Basic layout 101

[Generatorgus]

I've been "playing" around with model engines for a couple of years now, and have come to the realization that I have no idea how to do basic layouts,
My version is to put some Dykem on the piece and scratch lines on with a scriber using basic drafting techniques, which I'm quite familiar with. Not at all accurate.

Are there any tutorials showing this and the basic tools needed.

I'm sure I'll get at least a couple of replies.

Thanks in advance.

GUS

 

[Philjoe5]

Gus,
Some folks can get accurate (let's call that to within +/- 0.001") results with scribing using a height gauge or drafting techniques. I couldn't ever get close enough.

For drilling and milling I scribe out my lines first to keep me in the ballpark. Then I find my edges with an electronic edge finder. They aren't expensive, about $30. They can get you to within 0.001" if used carefully. Once you find the edges of your workpiece with a little trigonometry you can drill bolt circles, or other patterns accurately. The scribe lines will keep you from missing a turn on the x-y handwheels. Important if you don't have a DRO, which I don't.

Hope this helps,

Phil

 

[thayer]

I use dykem, a digital height gauge and an import surface plate to mark out my stock, but like Phil, mostly as a backup. I trust the edge finder and hand wheels a lot more than my layout skills. I am using the A2Z CNC monster mill, so my DRO is on screen in Mach3.

Then again, it was my layout that stopped an edge-finding problem before it got worse. I will often run my milling code set to just touch down on the stock to ensure everything is in the right place and noticed a significant miss when drilling the porting for my current build of Elmer's #33, see Post #5.
http://www.homemodelenginemachinist.com/f31/elmers-33-novice-makes-chips-19478/

I believe that issue came from not having the edge finder's tool holder fully seated on the spindle.

Thayer

 

[Philjoe5]

Another issue with the electronic edge finders with aluminum bodies is that if you overtighten them in a drill chuck you can distort them by 0.005" or more. Ask me how I know this. It took me a while to track this problem down. Once I solved this problem, I've managed to get accurate, repeatable results for the work I'm doing.

Phil

 

[thayer]

Interesting. My edge finder is mechanical though, and lives in its own tool holder.

 

[Forestgnome]

http://books.google.com/books?id=7e...sQ6AEwAA#v=onepage&q=machining layout&f=false

Starting on page 53.