ELS Control Panel Assembly and Wiring to the Launchpad

The wiring diagram is in the project WIKI



But for replacing the 5 pin header on the display board with an angled connector on the bottom side this part of the build was easy.  Drilled a 5/8 hole for the aircraft style connector GX16-8.   Viewed from the wire end the wires go ccw around the GX16-8. in the same order as the DuPont header starting with 5V. The heat shrink make me feel better about potential short.  Maybe I should have tangled the wires a bit to prevent cross talk.  They are short so maybe OK.

The order is

5V        RED
GND    BLACK
STB     BLUE
CLK    GREEN
DIO     YELLOW

This cable exits the bud box via the round connector.  The matting end of this connector is one end of the cable that ends up at the launchpad.    For now I am going to make that a single cable using cat5.    When the launchpad is mounted in a case I will break the cable with a 2nd 

The cat5 has 4 twisted pair.   
5V            BROWN                   
GND        BROWN/STRIPE     

STB         BLUE        

EARTH   BLUE/STRIPE
CLK        GREEN

EARTH   GREEN/STRIPE

DIO         ORANGE

EARTH   ORANGE/STRIPE

The 3 EARTHs are unconnected at the display end and tied to the chassis ground on the controller side.

The cat5 end of the cable prior to heat shrinking and all buttoned up. 

Two layers of heat shrink wrap were used over the wire bundle to get enough bulk for the strain relief clamp to grip.

The short Dupont to GX16-8 male is ready to go into the bud box.  The GX16-8 female needs to have a DuPont connect on the other end.  After a continuity test the display can be connected to the LaunchPad and tested.

I think there are 3 additional cables.

1. Launchpad to Motor Controller
2. Motor Controller to Motor
3. Launchpad to encoder.

The first is run entirely inside the electronics case.  There are screw terminals on the motor controller.  It connects to screw terminals on Jame's board.  It will get ferrules on both ends.  

The second has been supplied with the motor kit.

The encoder has a long pigtail   It connects to the launchpad with Dupont connectors.   Current plans are to used a 2nd GX16-8.   Maybe color code them and block of a different pin on each so they can not be interchanged.

SKR2 control board for 3D printer

Running Klipper on a Raspberry Pi 3 using a pre built 'ffluid' image.  

Klipper on the Pi talks to the corresponding klipper code on the controller at the port found by

ls /dev/serial/by-id/* 

which returned

root@fluiddpi:/home/howard# make flash FLASH_DEVICE=/dev/serial/by-id/usb-Klipper_stm32f429xx_2B004F001550305031353020-if00

The interface is at  http://fluiddpi.local so there is not need to log into the pi directly.

Jerry the cat has been been a pain.

Hung wet towels to increase the humidity and reduce static.  Pet the cat to see if its working sort of thing and it is.

Now have the Klipper on Pi talking to its firmware on the SKR2.  Complaining that the thermistors are not hooked up.   The Ramps 4.1 used Dupont connectors.  The SKR2 uses JST-XHP, I was thinking I had some but can't see them or see evidence that I ordered them on amazon.  Could have ordered them elsewhere.  Kit is inexpensive enough and will be here in 2 days.

Installed the drivers.

Removed all the wires from the Ramps 4.1 and unbundled them.   Hooked up the power supply and moved the jumper to switch from USB power to the connector aka supply.

This is where I ran into the connector problem.

Ordered new connectors only to find out I needed yet another crimper.  Today is the 6th and it should show in a day or two.   Have been working on ELS writing.

Although it will be nice to have the printer working dependably at this point it is a means to an end which is the ELS.

Crimper arrived.  To test my work I checked the resistance of the thermistors.

Bed 92K

Hot End 95K

First thing under control is the heat bed.  Not quite first chips but we are getting closer.

The following are hooked up.  DC power, thermistors, and end stops.   Getting the hang of the JST-XHP crimping.  Have wasted enough pins getting there.

Cats don't understand why I can't pet them as usual.  That is on demand.  Don't want to fry stuff.

Made a dumb ass newbie mistake and updated klipper.  It broke but have recovered.

Connected bed heater and verified endstops.  Has to change endstop pin definitions in printer.cfg

endstop_pin: !PC3 #^PC3

That was easy. They test OK now.

Started having trouble connecting to the SKR2.   Noticed the LED was dim.  Multimeter said the PSU was outputting 12V but when I swapped it for the bench supply it worked fine.  For a minute there it looked like the SRK2 was failing.  Intermittent problems with the PSU would explain a lot.

