the ball screw doesn’t look that small, only a few mm smaller diameter than a similar length screws from a real vertical. The 8k spindle at only like 2hp kind of is lame but most of the stuff I would do I’d rather have the rpm than the torque, especially with the less rigid machine. No rigid tapping kind of sucks, but if I know where the spindle position is written I can just write the macro to do it.
The garage frame building journey
- Thread starter sikocycles
- Start date
Damn. Heat treating aluminum at home is next level. Will a front triangle fit in that?
Awesome @lobsterCT !
Oh I think you can do it! Just get some tubes of dp420 and you’re off, right?
I thought they had to use printing to get the complexity of the double lap (or whatever they're called) joints?
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Although not simple, that could be machined from aluminium. I thought the 3-D printing was about being able to easily create custom geometry. Cut tubes, print lugs, glue up.
But it all seems kind of gimmicky to me considering the end results. A friend of mine has the AM150 and the frame probably weighs close to 10lbs. You can do that a lot cheaper with a custom steel bike and they just offer a lot of different sizes, nothing really custom.
If dp420 is one of the scotch weld variants, then no.
the scotch welds have the best shear strength of epoxies I looked at, but all of them have very low peal strength. For a design like atherton with the "double lap" or whatever they call it, scotch weld would be the ticket, but my lugs will be simpler, and need peal strength in the epoxy.
I went with one made by an American company called Lord Adhesives.
Nice work! So you also put a longer stroke shock in it? Why did you get away from the upper/back shock bolt hole? Looks like you used it and this should be the most progressive one, or?
@lobsterCT Sounds good!
@iRider I ended up there on the highest and most rearward hole but in those photos I hadn’t gotten around clearance issues, yet. I was working through it and that wasn’t the end goal. I’m trying to lower the leverage ratio and increase the progression. With max progression I had a too high leverage ratio making a 650lbs spring feel too soft. I changed some pivot points and managed to come down to a 600 without bottoming and the compression and rebound adjusters are now in a useable range.
I took the body off of a 267 and mated it to a 240 to make a 255x75 with an extender to get the progression and lower the leverage ratio. I’m very happy with the results. Working compression and rebound is much nicer! Here are some pics.
@iRider I ended up there on the highest and most rearward hole but in those photos I hadn’t gotten around clearance issues, yet. I was working through it and that wasn’t the end goal. I’m trying to lower the leverage ratio and increase the progression. With max progression I had a too high leverage ratio making a 650lbs spring feel too soft. I changed some pivot points and managed to come down to a 600 without bottoming and the compression and rebound adjusters are now in a useable range.
I took the body off of a 267 and mated it to a 240 to make a 255x75 with an extender to get the progression and lower the leverage ratio. I’m very happy with the results. Working compression and rebound is much nicer! Here are some pics.
Soon I might have a little project to add to this amazing thread. I dreamed of building a dirt jumping frame about twelve years ago, and that little dream brought to my life one of my best friends, the one who has the bike shop.
Today we started cutting the dropouts, and I can't contain the excitement I feel.
Today we started cutting the dropouts, and I can't contain the excitement I feel.
Thanks guys! I have been scavenging parts for this little project for over a month now. The idea is to use as many standards from the BMX world as possible, so another friend is machining the headtube for an integrated headset and the BB shell to accept a BMX Mid BB. It's going to have BMX hubs too, although with 26" wheels.
We are making v0.1 out of straight gauge 1.2mm 1045 tubes as 4130 is really expensive down here, but once we have the building details sorted out I'll surely be on the hunt for a set of 0.9 chromoly tubes, butted if possible.
We are making v0.1 out of straight gauge 1.2mm 1045 tubes as 4130 is really expensive down here, but once we have the building details sorted out I'll surely be on the hunt for a set of 0.9 chromoly tubes, butted if possible.
Solid sells alot of BMX frame building parts if you get stuck making them. https://solidbikes.bigcartel.com/
Probably
Also, here is one the frames my friend did before attacking our old project:
It has a pretty wild geometry, 69° HA, 76° SA, long reach, short stays, PF92 BB and sliding dropouts.
You could harvest the headtube and bb out of an old bmx frame too? I can send you tubes if you’d like. I have extras at home. They all fit inside each other (31.8,35&38) so the package would be a single tube. Let me know if that’d be helpful.
This dood is making loads of cool shit. We have lots of friends in common and ride in the same places but haven’t met in person yet. Check out his latest mutant.
He calls it the Ghettoblaster
Nice!
He calls it the Ghettoblaster
Nice!
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I managed to regrind my seatpost reamer on a belt grinder with a 3m Trizact belt and an angle table. It worked great.
Now that I had a working seat tube reamer I made some progress on a seat tube assembly.
Some pics from yesterday.
I’m out of gas so that’s it for now.
Now that I had a working seat tube reamer I made some progress on a seat tube assembly.
Some pics from yesterday.
I’m out of gas so that’s it for now.
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Fuuuck I can't upvote this more! Your progression is amazing!!!
How do you measure to make sure the jig is in the right configuration?
Front end mitered. Now clean and tack.
I go it by Headtube bottom. I know the distance from center of BB to top of the jig. Add the amount for the piece that holds the tool and then that minus what bike cas give me and set the Headtube bottom. I use the TT length for the distance
I go it by Headtube bottom. I know the distance from center of BB to top of the jig. Add the amount for the piece that holds the tool and then that minus what bike cas give me and set the Headtube bottom. I use the TT length for the distance
This is sick, Sicko! Nice work. Im looking forward to seeing the x-tube go in.
Yeah me too. That will be the hard part.
measure a thousand times. Miter once
measure a thousand times. Miter once
Are you going to use a smaller diameter tube and go through for a one piece pierced design or two tubes looking like one continuous tube? Gonna be sweet!
Tigs are looking tight!
Yes it is a 19mm or 16mm tube. Still deciding on size. Asfor pierced I am still deciding. Not sure my trigonometry is up to it but will decide soon.