> >
>

# Convert PSI to Torque

#1
10-10-15, 05:27 AM
Member
Join Date: Aug 2009
Location: USA
Posts: 4,940
Convert PSI to Torque

After searching a bit, it seems this conversion is not possible. I am considering building a trash compactor and need to be able to size whatever drive device I choose with my desired output. Motor outputs are given in torque. How can I determine if a certain sized motor is going to give me my desired PSI?

#2
10-10-15, 05:56 AM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,986
#3
10-10-15, 05:58 AM
Member
Join Date: Aug 2009
Location: USA
Posts: 4,940
That's pounds force, not torque.

#4
10-10-15, 06:00 AM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,986
Isn't torque measured in foot lbs?

#5
10-10-15, 06:04 AM
Member
Join Date: Aug 2009
Location: USA
Posts: 4,940
Torque is pounds per foot. Pounds force is pounds per square foot. Torque uses a linear dimension while pounds force uses area.

#6
10-10-15, 06:09 AM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,986
Okay, I guess that you are correct, it can't be done.

#7
10-10-15, 06:23 AM
Member
Join Date: Aug 2009
Location: USA
Posts: 4,940
There has got to be a way to figure this out! People design products like this all the time.

#8
10-10-15, 06:25 AM
Member
Join Date: Aug 2015
Location: USA
Posts: 219
I would assume that your not using hydraulics plenty of calculators for them.

#9
10-10-15, 06:36 AM
Member
Join Date: May 2015
Location: USA
Posts: 3,138
Well, you are missing key information. You have to know how you are going to convert from the rotary motion of the motor to the linear motion of the ram. And you need to know how much force at the ram is required to achieve the compaction you want/need. The specific parameters of that will allow you to do the calculation, whether it is mechanical or hydraulic.

#10
10-10-15, 08:14 AM
Member
Join Date: Aug 2009
Location: USA
Posts: 4,940
I want to crush cardboard boxes. The boxes I currently have received an ECT of 32 psi. The highest is 44 psi. I was thinking of having a 24" x 24" plate for crushing and a crushing force of 50 psi. That puts my total need at 28,800 lbs. However, I'm thinking I would only need that much force if I have the entire area packed with vertical cardboard, which isn't going to happen. So I'm not too sure what would an ideal total number would be.

So if I had the biggest box I could fit in the crusher, that would be 24" x 24" x 1/8". That would give me 72 square inches of edge. That would be 3600 pounds of total force needed. That's going to be expensive to generate.

#11
10-10-15, 11:26 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 16,900
I think you're missing the point when asking to convert psi and torque. It's like asking to convert gallons per minute to amperage. How you get from one to the other can be accomplished but there are different ways to do it. How it's done affects the answer.

I would first read up on box ratings. The rating on the box may not provide a good guide to the amount of crushing force needed to compress the box as you desire.

In your case you need to figure out how you want your machine to operate. You can use hydraulics, screws, gears, levers... Once you figure out what basic mechanism you're going to use then figure out how fast you want your crusher to move. Once you've nailed down those details then you can work out your power source one of whose specifications could be torque.

Say you choose a gear mechanism. The gear ratio you choose will affect the torque required to generate the desired crushing force. The rpm of the motor in conjunction with the gear ratio will determine how fast your crusher moves or cycles.

In the end you may find it easier to keep your eye out for a trash compactor. They already exist and are designed to do what you want. Most residential ones are smaller than your desired 24" x 24" but used compactors are free or really cheap. You may decide to live with the smaller crush chamber size or somehow rig a couple of them together.

#12
10-10-15, 05:00 PM
Member
Join Date: Aug 2009
Location: USA
Posts: 4,940
Existing trash compactors are pretty small. I don't think it will be large enough to process the majority of the boxes I receive. It seems the parts do to what I want is going to exceed the level I want to spend. I thought about sourcing parts from existing compactors, but I just don't know what I'm going to receive. I don't think it is worth the effort.

#13
10-10-15, 05:40 PM
Member
Join Date: Oct 2008
Location: New England
Posts: 9,806
Modify a small electric wood splitter, plenty of crushing force there and a wood splitter to boot.

Bud

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off