Show all posts by user
Safety...
Page 3 of 5
Pages: 12345
Results 61 — 90 of 125
QuoteNikki81
How do I calculate the correct voltage for my stepper drivers ? I have had a look at the wiki but I don't understand(I am not good with numbers) is it amps x inductance = voltage ?
Thanks Nikki
Nikki,
Close, right stadium, wrong seat.
For DC, it's Volts = Ohms * Amps. For AC, it gets a tad more complicated but boils down to Volts = Impedance * Amps. Impedance is a function of the
by
itchytweed
-
General
Second pix (speed cube) appears to be resonance ripples. Belts aren't impervious to stretch and the parts aren't resistant to vibrating. As long as something can shake, they will be there. The key is not to set them off or make it as minimal as possible.
by
itchytweed
-
Prusa i3 and variants
@milkypostman: Good ideas. Nice thing about aluminum...it heats up and cools off real quick. May have to give that a try.
Also, today I made a huge mod. Dropped the heat bed relay. I was finding that when the bed heater came on (bang-bang style), the first and second layers were messing up big time and getting patterns in them. So, I had some IRF4905 MOSFETs from a different project. I took one
by
itchytweed
-
Prusa i3 and variants
The love/hate affair with PLA continues. Plate glass with the ubiquitous purple washable glue stick does wonders....it's too good!!! I broke a blade trying to remove a print. No glue = no stick and ick.
Trying something different - parchment paper. Yes, the one and the same baking paper. So I tried a print on plain parchment, unheated. No joy. Parchment heated - no joy here. Parchment, glue and
by
itchytweed
-
Prusa i3 and variants
Got tired of the z-axis end switch moving with the wire tie. A pair of very rare 3-48 x 3/4" machine screws fixed that issue.
by
itchytweed
-
Prusa i3 and variants
Here is a picture of three runs that I did at three different z-axis slicing levels. Don't consider top infill.
by
itchytweed
-
General
Tried something new. I went and kicked up the accel rates big time (5000 mm/sec^2) just to wave my freak flag. It allowed me to see a good amount of flexure to the wooden end pieces that have the front foldover bearings and y-axis servo mounted to them when doing Hilbert curve infills. Considering replacing front and back pieces with V-slot. Methinks I am going to weigh the table and work the num
by
itchytweed
-
Prusa i3 and variants
I just finished building the I3V 12" unit. I am now getting prints that are measuring +/- 0.02 mm (0.0008 inches) from requested in PLA. I can't complain at all.
by
itchytweed
-
Prusa i3 and variants
This is a set of three 20mm^3 cubes printed with a hole sized for an M5 screw on each axis. They are printed in PLA at 100 mm/sec. At 0.4mm layer thickness, the 0.4 mm Hexagon was running at significant pressure as at the end of the print, there was a big goober left on the part at the z-axis lift when it was done. The 0.2 print seem to have small gaps on print restart after filament retraction -
by
itchytweed
-
Prusa i3 and variants
I have now populated the RUMBA with all DRV8825's and split the z-axis steppers onto their own driver. Plus, left them at 32x microstepping. Next mod is to put in the + axes limit switches. I would just feel better to have them.
I am currently doing prints at 0.1 mm z axis stepping. Maybe I will get a tad outrageous and try 0.05 mm steps.....gotta let my freak flag fly.
Also, the 16U2 has been
by
itchytweed
-
Prusa i3 and variants
QuoteReSiStAnCe
Quoteitchytweed
BTW, my version of the RUMBA board looks to have a separate COM port connection: RX, TX, GND and +5. Wonder if my FTDI USB to RS-232 will play on there? No drawings show the port and neither do the pictures on the wiki.
Have a look at the schematic of the Arduino Mega 2560 http://www.arduino.cc/en/uploads/Main/arduino-mega2560_R3-sch.pdf]found here or the RUMBA
by
itchytweed
-
Prusa i3 and variants
I have to second the idea of actually figuring out what is going on here. Are they opening up, shorting, going off-curve? I had mine open up but it was because the thermistor wire broke at the solder connection to the feed wire. The printer shut down on a MINTEMP fault. I would expect a MAXTEMP fault if the element shorted. The other possibility that I have in the back of my head is a "gray marke
by
itchytweed
-
General Mendel Topics
Quotedc42
Quoteitchytweed
Ohm does not like his law being violated.
Heated beds are big current eaters. Mine is 34 amps when running. This requires serious copper - running 10 gauge stranded feeder from the power supply.
For that sort of power, IMO a mains powered heated bed is generally a better option. That is what I have on my large delta. Of course, using mains voltage to heat the bed brin
by
itchytweed
-
Safety & Best Practices
QuoteNikki81
I think I have found the perfect setting I have been testing 0.25 with the 0.5 test cube.
