Heron's Aeolipile

[sbwhart]

Hi Ralph I,m Stew John spoke about me

I'll try and help you round your pressing problem (pun) 

:- 1 You have the die in the top mounted in a top pressure plate (fixed) that's bigger than the sheet you are trying to form

:- 2 The punch is in the bottom with a spring loaded preshure plate around it, the plate is slightly proud of the punch.

:- 3 The blank should be bigger than you realy need so that when the press is bottomed out, some of the sheet is still being nipped by the preshure plate.

:- 4 When the load is taken off the preshure plate stripps the work off the punch.

You need nice big rads on corners and lubrication on the sheet, try washing up liquid, swafega, WD40.

What your trying to do is restrict the plate just engough to make it iron its way into the die
You could use rubber for the springs Doggy rubber balls cut up (poor Doggy)

Problems you may encounter is the strip bursting this is usualy due to trying to form too much at one go, or to much pressure from the pressure plate, or the sheet may need anealing, you may have to do a partial form, before doing a finished form.

I've attached a sketch showing methodology for the tooling

Another option if you could get hold of a thick enough piece of rubber to use as the die, I did this for a city and guilds project:- made shallow ash trays.

How about replacing the punch with a rubber ball (just thought of that one)

If your toggle press hasn't got enough humph I've got a fly press you could use

If you need to chat it over John knows how to contact me

Good luck

Stew

 

[Circlip]

Hmm, Stew has reiterated three basic points from post 38 Ralph, Radii, annealing and lubrication. Yer NOT going to be able to do it in one bonk, and rather than trying to "Coin" the ball halves, a ring die might be more appropriate, and yes,the propper way to form this shape in industry would involve pressure and stripper plates and while you're building it all up, don't forget the open and closed height of the press (yes I did Stew, but only once).

    If you look at any of the BOOK descriptions on how to make toy boilers, annealing regularly is the key and this applies if you're going to try to spin it too. Can't remember if you've had a go at panel beating yet Ralph but it's certainly worth getting a piece of copper, annealing it and having a bash over a simple form just to see how long it takes to become too hard to work. Don't forget, rather than dash out buying a sheet of virgin Copper, a bit of old 50mm (OK for our pals over the pond 2") water or gas pipe flattens out to 150mm ( 6" ). Same rules apply to Brass re annealing but Brass seems to harden up quicker and you soon get the "Feel", soft metals "thud" while harder ones "ring".

   A few more bits to think about and watch yer fingers in that press. Hope Boggy issued you with an instruction sheet with it ( and it will be in English, might even be OLD English )and a CE cert ? ? 

    Regards   Ian.

  PS. Just for the record, cartridge cases used to be made from -------Cartridge Brass.

   

[sbwhart]

Hi Ian

Like your comment re shut height:- once saw a 2 1/2 Ton Taylor and Challen press, that had the main crank shaft bearing smashed off, (lovely cast iron Johns probibly got bits of it in his material box) when the setter failed to wind the pitman back after a tool change, he didn't do it again, 5 days suspension without pay.
 
Catridge brass is 70% copper 30% zinc for thise who are interested.

Have fun
 

Stew

[Divided he ad]

Ok... So there's a lot to reply to and talk about here!

Here goes....

Darren, I don't really want to heat the die... It is only ali and I am not sure if it would weaken it in anyway? I could always leave the blank warm before pressing? Don't know if that would be a bad thing? (suggestions?)

Peter, I see what you mean... It makes a lot of sense to do it in stages.... I might have to make some more punches!!!  Thin more difficult that thicker... Poss due to the stretch factor?... All things to consider!!


Hi Stew, welcome to my fun project     and MadModder too 

To start with the techy stuff.... I think I have a view of how things were/are done. I drew a crap o cad for you to view... Hopefully it is clear enough... I wonder if this would work?


I don't think I have the time/patience/abillity to make a press the type shown/described... Not too sure about the rubber ball thing either... Wouldn't the pressure split the ball ?

I understand the need for a greater radius on the lip of the die... This will be done (I know you told me Ian... But I thought a smaller radius can always be made larger... You know the rest of that saying!!)

