Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

To those who have been following the DLP thread(s):

I have spent the last few weeks experimenting with producing double sidedpcbs with my E260 laser printer. What I found is that the hack I havedocumented is not adequate for DS boards. The repeatability is almostperfect in the X axis, but the Y axis (defined as the axis through theprinter) varies a bit, sometimes quite a bit, from run to run.

The problem is that the paper path is not quite straight, which resultsin some friction and hesitation as the carrier moves, especially as ittraverses the space between the input rollers and the transfer roller.Once the carrier enters the printing area it seems to move at a constantrate.

The biggest culprit is the Manual Feed Paper Guide which forces thecarrier to actually bend a bit. In fact, if you tape the rear edge of thepcb to the carrier, the top surface of the pcb will touch the 4mm shaft,causing (in the worst case) the timing to be so bad that either thecarrier stops moving or the printer errors out.


I have redesigned and redocumented the hack and will be uploading thelatest version in the next few days. This only works with the MCUversion of the Modification! The changes are:

1 - The input rollers now use a 5 mm shaft and 13 mm rollers instead ofthe 4 and 10 currently used. I upped the shaft diameter because the 4 mmshaft fits too loosely in the notches. You can still use the 4mm shaft ifyou already bought it by wrapping 5 or so turns of electrical tape aroundthe ends to bulk them up to about 5mm. The added 3 mm to the rollerdiameter allows pcbs to easily fit under the shaft as the carrieradvances. Both the shaft collars and aluminum spacers (rollers) are now5mm ID. That said, if you already have the 10mm rollers they will stillwork, although thick pcbs might be a bit dicey.

2 - The Manual Feed paper Guide is not used and can bediscarded.

3 - I have also deleted the Center Bracket. It is not necessary since thecorrected paper path now feeds the carrier in a very straight line anddoes not touch the Center Bracket.

4 - The reflective sensor is not used as the NPIS. Instead we are usingthe U shaped transmissive sensor that was originally called the NarrowMedia Sensor. It is mounted on a small piece of aluminum angle that alsoacts as a centering guide. This new bracket is mounted on the swing-downFront Cover.

There are a few other changes that make the conversion a bit easier. Moredetails on both the improved hack and double sided boards tocome.

Mark