| Author | Message | ||
     Torquehd |
I'm surprised no one else has taken this project on. I've been a Buell patron for years. I spent so much time looking at the RS and RX while I was deployed, I remember all the excitement when the RX came out, the site was just buzzing with energy. FINALLY, I have a little leave for Chrismas. My poor girlfriend feels like I'm neglecting her. I can't help it, I could give up drinking or chewing before I could give up tinkering in the garage. Unfortunately, $19 grand is a little out of my reach right now. However, I can spend a few hundred and make my 1125 look somewhat similar to an EBR model (i've watched the John Britten documentary enough times, I should be an expert). I've spent well over a couple hundred hours just to get where I am now; doing this stuff by hand, eyeball and a tape measure is so labor intensive. If I had a 3D printer, I could have probably been finished by now. I started out doing three things: 1. making a plywood model of the subframe 2. making a tail section out of foam, and 3. making a fiberglass copy of the airbox cover.    I spent probably a hundred hours getting the subframe just right. The tail section was easy to rough-out; getting it symmetrical with straight lines took a LONG time.   Next, I covered the foam pillion with bondo. The fiberglass copy of the airbox was built-up with "greatstuff" expanding foam, then covered with bondo.    The subframe is currently on hold, until I get the pillion mold finalized. The main section is ready but the part that extends up under the pillion/passenger seat is still pending. After about a month of work, the pillion "plug" or original model is finally ready for making a negative mold of.   That's where I'm at right now. The airbox cover still needs a couple dozen hours of work. I should have the negative mold of the pillion finished tomorrow. Updates to follow. (Message edited by torquehd on December 21, 2013) (Message edited by torquehd on December 21, 2013) | ||
| Chauly |
Been through that myself. Tedious, but ultimately rewarding ;I look forward to the final result! | ||
| Sifo |
I've done a few similar projects in the past. It's always a lot of mental and physical effort. Rewarding though. Is the plan for the subframe to be built with glass? Definitely looking forward to seeing progress on this. | ||
| Strokizator |
That's a seriously cool project. My poor girlfriend feels like I'm neglecting her. Ya think? | ||
| Torquehd |
the left and right trusses of the subframe will be cast aluminum. the plywood is just a model. That's part of the reason it took so long - allowing for good draft/relief angles. I also had to contour the top rails, they "pinch" in toward the center of the bike under the seat. | ||
| Sifo |
CAST aluminum? That's ambitious for my abilities at least. I hope to see many more pictures. Looks like a great work in progress! | ||
| Hughlysses |
This is a very cool project. Nice work. I'm actually surprised nobody's done it before. I would think you could alternatively CNC mill the sides out of aluminum plate. | ||
| Nillaice |
That is IMPRESSIVE!!! I'd think that You'll need to do some math on casting those subframes a out if aluminum, cuz it'll start to contract and shrink as it cools and solidifies, most noticeably on the long straight sections. There's an equation for it, so it can be done. It might be easiest to scan the wood templates and play with the math on a casting program or something. Or cut up some sheets of 6061 AL | ||
| Sticks |
You can cast the subframe just fine. A runner bar that gates the metal in a few places and you have risers, ideally with insulated sleeves to continue to feed the heavy sections. The heavy bosses are where the shrinkage would end up if not fed more metal. The thin parts should freeze off, the trick would be to gate in enough places to feed everything and get it all to run. Pretty cool. | ||
| Rocket_in_uk |
Impressive indeed. Look forward to your finished result. Rocket in England | ||
| Thumper74 |
Lost wax method on the subframe? Google it. I'm too lazy to type it up right now. | ||
| Torquehd |
CNC... That would be fantastic, but you're talking money there. This is a project on a shoestring. I have a home made foundry setup, and I've tinkered with casting, but this will be my initial "useful" piece (besides the wall hook I made to hang my hat on). Won't be using the lost wax method. Plan on utilizing a runner bar like Sticks mentioned. Before I had developed a real plan, I cast a piece just to see how it would turn out. The model was rough particle board and the thing is pretty much a mess. This was about a year ago.  I haven't gotten too much into the thermodynamics behind shrinkage, but I know Al shrinks 2 percent. That's negligible for this piece (fudge factor). Forgot we had a Christmas party this afternoon, only thing I was able to get done was half of the negative mold. I made a parting line with masking tape, and supported it with Greatstuff. It really is great stuff. It's on my list that includes brake parts cleaner, bondo, and 550 chord.  As the Greatstuff cured, it pulled the tape away from the nice, clean parting line I made. Oops.  Nothing a little plasticene won't cure. Hopefully.   Thanks for the encouragement gents. | ||
| Torquehd |
Sifo, the body work is ultimately going to be carbon. I've got a bunch of carbon and resin just waiting to be used on a good project. I recently purchased the items required to vacuum bag, but the tight angles of the tail section may make it difficult to vacuum bag. If I can't vac and get a good surface finish, I'll end up having to paint the carbon. | ||
| Sifo |
