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#1
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![]() Yesterday I finally comnpleted my first ever aluminum trials frame. Actually, it's the first frame I've ever built, and my first ever machining project, ignoring the bc plates, which I started after it anyways. It has about 50-70 hours of shop time put into it. No more than 20 of those hours actually involved the cutter touching the metal, but setup on a manual mill when you're a beginner takes about 70% of the time. I think that if I made this exact same thing over again, I could do it in 30-40 hours. I ended up using 2 major tools on this, the lathe and the mill. Bandsaws were also used, but just because they are fast, efficient, and easier to setup. The material is 6061-T6 aluminum. I cut the parts out of 3 original forms. A 2"x5"x22" piece of bar stock, a piece of 1/2" plate, and a piece of 1.250"x0.180" wall thickness tubing. The bar was what the crown came out of, the legs came out of the plate, and the seattube was cut out of the tubing. The frame is 4.75" wide at it's widest point, but in the end it is effectively 4.5" wide at the crown, where it matters. There is an 8" seattube, which is plenty for me. Good thing, too, since it took 3 tries to cut the right size for the seatpost in it, and by the 3rd try 8" of tubing was all that was left. The seattube is made to fit a 27.2mm seatpost, and there's about 6-7" of space for the post to fit in. Past that the boring bar chattered too much to be usable on the tube, so I gave up. THe bvearing holders are machined into the frame, and are of a main cap style. They are for 40mm bearings, and have a small lip on the outside to help to retain the bearings. The bottoms are just stamped steel UDC bearing holders. I used 10-32" screws to attach the holders to the frame, which isn't ideal, but it works. A quick overview is that I haven't ridden the frame much, for 2 reasons. The first is I haven't had time to make a seatclamp for the thing, and the second is that my trials wheel needs a new hub, so I can't really do any good rides on it yet. The frame felt *extremely* stiff at the the shop, and there shouldn't be any of the issues with it that were found on Justin's SH frame. The basic design for the frame was taken off of a SH frame design, pictures of which can be found 'here.' (http://gallery.unicyclist.com/wjmuni/WJ_MUni_6) You can see a resemblence in the fork legs and crown/forkleg interface, but other than that, everything's changed. Rather than being 1.5" wide, the crown is 2" wide. There are 2 cross-membery thingies instead of 1, and they are of a different shape. That frame is for a muni, this one's for a trials. Mine has pins in the crown and seattube, while that one doesn't. The bearing holders are also drastically changed. My seattube is also thicker walled near the bottom and longer. The crtown-forkeleg is so different there's no reason to bother trying to explain it. There are other differences, but they aren't as major. I plan to put pins in the crown for foot on crown tricks, but my initial attempts at 1fww and standup ww have been already gone well with plenty of grip. Sadly it's raining right now, so I'm not going to try much more for a while. The crown-forkleg interface uses 2 1/4" spring steel roll pins and 2 stainless 10-32 screws to attach it, with the heads of the screws reccessed. They are placed at opposite corners to eachother. The seattube-crown interface went amazingly well. It has a 0.002" interference fit with the crown, plus 2 3/16" stainless roll pins on each side. There is also semi-permanent locktite that I slathered on there before inserting the tube. I put the tube in a freezer for 90 minutes, and then when I tested it on the crown, it had a nearly perfect fit. Now it's as solid or more so than if it were welded. If anyone wants details or pictures of fabrication of the frame I'll provide them, but otherwise I won't bother. I don't have pics of the cuts in progress (holdign a camera and running a mill at the same time sucks), but I can get pics of the tools used. I think I will anodize this frame blue to fit my rim (blue try-all), but I'm open to other ideas. Anything but red, since red, silver, and blue is just disgustingly patrotic (no offense, but I refuse to ride the Americycle). I found a site describing how to anodize at home, and I checked with the shop, and we have all the equipment neccessary for the task. I may anodize it Monday or Friday. I would like to hear any input you can t hink of on ways to lighten or strengthen the frame, or other possible improvements or changes, since this is just a prototype. Thanks for reading. +----------------------------------------------------------------+ | Attachment filename: entire frame.jpg | |Download attachment: http://www.unicyclist.com/attachment/280241| +----------------------------------------------------------------+ -- gerblefranklin - Trials Unicyclist http://gallery.unicyclist.com/Trials-Muni Nick's main man. "Democracy is just a word when the people are starving"-Immortal Technique ------------------------------------------------------------------------ gerblefranklin's Profile: http://www.unicyclist.com/profile/4295 View this thread: http://www.unicyclist.com/thread/38375 |
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#2
