# Be not annoyed, oh mighty mods, I post here hoping for more suggestions on Presscilla...



## MERLIncMan (Oct 23, 2022)

It is a ~30 ton general purpose hydraulic forge press thing, I posted in Hydraulics asking for suggestions, but it also fits here.

Before I call it complete, I am hoping for some suggestions from my fellow chip-makers.

Here is the other Post: https://www.hobby-machinist.com/threads/presscilla-im-interested-in-suggestions.102506/

Here is the video: 



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## wachuko (Oct 24, 2022)

Can’t help…just jumping in to say that it looks amazing.  Can’t wait to see it in action.


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## Eddyde (Oct 24, 2022)

First, That's a very nice looking build! Yes, please show a video of it being running and tested. Then it's complete.


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## MERLIncMan (Oct 24, 2022)

wachuko said:


> Can’t help…just jumping in to say that it looks amazing.  Can’t wait to see it in action.





Eddyde said:


> First, That's a very nice looking build! Yes, please show a video of it being running and tested. Then it's complete.



I've got to get the hydro-hose and oil, then install the breaker to run it, but I'll be certain to get you a video of the first squish 

Thanks for the look!


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## MERLIncMan (Nov 4, 2022)

wachuko said:


> Can’t help…just jumping in to say that it looks amazing.  Can’t wait to see it in action.





Eddyde said:


> First, That's a very nice looking build! Yes, please show a video of it being running and tested. Then it's complete.







.

More done, here is video


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## Nigel123 (Nov 4, 2022)

MERLIncMan said:


> .
> 
> More done, here is video


I built a press a while ago and use air pressure on the return to raise the cylinder back up
It has to have back to back seals so the air doesnt bypass into the hydraulics


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## MERLIncMan (Nov 4, 2022)

Nigel123 said:


> I built a press a while ago and use air pressure on the return to raise the cylinder back up
> It has to have back to back seals so the air doesnt bypass into the hydraulics


Nigel, you're saying that you put shop-air into the other side of the piston, and that it required a doubled up seal?


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## Nigel123 (Nov 5, 2022)

MERLIncMan said:


> Nigel, you're saying that you put shop-air into the other side of the piston, and that it required a doubled up seal?


If you have a double acting cylinder it should be okay
Mine needed a little modification as it was only single acting
It only takes about 50 or 60 lbs of air to return it
The regulator bleeds of the air as the cylinder extends so no valving was required


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## MERLIncMan (Nov 5, 2022)

Nigel123 said:


> If you have a double acting cylinder it should be okay
> Mine needed a little modification as it was only single acting
> It only takes about 50 or 60 lbs of air to return it
> The regulator bleeds of the air as the cylinder extends so no valving was required


Ok, no extra seals needed, but I would have to plumb shop air to it, or just pump it up with a Schrader valve once?


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## Nigel123 (Nov 5, 2022)

MERLIncMan said:


> Ok, no extra seals needed, but I would have to plumb shop air to it, or just pump it up with a Schrader valve once?


I plumbed shop air to it
not a big deal for me had air closeby
never tried pumping it up once didnt want the air pressure to increase with the stroke of the cylinder
the regulator i use ibleeds off the air so it doesnt rise more than 10 to 20 lbs above set pressure
your cylinder looked like it had a port for return was it bought as a retractable type?


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## OTmachine (Nov 5, 2022)

I would use an energized PTFE Seal instead of a U-cup.


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## Eddyde (Nov 5, 2022)

MERLIncMan said:


> or just pump it up with a Schrader valve once?


That's an interesting idea, I think it could work. However, I think it would require a small air tank or chamber to contain the compressed air. The volume of the air side of the hydraulic cylinder when bottomed out would be relatively small and the air might get compressed to too high a pressure. Say, if you had 60 psi in the air side of the system, with the cylinder fully extended up (air side), and it was attached to a chamber of equal volume it might get to perhaps 120 psi when the cylinder was down, that would still be within safe range for air and a Schrader valve. But if there was no chamber the air might get compressed to pressures approaching hydraulic pressure and that would not be safe and would impede the downward force you are trying to achieve.


