First Time Mendel Build

Hello Guys,

I bought a set of 3rd Generation electronics back in May from TechZone. I have managed to get the mechanical structure of my Mendel up. Right now, I am primarily stuck at getting the electronics to work. Over the past 3 weeks, I did a lot of troubleshooting, scouring the net for information and head banging. Below is a list of points so far

1) The motherboard firmware loads fine onto the motherboard. Whether I do it via Arduino IDE OR ReplicatorG, the red LED blinks when the firmware is being written in. I was able to jog the axis via ReplicatorG but haven't got any success with the RepRap host software. On ReplicatorG, I can jog Y and Z axis but not X. However, on Reprap host software, I keep getting this error message:

GCodeReaderAndWriter.getBTemp

2) If I load extruder firmware via Aruduino IDE, things start to go astray. Except for Power LED, no other LED blinks when program is being written. I did get the ' Done Uploading' from the IDE. Upon power on, the extruder motor starts cranking away and away and away....it will stop if I hit the reset button. All power LEDS light up. ReplicatorG reads this firmware as NULL, so nothing happens. Connecting to RepRap host software, I am not able to jog the axis or control the extruder in any way. But the heating element goes off and gets hot, hot enough to burn fingers.

3) If I load firmware via ReplicatorG, things are a little better. But same thing, no blinking LED but positive confirmation from ReplicatorG that firmware was uploaded. I can control the extruder motor by keying/playing around with the PWM and RPM numbers. There is a reading of "Current Temperature". However, I wasn't able to heat up when I key in a target temperature.

4) Mechanically, I think there's a problem with my Y axis but I don't know what. It travels fine along the mid section but as it nears the end of the Y-bars, I need to put in a lot more force (by hand) to move it all the way to the end. As such, my belts started slipping on the motor pinions as the carriages reach either ends of the bar. Is it because my bars aren't parallel along the axis. I did measure with the jig and it seems fine.

5) Big problem getting RepRapHost software to work on Win7 HomePrem 64 bit. I have read the relevant forum post (only one) and got turn off so I'm back using 32bit.

My machine config are as follows:

Non standard thermistor - I bought this at a local components wholesaler. I lost the brand and part number and i think i should be going back to them and ask. I have not generated any temp tables because of the hassle (as I've already stick the thermistor on). I am using the default temp table in RepRap firmware (the first one that's not commented out) I reckon that at the most, this will only affect my temp readouts & nothing else. Am I right on this?

Extruder Stepper Motors

TechZone 3rd Gen Electronics, shipped out around the last week of April 2010.

A2 bars & studdings

Rusted bearings - forgotten to oil it upon arrival.

Kapton Tape insulated Nichrome heating element - I couldn't get proper nichrome wire so I improvised.

Geared Extruder Design by Adrian Bowyer

Stepper Motors all from Zapp Automation

Plastic bits from nophead.

I have tried all Arduino Firmware/ReplicatorG firmware/RepRapHost Software/ReplicatorG Software permutations. I have also looked through the code and did the necessary configs. Just the ReplicatorG firmware I couldn't do congif because of the .hex format. I am using the latest firmware offered by ReplicatorG and firmware included in the RepRapHost software download.

Please advise. Really stuck at a roadblock with a tight deadline.

Thanks guys...

Tian Chang

Hi Tian,
Sorry I can't help with the software as I don't use it myself.

Regarding the thermistor: the important parameters are that it is rated for 300C and its resistance is high enough that it doesn't self heat when 5V/2 is applied to it. You are correct in thinking it will only affect the temperature measurement and heater control, as long as it doesn't short to the heating element. That will damage the micro.

The y-axis design is such that even if the rods where not parallel it should not bind as one side only has bearings above and below allowing the rod to wander sideways. The only reason I can think it would bind is if the rod diameter is bigger at the ends, but that would be very odd.

Quote

As such, my belts started slipping on the motor pinions as the carriages reach either ends of the bar. Is it because my bars aren't parallel along the axis. I did measure with the jig and it seems fine.

Are you saying you have this problem with more than one axis?

Edited 1 time(s). Last edit at 09/04/2010 05:58AM by nophead.

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[www.hydraraptor.blogspot.com]

Hello Nophead,

Thanks for replying. I really appreciate it.

I am having problems with only the Y axis. The rest of them I can move it well with no problems.

Any other leads I can pursue for the firmware? I am not looking for full blown Instructions. Just leads or maybe configs that have worked for you guys.

I imagine that if the y-bars are not parallel in the vertical plane then it could bind. I.e. if the ends of the bars are not all the same height. Since they are clamped against the threaded rods of the frame that would imply your frame is not square for some reason.

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[www.hydraraptor.blogspot.com]