The chat idea sounds like it could be fun Stew... We will have to see about it next time I get over to Crewe 

Ian,
I am about to trawl the interweb for all the info I can find on the subject of press forming and then plan to spend most of the afternoon trying to understand it all. (this could be interesting for a person with litereature induced narcolepsy.... For some reason I fall asleep when reading a page or so?)

Still I am going to give it a good go!

I'll also try to find some copper pipe... Bit hard top come by these days, everyone is selling it to scrappy's.
The cartridge brass might also be a bit of fun to find.... I'll give it all a go.... Might also try to find some about 0.25mm thick... Make it easier on myself! (possibly, see answer from Peter)

"Thud" and "ring".... Got it!

I took some time adjusting the press... Instruction was given on all that, I also have no intention on putting my hands near the business end!!


Fun.... Yes it is all fun... If it becomes no fun the project will become shelved until I decide it can be fun again  (No point in doing something you don't like doing ehh!!?)



Thank you for all the great responses Guys, I'll be putting the suggestions to work and see where we get to   



Ralph.

[bogstandard]

Thanks for coming to the rescue Stew, even I now know what is required.

Ralph, as far as I can ascertain, the metal isn't clamped around the top edge, just restrained (hence the spring loading), allowing it to flow down into the die as the punch pushes the metal down into it, and the punch pulls it into the die as required. You are not trying to stretch the metal, just making sure that no excess is allowed into the die, unlike your first brass pressing with the fold on the side.

I am more up on the punching of materials rather than press forming, and certainly know the damage a press brake or hydraulic press can do. Somewhere in my workshop I have some slugs of material, 1/2" diameter by 1/2" long that were punched out of submarine bulkheads, the material was too difficult to drill, it work hardened almost instantly. I still haven't found a use for them.
In fact the toggle press that Ralph has now, was used to punch 1/8" copper/composite laminated materials for use in an industrial lapping process, and I cut many thousands of pre shaped holes with it during the trials.

Getting back to the materials now. In the thickness that is being envisaged to be used, approx 0.5mm copper. That should be able to be formed in one pressing after first being well annealed. I think brass would be a struggle for the depth of mechanical pressing before it work hardened, the press just wouldn't be able to impart enough pressure and speed before it got to it's work hardened state, but I have no doubts about the copper being able to be deformed to that depth in one go. On the other hand, Stews' flypress would have no trouble giving brass the pressure it needed.

I suppose people are thinking, why go to all this trouble for a pair of half spheres. Not only is Ralph and other people learning a lot from this exercise. If it was wanted, once the technique is perfected, many thousands more little half spheres of all shapes and sizes could be made. Also it is things that are learned along the journey that can help with other projects that might arise. Even if it ends up as a failure to go down this route, look at all the other processes Ralph has learned about getting there. So nothing is ever a true failure, how many did it take Edison before he perfected his light bulb, but he sure learned a lot on the way.

I suppose this could have been a guaranteed success if a lot more research had been done, because these processes have been around a lot longer than we have, but the fun of it all is doing it from scratch and getting other people involved.

This all started with Ralph making a little ball turner for his lathe. It shows just how things soon progress.

Whatever next?

John

[Circlip]

  2 1/2 ton Stew ? that's nobut a bairns press, now 100 Ton HME bonking my signatures out of 3/8th carbon steel, used to shake the floor a bit, and assault the ear drums. My closed height disaster was having a tool made whose closed height was the same as the open height of the toggle press it was supposed to fit into. It was annoying in the fact that the bits of tool steel being "encased" in a die set was a job I used to set up on the shop floor before I was "promoted" to the D/O. A new "Toolmaker" transformed the setting operation from 2 Mins to 1/2Hr. Hmmmm.

  Another incident, though not mine, was a setter letting the press have one "Bonk" on a piece of strip,the full length of, but slightly narrower than the guides on a stage tool. Didn't break the shaft, but certainly made short work of a brand new tool ( £2K but 45 years ago). Oh how SOME of us laughed, but not in the earshot of the works manager who at the time was calling for all the fires of hell and damnation to fall on the setters head.

