Need a steel engineer

[Wayne County Hose]

I appreciate all your guys input. RFB is working with me on posting a drawing. I'll get something drawn up tonight or tomorrow and hopefully have it posted by Monday. This is exactly the input I'm looking for as you guys sound like you know what you're talking about. If you go to the website posted below, you will see a hydraulic cylinder disassembly table with the nut remover. I am trying to build something similar but on a smaller scale. Rather than a 15' table, I think I can do this on a piece of steel 8' long. Please take a couple minutes to look at the disassembly table on the website and tell me if I can accomplish this on a piece of square tube. Albeit, a large, thick piece, but these tables on the website are made to go to 50,000 lb.ft. and I only want to go to 5,000 lbs. Thanks again for your input, Andy.

Machinery Service & Design, a New Generation of Affordable Hydraulic Rebuilding Equipment

By the way, I have a friend that is a certified welder who will do all the welding. I have no employees, just me. I do work as safely as possible, believe me, but I don't have $20,000 to spend on a piece of equipment which is much larger than I'll ever need.

 

[jmc]

This is exactly the input I'm looking for as you guys sound like you know what you're talking about.

When someone specifies tube properties without regard to wall thickness, watch out.

Interesting project, BTW.

John

 

[Wayne County Hose]

When someone specifies tube properties without regard to wall thickness, watch out.

Interesting project, BTW.

John

I haven't really given enough info for anyone to be specific. I will have info ready by Monday. I did build my own disassembly/assembly/test table. I can disassemble and assemble cylinders then pressure test to 2200 p.s.i. for any amount of time. Usually I cycle the cylinders a few times and run them in all the way and manually close a 7,000 psi valve. Then, I walk away for about 15 minutes. If they hold pressure and don't leak, they are ready for the customer. Now, I need to be able to do this to excavator cylinders which is why I need to build this project.

 

[Darren]

I've always used a torque multiplier to remove large nuts. The 5,000 ft lbs you need is within the torque range of the heavier units. You'll have to anchor the cylinder, which means you can also anchor the torque multiplier. It won't be as slick as the setup you're building, but as long as you can get it on the nut, it will take it off.

If you're doing lots of large diameter cylinders, your idea will be better. If you don't do that many, the multiplier may save you money.

 

[Dirthog]

you will need a whole lot heaver table that you think we have one made by OTC which is 6x6 angle 1/2" thick it is 20ft long even with all the braces in it it is not heavy enough for the longer and larger excavator cyl there is a 40 to one multiplier mounted on the table and you can twist the table like a pretzel if you are not careful. The nuts on any thing much larger that a 120 size machine are way more than 5000 PSI the nuts on a 300 size start at 12000 psi for the bucket and the arm and boom are much more. Also they need to be pressure tested to 5000 Psi we have had more than one that was alright at low pressure but would bypass at working pressure.

 

[Wayne County Hose]

Thanks dirthog, I may have to rethink this. The large commercial ones specify that they be bolted to concrete with 3/4" anchors. This is to help prevent twisting. I'm thinking I may just have to build one of these tables and bolt it to the floor. The more I think about it, the more I come to the conclusion that if this could be done with a single piece of steel like I want to, that it would have been done by now. Now, to price out 2"x4"x.3875" steel. Ouch!

 

[Dirthog]

thats the was ours WAS bolted to the floor but with the twisting it takes it will not stay tight we have moved it several times to keep it bolted down

 

[MrJimi]

Thanks dirthog, I may have to rethink this. The large commercial ones specify that they be bolted to concrete with 3/4" anchors. This is to help prevent twisting. I'm thinking I may just have to build one of these tables and bolt it to the floor. The more I think about it, the more I come to the conclusion that if this could be done with a single piece of steel like I want to, that it would have been done by now. Now, to price out 2"x4"x.3875" steel. Ouch!

Andy, I bought a 4 foot by 8 foot by 3/8 plate for around $240, and they sheared it for me, Just remember, you only buy it once
Sounds like a great project
Jim

 

[mooseye]

I don't think you are going to find a single piece of steel that will withstand the twisting force you will be working with. If you did, it would likely be as big as a bridge truss.
You may, however, be able to construct a table out of multiple members that will handle it. Lots of diagonal bracing and heavy main structure. Fastening it to a concrete floor will be a benefit.
My first thought would be a heavy pipe section that would connect to the same part turning the nut. A heavy pipe with a bolted flange on the end that would go over the cylinder and could have holes at intervals to pin off the eye end, and then a mount on the far end to prevent deflection. All the torque would be transferred to the same end that is doing the turning.
Just a thought.

Okay, just reading back through and I see that I missed Iron horse's post which is basically the same idea I have.