Are those Teensy 2 boards on the sides? Or some Arduino Leonardo clones, perhaps?
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Are those Teensy 2 boards on the sides? Or some Arduino Leonardo clones, perhaps?
jwatte, they are Arduino Nano V3.1 boardsQuote:
Are those Teensy 2 boards on the sides?
https://www.mouser.com/ProductDetail...XAYdh8vxKmOPAO
Ah, yes, and you even said so in your post!
While waiting on parts for the bucket build I should think about
rebuilding the current handheld mule remote controller.
It's in a very sad shape.
Attachment 7346
lucky for me, I had someone else weld the frame for me.
and it turned out very sweet!.
(if I did it, even using cold rolled steel it would have been spaghetti.)
Attachment 7347
plan A
Attachment 7348
plan B
Attachment 7349
Baby steps.
Attachment 7350
Attachment 7351
Attachment 7352
Attachment 7353
baby steps.
Attachment 7354
Attachment 7355
Did you cut that circular pocket on a manual mill without a rotary table? Or are there stepper motors somwhere I'm not seeing them? :-D
Jwatte, that's one of the things that makes the 1.5 hour drive(each way) to the office worthQuote:
Did you cut that circular pocket on a manual mill without a rotary table?
the drive, the Mill has a conversational control on it(very sweet!), a lathe, surface grinder,
and Steel in the stock rack(life is good).
the ability to mill bearing seats or turn snap ring grooves comes in very handy with this type project.
Attachment 7358
Attachment 7356
Attachment 7357
I only have a single axis motor drive sitting around(sabertooth 50), and
I can't see a need to lift and dumping at the same time. so I got
a 80A DPDT 24vdc relay to switch between motors(lift/dump) using
the single sabertooth motor Drive.
to simplify the first setup, I'm going to have very basic controls for the lift/dump.
(2) toggle switches
(1) momentary push button
one toggle switch for Up/Down for lift
one toggle switch for Up/Dump for bucket
the momentary switch is an enable button.
I have (4) 5vdc NPN inductive prox switches for each end of travels.
Sounds like a simple way to get things going with what you have in the parts bin :-)
Although I wonder if you couldn't just drive it all with relays, cheaper than the motor controller, if you don't need PWM...
jwatte, while the 80A relays are cheap, the solid state relays needed for the arduino to control them are not, andQuote:
Although I wonder if you couldn't just drive it all with relays, cheaper than the motor controller,
I don't have a lot of them in my parts bin. because I have the sabertooth already that is the cheapest way to go.
there's also the gearing issue, the lifting chain sprockets are #50 13 teeth @3" dia., they are on a 1" shaft with
a drive sprocket #40 30 teeth @5" dia. , then the motor has #40 9 teeth @1.5" dia.
the motors are 1000W 180rpm.
I'm going to need the speed controller to get the right lifting and dumping speeds right.
I was thinking of using this SPST 300A 24Vdc relay for the Drive enable relay.
It was listed as continuous duty, but still gets very hot after prolonged use.
and it draws .5amps
Attachment 7359
this is the new remote controller enclosure(I think)
Attachment 7360
How hot is hot? What is the maximum running current of the entire drive system?
tician, too hot to touch, that was with no load.Quote:
How hot is hot?
Just relay connected to 24vdc battery over night.
two of these in series should give me a warm&fuzzy for a Drive enable relay(s).
Attachment 7361
two of them should draw .400 Amps (coil listed as 60 ohm)
baby steps.
which sucks because we got 6" of snow on way.
Attachment 7362
Two 60 Ohm coils in series would be 120 Ohm. 24V / 120 Ohm == 0.2A and ~4.8W of power (most of it as heat once the relay has been closed). 2.4W in a small plastic package might not be much of an improvement compared to 12W in a heavy metal enclosure that is supposed to be bolted to a metal chassis (heat sink).Quote:
Originally Posted by Tommy_T
Cost saving tip: You can drive the coils of the 80A relays with a simple MOSFET from the Arduino!
The BS170 turns on at about 2V gate voltage, and is good up to 500 mA coil current depending on specific package/cooling. You could also use a much higher rated MOSFET with logic level gate, like AOTF2618L or whatever.
Anyway, if you need speed control, then relays are out anyway. Just thought I'd mention this easy way to do it, in case this threads shows up on Google sometime.
Attachment 7366
tician, my bad. I'm going to be running the load output contacts in series.Quote:
Two 60 Ohm coils in series would be 120 Ohm.
that way if the contacts stick on one of relays the other can still drop the drive voltage
in case of emergency.
my drive power fuse is 100A. the relay is rated as 120A, too close for a warm&fuzzy feeling
but, two in series could.
jwatte, very good advice.Quote:
Cost saving tip: You can drive the coils of the 80A relays with a simple MOSFET from the Arduino!
I started using EATON solid state relays 15yrs ago for work, and over the years have found them to be
very reliable, but not cheap @$36.00 for the 15A units, @$26.00 2A units.
I also like using them because they isolate the 5vdc(control voltage) from the 24vdc(load voltage) in case of failure.