The supply does not have enough amps to run the printer but it has enough for testing.




This allows the extruder cooling fan to shut down at 50C

[heater_fan my_nozzle_fan]
pin: PB6
max_power: 1.0
heater: extruder
heater_temp: 50.0
fan_speed: 1.0

OK next day or so.

X and Y are working will wait to calibrate after I am printing.
Z and the extruder are not.
Klipper uses the distance traveled per turn instead of esteps.  
Z has a 5mm .8 screw.  
Setting the rotation_distance: to .8 causes the motor to buz and the CPU to crash.

March 14

It is now printing.   Printed a case that will work.  Plan to mount it and the PSU in original locations but with stand off's to allow better cooling.

Plan on building the QuickDraw bed probe. It has a docking arrangement that docks the probe to the side when not in use.  

Clough42 ELS lead screw project: New Banjo + Motor

 

Working from the pattern in the last blog I fleshed out the banjo a bit and started on the motor mount.  Need to extend the sliding part to include short slot and provide a location for the bolt to hold it down.  That has to go in a slot.   If there is room I will use carriage bolts in the slots with washers that fit over the square part of the bolt head.

The motor mount

The cutout for he belt may need to change and it needs screws to fasten it to the base plate.  Maybe some alignment features.

First view including encoder.  This was done to check clearances.

Need to calculate belt size range for the motor drive.
The line that translates the motor mount from the leadscrew position is

translate([55,60+slideForView,banjoThick/2])

using 24 and 72 tooth pulleys aks 1:3

The X offset is 55

The Y ranges from

60-25 = 35mm    ... hypot is 65.2  ...

60-0  =  60mm    ... hypot is 81.4  ...

This is not long enough if we extend the slots to the end cutting away some encoder adjustment

         60+35  =  95mm    ... hypot is 109.8  or 4.3 between centers

Requiring a belt of 368.40 mm pitch, what I can find is 

363-3M-06 / HDT Timing Belt 363 mm pitch length

While that is a good working lenght I need some additional adjustment.

 

Figured I might have to give up the slot to make enough room for the motor slide.

This is due to the size of the 3D printer bed 200x200mm aka 8x8 inches.

In the morning I need to take the template to the shop and test fit it with the fixed hole in mind.

The bolt can go between the slot nearest the encoder and the encoder. This will allow both slots to be quite long.

Figuring out what works is slowing this down.  Go figure.

Clough42 ELS lead screw project: New Banjo

After working on mounting both the encoder and stepper to the existing banjo I realized it was too fragile.  It has already undergone a repair via brazing in several locations.

I managed to get so far as to attempt running the encoder on the lathe but I was to impatient and broke the belt I joined. Using this tool and tire patching cement.   The cement needs 1 to 3 days to cure and I gave it an hour.

At this point I realized I would be making a harp designed to handle the motor and encoder.  But I had to decided how to make it.   I ruled out fabricating from steel because I don't have a mill.  My next choice was to cast it using cores to form the slots.  Then I started thinking about 3D printing patterns and realized I could give a 3D printed banjo a try.  The limitation here is the size of the printer bed, 8 inches or 200 mm square.  

It took a while for me to figure out how to cut rounded corners in openSCAD.    Maybe someday this will morph into a function but for now I only need to use it a few times so I will alter parameters as needed. 

// Code fragment ot create a curved section to cut corners round.

// The object ccreated here must be subtracted from the oject needing rounding

// after positioning it properly with the first translate.

hubRadi = 56 / 2;

s = 100;

difference()

{

#rotate_extrude($fn=200)

translate([hubRadi,0,0])

square(20,true);

difference()

{

cube(s,true);

translate([s/4,s/4,0])

cube([s/2+1,s/2+1,s+1],true);

}

}

The 'cutter' generated by the code fragment.

It was applied to the boss in the lower center of the banjo template.   The idea was to test the basic shape on the lathe.  It was printed with the body .5 mm thick and the boss 5mm tall to save filament.

The next video was taken while testing 

The next task is to correctly locate and construct the curved slot for the lower, and only, mounting bolt.  I printed a button with a center that fit the banjo.  This allowed the measurement of the distance if at a bit of an angle.

From the boss center to the inside edge measured 112mm, the outside 126nn.

(112+126)/2 = 119

The slot takes a 1/2" bolt.  For the first test 12mm will be used.  

I am going to start by generating a 12mm thick ring centered at 119mm from the hub.  

