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Has anyone wondered or knows what the slots and holes are for on the top plate of the rostock max?

or maybe no reason at all for them being there?

Best guess is they wanted to make sure it was ventilated and went a little overboard.

Maybe for this: http://www.youtube.com/watch?v=j8B1PypVCvU&hd=1 ...and other future extensions

aehM_Key wrote:Maybe for this: http://www.youtube.com/watch?v=j8B1PypVCvU&hd=1 ...and other future extensions

yeah i saw that before, but i thought maybe there was a reason for this version.

starting to get my heatbed prepped for wiring and I did not realize now small the thermistor really is. This is a delicate operation and now can I see why this could short out the rambo ports. Especially if your not careful.

Here are some close up shots. I put some thermal heatsink compound to fill in the air gaps. Double checked with a meter to make sure nothing was shorting. I will rtv it to seal it in place.

May I ask what type of camera you use to take those amazing closeups?

Casio EX-Z1050

(The pictures are ok, but there is much more possible, e.g. http://www.abload.de/img/new-out999993n7t.jpg )

Eaglezsoar wrote:May I ask what type of camera you use to take those amazing closeups?

Actually the close ups were taken by a microscope camera. Comes in handy when your troubleshooting circuit boards too.
I bought a cheap chinese made one off of ebay, seems to work descent and gets the job done.

Amazing!

(Sorry, I thought you where talking about the other ones. The camera is written in the Exif data.)

aehM_Key wrote:(Sorry, I thought you where talking about the other ones. The camera is written in the Exif data.)

Most of my photos were taken with the casio but not the close ups.

Heat spreader (http://www.3dfabricationworks.com/rosto ... rades.html) mounted on top of the Onyx heat bed. In between the heat spreader and the onyx I laid a layer of thermal heatsink compound to help with heat transfer. edit: I had problems with the aluminum bowing, so it was removed later on. Soldered everything underneath. 10awg Flexible silicone wire is no problem for tight spaces and its rated for 200 degrees Celsius. I should also mention that I used a 230/150 watt soldering iron to attach the larger 10 gauge wires to the heat bed. Fit perfectly through the existing hole, no need to widen. Solid state relay mounted behind my electronics door, wiring almost complete.

cambo3d wrote:Continuing into the morning hours.. I decided to mod my voitek power supply a little. Just to clean some wiring up and add few things. Here is a sneak peak.

CIMG1498.JPG

Dedicated 24v 31amp 750 watt Meanwell power supply and 25amp solid state relay for the Heated bed. To make sure my onyx gets to temp with the quickness.

CIMG1499.JPG

CIMG1500.JPG

CIMG1485.JPG

More to come later. I'm calling it a night.

Why not just use the 24v PS to power the RAMbo? It's rated for up to 36v. I have a MendelMax running on a 24v PS to power the linear y-axis upgrade kapton heater. It doesn't complain at all.

Why not just use the 24v PS to power the RAMbo? It's rated for up to 36v. I have a MendelMax running on a 24v PS to power the linear y-axis upgrade kapton heater. It doesn't complain at all.[/quote]


The steppers that I have aren't rated for 24v and I wanted a dedicated supply for the heat bed.

I believe was foshon is mentioning is that each power input has its own bus on the PCB. I can't confirm it because the wiki is down (http://reprap.org/wiki/Rambo). But if someone else more familiar with the board could confirm this it would be appreciated. Basically what the seperate bus means is that you can have 12V driving you steppers and 24V driving your heated bed with no conflict on the board. Just make sure you wire it up right..

On rail is for the heatbed,
on rail is for the hotend(s) and fan(s)
and the 3rd rail is for the electronics itself (could also be powered via USB, depends on the jumper) and the steppers.

MorbidSlowBurn wrote:I believe was foshon is mentioning is that each power input has its own bus on the PCB. I can't confirm it because the wiki is down (http://reprap.org/wiki/Rambo). But if someone else more familiar with the board could confirm this it would be appreciated. Basically what the seperate bus means is that you can have 12V driving you steppers and 24V driving your heated bed with no conflict on the board. Just make sure you wire it up right..

I have already researched all this. while you could run everything separately, my rambo is powered by the 12v pc supply for a reason.

The reason why I didn't run the 24v through the rambo is because of its 15amp current limitation for the heat bed and possibly the connectors that it uses. . The onyx will draw around 20 amps at 24v. The other rails are rated at 5amps. If you used a 12v supply for the heat bed this would be okay because at 12v the onyx draws only 10amps.

so before you start thinking you can just throw anything in there. There are other factors to consider.

Will you change the firmware from PID-PWM to maybe a bang-bang controller for the heatbed, or how will it work with the relay?

aehM_Key wrote:Will you change the firmware from PID-PWM to maybe a bang-bang controller for the heatbed, or how will it work with the relay?

The heat bed output on the rambo will be used as the input to activate the SSR. I will be trying the default configuration first. I will see what works best but PID is what I was aiming for. Solid state relays are used quite often for heater circuits with pid controller.

Sorry, I should have looked up earlier that a solid state relay isn't a relay
English is not my first language and especially all these special technical terms are sometimes problematic

cambo3d wrote:

MorbidSlowBurn wrote:I believe was foshon is mentioning is that each power input has its own bus on the PCB. I can't confirm it because the wiki is down (http://reprap.org/wiki/Rambo). But if someone else more familiar with the board could confirm this it would be appreciated. Basically what the seperate bus means is that you can have 12V driving you steppers and 24V driving your heated bed with no conflict on the board. Just make sure you wire it up right..

I have already researched all this. while you could run everything separately, my rambo is powered by the 12v pc supply for a reason.

The reason why I didn't run the 24v through the rambo is because of its 15amp current limitation for the heat bed and possibly the connectors that it uses. Also as stated before my steppers aren't rated for 24v.. The onyx will draw around 20 amps at 24v. The other rails are rated at 5amps. If you used a 12v supply for the heat bed this would be okay because at 12v the onyx draws only 10amps.

so before you start thinking you can just throw anything in there. There are other factors to consider.

That's interesting. My RAMPS 1.4 runs on a single 24v supply. I was under the impression that the RAMbo was a one board replacement. Forgive my intrusion.

it is provided you keep everything within specs.

more progress, ran the wires for the end stop switches, mounted the accessory fuse block.

Today I decided to tackle an issue that I put off since i started working on the wiring.

After installing the build surface. It was not flat and seemed to have a bow in the middle. The aluminum that I was using as a heat spreader wasn't completely flat to begin with but I should have been able to flatten it out somewhat once I tightened the screws down but it actually got worse. I took everything off to check tolerances of the spacers they were all between 3.99mm and 3.97mm, I had two that measured over 4mm. To my surprise star spacer was also fairly flat.

This leads me to believe that the actual mounting surface of the rostock was the culprit and I need to solve this. I suspect its lies in how tight I have the frame assembled and the tolerances of laser cut parts.

I've been thinking of implementing some sort of bed leveling device to account for some of the inconsistency of the rostock frame.