T8's 750 Cafe Racer Project

[T8erbug]

Click for video

Here is the solidworks model of the seat cowling. For now it's done. My buddy has two 3d printers at his house that are just big enough to print this part. We're printing it in two halves. It's on the printer now until about 3AM so as long as nothing goes wrong with either printer overnight we'll be able to mock it up and see how it looks on the bike tomorrow. It's about a 10HR print job. The longer a print job is the more likely something will go wrong so cross your fingers with me and hopefully this comes out right on the first try. The nice thing is if it doesn't fit or we need to make adjustments we just make them in the computer and print it again. Once I am left with a part I like and that fits I'll sand and prime it until it's smooth and looks exactly like the final part should. Once it's all pretty, I'll wax it and make a fiberglass mold or in other words a reverse of the part. The fiberglass mold will be nice because I can experiment with different materials (fiberglass/carbon fiber) and make multiples if necessary. Hopefully it all works out. Either way I'll report tomorrow.

[T8erbug]

3d print
















Everything came out looking pretty good off the printer with the exception of a little warpage on one of the parts. I decided to make a few revisions so the new parts are on the printer now. Update on Monday.

[John Kat]

Really amazing!
How much does it cost to produce?

[T8erbug]

2nd Iteration










Don't mind the aluminum here. It's just there to keep the part from falling since we only had half done at this point.


As you can see from the side view of the bike the profile shape of the tail section didn't change at all. In this iteration I changed the overall width to sit on the frame better and line up so the outside edge of the seat is tangent with the outside edge of the frame tube. The top view shows that I kept the overall shape as well. What I changed is the outer portion to hide the frame better and I think it came out looking pretty cool. Form follows function and this is a good example of that. Anyways, I think this is it! Time to move onto the under-butt section and then the plug will almost be complete. I'm stoked to finish this bad dude up. Once the mold is made I will probably make the final part out of carbon fiber. When I have a final part, the electronics/battery will have a home! This means it's almost time to start her up and take her for a romp. I'm beyond excited.

[T8erbug]

Really amazing!
How much does it cost to produce?

That's a loaded question! haha. To me it's basically the cost of material (which can be a number of different plastics) and is relatively cheap. That's because I design, model, and act as the engineer, tech, and printer operator (or Ben). We cut the middle man out.. err we are the middle men haha so we don't charge ourselves for our time. If you're thinking of doing something like this shoot me an email and I'll give you a realistic quote. I will say I have at least 5 hours in the design of my seat cowl. As simple as it looks, it's really quite a complex part. Then add to that the print time (which we got down to about 15 hours total) and setup. I'd say it would probably cost at or around $200 to have your part drawn, setup, and printed the first time then less with minor revisions and reprints. It's pretty cost effective if you're not quite sure about what you want or if you're planning on making a mold. I can honestly say I have at the very least 50 hours in this seat mold BEFORE we did the 3d print.. If we would have done this from the start I would have saved myself so much time and headache. (not trying to sound salesmany).. haha it's just true true

[mikerophone]

That is a thing of beauty. Nice work!

[T8erbug]

Here's a nice shot of the plug coming together. I sanded and primed the 3D print with Rustoleum red v2100 primer and it bonded really well to the plastic but just didn't build high enough to fill in the imperfections quickly. I had primed and wetsanded it several times and was making slow steady progress. It was starting to smooth out nicely with just a few small low spots. I wanted to speed things up so I went and bought some Rustoleum High Build/Sandable primer and what a mistake! I sprayed on a single coat and was devastated. Even though the red primer had cured for over a 24hr period the high build stuff turned it to goo. So, I had a high build primer (that dries quickly) sitting on a semi liquid base.. As the top layer dried, the bottom layer moved and shifted with it. It ended up looking like a desert after a rain storm.. Cracks everywhere. Needless to say I'd have been better off just taking the slow and steady road haha. In the end I was able to save the 3d printed part and start from scratch with a new primer. I stayed with Rustoleum but went with a purpose built sandable primer rather than a high build/sandable primer. I finally got it close to done and started to make a new front end that will become a part of the plug out of foam and body filler (just like last time). You may wonder why I didn't just 3d print the whole thing because I have the resources and the reason is that if you look closely at any of these old fuel tanks you'll see that they are not truly symmetrical from side to side. No two tanks are exactly alike and no side is an exact mirror image of the mating side. So, I chose to sculpt and form the front end to make it look symmetrical even though it won't be rather than having a perfectly symmetrical part butt up with an imperfect one and expose the dirty details. Anyways, here's a picture of the final profile/shape of the bike at the new shop. O yeah, so in other news I finally have a dedicated workspace. No more working in a garage that's meant for cars, no more working in barns, no more moving from place to place. I finally have a spot for a while! I also picked up a 1978 GS1000E from Rexburg, ID on Sunday. It runs.. Like crap. BUT it runs! I'm stoked to start working on it when I'm done with this one.

