Just an update on this: I replaced the original nuts (steel?) with brass nuts. Before fitting I ran an M8 die down both threaded rods and a tap in the brass nuts. For lubricaiton I used what I had to hand, some lightish machine oil. Early tests, but it looks ok. Mikeby 3D2B - General
Thanks guys for the confirmation >I'm assuming the coils are connected colour to colour? Yes Viktor, colour to colour., steppers rotated in synch.by 3D2B - Stepper Motors, Servo Motors, DC Motors
I built a RepRap Prusa. 2 x nema 17 steppers for the z axis. both turn in sync, controlled (I assumed ) by the same polulu driver. I noticed if I manually turn one z xis threaded rod, the other turns. nothing unusual there I figured , they are physically connected via the x axis smooth rods. But today I remove the threaded rods to do some repair work. The electronics is switched off. I notice sby 3D2B - Stepper Motors, Servo Motors, DC Motors
Hamish, Thanks for the update. I was thinking of posting to see if things were on track, so good stuff. See you there. Mikeby 3D2B - West of England RUG
On my Prusa Mendel the x axis smooth rods are going non-level. Of the 4 M8 nuts, 2 of them have ridden up & one down, slightly out of their sockets in the motor holder & idler. Not fully out , but protruding by up to maybe 4mm. Seems worse on the top than the bottom. Also an intrmittent problem on z axis , motors whirr & maybe one in 10 times, no movement. Seems less of a problem wheby 3D2B - General
Thanks Nophead, Yes the pulleys are 16 tooth. Now you've said it, its clear of course the driver is the rotation of the stepper shaft, irrespective of the number of teeth, a 1.8 degrees step is still a 1.8 degrees step. Mikeby 3D2B - General
Bob, Only just notice your post. Footprint on mine is about 18" wide x 17.5 inc deep (inc overhang parts). I have my PSU in a ventilated box 7" x 9.5" However my build was on a desk 5ft x 2.5 ft, which I found useful for tools, the build manual, elbow room etc. Computer & monitor to one side, so not on that desk. Also to consider electronics (if separate) computer - if you're using sayby 3D2B - General
Guys thanks again. My RAMPS came pre assembled, with jumpers hidden under the top PCB, so difficult to check without removing the pololu PCBs (anyone for bent pins ?) martinprice2004 Wrote: ------------------------------------------------------- > Yes stepsticks only do 1/8 microstepping. I was > scratching my head the other day trying to get > 1/16 out of some and failing! The MS3 jumby 3D2B - General
I'm working through cailbration for my Prusa Mendel by Triffid Hunter, it says: " know what your stepper drivers' microstep is set to. Most set pololus to 16x, GEN3 stepper driver 2.3 is fixed to 2 (half step). " I have pololu clones based on the A4988 chip, so assumed 16x How do I find/check the stepper drivers microstep setting? Also as my steppers are 1.8 deg, does that mean the full micby 3D2B - General
Ok thanks Crispy. I think I have it figured now. I used the same thermistor for the hot end , so the same lookup table, held in thermistortables.h should work. In case anyone needs it the look up table (held as an array) is in lookup table for RS thermistor 198-961. Of course if a different thermistor is used in the hot end, the software would need more of a tweak. Mikeby 3D2B - General
Thanks NelsonRap. Yes the pronterface I use suggests 110 degrees C for ABS & 60 degrees C for PLA. Presumably that 100k Ohms thermistor will be ok for giving feedback on either temperature, I just dont know if I need to tweak a software look up table anywhere. Mikeby 3D2B - General
Even though I'm just starting with PLA on my Prusa Mendel, thought I'd add a heated bed. Have one on order from reprapworld. meanwhile I'm getting my mind round what else to do on it. I have some spare thermistors : 100K thermistors left over from my hot end build. Can one of these thermistors be used for the heated bed? If yes do I need to tweak the software? Presumably I take off my mdf toby 3D2B - General
Hamish that's great! Sorry for delay in replying, I've been away on work for a couple of days and just got back. Confirmed that date is good for me. I'm not sure what I can contribute - I have a built Prusa Mendel but recently built so not calibrated & not printing great as yet. OTOH it could be either (i) a deadline for my to get it sorted or (ii) a opportunity for a more experienced handby 3D2B - West of England RUG
I'd be up for an outing to Ledbury. 'Bout 45 mins. drive for me so my partner could explore Ledbury's shops if its during the day. Hamish, RepRap_Project Says reprap blog started 23/March/2005 - nearest I can readily find to a 'birthday' - so how about March 24th : first Sat after that? Mikeby 3D2B - West of England RUG
Ok thanks Nudel. Looks like the pronterface is already printing a skirt. Pronterface has the reverse (= retract?) default as 1mm/min. I upped it to 2 & the quality got a lot worse(insufficient filament) very 'whispy' print. Presumably 0 = no retract, not a good idea. I'll have a go with the temperature settings. Mikeby 3D2B - General
