Yep – I can make a pile of parts that are all identical. I have made a bunch of these handles over the years. 2 bends, 6 holes, repeat. Nothing exciting, but a stack of 150 looks pretty cool.
Making a Bend Die
Here is the process I used to make a bend die for 3″ OD tube on a 4″ center line radius. I used a 4140 series alloy steel blank.
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- Cutting a disk off a 9″ dia x 13″ long chunk of alloy steel
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- Centerdrilling the disk
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- Drilling through hole with 1.5″ drill bit on my 1982 Bridgeport CNC mill
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- Milling counterbore
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- Facing end so it is perpendicular to through hole
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- Clean-up pass on my little lathe
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- Boring center for spindle clearance on the bender
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- Discovered the cnc lathe I was going to use couldn’t swing 9″, so onto another lathe to reduce the diameter so it could fit
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- One side roughed out on CNC lathe
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- Both sides roughed out – still needed to take a final pass across all sufaces
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- After final lathe pass and a little polishing
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- Milling the notch for the clamp die. .020″ per pass – took a while
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- Drilling the clamp die mounting holes
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- The clamp die notch is complete
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- Milling the keyway in bottom
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- Counterboring the clamp die holes
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- Forms for the wiper die pour
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- Pour complete
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- Tooling mounted on machine
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- First bend. The wiper die needs a little work to clean up the slight wrinkles, but pretty good for first try
Making a Nylon Mandrel for Aluminum
I needed to make a mandrel for bending 3″OD x .065 wall aluminum tube. Using nylon drastically reduces the friction during bending, so here is how I made one for this application.
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- Form tool I cut on the waterjet with the exact radius I needed
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- Assembled mandrel
Setting up for more marimba resonators
Time to turn this large crate of tubing into 100 resonator tubes for marimbas. The tooling is so large and heavy that it takes a scissor lift to get it on the machine even in pieces. The sizes are 3.5″ OD tube on 8″ centerline, 4″ OD tube on 8″ and 10″ centerlines. The tubing is 6061 aluminum annealed to a very soft temper. The tubing is so soft that the challenge is to hold it in the clamps without crushing or even marking it.
What is it??
This is something I fabricated late last fall using 3/8″ plate, 1/4″ plate, and some 3″ OD x .125 wall tubing. I will post more pics of it in action after it is identified.
Resonator Tubes for Marimbas
The large tooling in the previous post was made to bend resonator tubes for marimbas. This is where my wife’s percussion world meets my fabrication world, as the marimba was the instrument she focused on through college. The premier U.S. manufacturer of marimbas needed a source for the bent resonator tubes on a new instrument they had developed. The tubes are 3.5″ and 4.0″ x .065″ wall aluminum bent on 8″ and 10″ center line radii. These are some big tubes – the longest are close to 5 feet long and each has 2 bends. The biggest obstacle is these need to be cosmetic quality when completed – so die marks have to be kept to a minimum. It’s a real trick to securely clamp on dead soft annealed aluminum and apply literally tons of force in the bending process and leave only minimal marks! The second obstacle is keeping them unmarked – the batch of 6 sets (10 unique tubes per set) shown in the pictures below took a massive box the size of a small car and rolls of foam packing material to get them safely to the customer in New Jersey.
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- Marimba with Tubular Fabrication Bent Resonators
Long Overdue Update!
Ok, so it’s been a crazy year since the last update. I changed day jobs and went from a 10 mile rural commute to a 45 mile commute to downtown Atlanta. And, I’m in the final classes to finally finish my engineering degree. So, I fell a little behind on updating the website. But, the shop was still very busy, and I took pictures along the way!
First up was a project that came up last fall. I was approached by a premier manufacturer of marimbas (a percussion musical instrument) to make the bent resonator tubes. These tubes are large – 3.5″ and 4″ OD tube up to almost 6 feet long. They wanted to bend the 3.5″ on an 8″ CLR and the 4″ on 8 and 10″ CLR’s. Commercially available tooling was prohibitively expensive, so I worked out a modular system that minimized material and machining costs. These dies are huge and heavy! I’ll show the tubes in a future post.
I also worked out an interesting solution for the mandrel where I sleeved a much smaller mandrel in nylon plus a way to cast my own wiper dies.
Trying to catch up on posts!
Ok, so I got way behind on updating the projects list. I added several posts with galleries this evening covering the major projects I’ve had lately, and there are a couple of random pics in this post. It appears that the WordPress interface through an iPad is working much better than the last time I tried to upload photos, so I’ll try to stay on top of it better. Now I just need to make updates here post to FB automatically…
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- Lots of little tubes that will become handles for a tool a local company makes.
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- Repaired the ski tow frame that was all but snatched off the boat. Actually had the upper repair piece already bent to the proper dimension in the scrap bin from a different project!
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- Some 4″ exhaust parts
Mail Order Tubes
This job found me thanks to Google. The customer was Colorado State University, and the tubes were some kind of air sampling device for a laboratory. So, the entire project was done via email and FedEx!
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- Shrink wrap and cardboard to protect the ends.
High pressure welding…
These are some kind of manifolds for a plastic injection molding equipment. They are made of chromoly and were brought to me to be welded together. Ran a root then weaved a cover pass all in GTAW process.
