Monday, April 6, 2009

Final Assembly part 1

Last Thursday evening I had a go at assembling the final bits and pieces of the RepStrap. I started trying to mount the opto end stops... I came into a few annoying problems.

As you can see, the RepRap opto end stop does not like my Perspex opto end stop spacer... My holes where not lined up 100% and if I recall correctly either my dad or I said that we wern't building a swiss clock and we could just drill holes where ever so long as its roughly right.... WRONG!!!
Here is a shot of the reverse side once I forced the parts together... as you can see, its far from square.

Then there was a nother battle trying to get that to line up with my holes I drilled into the X & Y end brackes. Ok so I didn't drill my holes properly and rushed them a bit... But does this image not look a bit odd??? Where is the ethernet cable (cat5e) supposed to go? How is it supposed to reach into the connector? & yes if I swapped the opto end stop around that didn't help either because then its up against the drive screw / threaded rod.

I had to cut a bit off the end of the X stages threaded rod. I had a first go at using my Dremel. Its pretty cool...

Unfortunately the cutting disks dont last too long and snap easily... I borke 5 cutting disks that night! I only managed to cut both sides of the Y stage and one side of the X stage.

The next things I need to get done is, cut the other side of the X stage and cut for the Z stage as well. I ordered a piece of Perspex to mount all the PCB's and the hacked power supply on to.

One thing I can't quite understand is why or what is the great need for a OPTICAL end stop and not just a simple limit switch??? surely a simple limit switch is way cheaper???

That goes for the stepper driver board... It looks a lot more complicated than a board that Murray Horn designed.

If I get time - this could be a year from now - I will try contribute my modifications to the RepStrap and show where I deviated and what I think should change to have a successful RepStrap, but just a bit cheaper.

So far I would replace the Z bearing arm holders... The things that hold the Z satage to the vertical base. I used angle brackets for that. I would swap the opto end stops for limit switches. I would use Murray Horn's stepper boards to drive my stepper motors...

One last very annoying thing... I ordered the electronics from the RRRF. They were expensive and took a long time to arrive. The name says Complete Arduino Electronics Kit. In the RepStrap build instructions it say I will need SIX (6) opto end stops... WHY then does the COMPLETE Arduino kit only come with THREE (3) opto end stops???

Very annoying... Now I am going to have to etch another three (3) opto end stops myself - which will take time - and even worse... I will have to covert that opto end stop double sided board to a single sided board - which will take time - because I only have single sided copper and it took me forever (3 months) to master etching PCB's with ferric chloride... stuff I hate! :(


Anonymous said...

Can't you just go to to get optical endstop kits? they're USD $3 each.

OuZo said...

Thanks, but I live in South Africa and for me to put an order of $9 is not worth it because the shipping costs will be higher thank the cost of the package.