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Lightweight vent panel and bulkhead build


Stellaghost

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The problem is I built the former with what I had i can look to extend the sides on top former so it covers the area I want the wrinkles hammer form out easy enough may extend the sides and have another go once I've got folder made that should square this up with weight of blade and once folded will be locked in place regards Stephen

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16 hours ago, Stellaghost said:

On a side note press started to push alloy in to recess sub 3 tonne I have a two stage pump and it did go into second stage I took pump up to 25 ton to set the form regards Stephen 

Lol well that shows my press is way off 60ton.... I've got some spare pressure gauages there I should put one on and see what pressure it is getting 

Looks like you have nearly sorted it.... I'm uncertian what the lightweight pannels look like, but I'm assuming your going to cut a window in the raised section....

At the moment it looks like the pressed form is driving the movement in the outer piece, trying to shrink the outer lip causing ripples (your X section backs this up)

if so precut your hole in the pressed section with an undersized hole 5-9mm in from each side.... this will allow some stretching to happen to the edge that is being forced down, but as somebody else stated make your cuts clean and smooth with consistant radii so you don't get stress risers that tear 

 

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4 hours ago, De Ranged said:

Lol well that shows my press is way off 60ton.... I've got some spare pressure gauages there I should put one on and see what pressure it is getting 

Looks like you have nearly sorted it.... I'm uncertian what the lightweight pannels look like, but I'm assuming your going to cut a window in the raised section....

At the moment it looks like the pressed form is driving the movement in the outer piece, trying to shrink the outer lip causing ripples (your X section backs this up)

if so precut your hole in the pressed section with an undersized hole 5-9mm in from each side.... this will allow some stretching to happen to the edge that is being forced down, but as somebody else stated make your cuts clean and smooth with consistant radii so you don't get stress risers that tear 

 

New pressure gauge on your press should do the trick but I have a funny feeling you will be looking at a new Jack or pump

Lightweight panels are more or less the same as series vent panels and yes I will be cutting a section out of the pressed part to allow air flow

Thinking about making another piece of heavy plate to go around my top former to stop the wrinkles but I will have a go with another test piece but with a slot cut into the pressed section first regards Stephen

Edited by Stellaghost
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7 hours ago, FridgeFreezer said:

Oooh that's neat... I wonder if the punch part needs 2 sections, so the 1st bit clamps down on the outer to prevent crinkling before the centre forms the shape?

Lots of videos on YouTube from industrial processes like this that might give you some pointers as to how they manage it in production but it certainly feels like you're getting ever-closer to the right answer.

I think you need to not clamp the outside of the material until the former is bottomed out. With my dimple dies once the as the final shape is formed the dies bottom out and flatten the material out.

 

I think the biggest barrier here is the aluminium grade. I'm sure in my old department it was 1050 grade we used for anything that needed bending. If you tried bending anything like the 6082 (or the other grade I can't remember) it would just crack.

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5 minutes ago, landroversforever said:

I think you need to not clamp the outside of the material until the former is bottomed out. With my dimple dies once the as the final shape is formed the dies bottom out and flatten the material out.

 

I think the biggest barrier here is the aluminium grade. I'm sure in my old department it was 1050 grade we used for anything that needed bending. If you tried bending anything like the 6082 (or the other grade I can't remember) it would just crack.

I wasn't planning on clamping it solid because it will still need to creep into position I did find that thicker material had less distortion good point about aluminium grades not sure what I've been using just what was laid around mainly stuff that is used for signs having a clue what grade that will be Regards Stephen

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That was my point earlier - the sign ally will be a stiff grade to withstand wind etc. , have a word with your local Aalco distributor , they have good technical advice specialists . Aluminium also ages , another reason to go for new when you are close to getting sorted , which you are now by the look of it 

Steve

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Ran another test piece this this morning except with a slot in the middle all be it done very roughly what I found is that the longer sides had less wrinkles in however one of the ends split and the other didnt the one that didn't split had a slightly longer length from folds

So everything you guys are saying is right my material needs to be new and soft not age or work hardened so will definitely look at annealing I  also need to extend the edges of my top former use 3mm as that is what I built it for the other thing is I reckon I'm getting a bit of flex in the top former even though it is 40mm plate with that in mind I either need to brace it or use twin Jack's to make sure it all compresses evenly along the whole length appreciate all the comments guys it took me best part of 25 hours to make formers so I'm not letting it go each step brings us all closer to seeing a result regards Stephen 

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Shame my godmother's husband recently passed away because he'd tell you instantly what alloy would be best and how to anneal it. Was a true encyclopedia on all things to do with metallurgy, but a self proclaimed dinosaur since there weren't many of them around.

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4 hours ago, Ed Poore said:

Shame my godmother's husband recently passed away because he'd tell you instantly what alloy would be best and how to anneal it. Was a true encyclopedia on all things to do with metallurgy, but a self proclaimed dinosaur since there weren't many of them around.

What a shame .  landroversforever put me on the right track with 1050 grade from what I've researched its 1050H14 is what i need and of course some annealing will help also regards Stephen

Edited by Stellaghost
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3 hours ago, Blanco said:

Great project this👍,.......  just looking at your pile of discards I wonder how hard it would be to turn your forms into a mould and 'pour' a couple??

Thanks, a mold would be some size as I plan to make the full width vent panel with the vent recesses in and no welding in this area,end folds will need to be welded on once made regards Stephen

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Some bits in the post today to replace everything I binned decades ago you can see on the still attached hinges that the previous vent panel they were on has been well attacked by the tin worm regards Stephen 

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Edited by Stellaghost
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Not much progress other than a rough cut section of 20mm plate ready to go in the mill . This is to lightly clamp around top former to minimise rippling

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Other two photos are of the initial hammer form  and one of the test presses sprayed both with etch primer which makes them look better also test fitted flaps into recess looks pretty good no excessive clearance around the sides regards Stephen 

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They look good , very crisp . 

I was thinking about your pressure plate and wondered if clamping it in place using some 3mm HR plate ( always oversize on thickness ) around the outside of your workpiece allowing the Al (usually dead size) to move but not wrinkle so much - sort of self planishing ? 

Steve

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You guys must think I'm thick first I didn't know what Zintec was and now I definitely don't know what HR plate is lol 

Yes Steve I must admit I'm quite happy how they look once I get my clamping plate milled I'm going to try again but leave longer ends to see if that helps to minimise distortion a wee bit however even the rippling on the ends is not overly severe that it can't be worked out, I am contemplating trying it for full length with 1.6mm mild steel as I've got plenty of that, it will allow me to see how my alignment is so I can make adjustments prior to going for it in aluminium regards Stephen

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