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Benders and Bending Which bender is best? How do you use a bender? How do you calculate bends? Everything Bender related...


Benders and Bending Which bender is best? How do you use a bender? How do you calculate bends? Everything Bender related...

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  #41  
Old 12-17-2009, 10:38 PM
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Nutz4sand Nutz4sand is offline
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My pump is not identical but very similar to the one on the build idahoaj1 posted above. Its normally a 700 dollar retail pump but I got if off Evilbay for under 200 shipped to me.

You just gotta be persistant and in no hurry and a good deal will run in front of you if you stay vigilant.

As for the Electric ram type things you pay for a good one but some QUALITY trailer tongue jacks can lift 5000 pounds. They are niether small nor light but not to bad. Not bloody fast but thats a good thing while trying to hit a certain degree. They are somewhat limited in travel sometiems but some will approach 20 inches as they are fixed to a trialer tongue and need to lift clear.

There is also a hydraulic trailer jack setup on Evilbay that is kinda nice if you are a random bender. 12 volt systems do not like to be run and run and run and if a lot of bending is your thing 120 volt setups will be best. Running a big 12 volt motor a lot will take the brushes out of most kinda often.

Before I scored my pump off Ebay I bought a nice 120 volt motor and was gonna pirate the rest off a new log splitter. I had the motor and a shaft with step pulleys so I could tailer the speed and pressure some if need be/want to. At one point I was looking at power steering pumps too. I know a few who have used them and all thats relaly needed is an expanded reservoir if you use a long stroke cylinder.
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  #42  
Old 12-18-2009, 12:03 PM
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I wouldn't be scared at all using a PS pump. as was said before the relief pressure could surely be shimmed 500-1000 psi i would think.

The speed is a easy deal to with pulleys etc.

I wonder about the grinder application though if you used a reohstat then your power is gonna be limited somwhat to dial in the speed, probably be better off to just size the pulley right.

This is actually a pretty good idea.
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  #43  
Old 12-18-2009, 12:12 PM
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I guess my main questions at this point would be: What is the ideal RPM for a power steering pump, and what applications are the higher volume ones found in, vehicle wise?

Also, I have a semi truck wrecking yard next to me... wonder what their pumps are rated at?
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  #44  
Old 12-18-2009, 07:20 PM
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the ideal rpm would be the one that put out the GPM that you wanted. I would think that you could calculate the amount of cycle time for you cylinder bore/stroke under load and speed the pump up until the cycle time is right, or just use a flowmeter.

I would start with around 2000 rpm the ps pump shaft then go from there.
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  #45  
Old 03-01-2010, 12:39 AM
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any updates on this?
enquiring minds wanna see pix!!!
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  #46  
Old 03-01-2010, 01:04 AM
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Honestly, realized I could do it cheaper and easier with the Harbor Freight air ram, so I went with that instead. I'm sure I could have cobbled something together, but decided instead of spending more work trying to get a tool to work, I'd rather work on the rig and just go with a tried and true setup. I still have to make the bracket that clamps onto the ram, but thats not too hard and should go fast. My deadline for a long list of projects is the first week of April, which will hopefully include my exo cage in at least a basic and safe form.

I do think it would work though, and if you set it up right would probably bend easier and faster then the HF unit.

JH
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  #47  
Old 03-01-2010, 10:28 AM
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anyone know if the power steering pumps on semi-trucks do more pressure and flow than automotive types?
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  #48  
Old 03-01-2010, 10:41 AM
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I tested pressure on my hydro assist setup and found, at an idle my gm pump was pushing 1300 psi. http://www.offroadfabnet.com/forums/...ead.php?t=7104

My ps pulley is fairly close to the same size as the crank pulley and it idle's around 600 or so.
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  #49  
Old 03-01-2010, 11:38 AM
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but at what flow rate?
since there is no demand at idle, it could only be flowing a 1/10 of a gpm. we need 1 gpm or more for this thing to work correctly, speed wise.
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  #50  
Old 03-01-2010, 01:19 PM
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i haven't found any reliable factual numbers yet, but several places on the net mention that standard automotive type PS pumps are something like 4-5 GPM and 2000-2500 PSI. Mostly on forums, etc., so who knows the validity of the info.
I'm wondering if those numbers are sufficient if they are credible?

I'm also having a hard time finding what RPM is the 'sweet spot' for the automotive PS pumps too.

Last edited by idahoaj1; 03-01-2010 at 01:22 PM.
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  #51  
Old 03-01-2010, 04:10 PM
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4-5 GPM would be awesome, If i remeber correctly the high power electric power units that are sold by JD2 and others are only 2 gpm so anywhere nere there would be great.
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  #52  
Old 03-01-2010, 06:02 PM
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thats good info to have. I'm not at all worried about the flow, as Im sure that automotive units have more than enough flow, its the pressure that i'm concerned about.

I guess unless more information comes out, someone just needs to put one together and see if it works or not. to hell with the lack of reliable info! lol..
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  #53  
Old 03-01-2010, 11:48 PM
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Quote:
Originally Posted by idahoaj1 View Post
thats good info to have. I'm not at all worried about the flow, as Im sure that automotive units have more than enough flow, its the pressure that i'm concerned about.

