Hall effect sensors

[oblomov6]

Hello everybody!
Need some help and would in the same time like to uncover a Swedish Morgan build. I am two 6805 bearings away from having all parts and have started to try out my electronics! Everything works well except the Hall effect sensors, which I cant get to work at all…
Have never used these endstops but have a general understanding about them.
I have connected them Supply-S;Ground-(-);Output-(+), which should be right? And also I understand that the Morgan marlin code is set-up to support these endstops?
Anyway if anybody can shed some light into how I can get these working I would really appreciate it!
(I use a strong magnet, tried both sides)

Thanks!

[oblomov6]

Well it actually seems that my test hall was defect, tried another one out and it worked like a charm!

[Quentin Harley]

Great news. The sensors are a bit sensitive to incorrect connection, and I also killed one when I tested it initially. Good thing they are cheap.

[oblomov6]

Yeah! Unfortunately I don’t have a spare so I will have to wait a while before I get new ones here. But there is of course some calibration and other stuff to do in the meantime.

Thanks for a great design! Love building this machine!

[Quentin Harley]

Get yourself a handful next time. I love the Hall sensors in my little projects now. Wonder why I have not discovered them earlier…

[nethack]

Does anyone have part numbers for the Hall Effect sensors they used? I bought a few and they ended up being latching, so they won’t work for me.

Thanks!

don

[Quentin Harley]

I use A1101EUA. Cheap and effective.

[oblomov6]

Hi again!

Now I got all the parts(except one hall sensor…) and have mounted the machine! Feels nice!
But I still have problems with the hall effect sensors, when going m119 i can see that the sensors get triggered by my magnets but they don’t seem to have any effect when homing!
the case might be in relations with the fact that the sensors remain triggered when removing them, they only revert when I turn the magnet(i.e north pole).

I guess that there is something easy I am missing so I would be glad if somebody can point me in the right direction!

Cheers!

A little messy with the cables for the moment…

[Quentin Harley]

When you issue M119, which limits are triggered? It needs to be the MAX triggers.

[oblomov6]

Ah :), that explains it. Knew it was something elementary I was overlooking! Thanks Quentin!

[oblomov6]

Hello again Quentin! Now it is near a test print… well my batch of hall effect sensors have not arrived yet, but Everything else is in place and x-y have endstops.
So I tried out the x-y calibration routine but I can really figure out how it works. I wonder how the endstops work because the homing seem to disregard them, only moving x-y a small step each(always in counter-clockwise direction).
And when issuing m360 the arms sometimes go really wild :D, and sometimes only move a small bit. if I then get the position and put in the offset the new homing will put my arms all the way back and touch my ramps(I put it ontop) efficiently ending my callibration…

Anyways I would be thankful if you could give me some insight into how it works with the endstops etc.

Thanks for all the good work and help, really appreciate it!

Regards, Gustav

[oblomov6]

I think they are wired correctly, they get triggered right(being open when booting up the ramps). But something I find odd is that they stay triggered after passing. Shouldn’t they open again when the magnet has passed?

Thanks,
Gustav

[Quentin Harley]

The must open when passing… Which sensors are you using?

[oblomov6]

US1881

[Quentin Harley]

It looks like the US1881 is a lathing hall effect switch. It will therefore require another magnet of opposite polarity right next to the one you have to turn it off again.

I recommend you get the A1101 sensors I used. They are trigger sensors, and are only active when the magnet is near.

This would explain all the crazy behaviour!

[oblomov6]

ahh, that information will spare me a lot off, more, pain… I got a ton of magnets so It would be no problem to set one on the side. Though It will be more tricky for the z axis, but will probably work out fine.
Is there any other advantage to the a1101 or will It work out well for me with this configuration?

Anyway thanks for the help, it’s getting late here and need to go to work tomorrow so will try this out tomorrow.

Goodnight!
/Gustav

[Quentin Harley]

IF you have the magnets to spare, it should work out fine. The ends are not actually used during printing, and if homing is repeatable (which it should be) you machine will be just fine after calibration.

Good luck!

Cheers,
Q

[oblomov6]

Thanks for the help Quentin! Now the homing works well!
But i still have a little problem with the arms going wild…
It seems that the home position is lost directly after homing because if I hit m360 the arm goes way to long into the back and if I try to just joggle the pronterface controls with either x or y with 0.1mm the arm skipps over half the platform. m114 then shows x 0.0 y 0.0 z0.0 etc.

