truck bed crane...build or buy?

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Well, I've realized that I need a truck bed crane in order to load and unload certain things from my M715 truck.  After looking around, it seems like there is a huge gap between the cheaper consumer grade cranes and the higher end professional cranes (usually the consumer grade ones are around $300 and it pretty much jumps to $1500-$2000+ once you go above that).  Since I'm looking for a pretty stout crane with a long boom reach and 1000lb capacity at full extension, I'm wondering if it would be better to build my own or buy one.Looking at the consumer grade ones, they're pretty simple (and the materials used are pretty light weight all in all).  I think (here come the famous last words) that I could build one that would extend further and handle heavier loads than the consumer grade ones without too much problem.  Basically, keep a pretty similar design, beef up the materials (use 1/4" wall square tube/round tube instead of 3/16" wall in order to gain additional strength, etc...).  Does this sound in any way reasonable?  Or am I completely off my rocker here?Thanks guys.Ohh, here's a link to one of the consumer grade ones:http://www.amazon.com/dp/B000RH1T92/...6140_pe_vfe_d2And here's a link to one of the higher end professional grade ones:http://www.handsontools.com/Norco-78...h_p_11255.html--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:I'm sure the safety guys will cringe but I prefer to build my own stuff  A well executed design will likely be much stronger than the cheap cranes they sell at discount places. You can also add features that suit your needs.This is the crane I personally like, It doesn't take up any bed space http://www.westernmule.com/bumper_cranes.html
Reply:Just a thought, but when I was thinking of building one, I was stuck on the thought of using a long bottle jack. Or even a short bottle jack up close. And I wondered about the effects of weather. Then I saw a service truck where the boom would rotate but not go up and down. It was tall enough, and had a chainfall on it. It was very stout, and I would think stronger than one with a bottle jack.???"Where's Stick man????????" - 7A749"SHHHHHH!! I sent him over to snag that MIC-4 while tbone wasn't looking!" - duaneb55"I have bought a few of Tbone's things unlike Stick-Man who helps himself" - TozziWelding"Stick-man"
Reply:I built four little cranes for the county maintenance people about twenty five years ago. They used little electric winches to pick stuff up and you could use the winch to adjust the boom up and down and then pin it in place on a half circle plate with holes in it. I don't have pictures of things I built back then but they were fairly easy to build and they were for a 1000# if I remember correctly.
Reply:I think I can do one that'll work pretty well.  If I use a long ram hydraulic jack to lift and lower the boom, a 2000lb manual winch in order to be able to lower loads it should be pretty useful.  If I use 1/4" wall seamless square tube for the inside and outside portions of the boom build a 1/2" plate tension bar (pull?) across the top of the outside of the boom I should be able to get 1000lbs of lift capability at 4' extension.  The one thing I'm still contemplating is if there's a way to use an hydraulic ram inside the boom with a remote manual pump in order to extend and retract the boom while it has a load on it....Hopefully I'll be able to work this all out this winter --Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:I can't imagine considering buying something if I thought I could make it myself.  80% of the cost of anything is in the labor of something.  Not only will it be a proud achievement for yourself, but you can make it exactly how you want it, and if anything goes wrong with you, you will have no doubts in your mind on how to fix it.  Who knows, maybe you'll start making cranes for friends and such.Miller 330 a/bp water cooledI believe in gun control, I hold my gun with two hands.  If you want to know why, click here.Buy American or bye America.
