Method of attaching rods to rotor

[Storm_Eagle]

Protecting intellectual property can be challenging

Regarding your problem, is the overall shape sacred? If you can tolerate a .006" fillet on the inside corners, it would a candidate for wire edm machining. I have seen and held examples of wire edm machining where two separately made parts fit together so closely that you could not see the interface. If you are attempting to make a part for a prototype for proof of concept, it may be a viable way to go. Another approach may be 3D printing. Commercial enterprises are able to do some amazing things. One acquaintance is able to print working ball bearings. He can also print in stainless steel. Another is able to print in ceramics, again able to print working bearings.


.

It's just a proof of concept so far. So i can not justify the price of outsourcing the manufacturing. And metal 3D printing from what i have seen is not even close to the surface finish i want. From what i have seen of metal 3D printing there is post processing of the critical surfaces for bearing surfaces, etc. And if it comes to producing the part wire EDM is a far to slow and expensive process to manufacture this at scale. There is a reason why wire EDM is almost exclusively used to make tools like dies, and not finished products for the consumer market.

The accuracy and precision of these operations will certainly exceed those possible in a home workshop environment.

Why?
A boring head can make a pretty presice hole even in a benchtop mill, and even partial/interupted holes like in this case. Just drill the pockets for the rods with a undersized center cutting endmill first, and then finish it with a boring head. And the precision in the outer surfaces comes from using precision ground stock

 

[Alcap]

Could you hold the rods tightly to the rotor , a collet or jig . From the end trepan through the rods and rotor and a grove for a snap ring . Install one , flip over and do the other side . This site has some ideas better then I could ever explain . https://www.smalley.com/blog/what-retaining-ring-smalleys-retaining-ring-overview

 

[Eddyde]

Set screws against a flat in the studs are not going to draw it tightly in to the grove. And i am not sure what you mean by offsetting the hole in the stud to pull it in? Can you make a drawing of it?

I wasn't suggesting the setscrew only contact on the flat on the stud. The setscrew would have a conical tip that would engage a hole cross-drilled in the stud. The flat would be so the conical tip of the setscrew would engage the hole in the stud concentrically. Without the flat, the tip of the setscrew would impinge only on the closest path of the cross hole. The slight offset is so the conical tip wold "pull" the hole in the stud towards it thereby bringing the rod tight to the rotor. (whew) If that makes sense...
Anyway, it's kind of moot as your roll pin idea looks more viable. Though you could combine the two ideas by; Cutting a v-groove around the stud instead of the radiused groove. Position the threaded hole for the setscrew in the rotor above the stud and use the same conical taped setscrews. That would give easy adjustment and make the parts easier to remove then punching out roll pins.

 

[RJSakowski]

It's just a proof of concept so far. So i can not justify the price of outsourcing the manufacturing. And metal 3D printing from what i have seen is not even close to the surface finish i want. From what i have seen of metal 3D printing there is post processing of the critical surfaces for bearing surfaces, etc. And if it comes to producing the part wire EDM is a far to slow and expensive process to manufacture this at scale. There is a reason why wire EDM is almost exclusively used to make tools like dies, and not finished products for the consumer market.


Why?
A boring head can make a pretty presice hole even in a benchtop mill, and even partial/interupted holes like in this case. Just drill the pockets for the rods with a undersized center cutting endmill first, and then finish it with a boring head. And the precision in the outer surfaces comes from using precision ground stock

I wasn't suggesting either as a method of manufacturing.. When I was involved in a startup, we used 3D printing for prototypes. If was an effective way to deal with our proof of concept issues. I have former colleague who has a business involving making precision printed parts. While he uses the process to make ceramic parts, it can also be used for printing metal parts. https://xjet3d.com/additive-manufacturing-solutuins/printing-systems/metal-systems/
Wire EDM may be a slow process and unsuitable for production purposes but as a means of producing a prototype it could be a viable solution.

