicray - you are a pioneer in Wally. Wally was not ready for most beta builders yet, and you moved forward on your own version ahead of Nicholas' schedule to support the beta builds. You are doing more like alpha build and much on your own with changing things. You are being a big help by asking the right questions and showing how you are solving the problems you find.

Thank you and don't give up. Just realize you are ahead of the real beta builds and instructions.
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Re: Wally's Electronics

Postby Cozmicray » Sun Dec 22, 2013 3:06 am

Wally Beta was closed out in Sept before NYC maker fair.
Wally rolled out in Sept at NYC MF.

How long is normal for design to Beta

With the difficult build
and
difficult firmware and software

Will there be more that 20 Wally's?

It won't be my main 3D printer!

And when HP hits the market with 3D printer
SPLAT (are you bug or are you windshield)

:?:
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Re: Wally's Electronics

Postby Nicholas Seward » Sun Dec 22, 2013 4:01 am

I believe I have been very honest with the community about the state of affairs. This is not my day job and you are not paying me. I am working hard to answer any questions that you have (Have you ever gone more than 24 hours without a response to a question?) and to develop the documentation you desire. Why do I get the impression you feel entitled to more?

This is an experimental machine and by definition going to be a more difficult to build and operate than an established design.
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