Hydraulic Toyota truck project

While surfing the web looking for sources for stuff to rebuild the
engine in my 85 1-ton toyota truck, I got thinking about the flatbed I
want to mount on it.
So I started looking for makers of flatbeds to get ideas.
They are kind of hard to find, but I found a few including Knapheide,
who also make service bodies for trucks.
I saw this picture at the Knapheid site that got me thinking.
It is called a Knaphoist and it basically turns a flatbed truck into a
dump truck.
It is a very compact design, that I believe I can reverse engineer with
some help.
I am wondering if any of you hydraulic gurus can take a look at it and
make some guesses about the cyclinder specs and how big a pump one
would need.
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I plan on handling a lot of crushed rock for my driveway.
A dump bed would be really handy.
Reply to
Ernie Leimkuhler
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Many years ago Princess Auto sold kits to farmers. I checked my latest PA catalogue and I don't see them. I am thinking that there must be a supplier of lift kits for farm wagons below the 49th. The lift on the site has a problem that if you expect heavy lifts it just won't do it. A direct lifting multi-stage cylinder is better but needs a big hydraulic tank. Randy
While surfing the web looking for sources for stuff to rebuild the engine in my 85 1-ton toyota truck, I got thinking about the flatbed I want to mount on it. So I started looking for makers of flatbeds to get ideas. They are kind of hard to find, but I found a few including Knapheide, who also make service bodies for trucks.
I saw this picture at the Knapheid site that got me thinking. It is called a Knaphoist and it basically turns a flatbed truck into a dump truck.
It is a very compact design, that I believe I can reverse engineer with some help. I am wondering if any of you hydraulic gurus can take a look at it and make some guesses about the cyclinder specs and how big a pump one would need.
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I plan on handling a lot of crushed rock for my driveway. A dump bed would be really handy.
Reply to
R. Zimmerman
But a roller mat is a lot easier, cheaper, and will do the job just fine, with a lot less effect on the way the truck behaves.
Reply to
Ecnerwal
Cylinder and pump info is listed under the "specifications "link.
Cheers Trevor Jones
Reply to
Trevor Jones
Here is the page in the Pricess auto book:
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is the hoist cylinder only, but the hoist mechanism is listed on page 311. Check it out. It is a pdf, and will take a couple minutes to load.
They list 2 cylinders. One is a 4" bore, 7 ton, the other is a 5" bore 12 ton. 3000 psi max cont. pressure.
Cheers,
Dale
Reply to
Reality24
We have a local company (in Queensland, Australia) that makes tipping trailers using air bags and exhaust gas, the idea is so simple and easy to use you'd never want to try and use hydraulics on a small vehicle.
The bed is hinged at the rear, two spring loaded locks to hold the bed down at the front. The air bag is located under the trailer bed on a flat steel platform, its angled rearward so some basic geometry would be needed to set it up.
The exhaust hose has a valve on it and a rubber cone to fit onto the end of the exhaust.
Reply to
Roger Martin
A dump is nice, but it requires hydraulics and a PTO, or a huge electric hydraulic power pack. What type of PTO works on a Toyota truck?
Instead, consider getting a trailer you can dump. If you are doing enough work that requires a dump, you must have a small tractor to push that gravel around.
Put a ball in the bucket of your tractor so you can use the hydraulics of the tractor to dump the trailer.
My trailer was designed with this exact idea in mind. It can be stood on end (dumped) without breaking anything, even when hauling a few tons.
Reply to
frank
On Wed, 01 Oct 2003 06:37:17 GMT, Ernie Leimkuhler wrote something ......and in reply I say!:
OK I am no guru, but here's my take OOI. Hope some0one jumps in if I get it wrong.
It's not easy from the picture, so I made some assumptions.
This beastie will need some real force to work. It's no wonder they build their own frame, and do not rely on the truck bed. I have seen similar ideas that worked underneath the tray, but pointing forward. This meved the whole effort forward of the fulcrum more, and relieved the pressures a bit.
The problem is that the ram is at its worst when the load on it is greatest, because the load gets lighter and lighter as you lift the tray, both because you start to lose the load, and because as the load lifts, its centre of gravity moves back over the ram, and more and more of the weight is taken by the hinge, and not by the ram.
The advantage is that the tray can stay near the cab (although watch actual tilt clearance if you have anything that hange below the tray plane), and that a relatively small pump and tank are needed. A 3 stage ram _usually_ takes up greater amounts of hydro fluid, and usually needs the tray moved bac to give it room. ALso, to get the 60deg lift I am working on, it would need to be about 4.5' high closed, which could be a pest when operating.
I am assuming a 12' tray with no overhang. So the fulcrum will be 6' from the centre of gravity of the load, assuming an even load.
I am assuming that the base end of the ram can be 1' below the tray, or actually below the centre of the pin that attaches its other end to the fixture to the tray that these guys use.
I am assuming a 2' ram.
