PDA

View Full Version : X18 Seat Bases. (the aluminum part) REBUILD



Lenny
01-20-2005, 07:42 PM
I have taken apart my old seat base supports (sliders) on the X and "re-made" them. The design of old is terrible and they can move and put a lot of twist and turn strain on the three point support. The old holes are loose in the pedestal supports on the cockpit floor from many years of twisting and turning and jarring. Also, the mounting points (T-nuts) for mounting to the original seat bottom are close together and don't offer a lot of support. In getting the new seats from Bob at Bilt-Rite, I had the holes located on the larger 8 1/2" by 10 3/4" rectangular pattern. Much larger than the original.

Also, a feature of the old I did not like, was the way when you tightened the seat to where you wanted it you were basically compressing the two aluminum railes against the square aluminum extrusion in the middle. (seat slider base) This just sucks in the rails to bind against the slider base but puts unwanted strain on the new seat bottoms and T-nuts. I figured something had to be better. Pics below show how the old way works.

Lenny
01-20-2005, 07:48 PM
So, I drew up a picture of what I wanted, and it had to be strong, offer GREAT support for the new seats and be adjustable. I increased the three point attachment bolts to the cockpit floor to 3/8 from 1/4 in order to open up and freshen the holes in the fiberglass, as well as increase the strength. I started with 1/2" aluminum plate and had a groove (rabbet) milled along the sides to keep the two rails a perfect distance apart. I had the new seat hole locations drilled as well. I had the old rails 2 holes increased to three, and had them opened up and chamfered as well and attached them to the plate with SS Allen Head bolts. Loc-tite (ed) them in place. I still have to grind off the 1/16" protrusion from when these pics were taken. Now, with this done there would no longer be ANY compression of the rails on the bottom side of the seat to create any unwanted forces that could be transfered onto the seat base and T-nuts.

Next was the adjustability issue. The old way was not the way I wanted to go so I had 4 blocks machined with adjustable holes so it was no longer a compression fit, but a fixed one through the use of the holes. Then I had them fixed, (screwed and Loc-tite (ed)) into place.

Last are the pics of the finished product. You get the idea. They are ROCK solid, provide a ton of support, are adjustable, have ZERO wobble or play, and support the new bucket seats superbly. I was going to have this all welded but was told to stay away from that due to warpage. So, bolts it became. In the final pic, the actual fit is perfect. That is a "loose" picture to get the idea of how it works when mounted under the seat.

The only drawback I can see, is they (since they were machined out of 1/2" Aluminum c/w a rabbet) put the seats 3/8" higher in the hull. I feel that is a minor issue and not visible in any way. IMO :D

Besides, if I can look taller while driving this thing all the better. My goal is to look more like Ranman driving his 18 instead of "Tatu" driving mine... :)

TREYSTJOHN
01-20-2005, 09:24 PM
Nice upgrade and well needed. If one were to want a set, how much?

Lenny
01-20-2005, 09:59 PM
I can't supply the original extrusion. I can supply a remake with a "new" extrusion with the same hole pattern as stock for seat cushion base and seat slider base if needed.

This was keeping the original parts and adding to them. I think if anyone was seriously interested, a new extrusion, some G-codes and a large run would make them "cheap" Probably a couple hundred for a pair.

I have a pair of the "heavy duty" pedestal seat bases, sliders, swivels, you name it, BRAND NEW, in wrap, that I paid $245 for the pair for. I would let them go for $175.00US.
http://www.donzi.net/forums/showthread.php?t=30358