  I think there will be some thinning of the metal around the top edge John, cos once the metal starts sliding, I would expect it to wrinkle and resist the slide, despite any lubrication, and a spring pressure/stripper plate would increase in tension as the punch travels further down. Another thing that I don't think is helping is the location spigot on the punch. The hole in the sheet is going to be muchly distorted and bigger by the time you get to full depth.The ring die suggestion was so that the material had somewhere to go instead of trying to bottom, ( see Stews ref to broken crankshaft ) and yes I know it's a lot smaller than a power press, but the operation of a  toggle press relies on the "sweep through" action of the handle. Thats why they tend to be used for cropping and punching operations, a flypress tended to be used for bending.

  Trying to stop you getting disillusioned with this one Ralph cos I want to see you steam yer glasses up with it running.

   Regards Ian.

PS. Key words to bash in on "Search" could be Die sets and Die springs. Trouble is, when I came out of toolroom, Tinterweb didn't exist.

[CrewCab]

  Trying to stop you getting disillusioned with this one Ralph cos I want to see you steam yer glasses up with it running.

You n' me both Ian   

Ralph ............ you've certainly embarked on a steep learning curve here, but ........... that's no bad thing I think  .... I'm certainly expanding my "virtual" horizons and learning loads to boot, it doesn't matter if I will ever try these particular technique's the principle's will be invaluable ...........     

Keep up the good work Ralph ................ your audience is waiting with bated breath 

CC

[bogstandard]

I am in no way trying to put Ralph off the idea, in fact this method was the one I suggested because I had a little working knowledge of the processes involved, but because I had run out of the basics, was the reason I invited Stew to give a bit of insight on his dealings on the subject, to try to push it a little further along, using the materials and machines at Ralph's disposal, and nothing else. Maybe this wasn't the way to go, but if the avenue wasn't explored, you would never know where it would lead to, whether it be failure or success.

The process that is being explored is to turn a blank of a known size into a required shape, not by stretching the material but by deforming it so that it retains its original cross sectional thickness as far as possible. As stated in a previous bit to this topic, if this method doesn't work, the punch can still be used for a spinning form. There are always more ways to achieve what you want.

If Ralph really wanted to push it, I could most probably call in a favour and get some half spheres made for him, but Ralph nor anyone else would learn anything by doing that. It is the same as the die, one could very easily get one spark eroded out, and the offer has been made, but again, this has initially been turned down, as nothing would be learned about how to do it manually, and it was only the wrong material that caused it to be only a partial success. Everything else went like clockwork.

John

[Darren]

Quite..a hobby is all about diy, well as much as feasibly poss it is.

Ralph, only a suggestion, the heat I mean. The ally should take it fine, they make pistons out of the stuff and they get a touch warm at times.

But I'm not suggesting this is the way to go, could easily be the wrong way though, it was just a thought.

[sbwhart]

Hi Guys

Ralph as certainly got our little grey cells working. I've no doupt we could press a sphere its just a matter of getting the tooling correct, we use to make thousands of copper cones a week using the pressing method, and a good deal thicker than Ralph is trying to make. If my memory serves me right we did it in three pressings with interstage aneals.

You tooling scetch is spot on ralph you got the principles right, for what you are trying to do I don't think you will need steel pressure plates you could try making them out a chip board or melonean (spell) or even a plastic chopping board.

If you could get hold of thin guilding metal sheet you may have more sucess (90% copper 10% Zinc) its got excelent deep drawing and forming properties, its what bullet jackets are made from.

Her's another shop desaster:- It was with the reduction gear box of a 24" rolling mill, the oil feed to the gear box became blocked, the site widow was dirty and the oil couldn't be seen circulating, did the oiler clean the widow NO,  he kept checking the tank and was happy it wasn't going down. By the time the problem was spotted a 20 inch diameter hering bone gear had teath worn down to about 1/8" thick

Have fun, and keep trying, you don't know what can be done until you try.

Stew

 

[Divided he ad]

Ok.... Sorry I didn't make it too clear... I wasn't thinking of hard clamping, just nipped up. So that with lubrication it would move with the pressing action. I'm sure that it could work?!?!  I'm sure that I have some new landrover valve springs somewhere that could be used under the plate instead of the packers pictured in my scrauling?