Here comes the values right after homing(is this looking right?):

Marlin 1.0.0
echo: Last Updated: Sep 10 2013 22:07:10 | Author: (qharley, Morgan SCARA armlevel)
Compiled: Sep 10 2013
echo: Free Memory: 4636 PlannerBufferBytes: 1232
echo:Stored settings retreived:
echo:Steps per unit:
echo: M92 X215.00 Y215.00 Z100.00 E450.00
echo:Scaling factors:
echo: M365 X1.00 Y1.00 Z1.00
echo:Maximum feedrates (mm/s):
echo: M203 X300.00 Y300.00 Z300.00 E45.00
echo:Maximum Acceleration (mm/s2):
echo: M201 X500 Y500 Z500 E10000
echo:Acceleration: S=acceleration, T=retract acceleration
echo: M204 S24000.00 T3000.00
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum xY jerk (mm/s), Z=maximum Z jerk (mm/s)
echo: M205 S0.00 T0.00 B20000 X20.00 Z20.00 E5.00
echo:Home offset (mm):
echo: M206 X0.00 Y0.00 Z0.00
echo:PID settings:
echo: M301 P22.20 I1.08 D114.00
>>>m114
SENDING:M114
X:-35.00Y:-60.00Z:0.00E:0.00
SCARA Theta:114.64 Psi+Theta:241.12
SCARA Cal – Theta:114.64 Psi+Theta (90):36.47
SCARA step Cal – Theta:273.87 Psi+Theta:302.13

[Quentin Harley]

If the arms move too far, try dropping down the steps per degree:

Try M92 X200 Y200

Send a short video of the movement to help me understand what is happening there.

[Ron Hunt]

If you covered this I apologize for not catching it. Did you install the jumpers under the stepper controller on the RAMPS board?

[oblomov6]

Yeah a I could try a video when I find some precious time, a lot of work now(a good thing though…).
Tomorrow I will have a small course in my previous school(architecture), so I’m trying my best to get as much as possible running on the Morgan :D. Would be nice to have two fully functioning Repraps with me, but that is a little to late now.
After that maybe we will have more Swedish morgan builders..

Anyway, I do have jumpers installed under the stepper, though I realize I have all 3, which means 1/16 right? How would I configure for my 1/32?

Ok, now I need to rush to work, thanks for all the input.

Regards,
Gustav

[oblomov6]

Hello!

My Morgan is now up and running! Thanks for all the help(and the actual machine)!

It prints fairly well though I will have too fine tune it after hand, and I noticed that my prints gets a little bit “diamond” shaped. And I have rerun the calibration a couple of times, but still comes out almost exactly the same.
But I guess I could solve this problem with the x-y scaling?

Anyway it feels good to at last get my endstops(took a month for them to be delivered)

All the best,
Gustav

[Quentin Harley]

One thing you could check:

Are your arm sections all the same length (150mm nominal) Measure between the printed in lines at the bottom. If the toolhead sits too far out, try sanding the arm itself a bit before reattaching the head.

If they are all the same, but not 150mm, you should change it in the firmware, and then rerun the calibration.

If you still have issues, it could be that the wheels are not round enough, but the effects if this should not be that apparent.

If this is all done, you could do the SCARA-Cal adjustment. I am doing a write-up on it at the moment – should be done sometime this week.

[Steve]

Magnets.  Where do they go?
I was putting the belts on and was trying to use a slot on the backside.  While placing it I began to think about where the magnets go.
With the theta and psi arms in the middle, at what position do the magnets go.  Based on the endstops on the rods, I assume there’s some specific placement requirements. If you could describe the specific placement would help.
Thanks.

[oblomov6]

Hello!

Under the Topic “Reprap Morgan Building From Asia!But I need a help!” Quentin has shared some nice Pictures that will explain which position is the home position I.e. where the endstops should be triggered.

Hope it helps

/G

[Steve]

Thanks, but read the topic and saw nothing regarding magnet placement or hall sensors. I do dig the worm gear.
Besides, this message has the correct heading (w/o doc).
Thanks anyway

[oblomov6]

Ok, I will check this first thing tomorrow! Hopefully it will be something there that I can fix! That would save me some trouble calibrating!
Other than that I must say that the machine is a beauty to look at while printing!

Also one question regarding the J-head, I was thinking about adding two 40mm fans to the toolhead for print cooling and j-head cooling. How much weight do you think the arms will handle? I was thinking of doing a variant of this cooler: http://www.thingiverse.com/thing:119061

Regards,
Gustav

[oblomov6]

The hall effect sensors would go onto the z-axis smooth roads and the magnets on the drive wheels. When in home position these should line up, I.e. magnets trigger the hall effect sensors.

This position is arbitrary as the calibration process will account for making a individual offset.

Hope this was more helpful!

Cheers

[Quentin Harley]

With the arms close to the home position, as indicated on the pictures, place the magnets in the closest holes to where the endstops are mounted.

Check out my youtube channel. I made a video about the endstops.

