| Author | Message | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: |
OK, I'm in over my head on this one and I need a pointer to a shop or shops that can help me with this. Bear with me, as the setup is a bit long: I have a Neoplan N117/3 Spaceliner. Neoplan uses air bags for suspension, with a setup that is quite different from, for example, MCI and other coaches commonly discussed on this board. The setup involves six bags and three leveling valves. All four bags in the rear (two drive and two tag) are controlled by one valve, which sets ride height in the rear and also proportions the air between drive and tag. The other two valves are on the independently suspended front wheels, near the ends of the wishbones. Side-to-side leveling on the road is achieved strictly with the front bags, which respond very, very quickly, thus minimizing body roll in turns. The system also includes a solenoid to vent the entire system, thus lowering the coach to the stops, and another solenoid which sends an air signal to the three leveling valves to open fully, thus raising the coach to the maximum extension of the bags. The plumbing for this system is actually quite involved, but it works wonderfully. (As a side note, when I got the coach, it had an HWH air leveling system on it which was poorly plumbed into the factory air system and really screwed up the handling of the coach, but that's another story). We want to have a way to level the coach when parked, but don't want to mess with the factory air system plumbing -- it would require at least eight high-volume air solenoids, all metric, and some way to put limit switches in for upward travel (the existing raising system works through the road leveling valves, which have the limits built in). My thought right now is, instead, to have a system to mechanically adjust the settings of the three existing leveling valves. In other words, instead of the ends of the lever arms on the valves being dogged down on a manually adjusted slider (hard to reach, by the way) as they are now, I would attach the ends to some type of vertical track system, perhaps operated by an electric jackscrew. My problem is this: while I can easily envision such a solution, and I can probably even track down the jackscrews, I have neither the skill nor the facilities to actually build and install the system. The coach converter that is currently working on the coach for me is unwilling to mess with the suspension in this way. So I am looking for a shop with fabrication facilities and expertise to work with me to implement this, preferably in the Pacific Northwest. Any pointers and/or suggestions would be appreciated, either on- or off-board. Thanks. -Sean | ||
| Tom Caffrey (Pvcces) (64.114.233.163)
Rating: N/A |
Sean, what about Fast Fred's idea? He's planning to install three aircraft control cables where the knobs are easily reachable inside his 4106 so that the cable ends will adjust the length of the link on the valve. Done right, this system has the advantages of retaining the original system, being able to lift one end of the coach if it should drag and being easy to adjust for level when parked. These cables are sold by length and stroke, so limiting the amount of adjustment should be easy. The hard part will be building the end on the valve so it is strong enough, has room enough to avoid sharp bends and will not likely be affected by road hazards. You might call Southern Oregon Diesel to see if they would do work like this. They did some custom work for us, and they seemed very knowledgeable about these buses. For what it's worth. Tom Caffrey PD4106-2576 Suncatcher | ||
| Jayjay (198.81.26.230) Rating: N/A |
Fred and I discussed his idea, but I converted mine to all manual, and did away with the auto system completely since the auto won't provide enough to level in most campgrounds. The main problem is finding a way to disconnect the auto valve mechanism so the manual cable can take over. These auto systems are controled by a rod attached from the valve body to the chasis, and you will have to disconnect it before you can make anything work. Multiple solenoids begin a complicated, high maintenance, failure prone system. It will take two 1/4" ball valves, one pushbutton seat valve, and bunch of 1/4" D.O.T. tubing per bag to give you the manual leveling that you want, without deleting your automatic bags controls. About $350.00 in material, and two days labor. No, I won't do it! The only other solution I have is to trade your Spaceliner for my GM 4905- Uh... even up of course! Cheers...JJ | ||
| jmaxwell (66.42.92.21) Rating: N/A |
