Shop Made Tools

[redlee]

Work in progress.

[MaxxLagg]

Sorry for being slightly vague about the exact nature of the job. While I wouldn't consider the process proprietary in the traditional sense, it's my handy work but my employer's process. Just to keep their panties out of their crack, I won't actually call anything by name. The purpose here is just to maybe share some ideas for challenges that you may have and we can all learn from them. Again, not home shop stuff but cool tooling gives me wood.
Here is the crowder for the aforementioned resistance welding operation. The part width that is getting the secondary part welded to is about .500 wide. The part itself is still attached to the strip at this point and is only attached by a little tab. In addition, the part itself has a few 90 degree bends in it. You can kind of see the area that is being weld to the left and right. We're welding on a .050 thick by .156 diameter part. The part being welded needs to be located with respect to the part being welded to +/- .003 (in X and Z as depicted). The original crowder that located the part came in the Z direction and relied on a little notch with some lead in to catch the part and crowd it into position for the welding operation. Often, there simply wasn't enough action happening if the part was outside this narrow window that the lead could catch it. The green and pink details are cam driven via a rod in Z. They ride on linear bearings. There are cam followers attached to the pink detail that drive the 2 spring loaded crowders that have a much greater travel, thus more allowance for catching the part. They travel at 45 degrees relative to the part, catching it much more consistently and crowding into position for the welding operation. The whole unit is slightly adjustable side to side with a micrometer head (Not visible, just to the left, almost totally out of frame) to dial in the proper dimension.

[TGTool]

You're certainly not wrong. The ramp sections would have had to be where they are but the driven part could have been straight. It's probably hard to see in the pictures but it is basically a rack and pinion. there's a rack gear in the arc section driven by a pinion gear that is attached to the handle. While the rack gear section could have been straight sometimes the aesthetically pleasing nature of a design is preferable than a strictly functional one. Certainly the functional approach is usually cheaper, but in this case it didn't cost me any more to make it this way, and hey, it just looks cool.😁

Thanks. I know it's a complex issue. Your variable arc is a nice way to extend or shrink the length while keeping the entrance and exit at the same points vertically. So, having an arc and simply raising or lowering it would have screwed up the entrance and exit. There are, IIRC, four ramps to raise and lower and the adjacent plungers are nicely arranged radially. I didn't analyze carefully enough to judge if the ramp angles were all equal, but they wouldn't have to be. The center could be raised more than the two side sections as the transverse slide is moved.

Nevertheless, I take you point about esthetics and I like machines and tools that are visually and intellectually satisfying, not simply doing the minimal job they're expected. And I'll plead guilty too, to doing more than is required for reasons beyond simply function. It might be hard to prove that beautiful tools work just that tiny bit better than plain or ugly ones, but I'm glad they were made that way. And given CNC capability, many more complex geometries don't have a construction penalty the way they would have years ago when I was machining for a living. If I'd gotten that drawing and thought about setting up the rotary table and making up extensions to get the radius larger than the table top I'd have let out a big sigh before digging in.

Thanks for sharing that.

[MaxxLagg]

If the strip between machines travel freely between machines, a roller in the middle could change the slack and vary the distance by moving up and down but your solution is more elegant.

True, it would achieve the same effect and this essentially is exactly that but, unfortunately, the shape of the parts required a more contoured path.

[Noitoen]

Maybe you're right. But I think we would have had the same issue piloting the notch as we did inserting the screw. After all those progressions the screw hole became so misaligned that getting the screw to start was impossible. I have some pictures that I'll post later about locating the part for the resistance welding operation that we needed to properly locate because of these same challenges.

If the strip between machines travel freely between machines, a roller in the middle could change the slack and vary the distance by moving up and down but your solution is more elegant.

[rcaffin]

Nylatron GS (usually based on nylon 6,6)
"Molybdenum disulphide (MoS2) filled nylon offering improved strength and rigidity. With a lower coefficient of linear thermal expansion than Nylon 101, Nylatron GS parts maintain better fit and clearances, and have less tendency to seize as bearings."
Used for rotating bearings.
Cheers
Roger

[MaxxLagg]

Nice save.....!

Seems like the best method would have been to add a notch to the strip that is cut at the same time as the rest of the part features. The notch being in the carrier part of the strip. Probably way too late to add that feature after the punch tooling is done........

Since you say the parts are left in strip form until later, the notch would provide a way to index each part exactly at the next machine. Position accuracy should be essentially dead-on for every part every time.

