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Discussion in 'Some Assembly Required' started by XCgeek, May 8, 2013.
This thread is so full of awesome. Really enjoying this project, XCgeek.
No but the post office does...send me a dxf file and I'll cut whatever you want for the cost of postage. It'll be an international collaboration
Your going to regret saying that.
We'll all have you working 24 7 to complete our orders.
Yep, sure will
What was your drop box again Sailah
Lets be reasonable about it now, I offered the op because he was cutting out those dropouts with a grinder. And a damn fine job he did I might add.
If you want something I'm happy to do it, just make a reasonable request and cover postage. I have plenty of scrap steel and aluminum laying around. Remember the reasonable request... since youre all from australia I could do one shipment and you could distribute...
$45 usd for a flat rate express envelope max 2 kg delivered in 3-5 days
Things have been a little slower lately. First I managed to slice my wrist open on an unrelated project. That caused a 4 hr wait at the EM room for six stitches. About 2.5 hrs into the wait, the lovely nurse jabbed me with the local anesthetic. Pity that it had worn off by the time the doctor came by to do the stitching.
Not to matter, the project must go on.
The swing arm is coming along. I have all the tubs in and most of them fully welded. The jig gets in the way for some welds so now I have to pull it off the jig to finish it off. It will be interesting to see just how much the drops move once released from the jig
My welding still sucks but I can see improvement!
We then had a couple of days of rain and seeing as this is my home work space
I set out to perform other work where I was less likely to electrocute myself.
The next item on the list is the shock pivot. I decided on a linkage suspension design for a couple of reasons;
1) Most all dirt bikes use a link suspension design so there must be something in it,
2) A progressive suspension action will allow a plush initial ride while still allowing bottom out resistance,
3) I am using an air shock and air springs, unlike coil springs and very progressive. My experience with mountain bikes indicates that generally, most air shocks are too progressive and require too much sag to allow all the travel to be used,
4) My air shock (a Fox MXR mini bike shock) has an adjustable air chamber. Smaller air chamber equals more progressive, larger air volume equals less progressive. So I have some room for adjustment.
5) I am not sure what the best ratio would be. Many people assume that as an engineer, I can do some calculations and come up with the numbers. If that were the case, every bike would have the exact same design and ratios as they would be known to be the best. This is not the case because there is no best solution. In engineering, EVERYTHING is a compromise.
With my linkage design, I have made the linkage a falling rate as possible. When it turns out to be too falling rate (too linear or even worse, stiff early and softer later in the travel) then I can reduce my air volume. If that does not get enough progressiveness, then I can simply redesign and remake the linkage and pivot without having to change either the swingarm or main frame.
Blaa blaa Blaa all text and no pics makes this a sad thread.
And yes, despite having an offer to have these plates cut out on a water jet, I once again cut them both out by hand (grinder, drill press really).
Good news is that the shock actually fits nicely.
Next post. Lets finish that swingarm.
If you are tig welding steel.... use stainless steel filler rod...
try not to over heat the steel... all the impurity's come to the surface
as you are finding out... easyer said than done at times...
Even the steel tig filler rod has a lot of impurity's in it..
Gas filler rod..don't go near it..
Thanks for the tip. I will try that. I also need to go down in rod filler size. Most of my welds are coming out to hot. The only ones that are OK are where I am not adding in any filler wire
Not sure I would mess with the stainless fillers, that does'nt look bad, I just see bad stacks, no burning or anything.
Drop down a size on your filler and work a smaller puddle, if your having trouble with pulling always make sure to weld the open sides of the joints first, the closed sides last and it'll pull a little less...but it'll still pull so factor that into the fit.
Sometimes if you get out of square you can do some dry passes without filler here and there in strategically placed locations to pull it back into shape, which gives you the opportunity to make the welds look a little nicer.
Now this is a really nice build...
Please keep posting!
And hope your wrist gets better soon!
Fuck yeah! Love it. Flew down to LA to meet the owner of FX bikes when he first brought them to the US, as I'd been wanting to design/build something similar for a long time. You did a nice job with that bike, but this one looks even better. I ended up putting together a bigwheel CR80 / XR100 hybrid, and it was a blast. Almost exactly the same size as a mountain bike, and weighed about 160lbs, but it was a full-blown mini-moto. Think you'll be pretty happy with that kitaco engine too. Had a nice BBR-built big-bore in mine and it had plenty of power for riding trails. And for a guy who started this project with a disclaimer about not being a fabricator, you're doing a hell of a job. All those hand-cut brackets look fan-fucking-tastic. Keep up the good work!
Oh, and sailah, gonna be sending you some CAD files...
Do you have any plans beyond building one of these for yourself? Any aspirations to develop something like a frame/kit/complete bike? Or maybe sharing CAD files? Any chance?
Building a few more is sitting in the back of my mind. I need to improve my welding before then but it is being thought about.
That's great to hear. Excited to see how this turns out.
Things are finally starting to move along faster now. That is for a couple of reasons.
First is I quite my job. It was a good job and I mostly enjoyed what I did. It just got to the point where I did not agree with those above me and obviously, they were going no where so I did. So far, it has been the best this I ever did.
Second reason is that the tedious work of carefully coping tubes together and the finicky welding around these tube joints is done!
Welcome into existence my frame and swing arm assembled together.
Note that the shock is just temporarily bolted directly to the swing arm. I have the linkages made as per a post above but they have been painted now and I want to leave them for a couple of days to allow the point to harden.
There is still work to be done on both the frame and swing arm. Not much on the swing arm, just mounting the chain slider. More on the main frame (oil cooler mounts, hydro clutch mount, electrical components mounts, fuel tank mounts). But this is all much easier welding and I am noticing I am getting much faster at the welding with better results.
Now, reassemble the engine, turn up the rear hub axle and spacers and fit the engine into a rolling chassis so I see how all the alignments are going.
Pics of a rolling chassis next time?
Is it hard to embalm your wife in gold? Any issues?
Bike looks great
Really nice job!
Following closely. Keep up the good work.
Ditto. Planning a similar (though less ambitious) project along these lines.