The distorted hole has already been noticed from the forms I tested on Ian... I can remove the spigot if needed, but the holes are going to have things soldered onto and over them so they may yet need to be bigger?

I was going to make it from steel plate because I have it... And I want it to last... Once I get it working I plan on making a few for all sorts of things


I am reading everything that everyone is saying and I'm going to make a vey big list of all the points raised so far and sort through them... everything from plates to materials to forming action will be tried and tested... I will get a spere or 2000000000 made.... Well nearer 100 maybe?! I've got all sorts of little plans for them in the long run.... I just got to get it right!


I'm now looking at this as a summer completion project as opposed to the winter one originally envisaged.... Still I plan on enjoying the hell out of myself trying to get it right     



Ralph. ( Just currently searching tinterweb for stuff!  )

[Bernd]

Ralph,

Just went back through the whole thread. I noticed that you have the bottom die held down with a clamps. Now this is just a thought, but have you considered letting the bottom die float. In other words don't clamp it down. I'm thinking that perhaps there might be a small misalignment even though you have that pin in the center.

I would leave the bottom die unclamped, since there is no way it's going to move other than try to line up with the upper die. Take the pin out and try to form one without punching a hole. See if that makes a better part.

From rereading all what was done it seems like an alignment problem between the bottom and upper die.

Bernd

[Circlip]

Firstly, I hope you haven't taken any of my comments as a criticism JM, they were in no way intended to appear that way, just another road to Rome/Ancient Greece. Stews suggestion of a "Soft" pressure plate was certainly a good idea. UNFORTUNATELY Ralph has now changed the rules so it looks like a harder one is required ( 100 half shells ? )    Yer may have to put the pressure plate at the top, round the punch with your springs sandwiched between a backing plate on bolts with a clearance in the pressure plate and screwed into the backing plate. Just seen HS93's pickkys using a rivveting block, did the same thing for working vents on the Model Maker plan version RTTL (Vic Smeed). The Punch was a ball/pein hammer, using another hammer to strike with, it was at school, and taught me about annealing, and the vents were Copper, Ahhh, those were the days.

  Regards   Ian.

[bogstandard]

No Ian,

It was just me clearing myself of being a bit negative in my postings. It looked like I was saying it was almost doomed to failure, and up to this time, it is far from it. With all these experts on the case now, it just has to work, or a lot of people will be getting ready for redundancy.

John

[cedge]

I'm no expert, but it can certainly be done. I know for fact that Karsten modified a pedestal (bottle) jack to make them for his turbines. There was some small amount of rippling at the rims of his earliest work, but it was minor and he did eventually figure out how to beat that problem. His tooling was far more primitive than anything you guys have mentioned in this thread, so don't give up.

I'd be happy to ask him about this project, but he seems to have fallen off the face of the earth recently.

Steve

[Divided he ad]

Well I'm glad that everyone is happy 

I've been searching the webtinternet tonight and found a whole lot of people willing and able to produce such spheres. But no one willing to tell you how you can do it... Well I can't seem to find them if they are out there!

So it looks like we're all pioneers!!!  (well at least in sharing the info  )

Steve,

I thought of using a little bottle jack if the toggle press wasn't enough.... I have the jack on my bench    Not willing to even think more on it until all avenues are exhausted with the toggle press 

I will figure this out even if it takes all of us to do it 

I hope mr Gintschel is ok Steve, His works are what inspired much of my efforts. That said I think it would be a little cheeky to ask him to help make a model based on some of his designs! (imitation might be a form of flattery but I don't want to push it!)

I really am happy that so many people have taken an interest in this project  , I just hope the result does not dissapoint! 


Ralph.

[Circlip]

Not an incentive to change direction Ralph but if you haven't seen this one it's one to add to your arsenal

    http://www.eurospares.com/frame8.htm

     Regards   Ian.

[Darren]

That was really interesting Ian, thanks for posting it.

Darren

[Brass_Machine]

Not an incentive to change direction Ralph but if you haven't seen this one it's one to add to your arsenal

    http://www.eurospares.com/frame8.htm

     Regards   Ian.

