Building a scanner out of wood - bad idea?

[shobley]

Hi I recently put together a scanner on a wood breadboard. The more I look into this, the more I see people using aluminum.

I have pretty hefty heatsinks on my amps - I ran them last night for about 30 minutes and they were barely warm. But I'm wondering if I should re-engineer with aluminum.

The laser head, driver, and dac are all on aluminum angle stock with airflow under them.

Here's a pic:

[andy_con]

na its easy

http://www.laser-man.co.uk/2006/inde...id=45&Itemid=6

[shobley]

Thanks,

I kinda followed your lead when I built it.

Steve

[allthatwhichis]

My first projector was all on wood. I used CD cases for laser shims and fine tuned them with post it notes. Works well for a while, but you will want to go to metal one day.

[buffo]

Wood flexes. It swells and shrinks with humidity and temperature. Plus it's a lousy heat sink.

Aluminum is harder to work with, but only slightly so. You can cut alumimum with the same saw you use for wood, you just need to GO SLOW. Aluminum is stiffer, so things stay in alignment better. Aluminum is also a good heat sink.

Finally, Aluminum will hold things tighter than wood will. (Threads are less likely to strip.)

Wood is fine for prototyping, and for your first effort wood makes sense because it's easy to make changes. But aluminum is a lot better in the long run. Once you know how you want everything to be, re-make the projector base in aluminum and you'll be all set.

Adam

[mikkojay]

Hey shobley, good question- I have been thinking about it while waiting for my parts to show up in the mail.
Here is a nice chunk of AL
I found it on ebay while looking around- btw, it is in your state from what I can tell. Has anyone come up with any other creative enclosures? What about a reinforced PC/Server case? A toaster oven? The proverbial breadbox?
Carmangary (I think it was) had a pretty cool box fashioned out of diamond plate.
I used to work for a company that repaired older PC gear- our scrap boxes were like a goldmine for all kinds of brackets, gears, etc..
One other thing- as far as rigidity goes, all wood is definitely not created equal. A piece of oak with heli-coils would be OK, but I haven't decided yet. It will probably just depend on what kind of budget I have left, what I can find in my garage, and how big of a hurry I am in to see patterns on the wall. I have some pretty nice steel plate in the garage, but I don't want to build a 50 pound tank either. Hmmm-
This is cool, but I'd rather design and build something than pay that much.
Oooh, that reminds me, I have an old ham radio chassis in the attic- gotta go!
~Mike

[Dr Laser]

Building a scanner out of wood - bad idea?
Yes it is a bad idea indeed. Prototypes are better made from hard cardboard so it's easier for machine shop to cut you what you need from aluminum.
Beside everything Boffo already said I say wood is a great material for shelving, good for a fireplace but it TOTALLY unacceptable as a foundation for anything optical/heat/laser related. For a love of Laser God don't waist your time with wood.

[shobley]

oops...

too late.

[buffo]

No - not too late... Just remember this thread when you go to re-design it. The next version can be mounted on aluminum. (Trust me, there is always a "next version".)

Adam

[mikkojay]

This is about the means to an end, to scratch the first itch, with purist purity to evolve as it comes. The near end is to see if that pile of ebay cha-ching will really make the cool patterns in my head go from thought, to mouse, to pc, to scanner, to laser, to wall, to eyes! After that is scratched, we can sit back and get particular. It is nice to do it "right" the first time, but I usually redo nearly every project because I am normally my own worst critic (sounds like buffo knows what it is), so a quickie to see it work never hurts. Just my 2c
Cash$$ola is my biggest critic at the moment.
~Mike