The operative word in all that is “should” and in my experience Should and does are polar opposites.
Craig Townsend said:
Ray Dunakin said:
How do you plan to make them?
It should be quite simple. Because it is multiple H beams welded together to form a frame, I’m going to create 3 layers of etch. Top and bottom flanges (all one single piece) and then the web plates. When the web plates are intercepted with another web plate, I make a lap half lap joint. Every thing will be tab and slot so it should just slide together and solder. We will see.
Doing all the beam flanges in one sheet-part sounds good, saves all that mitering / soldering. And with the webs separate, it saves all that coping away of the flanges (which can be a real PITA).
For your webs, unless you’ll tab those into the flanges, K&S might have strip stock you could use which should cheapen up that aspect. Then just cut to length.
Cliff,
Still working on the design, but I’m thinking that by making the webs of the H beam out of etch, I can etch in lap joint if need by only etching in halfway through the metal, or create a majority of the web as a single piece that is folded. The outer web could be easily one piece with 4 folds with slots where each intermediate web attaches. That way it is an exact fit. Then the interior webs that intercept each other can be lap jointed by making an slot the thickness of the etch (or actually 1.3x the etch due to etching processes). When I get it drawn out, I’ll post a link here so you can see what I’m thinking about.
The nice thing about CAD modeling is that it’s cheap. Well the design part is cheap. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-undecided.gif)
Pete Lassen said:
The operative word in all that is “should” and in my experience Should and does are polar opposites.
That’s why I’m drawing it all in CAD. If the CAD says it works, and I use the CAD drawing to create my etch drawings then everything will work nicely together. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)
Craig Townsend said:
Cliff,
Still working on the design, but I’m thinking that by making the webs of the H beam out of etch, I can etch in lap joint if need by only etching in halfway through the metal, or create a majority of the web as a single piece that is folded. The outer web could be easily one piece with 4 folds with slots where each intermediate web attaches. That way it is an exact fit. Then the interior webs that intercept each other can be lap jointed by making an slot the thickness of the etch (or actually 1.3x the etch due to etching processes). When I get it drawn out, I’ll post a link here so you can see what I’m thinking about.
The nice thing about CAD modeling is that it’s cheap. Well the design part is cheap. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-undecided.gif)
Right, if you make the webs a 1-piece part with 4 bends, even simpler. Or tabbing individual webs into the ones being butting into, if I’m understanding you correctly.
Not quite getting the lap joint, but I’ll check out your model when your ready.
Are you planning on tabbing the webs into the flanges? That would make the parts self-locating / -fixturing.
I will try and finish the drag wing tonight and post some screen shots and a link to the model. Trying to design as many parts to be etched as possible, as the cost is per sheet size not part size, and I figure I’m going to have some empty space between some of the larger parts. And that 3D printing brass parts isn’t cheap (although I might have to hire Burl to help me make some if it’s cheaper than Shapeways.).
Well not quite done when I thought it would be done, nor is it done… But I think I have a way to work around the H beam issue. The etch is .022" thick, and the slots are 1.3 X Etch thickness or .029. That 1.3x is supposedly the minimum needed for an etched slot to function properly. If I calculate that right, that gives ~.007" for a light coat of solder. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-undecided.gif)(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)
Here’s the process of making it all ‘click’
Step/Part 1
Step/Part 2
Step/Part 3
nice and strong joint the way you designed it. that looks like the better way to do it.
Pete Lassen said:
nice and strong joint the way you designed it. that looks like the better way to do it.
Now I just have to figure out the mirror side of the web and flange. The irony of it all is that the entire thing gets covered in a sheet plate, so all this fancy work will get covered up. But I think the construction style will strengthen the blade. If I need to add weight, I can add some lead fishing weights to the open areas.
Okay, I’ve finally got it all figured out.
Here is the completed drag wing… It’s only 9 parts, counting the H beam as ‘1’ part.
This part is 99% done. Now the big debate. Should I process this all the way thru and get it etched, assemble it, or wait until the entire model is done?
Especially with those outer skin layers, that’ll be super strong!
Cliff Jennings said:
Especially with those outer skin layers, that’ll be super strong!
I drew it up exactly like the prototype plans that I had! I’m hoping it will be strong enough to actually function as a plow. Now just to learn how to get better at soldering, and get this piece together. I’m guessing I’ll be using a variety of solder and solder paste.
Very cool! It’s great to work with proto plans.
You’ve got one of those resistance soldering setups? I don’t but I hear it’s really helpful with brass assemblies.
I have a resistance soldering set up, but I’m still learning how to use it. I figure I’ll be using a variety of temp solders. Now on to the next part of the CAD drawing. I’m actually making faster progress than I thought. Slowly working my way up to the more complicated parts.
Nice. All in brass?
Cliff Jennings said:
Nice. All in brass?
That’s the plan for now. As many flat etched and folded parts as possible, and what can’t be etched will be 3D printed. Those same parts are 3D printed in brass on my plastic model anyway, so it’s not much of a change.