| Author |
Message |
Jim Shepherd (Rv_safetyman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 12:16 am: | |
Sometime ago, the subject of a hydraulic leveling jack systems came up on this board. I promised to post my system design on my bus project page.
Well, I finally got around to getting the project pages updated (see link below). The system and vendor details are documented on page 7.
My system is pretty basic, but it might give someone some ideas. If you have any specific questions, let me know.
Jim Shepherd
Evergreen, CO
’85 Eagle 10
http://rvsafetysystems.com
Bus Project details: http://www.rvsafetysystems.com/busproject.htm (updated 2/17/05) |
Brian (Bigbusguy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 10:47 am: | |
Looks good so far. But In the mounted jack photo it looks like there in not much holding it on .Are you just going to bolt it to the frame with 2 bolt in the bracket or is it welded some place I can not see?
Also do you have some way to stop the cyl from piviting or just folding over if the bus was to roll backwards some?
I wish I could put a better trans in my bus also but Im stuck with the stupid V drive GM has .
Brian 4905 Klamath Falls Oregon |
Jim Shepherd (Rv_safetyman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 11:33 am: | |
Brian, I try to balance detail vs. minutia. Some times I win, but often I am charged with being the “Minutia King”. I have a goal to thoroughly document several of the sub projects and post them in a PDF format for downloading. That will probably not happen until I get the bus on the road and have some time to get my wits about me (possible?).
Specifically to your questions, I built heavily reinforced 2 inch wide pads into the mounts. There are two pads. A five inch long pad on the back of the mount and a 3 inch long pad on one side of the mount. The bus structure sits on these pads and the mount is welded to the structure.
For the bending moment or pivoting resistance, I am welding a bar to the bulkhead plates shown on page 6. That will make the mount very sturdy.
I have not mounted the front units yet. I plan to weld a plate similar to the bulkhead plate shown on page 6 to the frame tubes on the front bulkhead. I will then mount the jack mount structure directly to the bulkhead plate. I will use the same pad system except that I will probably only use the 5 inch long pad and not the side pad.
I updated the page to reflect these comments.
Thanks for the interest.
Jim |
Robert Wood (Bobwoodsocal)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 11:44 am: | |
Wow, Jim, you did some solid work there. She will be a real hill eater when you get her done. Bob |
Ron Walker (Prevost82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 12:45 pm: | |
Hi Jim...looks good. You must be glad to be making headway on the motor install.
On your hyd jacks....I would be a little concerned with the rod size and using the standard rod bearing lenght (piston + gland lenght). At minimum, I would put a 2" long pipe spacer (2 1/2od x 2id x 2" lg) between the gland and piston, which would give you a third more bearing lenght to pervent the rod from buckling and prevent excess rod bearing load.
Most cylinders that are designed for this application (excessive side load) use an over size hollow rod ( 4" bore Cylinder /w a 3" od rod) the rod is made of heavy wall CDSMT material (3/8 wall)/w manufacter ends and chromed od, this is stronger that a solid rod in a side load application.
The other thing you should consider is using "line locks" rather than check valves, they thread into the cylinder then the hose attaches the the line lock, if a hose blows the cylinder won't leak down. It requires pressure from the opposite direction to release the line lock. With this system if a hose blows or has something happen to it that causes the hose to fail, and your running down the road the cylinder can't leak down /w the line locks, as it can with the check values....and you can probably envision the resulting mess that this would cause.
I am not trying to be critical … just something for you to consider
Ron |
CoryDaneRTS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 4:35 pm: | |
Jim
You have the same inverter that I purchased. Does the inverter put out a lot of heat when operating?
Does it require such a large space to operate at proper temperatures or what the space convenient for mounting such a large and heavy item?
Thanks
cd |
Jim Shepherd (Rv_safetyman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 1:12 pm: | |
My first reply will be to CoryDane.
Cory, Trace is now Xantrex (http://www.xantrex.com). Last year they had the SW owner’s manual posted on their web site, but I can't find it now. I downloaded the file (2.8meg) since I misplaced my manual.
In any case, the manual talks about how to mount. They do talk about making sure there is good airflow. They also want you to mount the unit vertically (as in my mounting) for better airflow. They also say that you should not put the unit in an enclosure. It does have a thermal shut down switch to protect it.
If you do not have the manual, I will send you a copy via CD.
Next reply is to Ron.
Thanks for the excellent thoughts. I too was concerned about the 2 inch rod size. I have been looking at jacks for at least 4 years – both home brew and commercial. Almost everything I found was 2 inches – even the commercial units. The main issue is not only the size of the “column” (2 inches), but the length (the longer the column, the more prone it is to bend). At the BC Gathering last year one fellow had cylinders similar to mine and had them extended the full length! Made me nervous.
I wanted the jacks for two reasons. The first is the obvious utility to level the bus. If I have a real uneven situation, I will be carrying blocks so that the cylinder will not extend more that one half of its travel. The other reason is for use in the garage. Here I will be on level concrete and there will be no wind loads. I will use the jacks to lift the bus for various service (after proper blocking!!!). I will use the full extend, if needed and then do the blocking.
I am not sure about “line locks”. From your description, they sound a lot like check valves or more correctly pilot activated check valves. My description of my valve says that has piloted check valves. The Salami number on the valve is 6233 0172. I can’t find any specific information on that valve.
You do make a good point about a system failure. The piloted check valves are for the lifting direction only. I can only hope that the jacks don’t find a way to “self-deploy”.
I also had an off-line question about the pump. The pump (“Hydraulic Power System”) is a John S Barnes CP 032. That company is now Haldex http://www.hbus.haldex.com/products/barnes.htm) and the pump looks like it is one of their HE models now. I don’t know the pressure or volume of my specific pump. I believe it produces at least 1500 PSI. It is not a high volume pump. I used it to jack up the bus with another jack of similar size to the ones I am using, except for a very short stroke, and it did not even know it was lifting the bus. The pump was used on a hydraulic hose crimper. This might be a good place to find one fairly cheap.
Sorry for the long reply
Jim |
CoryDaneRTS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, February 22, 2005 - 7:54 am: | |
Thanks Jim
I have the manual and now the pdf as well.
Was considering placing in a small room, sort of like a bay, can very easily place a fan in wall to circulate air.
All I can say is, it is a HEAVY MUG!
cd |
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