Hydraulic pump to weed eater platform

[julian1]

I was simply stating weed eater / verses hurst power unit weed eater wouldn't have very much power.

I am an electric an / maintenance mechanic and I have done allot of re-bar work too I use 36" bolt cutters and have to put all my weight in to it to cut 1/2"

so figure 300lbs (I'm a big guy) at 36" with the re-bar at 1" on the other side of a compound lever (bolt cutter) arraignment you do the math

as for the smart "fool1, fool2 / Patato Heads" comments we are trying to help.

grow up and be constructive not insultive.

Ill add you to my ignore list

tom

THANK YOU I APPRECIATE YOU NOT RESPONDING ESPECIALLY AFTER THE NON CONSTRUCTIVE BOAD MOTOR STATEMENT YOU SO INSULTINGLY PRESENTED.

 

[Scooby074]

EVERYBODY in this thread was trying to help. THe evenrude comment wasnt made as a insult,tom was stating he believes they actually use evenrude 2-stroke motors (ie weed eater as you call them) as a power source.

What your building (from your fractured description) is a "jaws of life" on a stick. ITS BEEN DONE. Theres this thing called Google... try it.

Theres lots of smart people on here, and I doubt your going to get them to do YOUR engineering for you, with your attitude.

 

[wvpolekat]

You don't want advice, you have already decided what you are going to do, you are looking for someone to agree with you.

Given the combined years of experience that you are getting answers from, perhaps you should give some heed to the fact that they are telling you that you are re-inventing the wheel.

I am sure if a usable amount of hydraulic work could be extracted from a small 2 cycle motor, it would have already been put on the market. I am sure there is a market for a light, portable, gas powered hydraulic power pack. But, if the most they can do is press pins out of a bicycle chain, there is not much point.

tommu56 provided you with an example of how much force/work needed to be done. I think that the general feedback you are getting is that your power source is not capable of doing this amount of work in a reasonable amount of time.

 

[David_Kb7uns]

Have seen an air powered set of bolt cutters before, they may be run from a small compressor or a small compressed air tank with regulator, think this may be a lighter way to go if you need to go up high with it, you may also look at the Stanley Hydraulic tools website as they did have a hydraulic pruner for trees and also a rotary saw. Maybe a screw driven set of jaws would give more force than the cylinder. They make small ones with battery powered hydraulic packs for cutting and crimping large cables.

Crimping Tools

David Kb7uns

 

[J_J]

This is about as portable as it gets up to 5/8.

Benner Nawman Rebar Cutters
DCC-1618 DC-16LZ
The DCC-1618 cordless rebar cutter will safely and cleanly cut rebar up to 5/8謦*iameter grade 60. This self-contained electric/hydraulic unit will also cut other items like chain, bolts, and rod. The DCC-1618 can be used in rescue operations, cut in close proximity to a trapped victim, does not throw sparks or heat. The cutting head quickly rotates up to 345 degrees for using in vertical, horizontal, or difficult applications. A safety relief valve for retracting the piston and a cutting guard are standard features. This tool ships complete with (2) each 18 volt DC batteries, 30-60 minute fast battery charger, removable side handle, plastic carrying case, and a tool kit. Available in 2007

Second and third pictre is a different tool. Hitachi VB16Y Rebar Cutter/Bender, Grade 60, EVS

 

[Soundguy]

I think the point of the boat motor response was a 'horsepower' thing.

to cut rebar of that size you will need significant power. that weedeater motor is not a powerhouse.. but does have a good top end speed...for this application you will either need alot of mechanical advantage or alot of muscle. you aren't getting alot of muscle on a weedeater engine. I see running it wot with a gear reducer to slow it, and using that to drve a motor, with perhaps a worm drive that then actuates a mechanicaly advantaged set of jaws.

many of the apps mentioned here use electrical motors that are torquey ( max at stall ).. but not so much high speed, plus a gear reduction system.. etc.

soundguy

 

[Wayne County Hose]

I am looking for all the information I can gather form experts such as you as to the development of a design which I will describe. I have a need for a hydra operation that operates a scisser type mechanical device that will shear 1/2 inch bolts or 1/2 inch rebarr. This device would be best designed by attaching a hydra pump onto a weed eater and engine platform. Operations would be for a person to power the pump by running the engine which produces fluid power to a sisser mechanism located about 6 feet from the head/pump. One blade would be stationary and the other stroke operational. Of course an expandable coil hose assembly would couple the pump and scisser/shear. I would expect the shear to opeate with either a pull or push piston and a trigger switch would operate the function device. Though I am a BSEE I have very very limited knowledge of hyra and would appreciate all the design help you can support me with, even if it is send me to another site. Just pls give me some direction.

Needed to assemble a prototype unit:
1) Estimated hp for engine and pump.
2) Trigger/switch ideas.
3) Scisser mech piston or other operational device.
4) Fluid reservoir container and size.
5) Formula/s used to estimate the above.

For what you would like to do, here is the best advice anyone could give you. Hire an engineer. This is not something that you sit down at a desk with a scratch pad and whip up in a half an hour. First, you have risk management. I could probably sit down and work all this up for you. But, if I make one small mistake in my calculations, somebody could become seriously injured. Not what I want on my conscience or on my liability insurance. If I were even to make something like this for myself, engineering this to be safe takes quite a bit of time and effort. I would think that with you having a BSEE you would realize all this. If you would like to figure these calculations out for yourself, go to the Eaton/Weatherhead website and purchase their Hydraulics Lightning Reference manual. Everything is in there that you may need.

There are loads of details you left out. 1/2" bolts come in many grades. What is the highest tensile strength of the material you intend to cut? I don't believe a coil hose would work too well for this. When you pressurize a hydraulic hose, it wants to straighten. A coil hose in this application would "Whip" itself straight and possibly injure the operator.

Personally, unless you used specially fabricated components, I believe this would probably be much too heavy for the normal man to handle with any regularity. I would investigate using a battery pack and using a small electric motor to power your shear. This would be much more easily switchable, have far fewer components to wear or break, and probably built using off the shelf components and be much lighter and way more reliable. It would also be much safer as you do not have gasoline, high temperature exhaust, and pressurized hydraulic oil in such close proximity. Have you ever seen a hydraulic hose cut by or near hot exhaust? Instant flamethrower. I had a friend that received 2nd degree burns from such an accident.

Good luck in your endeavor. Please realize that everyone responding was genuinely attempting to help you.

 

[firemanpat2910]

why reinvent the wheel? Search for Genesis Rescue systems
look at the mini cutter. It is designed for brake pedals, and such. The cutter heads have to be super strong to cut anything above a plain grade 2 bolt. If you dont like my answer , call me fool 3 but dont ever let me catch you, you wont like it.

 

[J_J]

To anyone that is interested, here is a 1 in rebar cutter. Even if you put this on the end of a 6 ft pole.shaft, and powered the pump with a 1 HP 2 stroke engine, it would weigh probably 30 to 40 lbs. I am also assuming that he needs to reach somewhere that is unsafe for close up work. As I said before, I have a backpack driven hydraulic pump, that will run a hydraulic loper, or hydraulic chainsaw. I believe the pressure is about 1500 psi, I have the book on it somewhere.


Electric/Hydraulic Rebar Cutter. Large selection of Masonry, Stone and Tile tools on the WEB.

 

[J_J]

Wayne,

Can you power a hydraulic cylinder using Nitrogen, from a backpack unit? Or would it have to be an air cylinder, etc? Someone mentioned rescue, and I believe that they use Nitrogen, but I don't know what powers the cylinder.