Sunday, September 11, 2011

Z-Coupling Upgrade

Testing the z-axis revealed that the z-couplings have a bad habit of letting the motor shaft slip from them over time resulting in the threaded rod dropping from positions.

If I had a working printer handy I would have used Prusa Z-Coupling modification by Nophead but instead opted for the low cost lead-screw variant by Keegi since the hardware store was more accessible at this point.

Vinyl tubing and a coupling nut

I used a lock washer and hex nut to keep the coupling in place so it didn't unscrew itself from the threaded rod.

The lock washer between the two nuts keeps enough tension/friction so the coupling wont unscrew itself

Part 4: Z-Axis Build out

After mounting the smooth rods and measuring their placement with a plumb line I proceeded to mount the z-axis motors. However the slits for the m3 bolts were not positioned exactly where they needed to be, so some TLC from my dremel and 15 minutes later the motors were mounted successfully.
Drilled bigger holes with my dremel
 Once I worked up the courage to mount the X-axis on the smooth bars I had to be quick the epoxy before it dried up. About 10 stressful minutes later my hands were covered in hardened epoxy film but the x-axis was mounted successfully on the smooth bars


The epoxy did a great job of holding the bushings to the x-axis


Clonedel Spring Implementation
One of the cool things about the clonedel design is that there is no weird hex shaft for the hex nut and spring assembly to get stuck in.  Also it just looks cooler because you can see the springs compress as the x-axis moves.





Saturday, September 10, 2011

Part 3: X-Axis Assembly

I've been holding off on this part for some time because I was trying to order some replacement parts from Metrix Create Space regarding a piece that was poured rather thin from my eBay supplier and which I sort of repaired by using epoxy to glue it back together. The part in question is responsible for clamping down on the two X-axis smooth rods but was damaged during shipping (I think). This piece exists because with Clonedel's you cant really cast holes when you make a mold.

Regardless I pressed on and assembled the X-axis with success, well see how it holds up, a replacement will be printed post hast anyways...just in case.

x-axis assembly

The repaired piece upon closer inspection

I will say that an advantage to this Clonedel part over traditional printed parts is the absence of the shaft for the spring and hex nut thus resulting in no jamming with the spring and bolt.

Part 2: Y-Axis Build Out

After rejigging the frame, tightening everything up again after moving into my office, I was ready to actually make some real progress and install the y-axis.

After inserting an extra hex nut to accommodate for the "modified" (violently dremeled off) m3x25 bolt that was protruding too far into the pulley assembly area I was ready to get things moving.
Using aluminum pulleys which I love

With the help of my office-mate I was able to apply the epoxy and then evenly attach the bottom MDF plate to the newly modified Resin bushings with brass sleeves. Again with my colleagues help, he held down the T5 timing belt as I secured them with the m3x25 bolts securing the Y-Axis in place. 

Bottom view of Y-Axis
T5 Belts has good amount of tension on it but not too much


The Y-Axis moved evenly and without too much resistance.A gracious amout of WD-40 the results were only improved by two fold. I have heard of people using felt bearings instead and I think this might be the way to go next time.

Back on Track

Working late, drinking, girls, hurricanes, and other social challenges have kept me busy but not too preoccupied that I forgot about the printer, just enough that I haven't been updating very much.

The metal boot attached to my door when I was evicted from my apartment for Hurricane Irene. I don't have enough 4-5 letter words to describe how I feel about college management and their interpretation of  "safety"(liability)
But no more! Grad school has started again, the city (DC) and its morally tempting temptations are 3.5 hours away (via Amtrak) and now that my office/lab is setup I have been building out the printer a lot. I have ordered a hot end (more on that later) and once that gets here I'll be almost good to go.
18th St (Adams Morgan) and in full bloom on a Saturday night....no RepRaps to be seen....

Also, like most inanimate objects I build from scratch, this one needs a name so I'm open to suggestions....