Serious HES derivative project proposal

[SolarLab]

Be careful there it's easy to fool yourself. The tonnage rating of a hyd press is the total piston force or hyd pressure x piston area. Then you divide that by the square surface area of the part being compressed to arrive at the compression force applied to the part, either psi or Mpa. Without looking it up I think 1 MPa is about 145 psi. 400 Mpa is ~58000 psi.

So for example, if you're compressing a part with 2 square inches of surface with a 400 Mpa press you're only applying 200 Mpa or 29000 psi to the part.

If you're thinking about making a hydraulic press, leverage can be your friend.

Cadman,

You're correct - 1 MPa = 145 psi, however I used "tsi (tons per square inch) - but not sure if I know what I'm doing!
However, I did not account for the area since that will vary - so the whole thing is better done in Solidworks Mech.
Some of the SMC papers talk about a 60 Ton Press for 800 MPa, but it's not well explained.

BTW, the strongest bolts I could find are Metric rated 12.2 at about 9500 MPa (again ?). Still working it...

In the "Convert" I used "tsi" or "tons per square inch" and MPa. It comes out to 1 tsi = 13.6 MPa or 30 tsi = 410.9 MPa.

Not sure if that's correct however; so I'd better do a bit more study! Anyway; I'd like to convert MPa to Tons to get a
ballpark figure to use between the "powdered SMC" spec sheets and the "Hydraulic Cylinder" requirement. From memory
I think it was around something like a 50 Ton hydraulic jack should give about a bit less than 800 MPa.

Trouble is I have no idea what I'm doing when it comes to compression pressures and conversions (?).

SL

[Dog-One]

https://www.amazon.com/Ton-Lab-Heat-Plate-Machine/dp/B09C7JDRJ2?ref_=ast_sto_dp

[url is too long] 

A quick tip for Amazon URLs...

You can remove most of the URL except the /dp/XXXXXXXXX part and
the link will take you straight to it.  An example for the above would be:
https://www.amazon.com/dp/B09C7JDRJ2

[Cadman]

SL,

Maybe this will help. Apologies in advance for the simplistic wording.

You have a hyd cyl (press) rated at 50 tons. Just imagine that as a big block of steel that weighs 50 tons. That's all there is to it at this point, you have 50 tons to work with.

Underneath that you place your punch and dies. The punch, which is the shape and area of your part, has a punch face surface area of 2 sq. in. Then you lower your 50 ton weight onto the punch. The punch face will have a distributed pressure of 25 tons per sq in, or 50,000 psi, or ~345 Mpa.

We're talking about a thin flat part so just divide the punch surface area by the press pressure to get the compression force on the SMC powder.

[bistander]

Hi all,
You might consider this approach to getting useable cores for first attempt prototypes which I've used recently. I am just experimenting with behavior of "wires in grooves" as member rakarskiy would say, or coils in slots to satisfy my own interpretation of theory. My investigation is on going but indications so far don't surprise me. Anyway, for your consideration, I'll attach a photo of my fixture. Made from sawing and grinding an old MOT, uWave Oven Transformer. For a piece of scrape, it turned out pretty good in my opinion. It does not heat at all, coils do occasionally. A second portion of the core fits on top for the tests. Good luck.
bi

[SolarLab]

Dog One - Thanks, good tip.

Cadman - Great explaination, thanks. Really helps a lot. Looks like my "Convert" conversions
are correct which makes "ball park" figuring significantly easier and understandable!

BTW - Just purchased the 30 Ton press in the above link; should be here Thursday. Their engineer
claims it's overbuilt but how much he didn't want to say. I'll reverse-engineer it in Solidworks
when it arrives. Hey, who knows! Maybe easily upgraded to 60 Ton with some major added support?

Bistander - nice work, curious as to how it will work out.

For Ref: A few fellows in Nigeria (Tech School) built a 40 Ton press for about  $400us and
documented it (attached pdf). It's quite good since they included all the calculations.

SL