question about RAMPS version numbers

After comparing the options for electroncis I've elected to build my own shield cuz 1) why the hell not and 2) I like how the design is modular (can replace individual components) while still being a single (double?) board. The gen 6 electronics are cool, but if something breaks the whole board is mostly useless. Anywho...

[www.reprap.org]
on the wiki there is a schematic labeled "RAMPS 1.2" but the bill of materials says "v1.1" at the bottom. Is that important? Do the different versions just move things around or do the components change?

Also, when the bill of materials calls for things like "eurostyle" terminals is that important if I live in America?

Additionally, there doesn't seem to be a list of the other parts necessary, like what connectors to get for the endstops and motors so that they connect to the shield correctly.

Motors plug directly into the pololu stepper driver boards. These boards come with .1" headers that you solder in. So you cut out four and solder them in sticking up instead of down.

I think the endstops are the same way, just a .1" (2.54mm) header.

OTOH, I still haven't figured out how to make a good connector on the ends of the wires to plug into those... which part do I order?

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I'm building it with Baling Wire

The only component change from 1.1 to 1.2 is needing a 20 pin 0.1" header instead of 10 pin. I updated the wiki page.

The eurostyle connectors are good, but you can replace them with some other 5.08 connecotor

We have been getting the connectors from here. [www.hansenhobbies.com] . You can get them from me at [ultimachine.com] also. I have not located the proper part number for them. And of course there are tons of other connectors out there that would work.

You will need 1 4 pin housing for each motor, and 1 3 pin for each end of the endstop cables. Make sure to get extra connectors to make up for ones you mess up.

Also, with the v1.2 of the board, there are motor connectors on RAMPS. You can attach all the headers on the Pololus pointing down and it looks much nicer.

Is this a picture of the 1.1 or 1.2? [www.reprap.org]
Do you mean that the version 1.2 circuit has you connect the motors to the board rather than directly to the stepper drivers?

I am inclined to get the DIY RAMPS kit but the website says it's out of stock.

I've been seeing if I can source the components on my own and just get the $10 PCB that is in stock...but it's slow going.

Okay, that other one must be an earlier version. This one is labeled 1.2 [www.reprap.org]
Is there a reason this one doesn't have any stackable headers? The BOM is listing 2x18, 6, and 8 stackable headers that must go around the perimeter, but I don't see them in the picture.

This is my attempt to figure out where the various things in the bill of materials are supposed to go.


Edited 1 time(s). Last edit at 01/30/2011 09:43PM by makeme.

The stackable headers go around the outside of the board. In my case, I used 0.1" pitch header connectors instead of the stackable ones, as I don't intend to mount anything on top of my RAMPS.

Cool.

In terms of buying the electrical components, what specifications is it important to meet?

For example, the BOM asks for a 5mm LED, and then points you towards a 3mm one.

In terms of capacitors, what specifications must be met or exceeded and what can be ignored? I'm sure the capacitance is important, but what about the voltage rating? Does the style matter, like, if the leads are axial can you just bend one down so it's parallel with the other one and use it the same way? Is it important that one of the capacitors is a different style from the others?

Voltage must be met or exceeded. Capacitance must be as specified. Capacitor type must be matched. You need electrolytics for most of them, with one ceramic. Case style is matter of convenience, if you can attach it to the board then it will work. Getting radial caps will make it easier to assemble but it should be possible to coerce an axial component into place.

makeme, your placement diagram looks good. You got it all correct.

The diode is supposed to be 3mm. It never got updated in the BOM from version 1.0. I updated the wiki page.

Also, the stackable headers being easier to solder on "home fabbed" single sided PCBs is the reason they are still in the BOM.

I followd the link to that German site and grabbed a few nuggets of information there (thanks google translate). That, combined with the little notes on the BOM itself allowed me to find everything on Element 14. But then I noticed that the Ultimachine store had the DIY kit listed, and that I wasn't so sure I trusted Element 14, so I just went with the expert-assembled kit. I don't think it was described as including the stackable headers, but after reflection I'm not sure that I have anything to add on top of the circuit anyway, and if I need to I suppose I can just switch them out.

It's cool. I learned some good stuff in the process.

Can I just use mechanical end stops instead of optos? Does it matter?

makeme Wrote:
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> Can I just use mechanical end stops instead of
> optos? Does it matter?

Yes you can. No it doesn't.

You might want to double-check if you should have a resistor in series with the switch though. It's been long enough that I don't remember. Do you want it pulled UP or pulled DOWN? If you deviate from "standard behavior" you'll need to make changes in the firmware to match.

I think it's set up so you can just wire a switch in and it'll work, but I can't remember which to connect it to (vcc and signal, or gnd and signal?) and if it's supposed to break the connection when the endstops are hit or it's supposed to make the connection when the endstops are hit. But it's one or the other, somewhat configurable in the firmware, and yes, it'll work and without much fuss. Lots of people do it, especially if they (like me) already happen to have the switches on hand.

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I'm building it with Baling Wire