What are the benefits to this style lift compared to a more conventional scissor lift. Yours looks like the scissors just balance the load instead of giving mechanical advantage.
mechanical advantage comes from the angle of the cylinder(s) at the moment of inertia. a positive angle on the cylinder provides more power when you need it the most.
copied from my website : pf-engineering.com/dump-trailer-plans "The bed-lift mechanism on this trailer is our unique hybrid design that combines the best aspects of a straight-cylinder lift with the benefits of a scissor lift, giving you more extension with a shorter cylinder, plus increased power during the most difficult part of the lift cycle - the start. If you look closely at the first video of our prototype (Oct. 15, 2021), the lower scissor brackets remain stationary, resting on the cross member, for the first 12" of the lift. This allows the cylinders to progress from their initial 30-degree lift-angle to 50 degrees before the scissor brackets begin lifting off the frame’s cross member. This takes all the stress off the scissor-pivot linkages during the most stressful part of the lift, and it gives the cylinders a good positive angle to work with right from the start. It also allows us to use fairly low hydraulic pressure with small bore (2.5") hydraulic cylinders, which increases the longevity of the hydraulic system and parts. The old garden tractor I used in the videos to lift 3000 lbs of stone only produces 800 psi, the maximum being at 2 GPM." that said, the conventional scissor lift is at its weakest point at the moment of inertia, or the very start of the lift. so just when you need the most lift power available, the conventional scissor lift falls short. designers have overcome this weakness by using huge bore hydraulic cylinders running high pressure - and it works - but you can also make a brick fly if you strap a large enough jet engine to it. my goal was to use low pressure, low gpm and be able to lift 3000 lbs from my garden tractor's hydraulics. ~ Paul
TruStudio, when the plans come out, you'll be able to build your own dump insert for a lot less than $2K! the hybrid lift is a modular design, so you'll likely have to setup two brackets and a cylinder on each side of your drive shaft. not a huge deal. the most expensive part will be the electric/hydraulic pump unless you can setup a drive pulley somewhere on your engine for belt driving a pump, something like the older snowplows had. ~ Paul @ P.F. Engineering www.pf-engineering.com
Y'all are my heroes. Seriously.
Looks great Paul! I'm looking forward to the plans.
Fantastic work! It looks well sized for the garden tractors!
P.F. Engineering is having a 25% off sale on all plans all October 2023 to celebrate our 25 years in business!
What are the benefits to this style lift compared to a more conventional scissor lift. Yours looks like the scissors just balance the load instead of giving mechanical advantage.
mechanical advantage comes from the angle of the cylinder(s) at the moment of inertia. a positive angle on the cylinder provides more power when you need it the most.
copied from my website : pf-engineering.com/dump-trailer-plans
"The bed-lift mechanism on this trailer is our unique hybrid design that combines the best aspects of a straight-cylinder lift with the benefits of a scissor lift, giving you more extension with a shorter cylinder, plus increased power during the most difficult part of the lift cycle - the start.
If you look closely at the first video of our prototype (Oct. 15, 2021), the lower scissor brackets remain stationary, resting on the cross member, for the first 12" of the lift. This allows the cylinders to progress from their initial 30-degree lift-angle to 50 degrees before the scissor brackets begin lifting off the frame’s cross member. This takes all the stress off the scissor-pivot linkages during the most stressful part of the lift, and it gives the cylinders a good positive angle to work with right from the start. It also allows us to use fairly low hydraulic pressure with small bore (2.5") hydraulic cylinders, which increases the longevity of the hydraulic system and parts. The old garden tractor I used in the videos to lift 3000 lbs of stone only produces 800 psi, the maximum being at 2 GPM."
that said, the conventional scissor lift is at its weakest point at the moment of inertia, or the very start of the lift. so just when you need the most lift power available, the conventional scissor lift falls short. designers have overcome this weakness by using huge bore hydraulic cylinders running high pressure - and it works - but you can also make a brick fly if you strap a large enough jet engine to it. my goal was to use low pressure, low gpm and be able to lift 3000 lbs from my garden tractor's hydraulics.
~ Paul
Hi, can you make a hydraulic dump insert for my 6' bed pickup truck? Can pay $2,000. We're located in NY
January 20, 2022 just a quick note that the plans for the dump trailer are ready for purchase at www.pf-engineering.com
TruStudio, when the plans come out, you'll be able to build your own dump insert for a lot less than $2K!
the hybrid lift is a modular design, so you'll likely have to setup two brackets and a cylinder on each side of your
drive shaft. not a huge deal. the most expensive part will be the electric/hydraulic pump unless you can
setup a drive pulley somewhere on your engine for belt driving a pump, something like the older snowplows had.
~ Paul @ P.F. Engineering
www.pf-engineering.com