if you're using the automated build platform, it's easier to just solder the trimmed plug on to the motor leads than solder the leads to the plug.
the black delrin pieces are shown with silver nuts being placed in the hex recesses. But nothing ever attaches to these later that is shown in the assembly guide. There are clear holes through to them, and I'm probably going to add some capscrews that will attach to them. It's not clear why they're shown or provide for, but I assume that they can be used to increase the stability of the position of the delrin guides.
I have the same issue, the same happens with a bearing that fits well in the shaft but is not shown in the instructions. There is an acrylic piece very similar to the one marked as "D" that seems to be an useless spare in the kit. I tried to place the bearing, the misterious acrylic piece and the bolts in those holes you mention, but it the acrylic piece doesn´t match, i still looking for the answer… Anyway, the MK6 works great, so maybe this is an anecdotic issue.
The alternate D part is likely the one used in the 1.75mm configured extruder where you don't need the thumb-wheel filament tensioner.
If you look back thru the instructions, you'll see the following:
Add nuts to Plate C.
Add four nuts to Plate C as shown. This is where you can mount a Magnetic Rotary Encoder if you choose to add one in the future.
In other words, they provide for points where you could mount a magnetic rotary encoder, or other bolt-on accessories you may choose to design at some later point in time.
They're optional, but those mount points exist across all the extruder designs from the first cupcake batch (MK3).
Found the attachment of the thermocouple to be the most problematic part of the build. I secured it with the capscrew and washer, but after the ceramic tape was in place, it came loose. I already had started to tape the ceramic tape in place, and it doesn't easily remove without tearing and damaging the tape.
My advice would be to tape the thermocouple lead in place firmly before adding the screw to retain it. You'll still need to be very careful that it is firmly enough gripped to not come loose during the rest of the handling.
Also : I think the instructions show adding the heater core first. I'd add the thermocouple first, then the heater core. The core can go in either way, so to make sure that the leads for both the TC and the HC come out the same side, attach the thermocouple, and then insert the heater core so the leads match.
TC Fix for a solid installation.
What has worked well with my Thermocouple is to —- drill a 1/8" (?) hole into the block near the TC mount location. The hole should be about 1/8" deep. I then wrapped the TC in Kapton to about two inches outside of where it will exit the final insulation wrapping ( I had a problem from maintenance where the TC wire insulation frayed and shorted to the block.). I then bent the tip of the TC by 90 degrees at less than 1/8" from the tip. I then put the tip into the hole I drilled. Next, using the MBI instructions for the TC install, capture the TC wire beneath the washer and screw. Now, all my yanking and such is against the captured wire not on the TC tip. The TC tip is buried in the drilled hole safe and secure. If you look at the New Ultimaker's block they did the same thing. Smart people think alike. ;-) I do not know why MBI didn't do this - I told them what I did in March via phone and email and they said it sounded, "OK." — Go figure? Maybe manufacturing lead times?
I would add a test at this step to verify that the thermocouple is insulated from the aluminum block. I had taped mine as recommended but when the screw was tightened the TC punched through the tape. A quick check with a multimeter at this stape could save the extruder controller down the road.
Just be aware if you shorten the cartridge leads that the internal leads are silver and if they look copper you haven't gone far enough.
Putting the PTFE tube in the freezer wasn't enough for me. Here is what I did to get it to work:
- Insert PTFE tube into threaded end of heater tube.
- Push through until heater tube and nozzle threads can be started into thermal core.
- Tighten heater tube followed by nozzle into thermal core. (Threading components into thermal core will push PTFE tube all the way into end of nozzle)
This trick utilizes the threads as the driving force to propell the PTFE tubing all the way to the end of the nozzle, rather than trying to fully seat the PTFE tube by pushing at the end. Doing it the way the instructions suggest is like trying to push a rope.
Supergluing the spacer feet is more than just gluing together parts that are held together by the nut/bolt combo. There is an extra piece of acrylic for each side that needs to be attached by gluing. I didn't realize this at the time of initial construction and ran into problems when I was trying to attach to the Z stage. In this picture
http://farm6.static.flickr.com/5030/5622184875_0195cdee0a.jpg
you can see the second layer of acrylic that makes the bottom of the assembly flat instead of balancing on the bottom boltheads.
I just wanted to point out that it would be convenient if the instructions showed that you need to punch a hole in the ceramic tape with the tube before putting the PTFE in there. However its not a huge complaint since you can punch the hole even with the PTFE tube in there.
Hey, can somebody expand a bit on what the thermocouple looks like when "wrapped" in the tape? The instructions here on the site say that it's needed and their photo doesn't show it. Am I looking to wrap it in a mini-cylinder of tape? Does the tip of that thermocouple need to make physical contact with anything, or is it OK inside that tube of tape? I'm guessing that the intention is that the washer compresses the tip in its tape against the heated body, and this suffices to couple the heat? How many layers of tape is too many?
Thanks! Andy
I just wanted to point out that it would be convenient if the instructions showed that you need to punch a hole in the ceramic tape with the tube before putting the PTFE in there. However its not a huge complaint since you can punch the hole even with the PTFE tube in there.
You might want to note that the plunger is that little plastic piece in the middle of the "C" pieces. It took me a while to figure out where it was!
Thanks! That's exactly why I was reading this page!