Safe T Plus steering stabilizer. June 2011 Blue one. Serial number is 01115405 Model 41-230
800-872-7233
United Safety Apparatus inc
2544 Lantrac Court
Decatur, GA 30035
Bought From PPL Motor homes 10777 S W Freeway Houston Tx 713-988-5555
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Linear actuator for the trim kit is 6104T 4” full travel, .5 inches per second. Paid $114
110 lb load 8.5 inches to 12.5 inches
Accele
562-809-5090
P.O. Box 92139
Long Beach Ca. 90809
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The actuator has a total travel of 4 inches. That is two inches each way of center. It is about 12 inches long. I marked the center, and each end of travel with a circle as seen in the photos. The Linear Actuator has an automatic stop at each end of the travel so you won't overwork it. The actuator has 110 lbs of force. I could have bought much higher but I knew it would take at least twice that to come close in moving the stiff shock. My 180 lbs would not move the shock in at all. Knowing already that 1/8 of an inch travel on the shock would be enough to change the center I knew I didn't need much but it would have to be very powerful. I had experimented with the shock by itself and found trying to get it to the perfect center was difficult and tapping the mounting u bolts a tiny bit was enough to change it a bit.
With this in mind I decided to try a 4/1 ratio using a lever. The final ratio is probably closer to 6/1. The goal was to have the actuator travel its full length each way so the internal stops would work and I didn't want to work the actuator hard. At 4/1 it was working kind of hard and it could not travel the full distance. I know this setup is crude but as my airplane building group proved together everyone achieves magic (TEAM). There will be many better ideas and improvements once people get the bug to build one themselves.
What is happening is the bolt for the shock is through the lever arm. The hole was cut to the exact size of the bolt. Washers are seen throughout the build to provide certain clearances. One being the end of the shock was hitting the mount when the arm was pulling it in and that reduced my range. The stack of washers which are greased are tight enough to remove slop and tight enough to hold things solid. What you cannot see in the picture is the (slot) I cut for the shock bolt to slide in. This slot has a slight arc to allow the large bolt to travel about 3/8 inch on each side of center. There is plenty of meat left in the original bracket in case the trim breaks. The large bolt cannot escape so the integrity of the system is really still there.
The small 1/4 inch bolt is the pivot point. I know it might seem strange to have the pivot point on the other side of the fulcrum but there was not enough room to do it otherwise.
The rear mounting bracket for the trim is a thin piece of metal about 1/8 inch thick. I used two u bolts to attach it. Its purpose is to hold square the rear of the actuator of course and the force is only 110 lbs max. This bracket could be fancied up a lot but with basic hand tools in my garage I didn't want to build something for the market place. Just something rugged and reliable.
Running the trim wire was easy enough but had to wiggle and strain of course. Keep in mind the rv has to have room for the wires to turn right and left and for the rv to raise and lower so you have to do some testing to make sure nothing gets pinched or ripped loose.
I have a box to mount the switch in already that is used for the modified SMI braking system. That is another story. I dumped the radio system control from that and have absolute positive and immediate control now and use about 1/2 the parts. Back to the story. The system draws 3.5 amps so wires can be small. Using a DPDT double pole, double throw switch I built a reversing switch. I was not able to get a switch that returns to center automatically locally so I settled for a toggle that has to be put back in the center position. That is fine for now and testing. I will order a better switch down the road.
The actuator takes four seconds to travel the full length, so only two seconds to travel 1/2 of that which is each side of center.
To make the thing move only takes about a 1 second tap to either side and trim is achieved. Nothing dramatic but nice smooth changes. I can make it pull left or right now and easily center it.
Oh yeah. About $150 total. I used a black pipe to bench test the thing if you need to know
CAUTION: Make absolutely sure you have clearance on top of the shock when you let the air out of the coach. My front air tank made contact with the shock so I had to simply mount the shock under the bracket instead of on top.
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Certified Senior Electronic Technician, Telecommunications Engineer, Telecommunications repair Service Center Owner, Original owner HR 2008
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