In a home shop environment, I can see difficulty in alignment and machining an existing component However I haven't the luxury of knowing the intended purpose, the required accuracy, surface finish requirements, material requirements, or budget . It is like you are asking "what's in the box?" and when we guess, you say, "no,guess again". I can understand a need to protect intellectual property but it is rather frustrating to keep guessing what is in the box. You came asking for a solution,and have rejected out of hand most of what has been offered. Perhaps it is time for you to sign an NDA with a private concern and get their advice.

 

[Storm_Eagle]

In a home shop environment, I can see difficulty in alignment and machining an existing component However I haven't the luxury of knowing the intended purpose, the required accuracy, surface finish requirements, material requirements, or budget . It is like you are asking "what's in the box?" and when we guess, you say, "no,guess again". I can understand a need to protect intellectual property but it is rather frustrating to keep guessing what is in the box. You came asking for a solution,and have rejected out of hand most of what has been offered. Perhaps it is time for you to sign an NDA with a private concern and get their advice.

It's a simple question. Come up with a fastening solution to attach the one part shown to the other part without external holes or permanent things like adhesives, and without any play or gaps in the assembly after. To solve this there is absolutely no need to know what the rest of the assembly looks like. If that was the case basically nothing would be able to be manufactured today if every worker and every subcontractor had to know everything about the whole system of a machine to make one part of it...

 

[RJSakowski]

It's a simple question. Come up with a fastening solution to attach the one part shown to the other part without external holes or permanent things like adhesives, and without any play or gaps in the assembly after. To solve this there is absolutely no need to know what the rest of the assembly looks like. If that was the case basically nothing would be able to be manufactured today if every worker and every subcontractor had to know everything about the whole system of a machine to make one part of it...

When multiple parties are working on different parts or subsystems, someone has drawn up a design specification which completely describes the interface conditions. In absence of the complete specification, there are usually meetings during which the missing information is discussed.

We often used third parties to make prototype components which exceeded our capabilities. When I designed components for manufacture by a third party, in addition to furnishing complete geometric, dimensional, and material specifications, I found is useful to discuss the intended use of the component. In some cases, it led the third party to offer a better way to accomplish our objectives. We had NDA's in place to protect our intellectual property.

But each to his own

 

[piper184]

Would brazing or silver soldering the rods to the rotor be an option?

Silver solder doesn't require a great deal of heat and is removable if needed.

Depending on the precision requirements of the finished product you might have to adjust the bore size to accommodate for the thickness of the filler.

Of course, if the assembly needs heat treating, well, never mind.

 

[Weldingrod1]

A variation on the D1-3 lathe spindle cams and pins could work.

South bend held their compound with a v groove and a matching v shaped end on setscrews IIRC. The v groove was offset a bit so when the setscrews went in, it only touched the bottom of the groove and pulled the compound down.
This picture shows the bottom
https://images.app.goo.gl/2BJuSG9CrKd3jhdJ9

Sent from my SM-G715A using Tapatalk

 

[RandyM]

When multiple parties are working on different parts or subsystems, someone has drawn up a design specification which completely describes the interface conditions. In absence of the complete specification, there are usually meetings during which the missing information is discussed.

We often used third parties to make prototype components which exceeded our capabilities. When I designed components for manufacture by a third party, in addition to furnishing complete geometric, dimensional, and material specifications, I found is useful to discuss the intended use of the component. In some cases, it led the third party to offer a better way to accomplish our objectives. We had NDA's in place to protect our intellectual property.

But each to his own

RJ, I am with ya. He states it is a simple question. He is correct, the question is simple, his design and solutions are not with all of his design limitations. He has 4 pages of simple answers not suitable for his liking. I myself have two more solutions that have not yet been mentioned that I think will work. Until we have all the design criteria I am not going participate in solving the problem. He can certainly supply us with all the information without divulging his money making motives. He obviously does not understand our frustration in trying to help. Good luck everyone.

 

[Storm_Eagle]

A variation on the D1-3 lathe spindle cams and pins could work.

Yes that would work. It is kind of like my original idea, but with a larger clamping surface. But because the cutout area in the studs is single sided, you have to do full rotations to adjust it, and therefore the thread pitch would have to be smaller than the clamping range of the camlock to be able to adjust it to fit. And i don't know what the clamping range of that kind of camlock is, or how it can be calculated.