- The above two allow a ram angle, when the tray is flat, of around 25 deg to the tray bed. It also allows the ram to act about 1.9' from the fulcrum, - to give a 60 deg tilt to the tray at full extension.
They mention a 4" diam ram and 3500- 4000 lb pressure in their specs and blurb. This means the ram can exert 4" sq * 4000 = 16000 lbs of force in a straight line.
I reckon that the force required to lift a one ton weight, centred at the 6' point on the tray, will be
(2240 lb (load) *
6'(tray half) / 1.9' (ram free end to fulcrum)) / 0.42 (sin 25 deg) = 16700 lb
I reckon that the 1' below the tray is generous, and the faltter it starts, the more the froce required to start with. You will need to have some overhang on the tray. For instance, if the overhang is 1', the force required = 13040 lb, because you only have 5' from load centre to fulcrum.
Assuming a lift time of 10 seconds. You need to pump 4" sq * 20.5" of fluid = 82" ^3. If I use the US 6pint gallon, this is about .23 * 6 = 1.4 gals/min.
****************************************************************************************** Those who can, do. Those who can't, teach. The rest sit around and make snide comments.
Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !!
Reply to
Old Nick
The thing about dump beds is the bed winds up not rigidly attached to the frame, sometimes not that securely attached either. I think you'd find a rigid bed more useful for your occasional load-limit top-heavy machinery hauling. Now you might build a dump box that mounts over the flatbed - there are some neat "insert" dump beds for pickups that have a smooth interior for easier sliding. No wheel well inserts etc.
I also like the suggestion of the roller mat. I haven't tried it with gravel, but I have several times brought home 2 yards of mulch dumped on a tarp in the pickup bed, and then either tied off the tarp to an anchor and driven the truck out from under it or just pulled out the tarp with power equipment. Gravel is more involved... am sure you can come up with something.
Reply to
Bob Powell
On Wed, 01 Oct 2003 11:11:50 GMT, Ecnerwal wrote something ......and in reply I say!:
Do they use those? I have often wondered but thought it was a crazy idea. Great for working underneath the shed etc!
hmmmmm
Actually here,in West Oz, licensing would be more easy. If you make your tray top a tipper, you have to license it again.
****************************************************************************************** Those who can, do. Those who can't, teach. The rest sit around and make snide comments.
Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !!
Reply to
Old Nick
On Thu, 2 Oct 2003 06:47:38 +1000, "Roger Martin" wrote something ......and in reply I say!:
Three issues. I was building one of these (actually thought of it before I heard about the mob making them. D'Oh!).
Issue one. I have one of the airjack bags that they use. It does not work any more, as it appears to have perished somewhere. I admit it took a few years (2-3?) but it was still a PITA.
Issue two. In WAus, in theory, you still need to relicence the vehicle if you make it a tipper, however.
Issue three. Your exhaust needs to be in top condition to run these things. My best trick was to blow an exhaust join.
****************************************************************************************** Those who can, do. Those who can't, teach. The rest sit around and make snide comments.
Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !!
Reply to
Old Nick
[[ This message was both posted and mailed: see the "To," "Cc," and "Newsgroups" headers for details. ]]
Now that idea I like a lot. Any chance of pictures or a website?
There was a company here in the US selling exhaust powered car jacks that were basically inflatable bags. Same idea.
Reply to
Ernie Leimkuhler
Sorry no website that I'm aware of, and for the life of me I cant remember their name either. I'll see if I can get a photo next week when I go to Brisbane.
I think they use a more robust arrangement - looks like material used in truck air springs. But I'm sure that an exhaust jack would work well and with a larger footprint it would require less chassis subframe modifications.
Big problem with any tipper is twisting the vehicle chassis, using hydraulics can put some really large loads onto chassis crossmembers. I've seen a few horizontally mounted rams which must rely upon the hinge pins being in good condition to rotate around. Regular dump trucks usually have a vertically (just off actually) mounted ram.
Reply to
Roger Martin
Here's something similar but it uses a compressor instead of exhaust.
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The Web site's pretty crappy but if you read the instructions you can get a pretty good idea of the setup. They installed one on the Trucks TV show and it looked decent.
Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com
"I'm not grown up enough to be so old!"
Reply to
Keith Marshall
I know a couple of guys that have used the kits to turn pickups into dump beds. They seem to me to be very light duty setups, very suitable for landscaping type tasks such as brush, limbs and mulch. But not so well suited to heavy loads such as rock or full bed of dirt. Heavy use resulted in worn out everything. Just an observation.
JTMcC.
Reply to
JTMcC
On Thu, 2 Oct 2003 14:34:14 +1000, "Roger Martin" wrote something ......and in reply I say!: If you check out the site thet Ernie refers to, they have a complete frame to support the thig, and don't rely on the truck frame. From the forces I worked out, I can see why.
****************************************************************************************** Those who can, do. Those who can't, teach. The rest sit around and make snide comments.
