pneumatic cheese press - stage 1 of build

[jlewis92]

Frame is mostly built. I haven't welded the top piece to the uprights yet as I have to drill some holes for the mounting flanges and it will be easier to do that before welding it.

Frame is 1.5" square tube steel
Air cylinder is 3.5" bore x 7.5" stroke rated for 884 lb at 100 psi
The foot on the end of the piston is a self-leveling acetal foot.
Hand valve is 5 port 3 way parker-origa 1/4" npt
Not pictured are two speed controls and the regulator.

I haven't decided where I will mount the regulator and the lever control. There aren't a whole lot of choices due to the size. I may weld a small tee on one of the uppers for additional mounting space if needed.

I did not do it, but early on, I thought about making an opening on the inside of the side uprights where they connect to the bottom cross piece. I could then feed the air hose down one of the uprights, through the lower tube and then back up the other upright. This would let me put the regulator on one side and hand lever on the other with most of the connecting hoses hidden. I think I will end up regretting not doing this, but I was trying to keep it simple.

[FRANCOIS]

that, my friend, is sexy.  Just be sure to leave enough room to stack all of your moulds in it.  Our pneumatic presses stack hoops from floor to over head height under one cylinder.

[jlewis92]

Franscois, thanks! I am just a one wheel at a time person for right now and I designed around that basis. But I recall thinking something analagous in regards to my beer brewing. I can see making a taller frame eventually, especially now that I've done one.  I'd have to upgrade my other gear, but now that I think about it, I do have a 14 gal stainless mash tun not in use anymore that would make a great cheese vat....

Many thanks to Eric in Thailand for his assistance as well as all the others who posted on using pneumatic cylinders for their press.

I am looking forward to the using the new press on my next cheddar. I know I can take plug samples, but its going to kill me waiting 6-9 months to cut the first cheddar from the new press to check the improvement to the texture.

[jlewis92]

Finished the press this past weekend. Its working as planned. I tested it at 115 psi to the air cylinder which should be about 1,000 lb pressing on the cheese.

Can't wait to try it on some cheddar this weekend.

[Beans]

The red looks great.
C

[DeejayDebi]

Looks real nice! I see corney kegs in the background!

[jlewis92]

Ha, ha yes, good eye. Pretty much no matter from which way I took the photo, brewing gear was going to end up in the background somewhere.

[DeejayDebi]

I can seee that! 

[jlewis92]

I had installed a self-leveling foot on the end of the piston (see photo above - its the white plastic piece). I can report that this definitely doesn't work. the idea was that it would compensate for slight misalignments. I was always a little worried it might have the opposite effect and it does.

Basically, if it is not exactly in the center the follower tips ever so slightly. With a fixed surface pushing down this is not problem because the cheese is forced to even out. With the self leveling foot, the foot takes the same tiny angle as the cheese and continues to push down which causes the cheese to tilt even more, and the cycle repeats till the foot has tipped the entire 15 degrees. At that point, curds were coming up around the large gap and then  the foot just pushed the follower out of the way.

Its only self leveling if the surface its on doesn't give. Oh well, not every idea can be a winner.

The piston with just a nut on it worked fine.

As for the mold handling high psi, it did ok, but I have to find the right schedule for increasing the psi. Jumping from 25 to 40 psi after 1 hr, there were too many curds being extruded through the netting and weep holes as well as through the tiny gap between follower and mold. I lowered it back to 25 psi and the problem ceased. By gradually moving to 30 psi there was little additional extrusion. I'm not sure if I moved more slowly to 40 psi, if the the curd extrusion would have been eliminated. I don't want to experiment further with this batch as I won't be awake to monitor it.

This was a hot pepper cheddar. In 4 gallons, I used 4 jalapenos, 2 habernaros, and a tablespoon of red pepper flakes. I'm glad I added the latter as a last minute addition. The addition of the red color is quite festive. I left out the annato purposefully, and I think the green, orange and red flakes look really nice against the white cheese. I'll post a photo tomorrow when I take it out of the mold.

[JimP]

That's a first class press you've made; glad to hear that the shakedown run is running basically smooth.

As for the mold handling high psi, it did ok, but I have to find the right schedule for increasing the psi. Jumping from 25 to 40 psi after 1 hr, there were too many curds being extruded through the netting and weep holes as well as through the tiny gap between follower and mold. I lowered it back to 25 psi and the problem ceased. By gradually moving to 30 psi there was little additional extrusion. I'm not sure if I moved more slowly to 40 psi, if the the curd extrusion would have been eliminated

Are you referring to your piston input pressure? or the mold/curd pressure?
If it's the piston pressure, then applied force to the follower would be (at 25 psi) 221lbf   [at 100 psi you had said 884 lbf] ; assuming mold dia of 8" the area is ~50 in2; making the mold/curd pressure ~4.4 psi. A smaller mold would mean an even greater mold/curd pressure.

A quick search on "cheddar pressure" seems to be saying that a light starting pressure (~2psi) for the first hour or two is enough. The 'Light Pressing Advocates' (toward which I lean) are saying that 2 psi may be enough for your final (mold) pressure -

per Sailor Con Queso:

My presses are certainly capable of 35 psi, but I never press over 5 psi.  In fact I routinely do cheddars with just 2 psi. The trick is to keep your curds warm then hoop quickly after milling and salting. In a commercial environment, curds are often stone cold by the time they get to the press, so it takes more force.

Just my newbie current understanding of the matter. Perhaps one of the giants (upon whose shoulders we strive to stand) will confirm / correct this.?

Back to your classy press - what kind of lever valve do you mounted on the side?
Great job!

[jlewis92]

Jim,

Psi's were as seen by the wheel.  Mold is 5.75".   Air pressure to the cylinder was 75 psi (25.5 to the wheel), 115 psi (39 psi to the wheel). 

I ended up with the following:
25 psi 1 hr, flip re-dress
39 psi 30 min,   flip and re-dress (too much curd extruding out)
25 psi 1.5  hr
31 psi 10 hr
34 psi 6 hr

the valve is a parker-oriega via McMaster Carr.  5 port (2 input, 2 output, exhaust) / 3 position with the center position being closed.

I will post a pic of my hot pepper cheddar under the hard cheese board.

[Boofer]

Jim,

Psi's were as seen by the wheel.  Mold is 5.75".   Air pressure to the cylinder was 75 psi (25.5 to the wheel), 115 psi (39 psi to the wheel). 

I ended up with the following:
25 psi 1 hr, flip re-dress
39 psi 30 min,   flip and re-dress (too much curd extruding out)
25 psi 1.5  hr
31 psi 10 hr
34 psi 6 hr

the valve is a parker-oriega via McMaster Carr.  5 port (2 input, 2 output, exhaust) / 3 position with the center position being closed.

I will post a pic of my hot pepper cheddar under the hard cheese board.

Holy cow! You have yourself a first-class pressing machine there, jlewis92.

If you're into hunting, you may find this interesting: How to Hunt Whitetail Deer with a 12 pound Mountain Howitzer Cannon. 

-Boofer-

[FRANCOIS]

Also note that bigger isn't always better.  You can press a cheese too hard, inhibiting proper aging and flavour development.

[Boofer]

Yeah, that was my point.    Too subtle?

-Boofer-

[DeejayDebi]

LOL I was wondering about that cannon and cheese piston connection myself.