DUMP TRAILERs Scissor vs Straight Cylinder

del · Dec 9, 2003

I have been looking at the numerous dump trailers on the
market and I haven't had it explained to me to my satisfaction
why a manufacturer will make two 6x10 10,000 Gross Wt trailers
one with just a cylinder mounted to a plate on the underside
of the bed and another trailer with the "scissor lift" type
mechanism. The scissor lift is usually on a beefier trailer
but not always.

The scissor lift seems mounted over a larger area which seems
like a better way to go.

Funny thing is I usually see the single post cylinder (w/o
the scissor lift) on trailers that have a tailgate that
would allow you to spread gravel.

Unless you driveway is glass smooth moving the trailer with
that cylinder up seems a recipe for disaster.

Any input would be appreciated on what you all are using or
think about this as my answers from dealers contradict each
other dramatically.

Although I hate to walk into a purchase ignorant, it's nice
to be a "virgin" about SOMETHING at least, once again!

del

Kubota L35, JD4210, Ford 1710, JD GT235 (most of the rainbow)
Hours on Tractors 1600, hours on operator 455,000

Deerlope · Dec 9, 2003

Mine you I am no expert on this subject but this is the way I see them. A single post dump will usually only go to about a 45drg. angle make it hard to get sticky suff to slide out, top soil for one. As for dump spreading it can being tricky on rough ground, just don't raise the box all the way at the start.
A sissors lift will usually put the box almost at a 90drg. angle. Thats the way I see them anyway.

have_blue · Dec 9, 2003

A single cylinder seems a bit weak, but the strength of the dumping mechanism is not in the cylinder.

The rear hinge must be very robust, and free from slack in all directions. The cylinder merely lifts the dump bed. It does not encounter any side loading. When lifting starts, the cylinder is stiff because it is not full extended. Once lifting starts, weight is transferred to the hinge. By the time the cylinder is extended a lot, nearly all the weight is on the hinge.

I may build a dump trailer some day, and I will try to balance it to where it nearly dumps itself.

SPIKER · Dec 9, 2003

Have BLue:

I built a dump trailer this past summer it does work well BUT with the DUMP HINGE closer to the middel it makes it hard to get the unit loaded, mine has a tendenancy to tip backwards into the dump mode if the load is not first filled up on the front half of the trailer first. mind you i built mine very short so that I could manuver it through my woods and stream to get the wash gravel out of the stream. it does work great for that but I can only pull it with tractor into there and then have to disconnect it and leave it on jacks untill it is full then reconnect it and drag it to where I want to dump it. (need tractor for filling trailer.) I haven't done it yet butI have ot build some stabelizor jacks for the back half of the trailer to keep it form tipping. I is not bad when 2 people are using it as one can say dump it farther up in front or center ect. but looking into trailer is hard form tractor seat.

biggest reason for sizzor vs straight is the fact that people build trailers different. one of the bigtgest is the hing point if moved fatrher forward a single cylinder is fine, if it is back at the end so you can load wheeld vehical into it then the sisor lift will move it much farther up and let the dump work, usually the sisors won't lift as much weight but will lift it higher.

Mark M /forums/images/graemlins/frown.gif

rozett · Dec 9, 2003

I have seen them with two lift cylinders also.... but I would stay away from those.

What are you guys seeing for pricing of these trailers? I am in the market for a 10-12K unit myself to haul firewood. I see prices in Florida much cheaper (20-30%) than here in the northeast. I keep an eye out on Ebay, but that is really a sellers marketplace.... unless you are very lucky.

755inNY · Dec 9, 2003

del,

I do not have any experience with a scissor lift. I have a 6x12, 10,000 gross dump trailer with a single cylinder. It works great even when loaded heavy. The couple of times it has failed to lift when requested was due to a bad electrical connection. My neighbor has another brand 6x12 10,000 gross with dual cylinders and power down. He has had nothing but problems with this trailer. I don't know if it is the hydraulic design and keeping the system balanced or what but he has had to off load by hand too many times (even with light loads)

I have never found a need for power down. Even with a partially dumped trailer I have been able to lower the box.

If the scissors type provides more dump angle, as others have suggested, it might be worth considering. With my cylinder lift trailer you have to pull forward to empty the box completely. This leaves an elongated pile almost the length of the box.

When selecting a trailer, look for one built heavy duty. The frame can be subjected to a lot of twisting when the loaded box is raised.

Jeff

jmc · Dec 9, 2003

Mine is a 6 ft 8 inch by 12 ft EZ-Dump (good name for a laxative), low profile with corner tie downs for hauling skid steers or compact tractors. 10,000 lb gross with power down twin cylinders. It tilts to 45 degrees, which looks pretty high when you're standing there. That's steep enough to unload damp clay. I think the power down is for safety so it can't slam down. Don't know how the other kind works- maybe a flow control valve? Also don't know why you were advised to avoid twins unless for extra cost or more to go wrong. Seems like less racking stress with an off center load.

John

rambler · Dec 10, 2003

Actually, the power down prevents the trailer from slamming _up_ if it is built with a long tail. Too much weight back there & single-acting hydraulics will allow the trailer to dump on it's own. I did that once with the old farm dump truck and a load of wet corn that didn't flow as it had packed - oh my, talk about EZ-Dump, that was me at the moment! /forums/images/graemlins/blush.gif

In the older designs, the twin cylinders are fed by a common hyd line, so the cylinder with least resistance would lift more - the load can actually twist & tilt more with 2 cylinders than one centered cylinder, as an uneven load is picked up by one corner in reality. I don't know if they have improved that situation with different plumbing/ valving on new twins.

The sissors lift loses some power to provide a higher lift - all should be engineered out to work properly with the particular hinge spacing & load limit of the particular trailer.

--->Paul

jmc · Dec 10, 2003

Paul,

The hinge on this trailer is clear at the back and the sidewalls are low so there is not much chance of an EZ-Dump moment.

Your point about about racking with twin cylinders is a good one and it hadn't occured to me. Both cylinders are fed by the same line via a "T". Its similiar to bending a 4 in one bucket jaw by clamping hard on something on one side of the bucket.

John

jsimon · Dec 12, 2003

I built a 5 x 10' lat year with a 5000# capacity. I bought the plans on the internet for it. The plans called out for 1 4" cylinder to dump it. I modified the plan to use 2 - 2 1/2" cylinders. I wanted 2 cylinders to KEEP it from twisting. The hinge is approx 18 inches from the rear of the trailer.

The trailer works great, but I would change several things,

1. I would use a sissor lift
2. I would make it as wide as possible (I load my BX22 on it, but I have to remove the mmm every time i load it)
3. I would make it power down, I have a flow control on it to regulate the speed when it is lowered with a load, but when it is cold out (Michigan weather) it lowers toooo slow.

Ok, sissor lift vs cylinder: In my humble opinion, the sissor lit would give you more dumping capacity, plus incresed dump angle (45 deg vs 50+ deg) becuase with the cylinder type the cylinder is laying almost flat, with a HEAVY load, the dump box does not want to start dumping (it is pushing almost strait against itself). The intial "breakover" is incredible.There have been times when I have had to help the box up for the first few inches.

The sissor lifts ae designed to accomadate this, thats why they are on dump trucks.

Sorry for the long post.

Hope that helps