[Steve]

Okay. Haven’t seen/found the alleged photo.
Watching video, I guess I’ll know what you mean by home.
Finishing soldering plugs, ready I guess for software.
Doc?

[Quentin Harley]

[oblomov6]

Well, everything seems exactly spot on… Unfortunately.. I remember that you talked about a phantom in the “How making calibration foolproof drove me insane…” topic. Did you eventually do this? in that case I would love to get both the model and the calculations.

Regards,
G

[Quentin Harley]

I’ll post it in the calibrations section later today

[oblomov6]

Hello Quentin!
Is the Calibrations soon to be up?
Tried to figure it out yesterday, got really close on a trail&error but I would be really glad to get some calculations instead!

[Quentin Harley]

I have added the calibration files to the Morgan git repository.

Print the STL, measure, and enter the dimensions and current step settings in the spreadsheet.

Let me know how it goes.

[oblomov6]

Great!! Tahnks a million! It workt good, but just an houre into the calibration printing a arm came loose and made the real problem apparent… It seems I have been a little bit sloppy with the mounting of the arms. Good new tough, it is now mounted secure and printing better than ever! I will probably try some fine tuning with the phantom in the weekend!
Sweet!

Best regards and thanks,
Gustav

[Quentin Harley]

Great news. Pictures of your prints mandatory!
Q

[oblomov6]

Sure thing! As soon as I get past the last calibrations!
Still having some minor(but of course Hugh in the long run..)

First my ATX dies when setting heat bed temp. (A issue I have ignored so far because i’m printing in PLA) it is a 500w 22A ATX with a 20W lightbulb on the 5v rail. I am a little baffled, does anybody know of a possible solution?

Second, Gap infill’s misses the perimeters, I guess it may be some sort of backlash. But I am beginning to suspect that this can have a link with the ATX problem(causing extra vibrations etc.). As the steppers does some “pausing” on the MQ15 sklic3r setting you provided(Lowering the trimpots does not help and taking them higher only results in a terrifying buzz from the steppers). So together with some not so smooth movement now and again So I wonder if the ATX provides some inconsistent power or some other interference.

Otherwise it prints straight and nice vertical perimeters, I will post some pictures as soon as I get some perfect prints :)!

Tinkering continues tomorrow, godnight!

/G

[Quentin Harley]

I use a very cheap 400W ATX, and even without a 5V load it just works – Go figure right…

Another supply I like is a 20A security camera 12V only supply. Works a charm on RAMPS, especially since you can adjust the output voltage. I adjust it until I get 12V on the bed under load. This does not bother the Mega at all.

I sometimes get the issue with gap infill myself. I suspect that the acceleration settings may be to blame here. Will have to play with it a bit if I can just get some of my printing backlog done.

Thanks for the updates!
Q

[oblomov6]

I guess that gap infill goes on the bridging acceleration setting?

[Quentin Harley]

Don’t know, but it is a good start. Perhaps check on the slic3r forums if there are similar issues.

[Steve]

Hi Quentin,
Just looking thru my parts – what is the third hall end stop holder supposed to go?
I’ve got one on each of the smooth rods, 1 above 1 below the respective wheels. Does one of the wheels get two? One on each rod?
Thanks.

[Quentin Harley]

Look at the youtube video. The third one is to sense the Z-axis home, with a small magnet on the bracket.

[Steve]

Hi Quentin, I was hooking up the endstops to the x_min and y_min pins and I began to wonder. Between psi and theta, which is considered the X axis and which is the Y axis?
Not sure that it would make a difference but thought I’d ask you. Is it appropriate for me to hookup the Min pins instead of the max for X, Y and Z ?
Just got my firmware loaded, so I think I’m ready for calibration, eh?
I was thinking about playing with the larger build plate. Figured knowing X and Y may be important when defining the larger build area. Have you played with a larger area? Any hints? Should be fun for pla, until I make a custom heated bed.
Thanks.

[Quentin Harley]

You have to use the MAX pins, as the firmware homing routine for Morgan works slightly differently to other machines, and relies on the MAX stops to be triggered.

Theta ( the thinner arms) are X and Psi ( strong arms ) are Y. The top wheel would then be X and the bottom one Y.

[Quentin Harley]

Ok, try this. Issue M119 before homing, and with the magnets obviously not aligned. What do you get? All should be open. If not, it might be wired incorrectly.

If all is well, keep sending M119, and move the arms to the home position, slowly by hand, and monitor the end stops. If it triggers over the magnets, all is well. If not, check the magnet polarity, and wiring.

As I said before, the MAX endstops needs to trigger in all axis. On RAMPS it is easy to connect to the wrong end-stop terminals – This was one of my first issues when still adapting the firmware.

[Author]

Posts