Sweet job. One caveat though...make sure that your layer value gives you integral steps ( / StepSize ) on your z-axis. If you end up with decimals, then there will be a rounding error and the part gets ripples.
by
itchytweed
-
General
Had a nice morning gift....no USB comms on the RUMBA. Two computers would not recognize the port and BOTH of the RX/TX lights were locked on solid. Ok, either firmware crash or 16U2 went toes up. Me not happy as I have just about finished dialing it in.
Went surfing and found many others with the same issue. Most were getting their boards replaced. So, easiest thing to do is reflash first and s
by
itchytweed
-
Controllers
Last night, I did a print run and shut the whole system down.
Came back this morning and powered it up. No USB serial comms and both the RX/TX lights were on solid. The laptop would not respond to the cable. So, a 16U2 crash. Started surfing looking for similar issues. Yes, there were and under the same conditions. So, first things first, reload firmware to the 16U2. It is far easier to do that
by
itchytweed
-
Prusa i3 and variants
Attached is my configuration.h file for my MakerFarm Prusa I3V 12". I am running the z-axis in 1/4 step mode to make their movement a bit more reliable. The threaded rods on the z-axis are M5*0.8.
by
itchytweed
-
Prusa i3 and variants
@blackLion - I will post my config.h from Marlin when I get home. It has the setting information for all of my steppers, X, Y, Z, E.
by
itchytweed
-
Prusa i3 and variants
As an example, my MakerFarm I3V uses M5*0.8 threaded rods for the z-axis movement. An M5 rod is 0.5 millimeters in width and the 0.8 means that the movement/pitch is 0.8 millimeters / turn.
A 200 step/rev encoder at 1/16 stepping does 3200 steps per rev. Now take 3200 steps per rev and divide by .8 mm / rev. 3200 / .8 = 4000 steps / millimeter. Depending on the steps/rev and pitch of the z-axis,
by
itchytweed
-
Prusa i3 and variants
The double hit - first hit is at fast home speed, the second hit is at homing speed and that is far slower. The slower speed compensates for inertia in the components and yields a more repeatable zero.
by
itchytweed
-
Prusa i3 and variants
Now I have my interior holes coming out just fine. PrintSettings > Advanced > Other > XY Size Compensation. I am using a 0.4mm nozzle on the Hexagon, so I set it at -0.2mm and my holes are coming out just fine.
by
itchytweed
-
Prusa i3 and variants
Ohm does not like his law being violated.
Heated beds are big current eaters. Mine is 34 amps when running. This requires serious copper - running 10 gauge stranded feeder from the power supply.
by
itchytweed
-
Safety & Best Practices
Did a couple more calibration prints last night. One was a one nozzle diameter box and a 20mm square afterwards. The nozzle is 0.4mm and I ended up with 0.4mm walls after averaging a bunch of measurements. After this, my 20mm box came out to 20.02mm, a side error of 0.01mm, which is 0.000394 in. Can't complain at all.
by
itchytweed
-
Prusa i3 and variants
ditched my tubing couplers on the z-axis and made my own out of setscrews and nylon spacers.
by
itchytweed
-
Prusa i3 and variants
+1 on the optical end switch. Very reliable and repeatable as there is no flexure or wear elements.
by
itchytweed
-
General
Glad it is running for you...as mine is running a one nozzle thick box.
I have found that with the newer, non-lead based solder (spitting on ground), connections are becoming more crap jobs than good. The plastic range is far less controlled and the chances of getting a poor joint (incomplete fillet, cracks) has increased. Bring back good ol' 60/40, 63/37, and 63/35/2 solders.
by
itchytweed
-
Prusa i3 and variants
Quotemilkypostman
The glue stick works well but I just tried the blue painters tape and it's way better with less mess. I had a hell of a time getting the excess glue off. I didn't have a scraper though.
It takes so little to make the print stick down. I have found that I can get about 8-10 prints out of one application. I put on just enough so there is only a very slight haze. When I do clean u
by
itchytweed
-
Prusa i3 and variants
If you think this "blog" is disjointed, you should see my notebook....
I printed out a set of gears for the extruder as the ones I have are powdering. So, I put a couple of drops of Tri-Flow lube on them and the dusting has settled down. But the gears pointed out to something about the frame. There is a torsional issue that affects the frame and its stability. High move rates can excite this and
by
itchytweed
-
Prusa i3 and variants
Look for my post about building my I3V. There is an entry about using a nylon spacer as a coupling by drilling two holes for setscrews. I am on my not-so-smart phone or I would post the link..
by
itchytweed
-
Prusa i3 and variants
Page 3 of 5
Pages: 12345