That's an interesting take Ian. I know the eurospares website well... I am on Mr. Moores motorcycle frame list as well.

Eric

[Divided he ad]

That looks pretty cool.... One of these days Ian I'll maybe try that out!?

But hopefully this current attampt at shape forming will finally work out, I'm just hunting down stock for cheap at the mo!



Soon i will get back onto this thread, with positive news I hope



Ralph.

[SPiN Racing]

Very very interesting thread.

I had tried to press a piece of Brass a month ago, but was in a hurry, and didnt think it through properly, and ended up doing something different.

HOWEVER... I did run across this clip.. or a clip simalar after the fact.

I know a lot may have bigger machines... and wondered if anyone had considered this option?

Metal Spinning
http://video.google.com/videoplay?docid=-8292524307449042055

Where the metal sheet is locked against a wood form, and then with a lever arm of sorts, spun/formed into shape.

[Divided he ad]

Scott,

I can't get that video to work? But I know about metal spinning. I have the DVD set from the 'metal spinning workshop' instructional videos from Terry Tynan.

I have just got to find the time to make the rest and tools... It will take a lot of work to make some of the stuff required.

I'm taking the press approach for a few reasons... 1] I've got it. 2] it's a challenge that I've never tried. 3] I've still got a lot to learn but....



This evening I've been having fun!!!.....

To start with.... My first ever use of a face plate, I've been taking notes Bernd.... Sacrificial ali plate used between work and face plate.




I cleaned the edges up and then bored it out for the punch to fit through (eventually with the collar on, I think?)



Finished plate.




I mounted it to the press using long bolts and some powerfull springs... As I figured might be needed after all the discussion earleir in the post....




Well I gave the press a good hard go and it did this....






The springs did alter the amount and style of the creasing. It also kept the domed form quite well, even if it didn't reach the bottom of the die!

So I tried it without the springs and the plate tight ....




And the results.... Non springs one is on the right.





Well I'm not down hearted... This was brass 0.7mm thick... I've got some copper 0.5 and 0.7mm on the way next week   


I decided that since I had two near forms I'd make some of the other tooling required....

An arbour for holding the domes while trimming... Machining nylon is fun!!!!  (M14x1.5 thread into the nylon and on the brass arbour.)




This was then threaded in the centre as well to take a M6x1.0 bolt from the front through the location hole in the dome, the dome could then be trimmed....






And finally... A little solder and a bout of emerying (is that a word?!)

   


I know it is not a ball.... It's a prototype for all my processes. I can now test all of my parts and mountings etc on this little fella 

I had a lot of fun today, got out into the shop about 14:00 ish and planned and pottered about, apart from a gap for tea and topgear I spent the night in there, good music and machining... Who could ask for more? I was in there right upto and through into the new year!.... One of the best new years eve's I've ever had! 


Comments etc welcome 




Ralph.

[Brass_Machine]

Looking good Ralph! I am super impressed. A little odd looking ball... great results though!

Eric

[bogstandard]

Ralph,

Are there any hard and fast rules that say it has to be a true sphere?

A sphere is just a, well, a sphere, your 'elipse' is SPECIAL.

It gives the look of speed, a sphere being distorted because of centifrugal force.

Play on that shape when making the support frame. You have the makings of something away from the 'norm'.

You can play with making true spheres another time.

N-I-C-E


Bogs

[sbwhart]

Ho Ho Ho Ralph
 
Your nearly there  , this is great progress even though you've not quite got a sphere you've certainly got some thing to work with:-

Could I suggest the following

1:- Increase the diameter of the blank to give the pressure plate a bigger surface to work on and stop the wrincle.

2:- Did you aneal the brass if not you could try this.

3:- Try a lubricant washing up liquid would be a good start.

4:- Try increasing the radius on the die

5:- Try a bit more pressure on the pressure plate by pre loading the springs a bit more

6:- Try polishing the surface of the pressure plate up a bit.

From now on it will be suck it and see< but think twice before you machine anything from the tool, try the adjustment route first as you can easlily get back where you started.

If none of the above works you may have to deepen the die

Have fun
 
Stew