Hoist decisions for my dumping flatdeck

Discussion in 'Trucks and Trailers' started by Gravel Rat, Feb 4, 2006.

  1. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    I priced out the steel to build myself a new deck I damn near crapped so I'am going to modify my current deck which is in okay shape needs some work.

    I have to make a decision do I go with a scissor hoist or go with a front mount hoist. A front mount hoist is much better but alot of work for me to set up I have to build a subframe etc.

    With the scissor hoist I can buy one with a subframe and pump all in one so all I have to do is attach the unit to the frame and bolt the hinges to the deck.

    The things I don't really like about the scissor hoist is it is heavy it adds 590lbs or so to the truck. The other thing I'am worried about is powering out scissor hoists are known to power out if you get too much weight on them.

    The one benefit of the scissor hoist is its easier to install.

    What do you guys think the deck will be 12x8 with loads of gravel up to 7000lbs on it. I definatly don't want to be shoveling off gravel because the hoist powered out.
     
  2. Eclipse

    Eclipse LawnSite Bronze Member
    Posts: 1,149

    FWIW - I have a freind who has worked for Monarch hydralics for over 20 years. When shopping for a dump trailer I asked him about the lift systems. He said that a properly designed scissor lift is better/stronger than just a striaght cylinder.

    At customer test sites he mentioned he has seen the tires pop and axles bend because the trailers have been so overloaded but the scissor lift had no problem lifting the load.
     
  3. Shadetree Ltd

    Shadetree Ltd LawnSite Senior Member
    Posts: 390

    Four years of scissor hoists in three trucks and these smaller trucks can't carry anywhere near the weight to stall the lift. We currently have two 9 tonne hoists.

    Scott
     
  4. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    With this being a dumping flatdeck a scissor hoist might be more stable under the deck where as the post hoist is grabbing the front right in the middle and the deck can twist side to side.

    I'am either going to buy a hoist from Del Hydraulics or West Coast Machinery two companies in the Lower Mainland that Shadetree probably knows.

    The hoist Del Hydraulics sells is a Nordic the one West Coast Machinery sells is Crysteel. I also can look at buying a Hoist from FG Russell they sell Omaha Standard or Thieman.

    The one thing as I meantioned is a scissor hoist with a subframe all built in is a easier quicker install. I could pull my deck off get the hoist mounted then I can slap some temporary mud flaps on and still beable to drive the truck while I modify the deck.

    If I went to the post hoist then my truck will be down as I will have to do alot of fab work building a subframe.

    One thing I'am concerned about with the scissor hoist is powering out I would like to hear some feedback on any troubles with the scissor hoists ?

    T.I.A
     
  5. gene gls

    gene gls LawnSite Gold Member
    Posts: 3,209


    I have an 8x10' flat bed with a 10 ton Rugbe hoist and it won't pick up 3 yards of top soil or stone. I have seen others in my area with the post hoist and they lift, no problem. Our town has one from Del that is great. A little higher in price. I won't get another scissor hoist. You need less sub frame with a post hoist whitch will keep the bed lower to the ground.
     
  6. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    Thats what I want to find out is the hoist going to power out. I have had a Del dump box before as I meantioned it would dump any kind of load I put on the truck it was a 3 stage post hoist. When I started hauling with the 88 F-450 went into the local pit picked up a load of gravel rolled accross the scale get back into my truck look at the scale slip and its holy beep. I had 4.5 ton of gravel on the truck off I go get to the jobsite pull the PTO let up the clutch the box raised and dumped no sweat.

    I was surely impressed the truck dumped many loads like that no problems with shoveling off some of the load.

    Dad had a 5 ton truck with a dump it was a off road unlicensed truck we used on our property. It had a 12' dump box low sides with a scissor hoist it powered out on a regular basis sure it was full loads but it sure struggled to dump the load. It had a massive cylinder under the box the hoist must have been rated for 20 ton.

    After what Gene said I'am going to reconsider my plans maybe I should stick with a telescoping hoist and spend the time to build a subframe.

    With the older F-450s is they have the hump over the rear axle so I need to make a subframe for the deck to sit on. Unless I make it so the front of the deck sits on a pad behind the cab and the rear hinge section has a subframe.

    The difference in price is also a consideration a front mount hoist with hinge kit is 2200 dollars I got a quote on a Crysteel hoist with built in subframe it was around 3000 dollars.

    For me to build a subframe for the post hoist will be about 200 dollars in steel but the subframe will be built out of heavier steel compared to the 10 gauge stamped steel the scissor hoist uses for a subframe.

    You guys have to keep in mind I'am using a 12' long deck I can get 60% of the load forward of the rear axle. I actually like to get as much forward as I can I don't like power steering especially with the twisty roads we have here. Keep those steer tires planted on the ground I already had a few scares with a truck with a light front end and you go into a corner and the truck keeps going straight :eek:

    I know most landscapers dumps south of the boarder are 8-9' boxes when I look through Ebay all the trucks I find in the 1-2 ton range are short mason box dumps. With a short box you get more of the weight over and behind the hoist so the the front of the box isn't being held down with a bunch of weight.