Created a ring and used two objects like sector arms from the hub to trim the ends.  Added a slot for the encoder.  I will round the other corners and time excess past the curved slot later

// curved slot for mounting bolt

difference()

{

cylinder(100, 126, 126, true);

union ()

{

cylinder(110, 112, 112, true); // hole in cylinder to make ring

// two sector arms to close end of slot

rotate(a = 46, v =[0, 0, 1]) // set angle

translate([0,-10,-5])

cube([130,30,10], false);

rotate(a = 110, v =[0, 0, 1]) // set angle

translate([0,-10,-5])

cube([130,70,10], false);

}

}

// encoder slot

rotate(a = 20, v =[0, 0, 1]) // set angle

translate([-15,40,-10])

cube([11,110,20], false); // 11 mm slot for encoder

The printer was not advancing the Z axis enough it at all.  Stopped the print after a few layers.  It was enough to get the comparisons I wanted.

Used the button printed for measuring the hub to mounting slot distance to register the pattern with the existing banjo.  This image is viewed from headstock looking back.

The curved mounting slot is where it needs to be or very close to it.   Looks like it could be shorter on left providing more strength.  Right is about right.  The slot for the encoder need not have to be in a specific place. It will tighten with rotation about the hub or movement in the slot.

With luck the area between the hub and curved slot is enough to mount the stepper motor.

The encoder in its slot.   The slot need to be a touch wider.  Here we can see that the curved slot maybe a tish to close to the encoder.

As of now the current plans are to replace the controller on the printer.  The new controller has stronger drivers.  This may help even if the problem is mechanical.  Not sure.  But I have the stuff may as well give it a try. Next step would be new bearings on the Z axis but it seems to be moving easy enough.  Thinking if the controller swap dowes not help I may temporialy counter weight the Z axis.

Clough42 ELS lead screw project: The Encoder

With luck I can place everything under the change gear cover. Use ball bearings where needed so nothing under the cover will need oiling.  Make it an oil free zone if that is possible.

Starting on the encoder end.  Plan is to replace the existing spur gear on the end of the spindle that drives the existing change gears.  It is 54mm in diameter.

circumference = pi * diameter =  3.14 * 54 = 169.56 mm

Am approximating here so call it 170 mm.

circumference / pitch = number of teeth

The GT2 2mm pitch is 2mm.  

170 / 2 = 85 teeth

Pulles were generated with a openSCAD script found on thingiverse.  I patched the script to make keyways with a code fragment provided in the comments by abratjason

Parametric Pulley with multiple belt profiles
by droftarts January 2012

Both the .scad and .stl files are located on a shared folder on My Google Drive.

I settled on 80 teeth.  It is a little smaller but a metal 80 tooth pulley maybe easier to find if I need to go that route. 

This picture was taken to help me visualize the mounting the decoder. If you look carefully you can see the black 80 tooth pulley The large hole to the lower right of the spindle will be the pivot for an arm holding the decode. 

Also printed the silver pulley for the encoder.  I keep calling these gears because they look like a gear.   Sadly the 6mm hole in the center printed a bit small.  I should have expected that and printed a series of low layer count trials to get the fit.  Maybe a 6mm drill bit.  Maybe reprint.  I also used 2 set screw at 180 degrees to reduce distortion.  Not sure if that was good.  Ah well can always use one.

The back pulley under encoder pulley is an example of what printing with non dry PLA looks like more on that later.  This was printed from the .stl on ThingiVerse.

The silver roll was baked and at about the same time as the black so I don't think this is newly acquired moisture.

The back role is back in the toaster oven.

Printed a copy of James's encoder mount.

This was the top of the print.   Apparently I did not bake the roll long enough to get the moisture on the inner layers.   There is a fair bit left on this roll so I effectively dried the outside inch or so of it.  I don't know if I will reprint this.

It looks like the stripe with the circle is an shallow alignment key.  It is not well define on this effort so if I use it it will be filed flat.

Additional blog Excerpts from Social Media

This blog is being over run with stuff I am saving off the net.
Don't care for that.

From now on all that info will be saved to a new blog

Excerpts from Social Media

Source for southern bentonite

Place tos buy southern bentonite
UNIWEST in Denver

and 

https://theofmp.com/?fbclid=IwAR0shwTs-9a8tFiQIFYxBY2tuINAyLATSmaiwxTa4Ge1J4CNd6RtnGwP1wc

 

Sodium Bentonite Map

This is not all inclusive.  Deposits exist in Texas and Oklahoma according to other sources.
From  Bentonite and Fuller's Earth Resources of the United States  1992