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Dump bed DIY need some help

Discussion in 'General Truck Info' started by SAITCHO, Mar 19, 2019.


    SAITCHO Member

    Hi guys, I got a 2003 Suzuki Carry DA63T with difflock on the way, should be here in may and I want to build myself a dump bed. I plan to build a clam type frame with hinges and go with the straight cylinder option. I looked into a scissor lift dump system but its too pricey to buy one and with the other mods I have in mind too complicated to design and fab for the time I have.

    My goal is to be able to dump 1500 LBS at a 50 degree angle. Here are the info ,measurement I would like to get so it gives me a base to start my calculations from.

    Cylinder info:
    1-Collapsed length and extended length.
    2-Diameter of the bore of the cylinder
    3-PSI of the hydraulic unit

    Measurement of the position of the two cylinder ends (when dump bed is closed).

    1-Horizontal distance between the end of the box(near the cab) and the top end of the cylinder.
    2-Horizontal distance between the end of the box(near the cab) and the bottom end of the cylinder.
    3-I need to know how far above and below both cylinder ends are relative to a horizontal line that goes from the center of the hings to the cab of the truck.

    With these measurement I will be able to figure out the starting cylinder angle and calculate the forces at play when dumping a load.

    One thing I would also like is to have a few picture of the hinge mechanism, and info relative to what kind of steel people used to beef up the frame, I want it to be strong but not more than needed.

    Thanks guys
  2. matt167

    matt167 Active Member

    If it were me, I would take the truck to a custom dump trailer builder and have them outfit it. Cost will be somwhere in the $3,500 range but they will overbuild it. The truck in stock configuration as a non dumper cannot withstand 1,500 lbs. The brakes and suspension on OEM heavy dumpers is all different from the OEM light dumper/ no dump trucks

    SAITCHO Member

    I have all the welding equipment and I like to make my own stuff, bring me satisfaction. I got the suspension covered for the extra load, but I didnt knew the brakes from a dump to a non dump where different. Can you give me more info about this so I can investigate this.

  4. matt167

    matt167 Active Member

    As far as I know, the rear end itself is different. The brakes/ drums are much larger on heavy dumpers. The light dumpers used regular brakes but they have a lower payload. I had a '92 Carry and 800lbs was nearly sitting on the bump stops with the front end lighter than a kite. I did it all the time and it was manageable but you need some serious thought into the rear end beyond throwing springs at it.

    I would just copy what a dump trailer uses with the electric over hydraulic pump. The wiring for those is dead simple that you could build dash switches pretty easy. Just go to a manufacture/ trailer dealer to buy the parts and take a look at like a 5x8 single axle dumper for ideas. The geometry will change very slightly with a 6'6" bed but very close. Copy the hinge mechanism, ram mechanism and of course also add in the safety prop. You can also add in remote switches for service so that you can put the prop up by yourself
  5. Jigs-n-fixtures

    Jigs-n-fixtures Active Member

    Ebay has dump trailer kits, which have the electro-hydraulic pump unit and the cylinder. But, all of them are probably oversized for your needs.

    I have a Hijet, lift/tipper. My pump had issues, and I was looking for options to replace it. I have a 2-liter reservoir, and the drive motor is about the size of the starter motor on the truck. The smallest reservoir, I could find was a 4-quart unit with a much larger motor. The entire package was about twice as large as my stock unit. Luckily, I was able to rebuild the motor on mine, and get it working again.

    I have a Bosski, 4X8-ft, tandem axle, atv dump trailer which uses an electric actuator, which might be a better option, if you can’t source one of the stock hydraulic units.

    The snow is pretty much off the trailer, and I’ll try to do annotated pictures of it, and my lift tomorrow.
  6. matt167

    matt167 Active Member

    those kits include the scissor. Not needed since it will be a different design from their kit. You need 3 ton of lifting force to lift 1,500 lbs reliably ( starting force ). You can use whatever single acting cylinders you want. The electro hydro units flow approx 2 gpm, so you can use 2 1.5" cylinders or one larger cylinder in the middle and achieve the same lift weight/ speed.