    To give you a idea the telescoping hoist I'am looking at only weighs around 250lbs but its rated for a 8 ton lift at the first stage has a 8 ton capacity once it reaches its second stage it has a 12 ton lift.

    The Crysteel LB-500 hoist has a 7.6 ton rating the hoist itself weighs 475pounds if I go up to the LB 510 I get a 9.2 ton rating but the hoist weighs 525lbs. When you figure your adding 525lbs of weight to the truck that is eating into the payload. Those lifting ratings are for a 50 degree dump angle which is what I want as I don't want stuff sticking on the deck as I have wood decking.

    If I went with a 45 degree dump angle the LB-500 has a 8.4 ton rating and the LB-510 has a 10 ton rating.

    A 45 degree dump angle isn't steep enough for me a landscaper buddy of mine has a 11' dump that only dumps 45 degree's and stuff sticks in his box.

    The post hoist will give me a 49 degree dump angle.

    So if you guys have anymore ideas I would like to hear them because on monday my credit card will be getting a little higher :laugh:
     
  7. Shadetree Ltd

    Shadetree Ltd LawnSite Senior Member
    Posts: 390

    Last spring Brad from West Coast took a bunch of my money (9' crysteel with 9 ton scissor installed on the 05 F450) and this past fall Nels from Del took a lot of my money for central hydraulics and a taigate salter. The scissors have lifted 4 yards of soaking wet sand, 4 yards of soaking wet soil and 5 yards of salt with no problems to speak of. I would highly recommend talking to Brad at west Coast explaining your concerns. I found him to be an honest guy with no run around. I am sure he will steer you in the right direction. If he says it will work he will stand behind it.

    Scott
     
  8. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    I have emailed Niels a few times about hoists and he does say the front mount hoist is the best but he did say a scissor hoist will work for my application.

    The scissor hoist from Niels is 2500 dollars or so the scissor hoist from WCM was around 3000 or so. The one from Niels I don't thing has a built in subframe.

    With a 12' fladeck I can get close to 4000lbs of gravel inbettween the headache rack and the centerline of the rear axle. My truck has a 84" cab axle. A short wheelbase truck with a 60" cab axle like you would use a 9' box on you only have about 4.5 feet bettween the cab sheild and the center line of the rear axle. You would have a tough time to get enough weight forward I doubt you would get 2000lbs forward of the rear axle.

    When you put a load into your trucks with a 9' box you will get more weight over the rear axle and behind the rear axle. So as you start to lift the box most of the weight is shifting rearward taking the weight off the hoist.

    With a truck like mine and you have 4000lbs in front of the axle that takes alot of grunt to get the box up and get the load shifting rearwards.

    To give you a idea if I loaded the area between the center line of the rear axle and the head ache rack and screeded flat with the 10" sideboards I could get 1.6 yards of gravel forward of the rear axle. So I recalculated the weight it would be 5000lbs forward of the rear axle and thats not heaped.

    I bet most of you guys put 3 yards into a swb truck with a 9' box the truck squats quite a bit.

    I wish I could find some formulas that would calculate the lifting force it takes for a scissor hoist to dump a load.

    The most I have heaped onto my trucks with 12' flatdecks is 2.5 yards as I only have 10" sideboards but my 88 F-450 I had had 20" side boards I could get 3 yards on it those were 9000lb loads. The loads I haul are all scale verified as it is a gravel mine I haul from I did haul a load of very wet topsoil I estimated the weight to be 10,000lbs the truck was really sucking wind hauling it.

    The pit has a 966 loader the bucket is usually 2 yards they also have a 590 Case backhoe its bucket is 1 yard aprox I usually will put 2 and 1/2 bucket fulls on my trucks with 12' deck and 10" sideboards.
     
  9. heather lawn sp

    heather lawn sp LawnSite Senior Member
    Posts: 681

    Just a thought. . .

    You mentioned the problem of material sticking to the wooden deck so you need the 50 degree dump angle. Have you seen the heavy polyethylene plastic dump truck floor liners? I have never used one but wonder if that would help with getting a clean dump.
     
  10. TerraVenture

    TerraVenture LawnSite Member
    Posts: 144

    gravel rat

    Most hoist manufacturers have already done the math and if you go to a dealer or call the manufacturer they should be able to help you. I had a Harsh hoist installed on my one ton 9' rack dump. I didn't do any calculations myself. The dealer showed me the literature. It showed the lifting capacity based on the distance from the pins. Obivously the lifting capacity changed with relation to the distance from the pivot pins. This relation also changed the dump angle. I have 18" of overhang on my truck and the hoist is rated for 8 ton.
    As for formulas, unless you use the manufacturers tables you goning to need a statics class to do the force balance calculations. You would need to assume some variables like load positioning, and friction. This is not something I can explain in an positn like this. You can get a statics book from your local library or college library to figure out yourself.

    The best thing to do is get all your info from a truck upfitter or hoist manufacturer not here in this forum.
     

Share This Page