press flexion

[JoseSnow]

Hi

Is it of if the distance of the middle part of my press rises 1cm when I press at 60 PSI?

It looks ok when pressing but still changes that little bit.



I still have an empty space that is not pressing.
How would you fix this problem?

[skidesmond]

You can place another board under the bottom or top mold to close the gap. The other option is to place thin spacers (I use 1/8 hardboard, 3 of them) under the bottom of the top mold in the tip and tail sections to force the hose into the bottom tip and tail blocks. Try either of those options first. You may have to shorten the height of the tip/tail blocks.

[chrismp]

add a brace in the middle to stop deflection...1cm is quite a bit. some angle iron and flat bar should do the trick. just have a look at the journals on here to see how people are building their support braces.

your hose inflates too much, thats why it doesn't conform to your mold. try to make the gap between the top and bottom mold as small as possible so the bladder doesn't inflate that much. that should solve your issues.

btw, both your problems aren't new to this community...try searching for them on google

[gozaimaas]

If you run a few welds across the top side of the top beam it will pull a slight curve into it which will counter act the flex.
Do the opposite on the bottom.

[JoseSnow]

Ok, I will add a brace in the middle and I will reduce the gap between the molds. Hope these works.
Thank you.

[ggardner90]

i placed a couple rows of .5in thick bamboo strips stacked 2 high between my cattrack and hose. it solved the problem

[JoseSnow]

So I did put an extra enforcment in the middle but still have a little deflection of 6 mm in the middle of my press at 80 PSI.

Is that fine?

Also I would like to know if its normal if the hoes loose 1 psi of air per hour.

[JoseSnow]

[gozaimaas]

The worst effect I can see assuming you have enough downforce across the entire job is that your bottom mould will no longer be accurate.
Go back and read my previous post if you really want to eliminate the problem.

[falls]

1 psi loss per hour will be fine. leave the compressor hooked up during pressing and it will keep the pressure even without having to work too hard.

[JoseSnow]

The worst effect I can see assuming you have enough downforce across the entire job is that your bottom mould will no longer be accurate.
Go back and read my previous post if you really want to eliminate the problem.

I dont understand what yo mean in the first post sorry, my english is not that good. Do you have an example?

I thought that the bottom mold will keep doing the same effect because is the bladder that adapts to the deflection of the press.

I might be wrong.

Thanks for your help!

[JoseSnow]

1 psi loss per hour will be fine. leave the compressor hooked up during pressing and it will keep the pressure even without having to work too hard.

Thank you Falls. I will follow your advice.

[gozaimaas]

The worst effect I can see assuming you have enough downforce across the entire job is that your bottom mould will no longer be accurate.
Go back and read my previous post if you really want to eliminate the problem.

I dont understand what yo mean in the first post sorry, my english is not that good. Do you have an example?

I thought that the bottom mold will keep doing the same effect because is the bladder that adapts to the deflection of the press.

I might be wrong.

Thanks for your help!

Ok, if you want to stop the steel beams from flexing under pressure one of the best ways is to counter act the flex in the first place. You can easily do this by running a few welds across the top of the beam.
Hopefully this pic will make it easier to understand

[MontuckyMadman]

Wont the heat from the welds distort it up not down?
cooling and shrinkage pull up not shrink down?
im not sure at all.

[gozaimaas]

The side you weld will become shorter. Trust me on that one