Saturday, 7 January 2012

Mendelmax Frame

Two weeks ago I assembled my mendelmax frame.

I'm not going to go into details how to assemble this, this is well documented on the web here

This is just my attempt at following these directions :)

I spent some time tapping the t-slot and drilling the two holes, as I didn't want to muck it up. Since I had no spares!

I thought I had all the required tools, only to find that not all tap handles are equal.  The t-slot needs to have some of the ends taped with a M5 tap. Unfortunately my tap handle can only hold taps M6 - M12.

Getting another Tap handle wasn't an option, as this was X-mas holidays time. Nothing is open!

I printed a M6 to M5 converter in PLA, this worked for two taps then the inside M5 part got stripped, PLA is just not strong enough. I then made some tiny aluminum jaws out of some L aluminum scraps I had.  This worked fine and allowed me to complete all 16 taps. Making the jaws nearly took as long as the taping!



First plastics and t-slot joined.


Front and back of the mendelmax


Both front and back joined with upper side bars.
If you look closely you can see the self tapped screws to the top of the four t-slot sections.


Lower side bars attached.


Top t-slot added. This is attached via the recessed self tapping screws I pointed out before. You really need a real Torx T-25 screwdriver for this. The head is 18mm down a 6mm diameter hole, and most magnetic tip changeable screwdrivers are just far to wide (like mine was)   

This is the basic MendelMax frame finished

I don't have any "Top Vertex Y 2 off" as the docs didn't mention these. I talked to the creator of the MendelMax about these, he said they are probably going to drop these parts as they are not needed.

I was planning on reusing my smooth rods from my Prusa, unfortunately you can't.  The Prusa Y is reusable as the MendelMax Y axis, but the Prusa Z is to small, the Y from the Prusa can be used as the Z on the MendelMax, but you have to get new Y smooth rods.

I'm now waiting for new smooth rod.

Friday, 6 January 2012

3d extrusion from 2d silhouette V2

I was trying out my script on a logo for a friend and it failed!

The logo was just text characters in a fancy font but contained the letter n, the script when working out the y size on the box only checked the left and right hand side of the box to see if it was still within the silhouette, thus it turned the n into a solid cube.

I had been planning an updated version already as I knew it wouldn't handle an enclosed hole in the silhouette, this is the same issue.

Here is the new code, still alpha, still has the exponent colour bug.

-------------start of silhouette2openscad.py code ------------


import Image, random
def findbox (x,y):
    xlen = 0;
    ylen = 0;
    holeflag = 0;
  
#    print '(x,y) = '+str(x)+' '+ str(y)
#    print 'current (x,y) '+ str(pix[x,y])
#    print 'current (x+1,y) '+ str(pix[x+1,y])
    while (pix[x+xlen+1,y] != 0):
        xlen = xlen + 1
#        print 'xlen = ['+str(xlen)+']'
#        print 'current (x+xlen+1) '+ str(pix[x+xlen+1,y]);
        if x+xlen+2 >= im.size[0]:
            break

#    print 'start y current (x,y) '+ str(pix[x,y])
#    print 'current (x+xlen,y+ylen+1) '+ str(pix[x+xlen,y+ylen+1])
    while (pix[x+xlen,y+ylen+1] != 0 and pix[x,y+ylen+1] != 0):
        ylen = ylen + 1

        for t in range(x,x+xlen):
            if (pix[t,y+ylen] == 0):
                ylen = ylen -1
                holeflag = 1;
                break

#        print 'ylen = ['+str(ylen)+']'
#        print 'current (y+ylen+1) '+ str(pix[x+xlen,y+ylen+1]);

#        if (y+ylen)%((xlen+1)) == 0 :
#            break
        if holeflag == 1:
            break
        if y+ylen+2 >= im.size[1]:
            break

    print 'color(['+str(random.random())+','+str(random.random())+','+str(random.random())+']) translate(['+str(x)+','+str(y)+',0]) cube(['+str(xlen+1+0.
0001)+','+str(ylen+1+0.0001)+',2.5],center =false);'
#    print 'translate(['+str(x)+','+str(y)+',0]) cube(['+str(xlen+1+0.0001)+','+str(ylen+1+0.0001)+',10],center =false);'
    im.paste((0),(x,y,x+xlen+1,y+ylen+1))
#    im.show()
    return

im = Image.open("logo.bmp")
#im.show()
pix = im.load()
#print pix[0,0]
#print im.size

for y in xrange(im.size[1]-1):
    for x in xrange(im.size[0]-1):
        #print pix[x,y]
        if pix[x,y] != 0:
            findbox (x,y)

-----------------end of code-----------------

 I wish there was a way to add attachments to this blog...

Tuesday, 3 January 2012

first update in 2012

Been keeping the reprap busy

I printed out a second green set of Prusa Iteration 2 parts for a customer, looks identical to the last set, so I didnt bother taking photos.

Today I started on an orange set for another customer.

I've not had any issues with my printer in some time, not even a nut has come loose, so I decided I would try printing a plate of vertex's estimated print time 8 hours!  (considering we have had over 40+ earthquakes in the last week, many over 4, some over 5, resulting in damages and loss of power in some areas. Probably not the best of ideas... but...)

First I had to regenerate the plates stl, to use my configuration.scad, this is not done automatically by the provided generation scripts with prusa iteration 2 source files.





They printed fine! and only took 6 hours 57 mins, thats 69.5 mins per vertex!
(I'm printing with a .35mm nozzle, and .25mm layers, 105mm/s max speed)

The reprap itself seems very tolerant of earthquakes, it wobbles, but the  x,y and z don't seem to move withing the frame. I may have to invest in a UPS at some stage though, for paranoia sake.


I'm not sure I would like to do this with the other plates, my retraction still doesn't work 100%