Carbon would be nice, especially if you can get a good outer layer. I was really wondering about the subframe though. I was pretty sure plywood wasn't the final plan, but didn't expect casting. That could turn out nice if you can pull it off. It's beyond what I've ever tried. Cool stuff! | ||
| Chauly |
Check out "lost foam" instead of lost wax. I've done a few of those over the years. Of course, if you want to make copies...  | ||
| Hughlysses |
Check out "lost foam" instead of lost wax. I wonder if Great Stuff will work for that? He could go into production pretty easily if it will. | ||
| Torquehd |
I tried using blue polystyrene as a model, it was being compressed a little under the weight of tamping, and would break up the sand when I lifted it out. With plywood, you can reuse the mold as many times as it takes to get a good casting, and for an amateur like me, it can take a time or two to get it right. I really want to do the body out of carbon, but i'm a total amateur and getting a good finish is difficult - even for experienced guys. I'm not set up to do resin infusion, which seems to be the only way to avoid getting air bubbles. | ||
| Chauly |
With lost foam, you leave it packed in sand. The foam vaporizes instantly, leaving the void. | ||
| Hughlysses |
To produce multiple copies, you make a negative mold. You cast a foam pattern in your mold, remove the foam pattern and pack it in sand, pour in your aluminum, and you've got a part. Repeat as necessary. | ||
| Ourdee |
For a one-off I'd just machine the aluminum piece. Really nice project. Hurry up, I want to see it. | ||
| Ourdee |
Will you be making a new seat pan? | ||
| Hughlysses |
For a one-off I'd just machine the aluminum piece. Really nice project. Hurry up, I want to see it. You could do this very low tech with a drill and a saber saw with a metal cutting blade. Drill out the corners; connect the holes with the saber saw. Clean up the edges with a Dremel tool or die grinder. | ||
| Torquehd |
Ourdee, I intend to make a new seat pan. The stock seat will fit with the dimensions i'm using, but the bottom of the seat doesn't follow the flat line of the subframe.  Why would you do lost foam? it seems like a better use of time to make one rigid, reusable model than have to make a new model each time - even if you're using a negative mold. Finished the negative pillion mold, and demolded it. The spray paint pulled off the mold, but the majority of it came right off the fiberglass with a plastic scraper. I think the heat generated by the curing process broke down the spraypaint and caused it to delaminate.   As expected, each half of the mold has a couple dozen pits/air bubbles. I'm in the process of cleaning and filling the voids with more resin. Will also sand and buff the inside of the mold before proceeding. Edit: I know exactly what happened. Looking at the pics, the layer that delaminated was the charcoal gray. That was the cheaper primer that I bought to test out. It was the only spraypaint that clogged up the sandpaper immediately, and it obviously can't take the heat! No more cheap spray paint. (Message edited by torquehd on December 23, 2013) | ||
| Hughlysses |
Why would you do lost foam? it seems like a better use of time to make one rigid, reusable model than have to make a new model each time - even if you're using a negative mold. Jesse, IIRC, one of the main advantages lost foam produces a better surface finish than conventional sand casting. Here's a decent wikipedia article on the process: http://en.wikipedia.org/wiki/Lost-foam_casting | ||
| 1313 |
IIRC, one of the main advantages lost foam produces a better surface finish than conventional sand casting. Thinking back to that college lab where we did some lost foam casting with Aluminum, I would have to add the caveat 'depending on the type of foam used' to the statement above. The smoother the foam, the smoother the result. Obviously what sparked this flashback was that we used pretty poor quality foam - and the results clearly showed it, 1313 | ||
| Torquehd |
I'll stick with what I've got. Maybe someday I'll have a project that calls for a model with no draft or something. Spent the day cleaning up (wet sanding and polishing) the mold faces. I also decided i'm going to vac bag the upper and lower halves, then join them together. I'll need a border around the edge of the molds for that. I came up with an idea to make collars that I can put on the molds, make the halves, then remove the collars and trim the upper and lower pieces, then put the original mold halves together and bind the upper and lower pieces.  The bottom is not going to be a solid piece. The fitment will be similar to the RX. | ||
| Gschuette |
HELL YEAH! This is awesome! Great work! | ||
| Torquehd |
Thanks Gschuette. Glad you share my enthusiasm. Enthusiasm tends to grow weary after awhile. One of the "collars" i made today is unsatisfactory. I didn't have the foresight to reinforce the back side, so the tape bent and the collar slumps inward. It would probably still work, but I really wanted the collars to be flush with the mold surface. Oh well. I used about 1 sq ft of fiberglass and a tiny bit of resin. All in all, each collar cost about $4.00. No major loss there. Probably going to have to take a break for a few days. Going to the girlfriend's parent's house for Christmas Eve, then having Christmas at our house. Merry Christmas, everybody! | ||
| Chauly |
Definitely spend some time with the GF;the relationship could potentially last a lot longer than the project! | ||
| Torquehd |
Definitely spend some time with the GF;the relationship could potentially last a lot longer than the project! That's the plan. We've been together a year and a half, I intend to make it permanent. The bottom collar came out perfect. 1"+ all the way around.  } |
