There were a couple of things that needed to be figured out before getting into the sliding mechanisms. First was the fact that since the front of the cockpit was now propped into its proper position, the canopy itself was having a hard time fitting properly. We needed to do some trimming of the canopy and I’ll also need to do some further re-shaping to make it fit better at a later date.
Part of making it fit better was adding some temporary windows. When the canopy doesn’t have any windows in place, the bottom of it is very flimsy and you have a hard time really knowing how it should sit. So we used some screws to secure some material that would serve the same purpose as the window. The bottom of the windows were secured by me being inside the cockpit, my dad holding down the outside bottom edge of the canopy, and then me screwing the window into place from the inside-out to hold the shape. After we had the window material secured we just trimmed off the sharp points of the screws in order to not cut ourselves. Just like many other builders have mentioned, this makes a huge difference to the feel of the canopy and how rigid it becomes.
Also, the canopy opening curves inward as it moves towards the front of the vehicle, but the sliding rails run parallel to the frame of the vehicle. This means that as the sliders move forward, there’s potential for them to start rubbing on the sides of the canopy opening. So we trimmed the sides of the canopy opening as well to hopefully give us a bit more wiggle room.
We knew that we were going to need some points on the back corners of the canopy that we could use to mount the sliders. The idea was to bolt them into place for now, and then embed them into the canopy with fiberglass once we have everything the way we want. These mounting points started off as a strip of 1.5×4″ plate steel to use as a base.
After that we created a plate with two studs welded onto it that will be used to bolt on the sliders for the canopy. We welded the plate on an angle to better make them plumb and stick into the cabin a bit to clear the sides of the canopy opening. (Note the picture below is upside down. The wider part of the brace is at the bottom of the canopy. We just had the canopy upside down for ease of access)
After we had them in place and figured out the angles that we wanted, we unbolted the mounts from the canopy and boxed them all in to be nice and strong. We even drilled and tapped a hole on the side so that when I embed them into the canopy with fiberglass, I can also bolt the side of the fiberglass into the brace as extra support.
Now came the tricky part. We needed to secure the rails to the side of the cockpit. The rails we used were standard galvanized garage door rails. We’ll end up using a curved piece of this track/rail for the center wheel, but that isn’t covered in this post. For the sides of the canopy we used straight rails and nylon garage door wheels. Our first attempt was to make the rails level so that the sides of the canopy would rise as it moved forward.
The really tricky part was to figure out how we were going to bend the sliders to the right shape to connect to the canopy, clear the seats and then also connect to the nylon garage door wheel. This took a lot of trial and error with me sitting inside the cockpit, my dad handing me a piece, closing the canopy, test fitting and then repeating that about 20 times per side.
Finally we had pieces that would fit, but what we found was that as we slid the canopy forward, it would only travel about 12″ before it started to rub on the sides of the canopy opening. What we realized was that running the rails level was the cause of this problem. We actually needed to run them parallel to the canopy opening. This meant that the sliders could move forward with the same amount of clearance with the body as it moved forward.
As you can see I still need to trim the bottom of the slider. The throw of my linear actuator for the canopy is 24″ so I needed to make sure the rails were at least 24″ long. Part of the lining up of the sliders was figuring out where the garage door wheel would fit. We ended eyeballing up the location, drilling and then sliding the shaft of the wheel through the hole. This allowed me to weld it to the slider inside the car and then trim and finish weld it off the vehicle.
Other details you’ll notice on the slider is that we put two studs on the bracket for a reason. We wanted to create a slot in the slider so that we could adjust the up/down as needed. By creating this slot in the slider, and the two studs to ensure that nothing would twist, gives us about 1″ of adjustment up and down based on any kind of weather stripping or other things that may cause fitment changes.
I still haven’t started on the center rail that goes down the middle of the car under the hood, but that’s next on the agenda. Right now you can grab the front of the canopy and slide it back and forth with ease. However, you realize just how important that center rail is. When the canopy gets out of alignment moving it forward/backward it will quickly bind. That center rail will ensure that both sides travel equally as it moves.