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What file should I give the machinist? I modeled the part in Fusion 360.

greenfish

Plastic
Joined
Jul 12, 2016
I want to have two copies of a part I modeled in Fusion 360. It's Aluminum 6061 or 7075 (whichever at this point).

It's a 7 mm diameter rod bent or milled or whatever 10-13 degrees at the ends and then milled flat at the ends with a tapped hole on each end. The overall length would be 340 mm.

I'm not quite ready for them to be made yet only because I'm not certain just yet on the overall length or diameter; I may want to change the length up to 20 mm and I may want to change the rod diameter up to 1 mm wider for the final model. In any case, I wanted to see what the machinist or manufacturer would want from me or if the f3d file is sufficient.

This would be my first time having something made.
 
The shop you have make the part may not use Fusion, and an f3d wouldn't be easily imported into other programs. A step file is nice depending on complexity. A 2d drawing showing the necessary dimensions and tolerances is mandatory. If you can provide a 3d model, you save the shop from recreating the model and charging for it.

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Is the step file file also a model and so would replace the f3d? I take it the step file is more universal for them to open in their CAM software?

I can create a 2D drawing from the model from within Fusion 360, but I'm not sure if I'm capturing everything I need for the machinist or manufacturer like all of the views they need or all of the measurements. I have great flexibility on most of it as far as tolerances.
 
STEP is one of the standard industry 3D file interchange standards. Think of it like PDF: lots of programs produce it, lots of programs accept it, but you don't edit it. You would keep your Fusion original file to make changes, and produce a new STEP output file to give the shop. I agree that a proper drawing in addition to the 3D file would prevent a lot of expensive mistakes.
 
One hole is an M5; the other an M6. Otherwise the part is symmetric.

The bends I do not see how to machine, and I'm not clear on how to determine an acceptable/doable radius on them given the material.

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Can I be Captain Obvious and observe that, except for the tapping, that's a beautiful example of a stamped/trimmed part, not a machined part?
 
Is it because of the bends or the "tabs" on the ends? It needs to be solid 6061 or 7075 if that matters. I don't know anything about the stamping process. I thought it might be turned first except for the ends, then bent manually perhaps, then milled at the ends.
 
no shame in it, but I'm guessing you haven't actually made much stuff using tools.

by definition, milling is a reductive process, and using a reductive process, you can't make the ends wider, only thinner. what you want to do, width wise, might not actually work even by "stamping" or "forging" both of which you can think of as "hammering' or "mashing" the ends.

parts such as this are usually made by taking a rod, "mashing" the ends, bending the offset or "squiggle" , trimming and drilling. if it were made by taking a larger piece of metal, cutting the middle down on the lathe and milling the ends, it would cost 80 to 200 times as much to make, and be inferior strength wise.

buy yourself some "armature wire" and a hammer. bang on it and learn.
 
Is it because of the bends or the "tabs" on the ends? It needs to be solid 6061 or 7075 if that matters. I don't know anything about the stamping process. I thought it might be turned first except for the ends, then bent manually perhaps, then milled at the ends.
Check out wire forming, like how coat hangers are made. It looks like your rod is 1/4" or 5/16", so this is still within wire forming size, especially in aluminum. Their dies are something like 2x or 3x diameter minimum though, so you may need to smooth your corners just a bit. They will also use ground or cold finished stock which will have a shiny finish. A lot of shops can do 2nd and 3rd ops, so stamping the ends probably won't be an issue. You may have to drill and tap the holes but I see this as using cheap drills loaded with drills and taps and zipping them out by hand.

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Is it because of the bends or the "tabs" on the ends?
It's because people make parts just like that by the hundreds of thousands, or the millions, in press dies. Feed solid rod in, squash the ends, offset the middle, trim and punch the squashed ends. I'm not a stamping guy, but I'd guess two hits per part, and you could probably do 40-60 parts per minute no problem.

Only question is whether the 7mm 6061 or 7075 in whatever temper you specify has enough ductility to squash without splitting. Generally, you'd specify a softer temper (-O or maybe -T4) for better formability. The usual -T6 temper might be unhappy on a cold press. If you found a vendor who can do hot stamping, no problem.

Now if you're not planning on making at least 10,000 of these, forget about having a progressive or compound press die made. But if you need them in large quantities, paying the upfront cost of a die will be a good investment. And you can work out the technical details with your diemaker.

If you just need a handful of these parts, you can probably bodge together some crude dies to use with a shop hydraulic press. For instance, the end flattening could be done one end at a time in a die that's no more than a piston and anvil with a controlled mininum distance.
 
If you just need a handful of these parts, you can probably bodge together some crude dies to use with a shop hydraulic press. For instance, the end flattening could be done one end at a time in a die that's no more than a piston and anvil with a controlled mininum distance.

NO!!! totally lost the whole forest for the trees my friend! he says he wants TWO, repeat TWO!!!

job for a HAMMER AND A DRILLPRESS!! H-A-M-M-E-R!!! you are right on about temper, though,,:D
 
This is a press brake and hydraulic press job. I worked at a place that banged out hundreds of these with dedicated tooling but would do prototypes in a few hours with basic tools. Like the other poster said its all about the correct temper because that end will split open otherwise.
 
I only want a pair or two pair made to start. I want them to be professional looking, not just banged out. I will have them ano'd in clear after I try the first pair.

I may be able to eliminate the bends and not have the tabs flared out at all, but I need to check some outside measurements and consider some forces. One goal is for the rod "not to bend" under some loads and some angles. To what degree, I have not yet determined.

I like how perfect machined parts can be, so I was hopeful that this could be machined.

I think within a month or so I should have some other analyses done, so I can determine some tolerances and perhaps re-model the part so as to make it (more) machinable.

In any case, are there recommendations for shops that may do the wire/rod bending for 6061 or 7075 AL plus the hot or cold stamping and flaring, and then drilling and tapping?
 
Without seeing/knowing what your part requires and the tolerances allowed it's difficult to offer good advice. The others are correct in stating that machining will drive the cost up quite a bit, especially for just 2 of something. As crude as it may sound you can achieve good results with just a solid bench vise, a few pieces of round stock, and a propane torch to preheat the 6061/7075 a bit. The ends should be drilled/tapped first, heat the bars/shafts, then insert into the vise (with round forms setup) and give it a squeeze until it bends to desired angle. All you're doing here is duplicating the action of a stamping press in a slower, controlled manner. Let them cool and use some Scotch-Brite pads (or suitable abrasive) to improve appearances. This is a basic level of making prototype components when you're changing/testing the design and keeps the cost as low as what your time is worth. I do this all the time, so does everybody else. However, if you've got lots of money to spend then do contact somebody (here preferably) and I'm sure you can have them made.
 








 
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