Gigabot repair and upgrade to ramps


I will be working on installing the Ramps controller on Gigabot. Ryan and I will be doing this together.

I’m looking at AD595 based thermocouple boards - these will linearize the thermocouple readings from heated bed. Ramps is set up by default for a thermistor sensor.

Any recommendations on a distributor?

Here is the info from rep-rap wiki:

Here is one source I found in US:

If anyone has better supplier let me know, but I don’t want to order from china or UK and wait 3 weeks for delivery. Lets print!!!


P.S. I will sort out the lifted ground and ground loop issue so we don’t get the ESD / Overvoltage destruction.

P.P.S. Ryan will have the honors of doing the “smoke test”, as my clumsiness probably ESD zapped the azteeg. (Ryan, I looked in my tools and saw that I was using an insulated screw driver, so I think Bill is right on this one – ESD not wedding ring).


you should look at a TI chip… you’ll have free almost unlimited samples with an academic e-mail address. Designing a board with this kind of chip is very simple. Something like two or three decoupling capacitors…

For ESD, I always prefered using clamping diode rather than having to floating ground.


That was the plan. I usually do clamping diodes as well. A TVS at the power supply can be a good measure too.


I have 8495 boards already assembled gathering dust. They work perfectly. I have several K thermocouples sitting around too. It’s a little higher temp range than the AD595 if I remember right but they’re both 0-5V output.

If you want one of the assembled boards, they’re yours. Call or email me.

I also have BAS40-04 dual schottky protection diodes…
I also have some beefcake ST diode/TVS transorb dual purpose thingys in D2Pak along with all manner of through-hole regular, schottky and zener diodes.

I’ll look over the RAMPS schemo and see what we can do to hive-proof it. It already has some clamps and isolation built in.

I have a lot of that stuff too, as my analog audio and RF circuits are super noise sensitive. I’ll let you know if we need anything. I do have a couple 100kV transient suppressor (in 5cm metal cube form). Might be overkill here…


Haven’t been around, but I updated the gigabot wiki page so everyone knows where I last was with this, and what the “to do” for the near future is.

Ryan and I started the upgrade of the Gigabit to RAMPS today. I will finish up the phase 1 wiring tomorrow night and get it back to printing.

At this point, it is a basic PLA setup, but I will be adding the heat bed and z probe in short order and soon will get it to print via the Viki LCD panel as well… but at least we’ll be able to get it back up and running. (We will be adding a Raspberry Pi for control.)


Awesome Bill and Ryan!
Can’t wait to be gigabotting again.


Thanks so much Bill. Can’t wait to fry it again!

Just a quick update on the Gigabot.

I was able to finish wiring up the RAMPS this weekend and do some preliminary prints. The Z Probe is now working as well. However, DO NOT USE IT just yet, the profiles have all changed and trying to print with old profiles WILL damage the printer.

#1) The original electronics used a different set of stepper configurations and drivers, which means that all your old gcode and profiles are belong to us. You can not use old configuration files to print on it. One major benefit to this is that the steps per mm and the motor currents are now properly tuned so the machine is much quieter than before and the motors run cool to the touch. This should make it much more reliable as well.

#2) Because of the new Z probe, the G28 command will mess the whole shebang up… YOU CAN NOT USE IT YET! I will be updating the firmware to prevent the Z from trying to run while it is not on the build plate, but until then, you WILL break the nozzle if you try to print anything!

#3) The Z probe works!!! Yipee… in fact, I printed a two foot square with an X through the middle and it worked flawlessly. However, this requires changes to the gcode to enable. Basically, after you run the homing commands, you run the probe (G29) command… that automatically maps out the build plate for a fantastic print! Did I mention it WORKS WONDERFULLY!!!

#4) The Viki display electronics appear to not be functioning, despite my best attempts. I’m going to swap it for a new Smart Electronics display instead… Since we are going to have a Raspberry Pi running it, I’ll print a large case for the both of them and permanently attach it to the top of the electronics box.

#5) Raspberry Pi… Ryan has an Octoprint build for the printer, we still need to configure it, but we have to get the printer done before we can finalize those configuration files. All users, when we are done, will use the Raspberry Pi as the primary interface to use the printer. This is so we can set up some specific profiles for prints and maintain the a) quality of the prints and b) integrity of the machine. This machine is too expensive to experiment on and we want everyone to have the chance to use it… if used properly, our profiles will allow you to achieve great results without needing to mess around with any settings, simply load your STL and set a few basic settings (material, quality, supports, etc.) and hit print… everything from slicing to positioning will be handled automatically for you.

#6) The Heat Bed is still not hooked up… scratch that… the thermocouple is not hooked up… the heat bed actually is… however, as a temporary measure, I am hooking up a thermistor to the top surface of the build plate, which will allow us to use it… but it is not ready just yet. We have an A2D converter on the way to hook up the thermocouple.


#7) WE NEED FILAMENT!!! This is an official call for donations of 3MM PLA filament… NinjaFlex filament and any other type of filament you want to run on it… right now, we have a ton of ABS, but on this type of printer, that’s a tall order getting it to work right… PLA is much easier, but we currently have NONE. (Ryan has a roll on the printer right now, but a) that’s his… and b) it’s Microcenter PLA, which basically falls apart of you try to print anything with it.


Bill -
I left a simple thermocouple amplifier board based on the AD8495 IC. 0.005V / degree C output on the gigabot, per Lorin’s request… The wires soldered to it are labelled. K+, K-, Power, P-Ground, Signal, S-Ground. From what I understand, that should work for the heated bed. If you’re not going to use it, let me know and I’ll grab it back.


I will use it!


I have a couple 1KG spools of 2.85mm PLA on order from a new vendor I’m trying. If it’s of reasonable quality, we might consider a group purchase of some larger spools. We might also consider changing out the volcano nozzle on the printrbot for a 1.75mm version at some point. It would be nice not to have to deal with printer specific filament.

  • Ry

I looked at installing this and it’s not going to work. It appears that Marlin has upgraded past that model due to it’s lack of precision… the MAX6625 and the A585 series are supported however.

I’ll just pick up a 6625 from my shop and install it.



FYI, I installed the MAX6675 board the other day, but had to disconnect it until I can debug Marlin… it appears that Marlin is not set up to have a thermocouple on the heatbed and not on the hot end… so I have to do some code rewiring to get it to understand that’s what I want it to do. Until then, it’s back to being a plain old PLA printer.

I’m not available this week or next, but after that I’ll be able to get back on it.