Attachment 7367
Mechanical relay ratings are mostly about thermal limits of the contacts and wiring, and not about welding itself closed. Since a relay failing closed is most likely to happen during the sparking current surge at turn on (arc welding the contacts together), it would be far better to just add a proper pre-charge circuit to eliminate that sparking. A smaller ~10A relay and a low value, multi-watt resistor (e.g. 100 Ohm / 5W) connected from the battery to the load to slowly bring the motor drivers up to ~20V before turning on the main relay/contactor will largely eliminate the risk of the main relay/contactor failing closed.
tician, I agree, something like a RC snubber would add to the warm&fuzzy feeling.Quote:
it would be far better to just add a proper pre-charge circuit to eliminate that sparking.
If the motor controller isn't running, then the current during close is negligible (unless it has really big/low-ESR capacitors.)
You can also pre-charge with a 10 kOhm resistor in parallel, but really, not closing the contact straight into load is the best solution :-)
(If you use raw relays without a controller, you don't have that opportunity.)
baby steps.
Attachment 7372
Attachment 7371
I should have the remote controller done by time the lift is ready.
when this mod. is complete there should be 3 sabertooth 2x60 speed controllers,
and I found an extra 4 channel thermocouple board (spi) so it would be nice to
monitor the drive temperatures on the PC software control screen.
Attachment 7373
mother nature must be checking in on this topic, 20 miles south of me got 10" of snow this week.
she dropped none on me.
I was thinking of using 2 Arduino Nano's for controlling the mule, but I got intermittent results
using the software serial on the Nano at 115200 baud. "SoftwareSerial mySerial(9, 10); // RX, TX"
not sure if it's some type of conflict(maybe spi), but because I have a few Mega clones in the parts bin
I'm going to use 1 Mega and one Nano.
the Nano is only for Drive Enable and uses no serial comm, using the Mega also gives me the option
of adding GPS and other sensors.(hours of entertainment)
I'm interested in testing GPS when the leafs are off the trees.(it's very bad when they are on the trees)
SoftwareSerial is always intermittent at speeds above 9600 bps :-(
The interrupts used to drive functions such as millis() end up causing the conflict even if you don't do anything else.
For what it's worth, the Teensy 3.2 is about the same size as the Nano, except it has more capabilities than a Mega (except not as many pins -- the Teensy 3.5 gets close, though!)
jwatte, I've never worked or played with a Teensy yet. sounds like a goodQuote:
Teensy 3.2 is about the same size as the Nano
way to spend a winter.(testing Teensy's,Pi's and Edison's)
I'm also not going to be able the use the cheap plastic relays, while they are Big!(sames as sabertooth 50)
I could find room for them but, within 20min. I started smelling melting plastic, hard to get a warm&fuzzy
with that smell.
It's possible it would go way after awhile, but I'm chucking them in a bad parts storage bin.
plan C should be in the mail today.
Attachment 7374
Oh, yeah, some relays have a limited duty cycle -- for starter motors that aren't intended to run all the time.Quote:
within 20min. I started smelling melting plastic
In the end, MOSFETs almost always win for longevity! And that's where the Sabretooths of the world come in.
Although, honestly, one could probably build a much cheaper simple H-bridge board with enormous power capacity ... Maybe a business opportunity? :-)
jwatte, if plan D fails I may just do something like that.Quote:
one could probably build a much cheaper simple H-bridge board with enormous power capacity
plan D is to use the same thing I would use to enable a drive on a machine.
I can get these with 24Vdc coils.
Attachment 7375
these passed the 24 hour heat test.
Attachment 7376
they also have a 200A version with the same foot print.
which I'll most likely use when both sabertooth 2x60's are in use.
when I made the motor mount brackets, I made all four at same time.
but, not sure if I'll get all four installed this season(I'm slow).
Attachment 7377
baby steps
Attachment 7380
Attachment 7381
Attachment 7402 Attachment 7403
I'm going to test lifting the bucket while still just bolted together, before I take it back
to the welder. the bucket with dump motor and brackets is only 160lb.
"only"
Lucky for me I ordered a manufactured steel bucket(80lb) from Home Depot, if I made it,Quote:
"only"
chances are it would weigh 300lb.(like the lifting frame I'm working on)
there is lots of aluminium in the stock rack at work, but it's for current jobs, there's lots
of steel that is left over from past jobs that I can use for free(free is good, but very heavy)
with the bucket lift installed on the mule I shouldn't have to add any sand bags for weight
to get traction.
Attachment 7405
Free material is best material!
(Or, as I prefer to think of it: Made of pure scrapbinium!)
I should have the bucket mounted to the lift soon
Attachment 7406
Attachment 7407
Attachment 7408
Attachment 7409
plan A is to use one 1000W motor for lifting and one for dumping.
plan B is to use two 1000W motors for lifting and one for dumping.
Attachment 7410
Attachment 7411
Attachment 7412
Attachment 7413
the lift works as envisioned, 5 sec. for full lift height, tested lifting 290lb, it lifted
it with no measurable slow down.(Sweet!) the braking system worked perfect also.
everything very smooth, and very quiet.
now for the dumping system.
baby steps.
got the prox switches for the lift installed.
Attachment 7415
also moved the bucket out 2" to give me room to mount the dump
motor under the bucket support arm(so it doesn't block camera view) .
seeing where you go is important :-)