nzvet
05-20-2008, 08:37 PM
Any chance you can link to the builders instructions or post a set of your own?? I really like this design, and wouldn't mind giving it a try.
Wizard !
Wasn’t able to find my original contact’s email but here’s a summary of how I constructed the moulded seat.
The mould I made is from 19mm MDF board but can be made from thicker plywood and 4x2’s to hold the 3 frame profiles apart.
http://i151.photobucket.com/albums/s156/nzvet/Seats/P10208421.jpg
The rigidity of the mould is important, not so much what you make it from. To get it the right profile shape for your back, cut the mould profiles to what you think will be right, assemble, stand mould upright, place a piece of ply on it and sit on it. You can then make adjustments to the profile shapes as needed. This takes a bit of time but I think is worth it. You may find that after riding your new seat you’ll make further adjustments to the profiles. The basic angles I started with was the top and base of the seat at 90 degrees to one another with the back of the seat at 120 degrees from the base. The seat base of the mould is to the left. Let me know if this doesn’t make sense!
I obtained a half sheet of bendable ply from a local supplier. This is like normal plywood but the grain runs the same way in each of the layers. It’s great stuff and is incredibly flexible.
http://i151.photobucket.com/albums/s156/nzvet/P10208541.jpg
I used a 6mm 3 ply sheet which allowed me enough to make the three laminations.
Start by cutting three sheets of the ply to a larger size than your seat will end up. You’ll trim this to size later. I then brushed epoxy on one side of two of the sheets and pressed the epoxied sides together. I then placed the sheets on the ground and stood all over them until the epoxy oozed out the edges. A bit messy but you want to make sure you’ve got as much air out from between the sheets as possible. Then push the ply sheet into your mould.
Here’s a mock up of a piece of ply clamped on the mould. I used about 8 clamps and a variety of weights to secure the two epoxied sheets firmly in the mould.
http://i151.photobucket.com/albums/s156/nzvet/P10208551.jpg
Leave this overnight to allow time for the epoxy to set. The next day, remove from the mould and you have the shaped seat. Next, take the third sheet of ply. Epoxy one side and epoxy the back side of your seat and clamp the two together. Again, use as many clamps ‘ weights as you can to secure the two. Try and get the epoxy oozing out the edges again.
Leave overnight to set. In the morning your can start trimming your seat to the finished shape you want. Here’s my finished seat sitting on the mould.
http://i151.photobucket.com/albums/s156/nzvet/P10208531.jpg
I fibreglassed my seat but I think this is overkill. The seat, I found is stiff enough without glassing. The bendable ply I used is not treated so would have needed a coat of epoxy or some sort of sealer to keep the moisture out.
The end result is a seat that appears bulletproof and will probably last forever!
Let me know if there's anything you’d like me to clarify.
Best regards
Steve
Wizard !
Wasn’t able to find my original contact’s email but here’s a summary of how I constructed the moulded seat.
The mould I made is from 19mm MDF board but can be made from thicker plywood and 4x2’s to hold the 3 frame profiles apart.
http://i151.photobucket.com/albums/s156/nzvet/Seats/P10208421.jpg
The rigidity of the mould is important, not so much what you make it from. To get it the right profile shape for your back, cut the mould profiles to what you think will be right, assemble, stand mould upright, place a piece of ply on it and sit on it. You can then make adjustments to the profile shapes as needed. This takes a bit of time but I think is worth it. You may find that after riding your new seat you’ll make further adjustments to the profiles. The basic angles I started with was the top and base of the seat at 90 degrees to one another with the back of the seat at 120 degrees from the base. The seat base of the mould is to the left. Let me know if this doesn’t make sense!
I obtained a half sheet of bendable ply from a local supplier. This is like normal plywood but the grain runs the same way in each of the layers. It’s great stuff and is incredibly flexible.
http://i151.photobucket.com/albums/s156/nzvet/P10208541.jpg
I used a 6mm 3 ply sheet which allowed me enough to make the three laminations.
Start by cutting three sheets of the ply to a larger size than your seat will end up. You’ll trim this to size later. I then brushed epoxy on one side of two of the sheets and pressed the epoxied sides together. I then placed the sheets on the ground and stood all over them until the epoxy oozed out the edges. A bit messy but you want to make sure you’ve got as much air out from between the sheets as possible. Then push the ply sheet into your mould.
Here’s a mock up of a piece of ply clamped on the mould. I used about 8 clamps and a variety of weights to secure the two epoxied sheets firmly in the mould.
http://i151.photobucket.com/albums/s156/nzvet/P10208551.jpg
Leave this overnight to allow time for the epoxy to set. The next day, remove from the mould and you have the shaped seat. Next, take the third sheet of ply. Epoxy one side and epoxy the back side of your seat and clamp the two together. Again, use as many clamps ‘ weights as you can to secure the two. Try and get the epoxy oozing out the edges again.
Leave overnight to set. In the morning your can start trimming your seat to the finished shape you want. Here’s my finished seat sitting on the mould.
http://i151.photobucket.com/albums/s156/nzvet/P10208531.jpg
I fibreglassed my seat but I think this is overkill. The seat, I found is stiff enough without glassing. The bendable ply I used is not treated so would have needed a coat of epoxy or some sort of sealer to keep the moisture out.
The end result is a seat that appears bulletproof and will probably last forever!
Let me know if there's anything you’d like me to clarify.
Best regards
Steve