    SAITCHO Member

    I looked at those kits and they are indeed too overkill for my needs. I also thought about 1 vs 2 cylinder. Two cylinder prevent bed warpage but you need a flow divider to make sure they both goes up at same time if your load is uneven and those are pricey. And the starting force needed is linked to the position of the top of the ram relative to the bed, the closer to the hinge the more force needed. Another critical factor is the cylinder starting angle. Thats why I would like to have some basic measurement to give me a rough idea where to start my design at.
  8. matt167

    matt167 Active Member

    yeah, I would just use the pump/ res that I linked and a single acting cylinder like from Surplus Center. Build your own dump frame/ hinge. It' the same style pump used in truck bed dump conversion and could mount right to the frame. Too many design variations in the trucks to lock down measurements for a specific one from another beyond basic distances which may or may not translate. Figure out the geometry/ template with 2x4 framing.

    I could give you measurements from a 12' 12 ton dump trailer but I doubt the measurements mean anything beyond the lift cylinder lifts from dead center and the cylinder attaches to the frame on the rail at the front edge of the box. Ram is horizontal when box is down.
  9. Jigs-n-fixtures

    Jigs-n-fixtures Active Member

    Cross member with ram pivot seen from front.

    19D9F151-8241-4F25-BDCE-2ADF6935C6C6.jpeg Ram extended length.

    Distance from rear crossmember to lower pivot
    Distance from rear of cab to pivot

    Had a chance to do some pictures/measurements of my Hijet this weekend. I uploaded them to a media folder: S110P

    The diameter of the ram is just under 2.5 inches.

    SAITCHO Member

    Many thanks Jigs, that is exactly the kind of pictures and measurements I wanted to get a head start on calculating forces involved before I have the truck on hand. If the ram is 2.5 inch then it must be a 4 inch cylinder?
  11. Jigs-n-fixtures

    Jigs-n-fixtures Active Member

    I didn’t measure the housing, just the ram itself. I’ll look tomorrow after work. Any other measurements or pictures you’d like while I’m at it?

    SAITCHO Member

    The last one id like to know is the distance from the end of the bed(near the cab) to the attachment point of the top of the ram. Thanks again for your time its much appreciated.
  13. Jigs-n-fixtures

    Jigs-n-fixtures Active Member

    Found a bit more information that might help.

    The cylinder bore is 63 mm Dia, with a stroke of 486-mm.

    SAITCHO Member

    Thanks a lot as always. Truck just landed in Vancouver will receive it next week so I will be able to take real measurement instead of educated guesses. I found a place where you can cuztomize your hydraulic power pack to suit your needs so now I need to figure if I want a single or double acting pump. Power draw is quite lower on the way down so I might go that way.
  15. Jigs-n-fixtures

    Jigs-n-fixtures Active Member

    I’d stay with a single acting. None of the factory setups use dual acting cylinders. In part because ou run the risk of bringing the bed down too fast, and hammering your frame.

    I have a copy of the S83 Hijet manual covering the scissors/tipper set up. It’s too large to post to the forum. PM me if you would like me to email you a copy.

    SAITCHO Member

    I thought having dual acting gave you control on the way down...... will look into that. Thanks
  17. Jigs-n-fixtures

    Jigs-n-fixtures Active Member

    The stock setup uses a single acting cylinder, and a solenoid valve for the drop. You have to hold the switch in to keep the bed coming down, and they have a valve at the final part of the down stroke which is closed by the cylinder as it gets close to the end of the stroke which progressively decreases the flow rate for the last of the drop to give you a soft landing.

    There are details in the manual I sent. Hopefully it makes it through.

    SAITCHO Member

    I got it thanks, now I want a PTO pump... but I guess I will have to settle for a 12v one.
  19. Jigs-n-fixtures

    Jigs-n-fixtures Active Member

    The one in the manual i sent uses an Air conditioning clutch, and mounted the pump, where the compressor would be if it had AC. They did have pto transmissions. But they are pretty rare.

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