Nick White --- HEAD:Hertz Music Please remove ns from my header address to reply via email !!
Reply to
Old Nick
On Thu, 02 Oct 2003 06:02:32 +0800, Old Nick wrote something ......and in reply I say!:
Oh well...it was fun writing it........
>On Wed, 01 Oct 2003 06:37:17 GMT, Ernie Leimkuhler > wrote something >......and in reply I say!: > >OK I am no guru, but here's my take OOI. Hope some0one jumps in if I >get it wrong. > >It's not easy from the picture, so I made some assumptions. > >This beastie will need some real force to work. It's no wonder they >build their own frame, and do not rely on the truck bed. I have seen >similar ideas that worked underneath the tray, but pointing forward. >This meved the whole effort forward of the fulcrum more, and relieved >the pressures a bit. > >The problem is that the ram is at its worst when the load on it is >greatest, because the load gets lighter and lighter as you lift the >tray, both because you start to lose the load, and because as the load >lifts, its centre of gravity moves back over the ram, and more and >more of the weight is taken by the hinge, and not by the ram. > >The advantage is that the tray can stay near the cab (although watch >actual tilt clearance if you have anything that hange below the tray >plane), and that a relatively small pump and tank are needed. A 3 >stage ram _usually_ takes up greater amounts of hydro fluid, and >usually needs the tray moved bac to give it room. ALso, to get the >60deg lift I am working on, it would need to be about 4.5' high >closed, which could be a pest when operating. > >I am assuming a 12' tray with no overhang. So the fulcrum will be 6' >from the centre of gravity of the load, assuming an even load. > >I am assuming that the base end of the ram can be 1' below the tray, >or actually below the centre of the pin that attaches its other end to >the fixture to the tray that these guys use. > >I am assuming a 2' ram. > > - The above two allow a ram angle, when the tray is flat, of around >25 deg to the tray bed. It also allows the ram to act about 1.9' from >the fulcrum, > - to give a 60 deg tilt to the tray at full extension. > >They mention a 4" diam ram and 3500- 4000 lb pressure in their specs >and blurb. This means the ram can exert 4" sq * 4000 = 16000 lbs of >force in a straight line. > >I reckon that the force required to lift a one ton weight, centred at >the 6' point on the tray, will be > >(2240 lb (load) >* 6'(tray half) / 1.9' (ram free end to fulcrum)) >/ 0.42 (sin 25 deg) >= 16700 lb > >I reckon that the 1' below the tray is generous, and the faltter it >starts, the more the froce required to start with. You will need to >have some overhang on the tray. For instance, if the overhang is 1', >the force required = 13040 lb, because you only have 5' from load >centre to fulcrum. > >Assuming a lift time of 10 seconds. You need to pump 4" sq * 20.5" of >fluid = 82" ^3. If I use the US 6pint gallon, this is about .23 * 6 = >1.4 gals/min. > >>While surfing the web looking for sources for stuff to rebuild the >>engine in my 85 1-ton toyota truck, I got thinking about the flatbed I >>want to mount on it. >>So I started looking for makers of flatbeds to get ideas. >>They are kind of hard to find, but I found a few including Knapheide, >>who also make service bodies for trucks. >> >>I saw this picture at the Knapheid site that got me thinking. >>It is called a Knaphoist and it basically turns a flatbed truck into a >>dump truck. >> >>It is a very compact design, that I believe I can reverse engineer with >>some help. >>I am wondering if any of you hydraulic gurus can take a look at it and >>make some guesses about the cyclinder specs and how big a pump one >>would need. >> >>
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>>I plan on handling a lot of crushed rock for my driveway. >>A dump bed would be really handy. > >****************************************************************************************** >Those who can, do. Those who can't, teach. >The rest sit around and make snide comments. > >Nick White --- HEAD:Hertz Music >Please remove ns from my header address to reply via email > !! >
Reply to
Old Nick
Ernie,
You might want to check with the Washington highway patrol before you convert to flatbed. In CA this means you are going to have to stop at truck scales, and your taxes get jacked way up.
A tip bed pickup however is probably still a pickup.
Reply to
Roger Shoaf
I already checked with the Washington State Patrol. Because it already is a 1-ton truck, they don't care if I turn it into a flatbed.
It would still be exempt from truck scales.
I might not go as far as the tiltbed, but I will be going to a flatbed. I like the idea of a ramp that slides under the bed, and toolboxes under the sides.
And also Flip down side rails that can recieve plywood panels for hauling loose materiel.
Kind of fun to design.
First I need to get the engine replaced with one I rebuild myself, then the flatbed.
Reply to
Ernie Leimkuhler
[...]
They list a patent number. Please go to the USPTO web site
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, and type that patent number (US3791695) in their search tools for the patent. The patent has plans. Admitedly, they are lawyers plans (it's still a patent), but they may be of help. The patent expired at least 10 years ago, in case you wonder.
Reply to
jerry_tig2003

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