With a bit of slack between machines, the notch should be able to be captured by the advance mechanism even with a bit of error in the advance. Or, the advance might be controlled by the second operation, which would automatically keep everything in alignment.

Maybe you're right. But I think we would have had the same issue piloting the notch as we did inserting the screw. After all those progressions the screw hole became so misaligned that getting the screw to start was impossible. I have some pictures that I'll post later about locating the part for the resistance welding operation that we needed to properly locate because of these same challenges.

[MaxxLagg]

I'm sure the setup guys, not to mention the department head, LOVE that change.

I am curious about one aspect of the design. I'm not clear why the slide bar with the ramps needs to be an arc. I know the tracks for the skeleton above have to be arc shaped. Can you say something about what I'm missing?

You're certainly not wrong. The ramp sections would have had to be where they are but the driven part could have been straight. It's probably hard to see in the pictures but it is basically a rack and pinion. there's a rack gear in the arc section driven by a pinion gear that is attached to the handle. While the rack gear section could have been straight sometimes the aesthetically pleasing nature of a design is preferable than a strictly functional one. Certainly the functional approach is usually cheaper, but in this case it didn't cost me any more to make it this way, and hey, it just looks cool.😁

[J Tiers]

Nice save.....!

Seems like the best method would have been to add a notch to the strip that is cut at the same time as the rest of the part features. The notch being in the carrier part of the strip. Probably way too late to add that feature after the punch tooling is done........

Since you say the parts are left in strip form until later, the notch would provide a way to index each part exactly at the next machine. Position accuracy should be essentially dead-on for every part every time.

With a bit of slack between machines, the notch should be able to be captured by the advance mechanism even with a bit of error in the advance. Or, the advance might be controlled by the second operation, which would automatically keep everything in alignment.

[ezduzit]

I'm sure the setup guys, not to mention the department head, LOVE that change.

I am curious about one aspect of the design. I'm not clear why the slide bar with the ramps needs to be an arc. I know the tracks for the skeleton above have to be arc shaped. Can you say something about what I'm missing?

The variable arc allows movement in the X axis, hence a variable length path, as the distance between the 2 dies is fixed.

[TGTool]

I'm sure the setup guys, not to mention the department head, LOVE that change.

I am curious about one aspect of the design. I'm not clear why the slide bar with the ramps needs to be an arc. I know the tracks for the skeleton above have to be arc shaped. Can you say something about what I'm missing?

[MaxxLagg]

This is an interesting one (at least to me). We have this process that uses 2 presses. One is a standard punch press, the other is a cam actuated (think VertiSlide type of machine for some of the old-timers that know of such things). In the standard punch press there is a die that makes a part. This part is not singulated but is left in strip form. It travels to the other machine where a screw is inserted and another component is resistance welded on. Since these are two separate machines, the distance (progression) between one process (The die) and the other two processes is critical. There are something like 150-200 progressions, don't remember how many, between operations. Lots of things affect this progression; temperature, sharpness of the die, stock hardness, and most importantly, distance. This distance was the most critical factor and the one that was easiest to mess up and the most difficult to adjust. Because of the second two operations, if this progress was off then it was impossible to insert the screw because the progression would be off enough to miss the hole. This solution for years was to move the die fore or aft relative to the 2nd operation a little bit to get the progression back in. A tedious and mistake prone endeavor.

My solution was to design and make this device. It basically makes the path between the two processes a variable distance. The radius portion of the track is moveable, to a larger or smaller radius, via segments. Need more or less distance? Just dial it in. As the strip of parts travel along the chord segment of the radius, making the radius larger or smaller makes the arc length the strip travels longer or shorter. It has a total of .100 +/- overall progression adjustment. We are able to adjust the progression on the fly now.

[MaxxLagg]

Weld testing fixture that I designed and made. There is a rotary cylinder inside the mechanism that can rotate through a 90 or 180 degree (depending on which of the two parts they're testing) that tests the weld strength. It is operated by a totally pneumatic circuit that is anti-tiedown and is actuated by the two palm switches. The pneumatics makes it totally portable, and required no electricity or control logic other than what the pneumatic circuit provides.

[MaxxLagg]

Lovely work Maxx. Your packing machine parts, is that Iglidur or similar material on the horizontal element?

This material is called Nyltron GS. Not sure how it compares to Iglidur. I'm not familiar with that material other than what I just looked up on Google. It's just basically a high wear resistance nylon. There really isn't any lubricity component.

[redlee]

Looks real nice.