ErnieA said:
I'm interested in why you feel the Aluminum is "too soft". I make them out of aluminum all the time and there is no reason to be beating on these tools with anything but a soft mallet, no? I buy scrap aluminum bar stock to make my drivers and the cost is a lot less expensive than you later post quote. May I suggest anyone wanting to make their own look into a metal recycler and see what they have before buying "new metal". Plastic, urethane and tefflon are also available in scrap at many plastic manufacturers. We have several in Portland OR and I frequent their scrap bins to see what they have to offer and the prices for odds and ends are dirt cheap.
Knurling is the fun part! What kind of machinist are you anyway?
Just kidding!
The problem is: You have a beautiful, turned, tool with high tolerances, bright, shiny, made of aluminum...then it rolls off your workbench and onto the floor and it gets a great big ding on it. If the ding's bad enough, is the guy going to be able to file it to clear? If it's delrin, anyone can carve that with an xacto knife.
The prototype was made using scrap I had laying about...I wasted about 40% of it because it wasn't close to final dimension. Buying new stock lets you spend a lot less time getting the scrap to fit.
At the numbers I'm making, I want to be able to screw something up and not take a loss on it.
You know what that prototype cost to make? My time...oh, and the carbide bit, that wasn't free...and the lathe...and the inherent knowledge it took to turn the part to tolerance. I'm not expecting to get rich off it, but I'm also not looking to lose money on it either.
I make my own tools all the time, and often say 'if it exists, it's ALWAYS cheaper to buy it', and it's great to have the stuff on hand to make that one, specific, spacer. But you're not giving yourself enough credit, nor covering your costs, when you say things like 'I buy scrap aluminum bar stock to make my drivers and the cost is a lot less expensive than you later post quote.'