Sunday, 14 February 2010

Dremel Grip

Busy elsewhere last week, and now a lot of planning, thinking, and fantasizing, and finally a little bit of prototype cutting. First I got carried away with some engineering software to "increase productivity" and make my plans neater. In the end, it took several hours to create a drawing that by hand would have taken 5 minutes. To top it off, the software has a bug and I couldn't print the design the normal way. Howl!

The plan.

I drafted a grip for the Dremel drill. The idea is to have a pair of these, one larger at the back, one smaller at the front, to hold the Dremel in place on the z-axis car. I decided to go with 16mm MDF, which isn't ideal, but remember, I'm working on a prototype/version 1. MDF bends and also cracks easily, but it's also easily available. The grip pair needs to be exchangable so I can also fit my Bosch power drill and - if I ever should buy one - a real router.

The grip idea is not ideal. I might look at an alternative, eg, metal band, or double the width to 32mm by pairing them up. But for now it'll do.

I also spent some time on evaluating different configurations for the ball bearing slides. I think the best way to go is to have each pair of slides "side mounted", ie, their "tops" look at each other or away from each other, in the same way as you would side-mount them in a drawer cabinet. This seems to minimise their jiggle room. This also led to a pretty clear idea on how I would build each axis. More on that in 100 hours, after spending more time with the design software.

The actual wood cutting (effectively 7 small cuts plus one circular hole) was more laborious than anticipated. The main issue was my circular hole cutter. The beast is old and might just be good enough to cut cheese and even the drill bit was worn out. Swapping the drill bit became impossible because the set screw was locked in. Some force killed the rather soft and already worn metal screw head and I had to cut a new cross to be able to use a screwdriver to get it out. Adding some lubricant made it all a bit easier. Then the pitch of the screw was "like no other", so I couldn't replace it. Fortunately my repair was good enough to get the screw back in and get on at least for now. Bottom line: I need a new hole cutter.

The  implementation.

For the fun of it I also cut a 600mm board with my jigsaw to see how straight I am. The best I can do with my skills and tools is between 0.5mm to 1.0mm precision over 600mm. Ok, but not great. I hope that version 1 of my router will be more precise so it can cut the parts for version 2.

The logical extension is that version 9 should be able to split atoms.

No comments: