Using RAMPS

[tom10122]

Is there a tutorial around for RAMPS? I'm ordering a 1.4v on ebay and am not familar with operating ramps. I Planned on USing pronterface to control it do i need to use a thermistor with it ? I already have a velleman wired up for temp control and the thermistor is different. ALso , can i run it without endstops? THanks

[Eaglezsoar]

Start here: http://reprap.org/wiki/RAMPS_1.4
It shows all the wiring diagrams and other info.

You will need a thermistor for the hotend and heatbed if you plan on using a heatbed.
Thermistors are normally 100K. The Velleman thermistor is 4K and will not work with Ramps.
You will need to use endstops on your 3D printer.

[tom10122]

But I can just ignore the heating option and use my velleman?

[Eaglezsoar]

Yes, you could do that but you realize you give up the ability to control the temperature from the firmware.
I also hope you are talking about controlling the heatbed from the Velleman and not the hotend. You really
need the firmware to control the hotend.

[tom10122]

I was just going to leave my velleman setup for my hotend, My temp is right I don't see a point to switching it if it isnt needed.

[Flateric]

I run a Ramps v1.4 setup for a very long time now on my Rmax. You'll find it is not really all that difficult. Just more of unknowns that get you worrying, but in the end it is essentially the same as running a Rambo. Only 1 thing is you really have to run a cooling fan on the ramps board at all times to keep the polos from overheating and stalling out on you.

As long as you wire it up according to the link than it is essentially the same in every way to Rambo. Same firmware etc, just select board type 33. Although with the seemecnc firmware it would not compile when I did this due to errors for some reason. Let me know with any questions you may have, I'll do my best for ya.

[tom10122]

ANybody have an Idea of how far apart the pololu chips are apart? I have a big Heatsink and wanna know if it will work or if I need to find a new one.

[Flateric]

The problem with the polo's and the fact that they are each mounted on their own little daughter card is that this creates a situation where they are all at ever so slightly different heights and positions. The only effective way to put a heatsink on them is indavidually. And then they have to be attached well and the base footprint is fairly small to avoid shorting with components that are very close to them on the same daughter card.

[tom10122]

I think I can overcome that, i have quite a few heatsinks from some gamecubes systems I have been modding and they have a millimeter or two of thermal compound which I think should work when positioned right

[tom10122]

My Ramps is coming today and I haven't the slightest Idea what to do. I have my motors rewired to hook up with the ramps, DIY endstops, but software is my weakness. Do I just load Marlin on it then connect to pronterface? are all the calibration settings in The marlin firmware?

[jdtram]

You'll have to make quite a few changes in the firmware. If you're completely set on not allowing Ramps to control your hot end you'll need to disable the thermistor in the firmware or the printer will not get to a ready state. You'll have to set the motherboard type to 33 and calibrate your motors. The link that was posted previously has all of the information you'll need. I upgraded to Ramps almost a year ago and it's been one of the best upgrades.

[tom10122]

I disabled all the temp sensors, swt to type 33. BUt how do I calibrate my motors? ALso in the link it talks of jumpering the drivers to enable 1/16 steps is that already done or is it needed?

[tom10122]

it also seems like the arduino board gets hot, is that normal? Not printing yet just trying to connect

[Eaglezsoar]

I disabled all the temp sensors, swt to type 33. BUt how do I calibrate my motors? ALso in the link it talks of jumpering the drivers to enable 1/16 steps is that already done or is it needed?

The jumpers are under the motor drivers. You will have to unplug the drivers to see them. If all are jumpered then that is 1/16 stepping.
It is normal for the board to be warm to slightly hot, you need to have heatsinks on the driver chips and there should be a fan blowing on the
board around the area where the drivers are.

[tom10122]

no jumpers, I found the problem with the heat, the areduino was getting 12v form the ramps and caused it to get really hot. Still having issues connecting to pronterface

[Eaglezsoar]

no jumpers, I found the problem with the heat, the areduino was getting 12v form the ramps and caused it to get really hot. Still having issues connecting to pronterface

No jumpers - that means the drivers are set to use full step stepping, you will need to jumper those connectors and run at 1/16 stepping.
But it is your printer do what feels right. You will probably have the worlds first 3D printer running at full step and the hotend controlled
by a velleman thermostat.

[tom10122]

what is the difference in stepping, accuracy?

[tom10122]

ANDDDD i put the pololu on backwards, It wont work. Is there a diode i can jumper or is it shot?

[tom10122]

HOw hot do the chips get without heat sinks ? Because mine overheat after seconds!

[Flateric]

Normal I hate to say.

[foshon]

Make sure you set the current on the driver, its the little pot on the board. Be careful they are easy to break. You only need enough to hold and move the motor effectively, On my MM I don’t think I have any set much more than a third of the way up.

[Flateric]

But they still get hot and need to be cooled correct? With some type of miniture Aluminium block or actively with a fan of some kind? Just to be sure you do not get cut out?

[Polygonhell]

Depends a lot on the steppers, you can usually tune them to run without heatsink and fans, but the sweet spot can be incredibly small. They're much easier to tune with heat sinks and a fan.

[Flateric]

That's what I thought.

Rambo uses different step drivers I assume since it can easily be run without heatsink or fan cooling?

[Polygonhell]

The drivers are designed to shed heat from the back side of the device, the intent being that a copper pad is placed on the board itself to act as a small heatsink, I suspect that Rambo is in a better position with this than the pololu daughter boards if for no other reason than there is no airflow under the daughter boards.