SD Press - Under the Kimono (Page 8 of 12)

Sorry for the decreased presence, guys. I still try to check in and help out whenever I can. Here's a bit on the PWM header:

The PWM header (CN17) is meant to be an optional expansion and is not used for anything as the printer is shipped. It is controlled by a FET (Q7) which is connected to pin 41 on the AT90 which is properly mapped as pin 16 for the fan pin in the firmware. Using the M105 command will properly change the state of this pin. However, unfortunately there was a mistake on the board where the FET to be connected incorrectly (the gate and source pins are reversed), causing it to be always on and not able to properly control the PWM header. We regret that this has happened and have since made the necessary changes to the board to fix this issue.

https://www.youtube.com/watch?v=1ytCEuuW2_A

So that explains the weird behavior I was seeing on my scope. A dirty 12v feed.

Any way that FET could be rewired with a rework station, or is it something that would require a breakout board to fix?

I have a hot air reflow station. Just wasn't sure if the fet could be flipped, or if the traces on the board were located incorrectly.

If you make the change, I'd appreciate any pics/notes you could post describing the process.

I'm not sure if I'll give it a try or not...  but it's tempting.

Well, that shouldn't be too bad to fix. I'll probably look into fixing it when I have a little more time.

By the way, is there a schematic for the Press board somewhere?

Lame.

Yeah. I could understand it if their board was substantially different from the open source boards, but let's be honest, it isn't. So they aren't really protecting anything.

MacGyverX,

Could you adjust the size of the two mounting holes?  The screws I have are pan-head screws (Head is 5.85 mm diameter, 2.5mm thick - may a 6mm opening, 3mm deep?)

the lower left mounting tab for the fan presses up against the bed probe.  I think the best solution would be to simply remove that tab (3 mounting holes for the fan should be enough).  The other option would be to add about 1.5mm of thickness to the rear of the mount (the part that is up agains the print head.  -- I think I prefer the first option, because it keeps things thinner.

The bigger problem is that the blower doesn't fit... I guess I didn't think about the fact that I was replacing a 40mm fan with a 50mm blower... but it cannot sit as low as needed, due to the carriage.  Any way to add a tab or something to the top of the mount that the blower could be mounted to? there's definitely no room on the right side of the printhead to add a bracket there.
If not, there's a slim chance that I could drill a hole through the blower casing without interfering with the fan blades, but it'd be awfully close.  I couldn't find a 40mmx15mm blower anywhere.. they are all 40x20, which would be too big.

Any other ideas?

Blower:

I failed to account for the tab for the lever on the stock extruder. Totally my fault there. I'll see about mounting it under the carriage behind the hot end. I'll switch back to the stock setup so I don't make another mistake like that.

What I really need to do is model the entire X/Y carriage. I'll start that later today.

On a completely unrelated note. I swapped out the stock extruder on my SD2. Did the firmware update for it. Installed the new hotness. Just to find out who ever installed the hobbed gear on the extruder at SD completely stripped out the grub screw (like completely...). Further more, When I have the unit flipped over. I saw one of the traces lifted off the Printrboard. (!!!) I was just printing mins before I took it apart. Electrically is works- But crazy fire hazard. So now I need a new controller. (*sigh* yay..)

Yeah. This month or so has not been nice to me. I ordered a RAMBo (1.2) board for the SD2. It has a nice feature set. I guess for some folks the downfall would be the integrated drivers and the 1/16 microstepping. But I have not issues with that. One of the nice things about it is it has a software controlled trimpot & microstepping (so no jumpers or the 'tongue to the left while turning the trimpot' for adjustments.)

Anyway, back to the Press stuff. I am about a quarter done on getting measurements of the X/Y gantry. I have not switched the business end out due the fact I am not down to one working printer. (Just in case I need to print something for the SD2, I can.)

No problem. I actually just deleted the post because after checking, all I have is an x and y motor... unless you think you can push filament with a GT2 pulley