I guess unless more information comes out, someone just needs to put one together and see if it works or not. to hell with the lack of reliable info! lol..
I agree. The flow will just dictate speed. Too much flow will just eat horsepower from the motor anyway. You dont need much at all. If my pump can run my steering box and a 1.5" dia. ram at the same time as fast as i can turn the wheel then it will run a bender just fine.
I'd just build the F'n thing. I'd almost bet money that it will work just fine.
If i had an extra pump laying around, I'd hook a motor to it just to test pressures. I would test it direct drive 1:1 first. Most common ac motor speed is around 1700rpms.
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  #54  
Old 03-01-2010, 11:58 PM
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Quote:
Originally Posted by CarterKraft View Post
but at what flow rate?
since there is no demand at idle, it could only be flowing a 1/10 of a gpm. we need 1 gpm or more for this thing to work correctly, speed wise.
There is still full demand at an idle. It still has to fill the ram and turn the wheels at the same rate as if it were revved. it's still the same size orfice in the pump no matter what speed its turning. The higher rpm's change the pressure, and the pressure affects the flow.

the speed of the bender will be determined by both the pressure and flow rate. For example, the hydraulics i use at work are driven by very high pressure pumps. In order to keep things from tearing apart, we install in line restrictors. They have a tiny hole to let the fluid pass through. You could barely fit a hair through the hole. Those cylinders still would move too fast for a bender application. Without them they will rip themselves apart.
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  #55  
Old 03-02-2010, 09:34 AM
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IT WILL WORK!

I mentioned earlier,I've known my neibor for 15yrs and he has been using it long before i knew him.Its just an old(early 70s truck) gm pump powered by and old electric motor.Its on an old hossfeld bender,full time fabricator.The reason he chose the truck pump at the time he said it was the highest rate or flow ,i forget which,plus the pulley is removable.

He sold it to another niebor and i havnt had time to get pics.
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  #56  
Old 03-02-2010, 10:23 AM
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idahoaj1 idahoaj1 is offline
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by truck pump, do you mean pickup truck, or larger farm truck?
Also, what type of pump was it? remote reservoir, or the one that fits in the can reservoir?
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  #57  
Old 03-02-2010, 12:20 PM
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Sorry,pickup truck,built in res.I meant to say highest pressure in my earlier post,sorry.Stock res. seems to be plenty,the hossfeld ram is pretty long too,but it works.

Its so simple its rediculous.

He use to sell them years ago,I mean like more than 20 yrs ago.The only additional thing is a relay valve,all you have in your hand is a small pendant with two buttons,in and out.

I have to go get the pics too hard for me to splain !
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  #58  
Old 11-26-2014, 11:42 PM
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Fattcat69 Fattcat69 is offline
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Wow amazing thread that is old ....

I just finished reading this thread because im wanting to do this... What ever happened. There is some seriously great information here. I purchased the HF air hydro pump and its a bit to slow for my liking. Plus the constant Compressor running is annoying. So looking through these amazing pages and the fact that i have a good 220 compressor motor and at least 5 various Auto PS pumps laying in my shed, I need to do this... So with the knowledge i have gained i need a cylinder and a valve.. and plumbing and and and .... lol

Well i hope i can bring this thread some life here, I will pay my membership so i can post some pics of what im working with... It is basically a protools 105hd i went vertical with. I believe i have enough room on my portable stand to add the motor pump and i will build a nice small fluid res as well... WOW im excited now
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  #59  
Old 11-28-2014, 12:33 AM
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So far so good...

Well here is a pic of what i have going... For some reason i love scrap! im a scrap metal horder!! lol always comes in handy... The main frame is 19.25 x 33.50... i used some scrap C channel for the main bender arm mounts. 1.50x3" which may need some gussets for extra bracing but im not sure yet... I have the HF air ram dialed in now and it throws around 55 deg on the deg wheel...Im not really happy with the Slow air ram and hearing my compressor run.



So now i would like to attempt going elect hydraulic. After reading this column i think building a remote power supply is the way to go with quick disconnects.. That way i can utilize the Hydraulic power for my press as well. Ive been looking at cylinders all day. With this stand I have room to run a long cylinder around 34.50 max..

There are so many cylinders! I could look all day its insane!... lolol I have hopefully narrowed it down based on some of the notes ive taken from this amazing link.
Im looking at a 2.5 bore cylinder with 24" stroke. The cylinder is rated for 2500 to 3850 psi... its a double action setup as well... Collapsed it is 34.25 and extended its 58.25...
I have a few different saginaw gm power steering pumps and a 220v compressor motor to use. i also need to buy a log splitter valve.. I see that some of these valves are rated gpm.. Should i look for max gpm or does this need to be more precise to the pumps specs? Im going to have a ton of questions on this but im seriously excited to try this build out!
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  #60  
Old 11-28-2014, 06:35 PM
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Gathering some parts...

So This will be my portable station... its 19.25 x 27" Im going to just try using an old ammo can i have for a res tank. Ill try building a floor at 13.5 on this stand for the electric motor, Im thinking a half floor so that the pump can be adjusted. or a fixed mount for the pump and take the adjustments from the motor side...

http://www.offroadfabnet.com/forums/...1&d=1417216773

The motor specs are here..

http://www.offroadfabnet.com/forums/...1&d=1417217218

Today i ordered my cylinder and the log splitter valve..

The original bender frame will need some work to make the larger cylinder fit but i think it will be well worth the time...

3"x24" stroke tie rod hydraulic cylinder.
compressed size is 34.25 the HF air ram is at 24" so its quite abit longer..
shaft diameter is 1.25 made from SAE C 1045 chome hardened rod... Same as the HF specs i believe..

The cylinder has 1/2 inch ports. as well as the splitter valve on the work load side.. Splitter valve has 3/4" on the flow fittings..

Splitter is a Dalton 18gpm detent return w kickout and adjustable relief valve
2250 to 3500 psi...

Well im hoping this works.. Wife is looking at me with her crazy eyes but is in total agreement that the HF set up is loud and annoying...
Since she works with me in the shop alot. I have noticed her leaving whenever i fire up the bender and the air compressor.... lol hmmm mabie that isnt a bad thing lmao
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