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Fruit Squisher

Started by metalspinner, September 25, 2010, 12:45:59 PM

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metalspinner

QuoteLooks like your spur gear set up will increase your RPM but you lose torque.

dablack,

Yes, the speed has been increased by 2.5x's.  But you lost me on the torque.  Maybe you can give me a quick lesson?

The extra speed really helped to get the flywheel moving and to keep the cutterhead moving as apple pressure was applied.  One thing that needed to be understood by the kid applying the pressure was that he was actually a brake and very little effort was needed to push the apples on the cutter.

Is there a way to increase the speed and torque? Other than having a dad turn the crank. ;)



QuoteOctober '76 issue.

SD,
I was 5 in 1976. :D
I do what the little voices in my wife's head tell me to do.

SwampDonkey

It's online, and your old enough to read it now. :D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

Dave Shepard

Force in x Distance in = Force out x Distance out. If you want to increase the force generated by your machine (this being the two gears in the photo) you will need to increase the force applied to the machine, or increase the distance the original force is applied to. If the big sprocket is 2.5 times the diameter of the little one, you will have 2.5 times the distance, but less force.
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

WDH

My favorite part is the cover  8).

That is Apple Squishing By Youth Committee  :D.
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

sandhills

Good for you, my favorite part was watching the good time those kids were having while learning/doing something very worthwhile.  You made a lasting memory for them, I know because I was half their age when I helped relatives do the same thing and still remember the taste of the fresh cider, you earned a big pat on the back and I hope you're VERY proud!

dablack

David beat me to it.  Torque is in the units of Foot-Lbs.  So that means Distance x Force.   For easy numbers lets say the handle on the crank is 2' long and your are pushing with 3 lbs of force.  That means you are producing 6 ft-lbs of torque.  That torque is being transmitted via shaft to your large sprocket (spur gear).  For easy math we will say that your big spur gear is 8" across.  So from that shaft to the edge of the gear is 4" (1/3').  So with 6 ft-lbs going to a chain 1/3' away, we are getting 18 lbs of force in the chain ( 6 ft-lbs divided by 1/3 ft....see the ft are on top and bottom so they cancel out, leaving us with lbs aka force).  Now we are going to your little spur via the chain.  For easy math lets say it is 4" across, so that would mean we have 18 lbs of force (in the chain) 2" away from your second shaft.  18 lbs x 1/6 ft = 3 ft-lbs.  So, you produced 6ft-lbs with your work.  Since the handle is farther away from the shaft than the big spur, we multiplied your force.  You pushed with 3 lbs, but we got 18 lbs in the chain (but it is still 6 ft-lbs in that first shaft).  Then we got 3 ft-lbs there.  So, with an input of 6ft-lbs, we got 3 ft-lbs out.  That makes sense in this example because your big gear is twice the size of your little gear.  Also, in this example, if we turned the input crank at 30 rev/min (one turn every two seconds), we would get a output rpm of 60 rev/min.  So, like I said, you gained RPM  but lost torque........I design huge multi stage gear boxes for a living...plus, I love physics.  Sounds like from what you have said, you have plenty of torque.  Nice job.

Austin
Building my own house in East TX

metalspinner

Surprisingly, I may have followed that! (After reading it several times. ;))  Thanks for following up. :)

If I wanted to continue developing this drive system should I look for ways to enlarge the arcs of the handle and/or the sprockets?  If I increase the diameter of the little sprocket, I will not lose so much torque from the drive sprocket, but I will sacrifice speed? If my assumption is wrong please correct me.

An important rule in making cider is the finer the crushed pulp, the more juice can be extracted. The cell walls needs to be crushed to allow the juice to escape. To me that means speed at the cutter head.

If I increased the handle length in your example to 3' long, then I will start the formula with 9ft-lbs of torque. Should this keep my RPM the same at the cutterhead , but transfer more torque?

ugh. ::)
I do what the little voices in my wife's head tell me to do.

dablack

Everything you said is correct. 

The real question is, what do you need to rip those apples apart.  From watching the videos, it doesn't look like the grinder slowed down much when the apples were pressed into the machine.  Seeing that makes me think that your torque is fine.  That big flywheel really helps maintain both RPM and Torque. 

So, if you think you have a problem, do you think you need to speed through the problem or power through the problem?  Would more speed help or would more power help.  You can't have both. 

Remember, if you increase the length of the hand crank, you are having to put in 3lbs of force over a longer distance.  The circumference of a 4' circle (2' crank) is much smaller than the circumference of a 6' circle (3' crank).

So, back to the main question.  What makes the machine work better, when you turn the handle faster or put more force into the handle?
Building my own house in East TX

metalspinner

QuoteWould more speed help or would more power help.  You can't have both.

I think the speed is most important. ;) 

The boys on top need to limit their excitement when pressing down on the apples.  That will solve the slowing down issue. 

I toyed with the idea of putting a full bicycle gear changing apparatus on the thing. Would this have been able to give me the flexibity to increase the speed and keep up the torque?

I'm thinking next years adaptations just might be the electrical kind, anyway. :D
I do what the little voices in my wife's head tell me to do.

dablack

No, the bike parts won't increase torque with RPM.  There is always a trade off.  It is just like your car.  With a manual tranmission, you start off in 1st gear to get moving.  That gear has the most gear multiplication (torque multiplication) and it helps get the car moving.  The bad part of first gear is your engine has to use lots of RPM to get few RPM from your tires.  See, in first gear you got torque but lost RPMs.  2nd gear gives up some torque multiplication for a little more RPM and if you drive a classic (or an 80s truck) it tops out with 4th gear (which is usually 1:1).  That means, the engine and driveshaft are turning the same RPM.  Their is neither torque mutlipication nor an RPM loss.  In newer cars you have overdrive.  Basically there, you give up more torque for an increase in RPM after the transmission.  The driveshaft is turning faster than the engine. 

Knowing this, you understand why you don't take off in 5th gear from a stand still. 

Now, if RPMs are the most important thing, I would either make your big gear bigger or your little gear smaller (or both). 
Building my own house in East TX

metalspinner

Crystal clear! 

Thanks, dablack :)
I do what the little voices in my wife's head tell me to do.

Don_Papenburg

make the pulverizer with sawblades spaced about 1/16" apart and spin that with adrill or electric motor . Now you will be getting maximum juice.
Frick saw mill  '58   820 John Deere power. Diamond T trucks

mike_belben

Excellent thread.  MetalSpinner you are a parenting role model.  God bless you sir.  Im gonna plant fruit trees and pray i meet grandkids who will wanna pick em. 
Praise The Lord

welderskelter

I have heard of people using a newly purchased garbage disposal to grind apples.

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