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PostPosted: Tue May 06, 2008 9:40 pm 
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Joined: Thu Aug 11, 2005 10:45 am
Posts: 461
Location: Ames, IA
My wife and I use the swing arm table that came with our 2005 22' BFT a lot and consider it a valuable feature which makes the smaller size of our coach workable. We like the fact that it stows easily and takes very little effort to set up. Unfortunately the table swivel assembly loosens up over time and the table begins to wobble. Dodgen supplied a new swivel assembly under warranty but it was essentially the same design and also began to wobble with use. Like many others we tolerated a wobbly table for several years in return for the benefits. After considerable research however, I have been able to modify the table mounting assembly to remove the wobble at a cost of about $100 for the materials. The following paragraphs and pictures show the modifications.

The two design elements I set out to improve were the tendency for the table to wobble and the tendency for the wood screws that hold the table to the mounting plate to pull out of the wood on the underside of the table if a large load is placed on the outboard end of the table away from the swing arm. I also decided to move the mounting point for the swivel mechanism on the underside of the table toward the forward end of the coach as much as possible to have more room for the driver's side seat to move back.

To do this, I replaced the OEM swivel bearing with a Delrin bushing approximately 2" long mounted to the underside of the table. It rides on a ¾" steel pin projecting upward about 2" from the swing arm. Delrin is a hard plastic material made by Dupont for almost 50 years and is widely used in industry for bushings. The bushing assembly I chose is made by Swivl-Eze Marine, (1400 Meadowlark Lane, Lancaster TX) for use in supporting the pedestal seats in bass boats. I figured anything strong enough for seat supports would work as a table support. The bushing assembly is Swivl-Eze part number SP-67739 and I found mine at Wal-Mart. (Note Swivl-Eze also makes and Wal-Mart also sells a plastic bushing on a cast aluminum plate with a part number that is close to this number however you would have trouble modifying the aluminum plate in the manner I describe here.) Boater's World sells them online (http://www.boatersworld.com) for about $27 if you can't find it at Wal-Mart. The assembly consists of the Delrin bushing mounted in a steel support tube which is then welded perpendicularly to a 7" square stainless steel plate. In order to mount the assembly to the table, I used three ¾" angle brackets and cut them to run most of the length of the table. Before mounting them to the table I rounded the ends of the lower side to keep them from catching on clothing and painted them black. I drilled several holes in the angle brackets and bushing mounting plate and used flat head machine screws and nyloc nuts to join them together with the angle bracket on top of the mounting plate. I counter bored the holes beneath the heads so that the screws were flat with the top of the angle brackets. You could also weld the plate to the brackets but I did not want to chance damaging the Delrin bushing with the heat from the welding and chose to use mechanical fasteners. This method allowed me to mount the brackets flush to the table with wood screws like BF used originally. The bushing plate sits below the brackets about an eighth of an inch and does not touch the table. This is ok since the bushing itself sticks out from the top of the mounting plate about an eight of an inch and mounting it in this way gives it the necessary clearance to the table. Two of the angle pieces were mounted longitudinally and the third was set transversely. The plate was mounted so that the center of the bushing is 5-7/16" from the forward end of the table. This distance will provide clearance for the driver's seat to move back yet allow the table to swing easily between the front seats. Mounting the table to the brackets and then fastening the brackets to the bushing mounting plate allows the angle brackets to support the table throughout its length and removes the tendency of the wood screws to pull out of the table.

I had to have the pin that the bushing rides on made up at a local machine shop at a cost of $50. Swivl-Eze makes a pin assembly (P/N SP-1002, $14 at Boaters World) that is of the correct diameter to mate to the bushing but it is welded to a flat plate and not suitable for mounting directly on the arm. You could machine your own pin from mild steel but you would then need to match it to the ID of your bushing to a close tolerance of about 0.001" or less to prevent wobble and smooth the surface so that it rides easily within the bushing without galling it. Since the pin made by Swivl-Eze was the correct diameter, I decided to use their pin and removed it from the plate it came on by grinding the welds. I took it to the machine shop and had them cut it to length (3-1/4") and use a lathe to cut 5/8" x 18 tpi threads in it for 5/8" at one end. These threads allow it to be screwed into the nut welded to the top of the OEM swing arm where the OEM swivel bearing was originally mounted. I had the machinist turn the threads to a snug fit to prevent wobble. I also had to chase the nut on the swing arm out with a 5/8" x 18 tpi tap to clean up the threads. I used Loctite Blue to hold the stud in place when it was threaded into the swing arm so that it does not back out of the nut when the table is rotated. I cleaned up the nut face with a file and added a ¾" washer which rides between the two pieces so that they rotate easily. Unlike the OEM swivel assembly which tended to shed grease after a while, Delrin is a self-lubricating material so no grease is needed. When modified and installed in this manner, the table will sit higher than it did originally. If this is not to your liking, you can cut a bit off the bottom of the swing arm and redrill the holes for the securing pin so that the swing arms sets lower in its mounting to the coach.

Dave Potter
Woodinville, WA
david_potter@msn.com

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Attachments:
RVTable_Pintle.jpg
RVTable_Pintle.jpg [ 63.31 KiB | Viewed 6984 times ]
RVTable_Bushing.jpg
RVTable_Bushing.jpg [ 55.55 KiB | Viewed 6984 times ]
RVTable_Bushing_Closeup.jpg
RVTable_Bushing_Closeup.jpg [ 58.77 KiB | Viewed 6984 times ]

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