Once heated up, my Prusa Mendel oozes filament before I start a print - is this normal? If not what can needs to be done to stop it? I tried the pyramid print and got a result similar to the initial picture in this thread Similar result I too am getting the thin strands of PLA between the corner 'struts' of the pyramid. I assumng likely the oozing & the stranding are linked. What can bby 3D2B - General
Drogon, Do lots of reading up first. As I understand it the Prusa Mendel is a (simplified) variant on the Mendel. I found this guide really useful: 3D printer building introduction Of course if there's somone near you with one who can & is willing to help that would be good. Part of the confusion is the different permutations of what's possible. Reading up should help. For the size queby 3D2B - General
Ok thanks to you all. Looks like you can either reverse it out or poke through the new filament. I was switching from blue to green PLA. I extruded some more of the blue & found I could poke in the new green PLA. Contining with extruding after a while the green came out. Mikeby 3D2B - General
My Prusa build has made some progress, with my first plausibly decent print tonight! Working in PLA to start. I was left with just a few inches of filament to feed in so to clear it I thought I'd run another small print until it ran out. I stoppped when no more was being extruded When i look into the top of my Wades geared extruder I can still see some of the filament. How do i clear it ? heby 3D2B - General
Cosmic, Thanks for the info. This was the first (sort-of) "home brew" PCB I'd hooked up to a USB port. Before that & a while back (pre this project) it was to 25 pin serial & parallel ports. Perhaps it was some other problem than a wrongly oriented endstop link to the circuit, but fixed anyway. Mikeby 3D2B - General
I'm currently trial running my new build Prusa Mendel from my main computer, using pronterface, but would like to free up the comp. I have a spare old laptop gathering dust. Win XP, 1GHz, with just 248 MB RAM. I've searched but can't find the minimum system requirements to run pronterface. Would the laptop do it? Obviously I could just try it , but if the spec is borderline... Thanks in advby 3D2B - RepRap Host
Dale, That's great thanks. I loosened the wing nuts, gave the filament a bit of a shove & in it went. Tightened the wing nuts back a bit. I now have done my first extruded plastic. Mikeby 3D2B - General
My Prusa Mendel build is progressing. All motors and the hot end now working. I'm using Wade's geared extruder with 3mm PLA. The hobbed bolt I had pre manufactured. Searching on the boards here & on google I didn't find any help on this one: When I guide my first test piece of PLA into the small hole in the top of the extruder & then key 'extrude 10mm' in pronerface nothing happens I eby 3D2B - General
I have a ramps 1.4 board + arduino clone, supplied pre built from Reprapworld. I'm not getting any power out from the extruder heater pins to feed the power resistor. Am I right in that there should be a green LED lit when the extruder heater is working? Mike ok have sorted this one.by 3D2B - RAMPS Electronics
Building a Prusa Mendel. Using the hot end from Adrians universal mini extruder: Universal mini extruder the thermistor is the more robust one, referred to at the bottom Thermistor I have updated the firmware table with the data provided for that resistor. When I use 'check temp;' in pronterface I get ok T:0 B:0 In pronterface I set heater to 185 (for PLA) I waited 5 minutes for the heater tby 3D2B - General
Building a Prusa Mendel I have had the arduino / ramps set up working ok on COM 6 , pronterface communicating with the steppers ok. Sprinter firmware loaded , no lights on the arduino board (if I remember right). I needed to adjust the firmware. I happened to notice that the usb cable was still attached to the arduino (the 12V up to 20A supply was not conncted).. To be on the safe side I pulledby 3D2B - General
That's great guys, makes sense. Thanks. Mikeby 3D2B - General
I'm in the process of a Prusa build. Mechanical endstops, the small 'morse key' rocker type. I now have my steppers moving on all 3 axes & on the extruder. When I test 'home' for the X axis , the mechanics moves along , touches the switch as expected , then moves away about an inch, comes back again then stops. Same process for the switch on Y axis. (The Z axis switch is not ready to test yeby 3D2B - General
NelsonRap, thanks for the reply. On looking more closely at the other constructor's BOM, he in fact changed and I dont think ordered his thermistor from reprapworld, so I'm not 100% sure I had the right one anyway. Also I checked the spec on the one from the local electronics store , it's max temp was 150 deg C. Not sure if that's ok, one posting I read said the temp drops off along the thermisby 3D2B - General
I bought my hardware kit from them. Straightforward, no real problems, one minor in that the hobbed bolt was for Wades extruder as described , the hot end they sent was for Adrians. Since I'm building with Wade's I had to do a little hack, but no major problem. Parts ordered Oct 23rd , arrived Oct 26th (I'm based in the UK). Mikeby 3D2B - Reprappers