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## MERLIncMan (Nov 5, 2022)

Nigel123 said:


> I plumbed shop air to it
> not a big deal for me had air closeby
> never tried pumping it up once didnt want the air pressure to increase with the stroke of the cylinder
> the regulator i use ibleeds off the air so it doesnt rise more than 10 to 20 lbs above set pressure
> your cylinder looked like it had a port for return was it bought as a retractable type?


The port you see in my video is just a sintered bronze muffler that I put on it to prevent bugs and junk from getting in that side of the piston - it's supposed to be a double acter.


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## MERLIncMan (Nov 5, 2022)

Eddyde said:


> That's an interesting idea, I think it could work. However, I think it would require a small air tank or chamber to contain the compressed air. The volume of the air side of the hydraulic cylinder when bottomed out would be relatively small and the air might get compressed to too high a pressure. Say, if you had 60 psi in the air side of the system, with the cylinder fully extended up (air side), and it was attached to a chamber of equal volume it might get to perhaps 120 psi when the cylinder was down, that would still be within safe range for air and a Schrader valve. But if there was no chamber the air might get compressed to pressures approaching hydraulic pressure and that would not be safe and would impede the downward force you are trying to achieve.


A pony tank you say? Hmmmm.....


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## MERLIncMan (Nov 5, 2022)

OTmachine said:


> I would use an energized PTFE Seal instead of a U-cup.


One could make such an argument


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## Eddyde (Nov 5, 2022)

Another safety concern with over compressed air would be the potential dieseling of any oil residue in the cylinder.


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## OTmachine (Nov 5, 2022)

You could just put a hydraulic accumulator on the bottom side or just use the simple external or internal mounted spring(s).


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## MERLIncMan (Nov 5, 2022)

OTmachine said:


> You could just put a hydraulic accumulator on the bottom side or just use the simple external or internal mounted spring(s).


These are good ideas. I tried extension springs (as shown in the video), they did not work. I cannot find a compression spring of such dimension as to go inside the lower part of the piston. Perhaps I will look again - need something around 4"ID and 10" long - a car spring maybe so. As far as an accumulator, this is a neat thought, but that would be merely another piston/bladder with a spring/air in it wouldn't it? Seems redundant if I've already got a dead side of a piston to use.


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## OTmachine (Nov 5, 2022)

MERLIncMan said:


> These are good ideas. I tried extension springs (as shown in the video), they did not work. I cannot find a compression spring of such dimension as to go inside the lower part of the piston. Perhaps I will look again - need something around 4"ID and 10" long - a car spring maybe so. As far as an accumulator, this is a neat thought, but that would be merely another piston/bladder with a spring/air in it wouldn't it? Seems redundant if I've already got a dead side of a piston to use.


It would be entirely hydraulic.  No oxygen.  Hence, no chance of KaBoom!  Most accumulators are charged with an inert gas like nitrogen.


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## Eddyde (Nov 5, 2022)

I watched the video again. It looks like there might be too much friction between the hammer and the column?  If so, maybe some roller bearing guides could help?
Also, you might not need a new pump to use the double acting cylinder. It might be possible to just replace the spool valve to one that can toggle between the cylinder ports.


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## MERLIncMan (Nov 5, 2022)

Eddyde said:


> I watched the video again. It looks like there might be too much friction between the hammer and the column?  If so, maybe some roller bearing guides could help?
> Also, you might not need a new pump to use the double acting cylinder. It might be possible to just replace the spool valve to one that can toggle between the cylinder ports.


Thank you for the suggestions! The hammer and the column are a little tight, but I can change it as desired; I've got HDPE tape in there with lithium grease, it's nice and slick. The backpressure of the fluid returning through the line is more of an issue than the ways I think.

I've strongly considered the spool in there, but the valve block is the issue rather than the spool - I could bypass the factory valve if I can figure a place for fluid return - then I'd just put in a cheapo 3-way spool valve.


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