[mikerophone]

Did you buy that red 78 1000E with the hideous double hump seat and duck taped sissy bar? Dana coils, newer tires and electrics problem where the battery drains?

It was still listed on KSL as of last night and I half considered it but it but you're a lot closer, glad you swiped it up!

[T8erbug]

Did you buy that red 78 1000E with the hideous double hump seat and duck taped sissy bar? Dana coils, newer tires and electrics problem where the battery drains?

It was still listed on KSL as of last night and I half considered it but it but you're a lot closer, glad you swiped it up!

HAHA yeah that's the one! It also came complete with: High CCA lawn mower battery, aftermarket square headlamp, sweet flamin' skulls double stick taped to each side of the tank, AND a beautiful rivet job on the front fender. Did I mention the custom headlamp bracketry and all the custom work it took to fit that huge arse battery in there? The previous owner gutted the interior to fit the battery and even cut the rear brake M/C out and mounted it with zip ties on the exterior... Wowsers haha. I'll definitely have to take some pictures for your enjoyment. I was able to get it for $350 though. Tough to find a runner with 1000cc's in any shape for that price! I had a fishing tournament in Burley so I figured I'd make the extra little jaunt up to Rexburg. I scored a 1.25" receiver hitch for my civic on the classifieds for $40 and made some modifications to a 2" ball hitch I got for $10 so I figured it wouldn't cost me too much extra to just haul a little trailer up there and have a look. It worked out great and the hitch even held up

[Chuck78]

Cool, more GS's is great! I finally have a garage at the house we're rehabbing & settling down in, AND an exterior basement entrance! Looking like I'll be able to become more of a GS hoarder!!! GS550 upgrades & friend's GS750C are next, then build a 325lb barebones big bore 475cc 11:1 racer out of this GS425E, & trying to pick up a beat up Rickman CR750 aftermarket CB/Z1/GS frame modded to fit a GS1100E engine already (since I can't afford a CR1000/Predator/CR-E Endurance Racer complete bike (the rare GS Rickman versions)

Your bike is looking GREAT, can't wait to see the day you get to do some mountain riding/canyon carving/track time on it! I'll have to pay you a visit next time I'm able to ride from Ohio to visit my friends in Boulder...

[T8erbug]

Cool, more GS's is great! I finally have a garage at the house we're rehabbing & settling down in, AND an exterior basement entrance! Looking like I'll be able to become more of a GS hoarder!!! GS550 upgrades & friend's GS750C are next, then build a 325lb barebones big bore 475cc 11:1 racer out of this GS425E, & trying to pick up a beat up Rickman CR750 aftermarket CB/Z1/GS frame modded to fit a GS1100E engine already (since I can't afford a CR1000/Predator/CR-E Endurance Racer complete bike (the rare GS Rickman versions)

Your bike is looking GREAT, can't wait to see the day you get to do some mountain riding/canyon carving/track time on it! I'll have to pay you a visit next time I'm able to ride from Ohio to visit my friends in Boulder...

That's awesome Chuck! I'm happy to see that I'm not the only one "hoarding" bikes haha. I have seven now and I was starting to think I was getting out of line.. buuuut as long as I compare myself to you guys I'm right on track haha. Definitely stop by if you're around! Hopefully I'll have this girl done by then so we can go hit up some canyons. There are a ton of good ones here. Salty Bike Revival did a bike show in Salt Lake City this year and it was awesome. If you get a chance to come here you oughta try and plan it around then. Tons of cool bikes

[T8erbug]

Not to derail my own thread but check out the custom engineering and design work from the previous owner on my new-to-me GS1000 bahaha!



















What a gem

[steve murdoch]

Hopefully that rare Yosh pipe has not had any of that "custom" work.
That seat should be in the duct tape hall of fame.

[dorkburger]

Its nice once in a while to buy a bike that can simply be ridden as bought, with no need for work.....

Good God!

[mikerophone]

Hahaha that's the one, I love it! Man who Mount their master cylinder to their plastic side cover?!

Even with all that I would've bought it and almost did like you said a 1000 is hard to find at least around our neck of the woods so I think you did OK, can't wait to see what you do with it!