Sean: I recall your admonishment some weeks ago about the high volume quick re-act front valves. Apparently, my Jetliner is different than yours, although the basic are the same. I did not have the quick fill and quick dump solenoids u refer to and my front valves were the same as the single back valve. I converted to a fully manual system since I didn't have the quick re-act valves on the front. I have not road tested it yet, but I stayed with 3/8" manual valves and lines. I left the auto valves in just in case I encounter the roll and pitch u warned of. I am wondering about small pneumatic operators(air motors) to adjust the travel arms on your level valves. The space is tight on the rear valve on mine, so it would require a small air motor. If u were to mount the air operators solidly to the framing and then connect the road valve arms to the air motors it should be possible to control the air motors with a seat valve (low volume is the problem with them) and increase or decrease the throw of the rod to adjust the height setting of the valve. If I encounter problems, I am going to investigate this solution. Johnson Controls, many yrs. ago, made small air operators that had an amazing size/force ratio. A company named Barber-Coleman made some small rotational motors in 24 volt that did essentially the same thing with a cam arm on the motor that had built in adjustable limit switches in both directions. Just some thoughts | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: N/A |
OK, a number of items to respond to here: Tom: Yes, the idea Fast Fred has been promoting is exactly the sort of mechanism I am envisioning, except that the cables themselves simply will not work in my coach for a bunch of reasons (my driver seat is lower than the front axle -- the route the cable would have to take would have so many bends as to preclude its smooth operation). That's why I am looking for an electromechanical actuator to do the same job. I will touch base with SOD per your suggestion. Jayjay: My bus would roll over onto its side if I eliminated the automatic valves. It's 13'4" tall and the passenger deck runs over my head while I'm sitting in the driver seat. The system that we ripped out occluded the front leveling valves from about 3/8" down to about 3/16" and the handling was completely unacceptable. Also, the parts list you suggest is far short of what would be needed to convert this particular coach (you really need to see the plumbing diagram to believe it), plus all my fittings are metric -- more like $1,500 in parts. jmaxwell: I think you are simply suggesting air actuators instead of the electromechanical ones I am envisioning. That might work, but I'd rather not use any more air if I can avoid it -- I think jackscrews are more fail-safe. Also bear in mind that very little force is required to move the leveling valve arm. I think I have room in all three locations for the jackscrews -- I'm thinking of something with perhaps 12" of travel. I will look into the Barber-Coleman items, but getting the mechanisms for the actuators is not my real concern, but, rather, finding someone who can fabricate and install a finished system. Thanks, everyone, for the suggestions thus far. Still seeking more recommendations, though, particularly for a shop that can do this work. -Sean | ||
| Jayjay (198.81.26.230) Rating: N/A |
I beg your pardon for my ignorance of the tube size used in your system. Yes, seat valves are quite slow, and the bags size and configuration is much different in the GM's My rig is at 11'6" and 24.5K lbs. so that would make a big difference too. I still think you should trade me even up. ...JJ | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: N/A |
You know, JJ, if you had hit me up six months ago (when I was ready to just push the darn thing off a cliff) I probably woulda traded you straight across :-) Now that I've put a ton of money into her, though, I'm gonna see it through to the end. -Sean | ||
| Jeff Miller (205.217.70.113)
Rating: N/A |
Without the benefit of an air schematic, it sounds like you have a fairly simple setup for an air leveling system, albeit manual. What I'd suggest is to use the air solenoids (which are 2-way valves that connect the bags either to a vent (dump) or to the leveling valves), connect the vent side to new 2-way solenoids (one side supply/raise, other side vent/lower) with switches on the dash to raise/lower each corner. The standard mode would be running through your air leveling valves for driving. When parked, you would switch your dump switch on, thus giving control to the individual solenoids connected to the dump vents. One valve for each corner, the tag can be separate or simply dumped if you wish to simplify the system, it is not needed to hold the weight of the parked coach. | ||
| Sean Welsh (Sean) (64.81.73.194)
Rating: N/A |
Jeff, All my bags "dump" through one vent (via 6 check valves). Otherwise, your idea would be great! -Sean | ||
| JohnC (12.106.199.175) Rating: N/A |
If you want to use Fast Freds approach, but don't have room for the cables, use 12 volt linear actuators. You can specify the stroke length and power (ft lbs) and they normally cost under $100. Use Google for the search engine. | ||
| FAST FRED (209.26.115.193) Rating: N/A |
The usual problem with cables is too tight a radius for a bend , not how many bends. BE sure to use simple green Antifreez to lube cables , keeps the rust & sticking hassels away. FAST FRED |
