Thursday, January 7, 2010

Extruder Block

Extruder Block Front




Here's my extruder block. The addition of a usable bandsaw has helped immensely, and the pedestal drill is significantly tighter, although still can't drill a straight hole. As you can see, this piece is a fair bit neater than my others. I have tried it with my splined motor (no pics yet though), and it works fairly well on some copper cored wire. I haven't made the large cut-out for the thermal break yet as I haven't actually decided whether or not I'm going to make my melt barrel that way.

Originally, the bearing was too far over by about half a mm, so I enlarged the hole a little bit and put in a matchstick to hold it in the proper place.

I have read the A4983 datasheet with an eye to current capacity, and I will have to heatsink them. The current pot and Vbb capacitor on the pololu breakout boards are taller than the chip, so that will make it a fun exercise. I think I will leave the pot sticking out the side, and either put a copper strap over the chips or cut a recess for the Vbb capacitor. A 40mm chipset heatsink has made itself available for this project.

1 comment:

  1. Well done I'm making the ext ruder block for my Mendel version out of Acrylic block as its easier to see what your doing in 3D.
    I have already made one for the Darwin ext ruder out of Acrylic block not sure if I blogged that one yet. Interested in you mentioning the A4983 as I have those and A4980 devices I got tiny little stick on heat sinks from Farnell over a year ago with the idea of using them on the A4980 devices.
    Just soldering the chips on will be a fun exercise as the pin pitch is half that of the A4982 devices I tried to find the larger package but no where had them.

    I got a chest infection so not done much this week aside from making Stepper controllers, ribbon cable and re-working the 1.1 motherboard and 1.2 Ext ruder controller (Removing the Ethernet connectors and AT power connector..Didn'T read the Extra notes on modifying these boards for Mendel till Tuesday.