How to Calculate Pressure Exerted by C in a Lever and Fulcrum Configuration?

[JBA]

Below is a sketch of how I visualize the crosspiece to lifting arm connections. (See above for details)

 

[john101]

Ok, I think I got the problem I was having now.

The tube is welded to the crosspiece bars only.

No U piece.

I get what you mean re the lifting assembly at the other end.

Rough idea:

Showing 2" edge of tube with 1" thick bar with hole inserted with additions either side, shaft through them and case wall and piston etc.

 

[JBA]

That is a good start but now the challenge is finding a way to get the same strong reinforcement and load transfer connection between the axle plate and the arm that is now at the top end of the arms.

I am turning a number of variations for that connection running through my mind right now. I need to know what range of bars and plate you have or have access to that I can work with, including the width of the 1" bar you have. Once I have that information I will work on coming up with some connection suggestions.

 

[john101]

I have a number of the 1" which are actually 1 3/16 x 2 9/16 x 7 3/4 " that fit very nicely in the 2x3 tube. they are all pre-drilled for the shaft so I need to use them. Then I have 1/4", 3/16" plate.

 

[JBA]

I think I have found a possible solution for connecting the tubing to the axle bar using your available materials, but, I need to know the distance between the inside edges of the two holes in the 7 3/4 long axle bar(s) and the length from the the inside edge of the axle hole to the opposite end of the bar.

 

[john101]

This is a drawing of the bar.

The lower hole is where the axle goes (c).

The upper hole is serrated and gripped on to a serrated torsion bar suspension on the 'rail car' by clamping it on with a bolt through the small hole.

Can you describe in more detail which dimensions you are after?

note. after writing the above I reread your post and I think you mean between the two bars in the two arms. ?

 

[JBA]

Using your above figure as reference, I am asking for the distance from the top edge of the bottom hole to the bottom edge of the top hole; and also, the distance from the top edge of the bottom hole to the top end of the bar.

 

[john101]

the distance from the top edge of the bottom hole to the bottom edge of the top hole is 3 3/16".

the distance from the top edge of the bottom hole to the top end of the bar is 5 1/2".

 

[JBA]

OK, what I am going to suggest requires a fair amount of fabrication so I will make some illustrations to help you to understand it.

 

[JBA]

One more question, What type and size of spacer on the axle between the inside of the lifting arm and the side of the box are you planning on using.

 

[john101]

my idea is to cut the lower part off a couple of bars and use them as the spacers.

 

[JBA]

Are you going to drill them to fit around the shaft or just place them on the inner face of the lifting tube?

 

[john101]

I mean to cut the lower part that is pre-drilled.

 

[JBA]

Ok, I can work with that.

 

[JBA]

Attached is a suggested bottom connection design. The stacked 1/4" & 3/16" strips welded to the outside face of the axle bar are there to bring that to the 1 5/8" thickness required for a close side to side fit inside the 3 x 2 tubing for a strong welding attachment from the tube to the bar. I would have placed the 1/4" plate on one side of the bar and the 3/16' plate on the other but that will affect the inside 1" spacer clearance between the bar and body of the unit. Unfortunately, the top hole in the bar forced me to shorten the weld slot on the bar side without the added spacers.

I have also added reinforcing strips to the outside of the 2" faces of the tubing in the bottom region where there has been material removed for the welding slots in the 3" faces.

I made a composite using part of one of your figures to reduce my drafting time and the time of my response.

Review this layout and let me know what you think and any questions you have.

 

[john101]

Ok, that's a neat setup. I'm sure I understand all of it. I can do that. At the moment I'm finishing off the cross piece and starting preparing the arms. I'll post pics later.

 

[john101]

current: car battery for visual scale.

yet to add strengthening strips.

Cut crosspiece inserts too short to have them protrude beyond outer strips.

Arms not cut to length. Don't want to make mistake again of precutting to find mistake later.

found I've cut the c shaft too short. ie can't add third outer layer. I think I was miscalculating/mismeasuring for the inner strips.

 

[JBA]

Explain exactly what you mean by the "third outer layer".

Be sure to make a good weld connection between the crosspiece and the bottom slot and the reinforcing plates

 

[john101]

I mean this layer pointed to in red. The rod reaches to the red dotted line.

 

[JBA]

OK, I don't see that as any issue for the arm or the end attachment as long as you are still going to use the two inserted spacer plates for welding.

 

[john101]

Yes I will. That's good. Thank you.