The first version of the mount (https://solidoodletips.wordpress.com/2012/08/01/dial-indicator-project/) didn’t quite work out. The magnets are strong enough to hold it, but they can still slide back and forth on the bolts. As the indicator’s plunger drags across the bed, the mount can wiggle and throw off the measurement.
I ‘m using 4 bolts as attachment points so there is less chance of pivoting, and made holes sized for the bolts so the mount can fit over them and sit flush with the face of the extruder. The hot end sticks out a little from the acrylic, so I left a notch for that.
I added holes in the back to push the magnets in so they would hold on to the bolts once the mount is set onto them. I would rather print this lying down so the holes would be drawn horizontally rather than vertically to give them a better chance of coming out round. I also want to have the hole for the gauge done horizontally, so I split the mount into two pieces.
The holes need to be in exactly the right spot, and the right size to make a solid fit. Since interior holes don’t print at the size designed, the surest approach is to print a few tests.
There are some strings running through the bolt holes from plastic oozing while the extruder moved past them. I’ll need to check on the retraction settings to see if I can minimize that. In the meantime, a bit of work with the exacto takes care of that.
One problem with printing multiple parts at once is that when the extruder moves from one part to the other, it can drag a little plastic with it, leaving blobs at the exit points. Retraction can help with this too, but printing one thing at a time will leave a smoother surface.
Now that I have the mounting plate worked out, I can use it as a base to put a fan on the extruder with a duct to blow air on the plastic just around the extruder. This would help cool small parts and PLA. It would look something like this one, from http://www.thingiverse.com/thing:16955.