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![]() BTW, the pics are cropped so as to keep the file sizes down for those of us not gifted with the power of fast internet access. +----------------------------------------------------------------+ | Attachment filename: crown+forkleg.jpg | |Download attachment: http://www.unicyclist.com/attachment/280242| +----------------------------------------------------------------+ -- gerblefranklin - Trials Unicyclist http://gallery.unicyclist.com/Trials-Muni Nick's main man. "Democracy is just a word when the people are starving"-Immortal Technique ------------------------------------------------------------------------ gerblefranklin's Profile: http://www.unicyclist.com/profile/4295 View this thread: http://www.unicyclist.com/thread/38375 |
#3
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![]() Here's the clearance. It was a bit tighter than I'd like, but I still think it can work. +----------------------------------------------------------------+ | Attachment filename: clearance of tire.jpg | |Download attachment: http://www.unicyclist.com/attachment/280243| +----------------------------------------------------------------+ -- gerblefranklin - Trials Unicyclist http://gallery.unicyclist.com/Trials-Muni Nick's main man. "Democracy is just a word when the people are starving"-Immortal Technique ------------------------------------------------------------------------ gerblefranklin's Profile: http://www.unicyclist.com/profile/4295 View this thread: http://www.unicyclist.com/thread/38375 |
#4
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![]() I WANT ONE[image: http://www.observedtrials.net/vb/ima...ie/greddy.gif] HOW MUCH -- brockfisher05 - ride the north-shore well I had dream I, stood beneath an orange sky ADD ME AT: ------------------------------------------------------------------------ brockfisher05's Profile: http://www.unicyclist.com/profile/8363 View this thread: http://www.unicyclist.com/thread/38375 |
#5
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![]() Thanks, but at 50 hours by minimum wage standards in SF ignoring material costs, this frame would run around $400+USD (SF is 8.75 an hour, but I rounded to $8). If you paid a machinist to do this, it'd cost you around $1000-$1500. I'm happy to share the plans with anyone who wants them, but the only other people who will be getting these are the 3 people who have been kind enough to test subsequent models. The material costs for this aluminum actually runs about $75-$100 per frame, but I got a deal so I have enough al. for about 5-8 of these frames for $40. Sorry. It's also worthy of mention that this frame took 3 months to make, and most aren't patient enough for that. -- gerblefranklin - Trials Unicyclist http://gallery.unicyclist.com/Trials-Muni Nick's main man. "Democracy is just a word when the people are starving"-Immortal Technique ------------------------------------------------------------------------ gerblefranklin's Profile: http://www.unicyclist.com/profile/4295 View this thread: http://www.unicyclist.com/thread/38375 |
#6
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![]() i was just kiiden about gettin one i know how hard it is to build a bike frame . But I like the frame -- brockfisher05 - ride the north-shore well I had dream I, stood beneath an orange sky ADD ME AT: ------------------------------------------------------------------------ brockfisher05's Profile: http://www.unicyclist.com/profile/8363 View this thread: http://www.unicyclist.com/thread/38375 |
#7
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![]() As a good Socialist, I expect you will be making these for all your Unicycling Comrades. We don't have the skills, nor the funds to afford such a masterpiece. Please Comrade do the right thing. From each according to their talents, to each according to their needs. ![]() -- bugman - Survivor 2004 Wolfman Duathalon "The world is a dangerous place to live, not because of the people who are evil, but because of the people who don't do anything about it." Albert Einstein ------------------------------------------------------------------------ bugman's Profile: http://www.unicyclist.com/profile/3812 View this thread: http://www.unicyclist.com/thread/38375 |
#8
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![]() Nice work! One suggestion I have is to smooth the shoulders where your legs will pass to minimize catching. -- U-Turn - Member of Generation XO Weep in the dojo... laugh on the battlefield. '29er Tire Study' (http://u-turn.unicyclist.com/29erTireStudy/) 'Strongest Coker Wheel in the World' (http://www.unicyclist.com/gallery/albup39) 'New York Unicycle Club' (http://www.newyorkunicycle.com) -- Dave Stockton ------------------------------------------------------------------------ U-Turn's Profile: http://www.unicyclist.com/profile/691 View this thread: http://www.unicyclist.com/thread/38375 |
#9
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![]() That is a very beautifull uni, id paint it maroon... Chase -- Unitik908 - Level 5 All hail the exhaulted Sigpoose, for he is forever king... R.I.P Unibiker ------------------------------------------------------------------------ Unitik908's Profile: http://www.unicyclist.com/profile/8690 View this thread: http://www.unicyclist.com/thread/38375 |
#10
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![]() Slick looking. ![]() Hmmm... I have access to a machine shop, get plans... learn things... make cool frame! Ahh, let us know how it works when you're riding on it. -- Bob22b - MCL Tearer :d ------------------------------------------------------------------------ Bob22b's Profile: http://www.unicyclist.com/profile/8153 View this thread: http://www.unicyclist.com/thread/38375 |
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