Reply:Originally Posted by wintermuteI think I can do one that'll work pretty well.  If I use a long ram hydraulic jack to lift and lower the boom, a 2000lb manual winch in order to be able to lower loads it should be pretty useful.  If I use 1/4" wall seamless square tube for the inside and outside portions of the boom build a 1/2" plate tension bar (pull?) across the top of the outside of the boom I should be able to get 1000lbs of lift capability at 4' extension.  The one thing I'm still contemplating is if there's a way to use an hydraulic ram inside the boom with a remote manual pump in order to extend and retract the boom while it has a load on it....Hopefully I'll be able to work this all out this winter --Wintermute
Reply:Having purchased a cheap truck crane, I'll say you're definitely better off building your own or buying the more expensive commerical equipment.  If you go with a manual winch setup, buy a good one.  Cheap cable winches are not worth the head aches.  If you buy a powered winch, make sure to buy one that's rated and designed for overhead lifting.  Lot's of cheap power winches on the market for horizontal pulling.  Not so many that have the safety brakes needed for vertical lifting.Look closely at the possible need for outriggers or a jack leg underneath the crane.  1000lbs at 4 feet is a hell of a moment-arm on the body and frame of your truck, no matter how big it is.  Just a couple quick thoughts.  Please post your design sketches and ideas for a crane, as I'll be building one too this winter.  The POS crane I bought to get a couple projects done is headed for the scrap bin.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:A_DAB_will_do,I'll post my CAD drawings as I work on the design to you have something to reference off of if you want to use it.For the strengths, I'm pretty rusty in my Moment calculations, however, I'm pretty sure that if I remember correctly, at 4', 1000lbs translates to 4000ft-lbs on the fulcrum point (displacement vector times force vector).With an 8T long ram jack in plate at an angle and linked to the boom 1' from the fulcrum, the jack shouldn't be pushing more than 3000ft-lbs.As for the Moment at the mounting point on the truck, it's something I'm not sure about.  I thought it was the same calculation just using the third line of the triangle.  If I have a 4' high post and a 4' long boom, that make the third leg 5.66' at it's maximum length (right angle post to boom).  At 5.66' it would be exerting roughly 5660ft-lbs at the base of the crane.  That would give me either the option of outriggers or using a counterweight on the boom by extending the back of the boom past the post and then using just a vertical support under the crane since I'd be converting the Moment force to downward pressure.  If I extended the tail of the boom past the top of the post it would also give me additional space to install a hydraulic ram into the boom as well.Does any of that make sense...it's been along time since I had to do any of those calculations.Anyone who's less rusty on their physics here want to chime in?--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:Thanks very much wintermute.  I'm shopping around for ideas, and I appreciate your sharing what you come up with.As far as your calculations are concerned, it's been too long since I last attempted that sort of thing for me to say off the top of my head if you're right or wrong.  My purpose in mentioning it was to get you thinking about the frame and body of the truck you're mounting this too.  The el cheapo crane I have is rated for 500lbs at 5 ft.  It's bolted to flat bed on my truck and I can see the bed flexing when I'm moving heavy loads at the full reach of the crane.  A crane rated at twice(or more) that load capacity will require some thought in how to brace and support the crane.  There was another post not too long ago, by a guy going by the name of combat jump(?), where he upgraded a cheap jib crane.  Do a search on that thread for some good design ideas.My crane also has a very, very cheap manual winch, and the ratchet lock on it has jammed up on me twice.  It's very hard and somewhat dangerous to unjam it with a load on the crane.  Not to mention the time wasted screwing around with it in the middle of a job.  This is why I emphasize buying quality moving parts for your crane project. Originally Posted by wintermuteA_DAB_will_do,I'll post my CAD drawings as I work on the design to you have something to reference off of if you want to use it.For the strengths, I'm pretty rusty in my Moment calculations, however, I'm pretty sure that if I remember correctly, at 4', 1000lbs translates to 4000ft-lbs on the fulcrum point (displacement vector times force vector).With an 8T long ram jack in plate at an angle and linked to the boom 1' from the fulcrum, the jack shouldn't be pushing more than 3000ft-lbs.As for the Moment at the mounting point on the truck, it's something I'm not sure about.  I thought it was the same calculation just using the third line of the triangle.  If I have a 4' high post and a 4' long boom, that make the third leg 5.66' at it's maximum length (right angle post to boom).  At 5.66' it would be exerting roughly 5660ft-lbs at the base of the crane.  That would give me either the option of outriggers or using a counterweight on the boom by extending the back of the boom past the post and then using just a vertical support under the crane since I'd be converting the Moment force to downward pressure.  If I extended the tail of the boom past the top of the post it would also give me additional space to install a hydraulic ram into the boom as well.Does any of that make sense...it's been along time since I had to do any of those calculations.Anyone who's less rusty on their physics here want to chime in?--Wintermute
Reply:Build it.http://www.facebook.com/profile.php?id=100000825140116 Lincoln Weldanpower Model # AC-225/DC-210/6 portable,LN-25 suitcase feeder,Harbor Freight 80 AMP Inverter DC Tig
Reply:Here's the previous thread I mentioned on truck crane mods:http://weldingweb.com/vbb/showthread.php?t=39245Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Here's a website for a company that builds some heavier duty truck bed cranes.  Good for design ideas.  http://www.rugerindustries.com/truckmounted_cranes.html Originally Posted by A_DAB_will_doHere's the previous thread I mentioned on truck crane mods:http://weldingweb.com/vbb/showthread.php?t=39245
Reply:Originally Posted by A_DAB_will_doHere's a website for a company that builds some heavier duty truck bed cranes.  Good for design ideas.  http://www.rugerindustries.com/truckmounted_cranes.html
Reply:Wintermute, keep in mind that if you use a counterweight, it's either got to be short and heavy which will add a lot of unnecessary weight to your truck, or long and somewhat lighter which means in certain situations the tailswing radius could be an issue and also your mount location may be more limited because of tailswing and rear overhang.I think these reasons are why most conventional truck-mount cranes don't have counterweights.