I recently contacted a well known titanium frame building company, Airborne. I asked them if they had any intentions of building a unicycle frame in the new future out of titanium. Apparently the guy I spoke with on the phone (Jeremy) has had a few calls about titanium unicycle frames. He said they didn’t have anything planned since the demand isn’t that great, and they really didn’t have a design on a frame. I asked him if I sent him some CAD drawings digitally if they’d be interested in checking things out. This is where things get interesting…
The guy asks me to hold for a second, about 2-3 minutes later he comes back. He said he talked with the main guy there and was extremely interested in building something of that sort. We talked briefly about mountain unicycling and what the requirements were on a frame.
Basically I need to get some CAD drawings drawn up of a good frame, but have no experience with CAD. I was wondering if anyone could help me out with this? What’s a good program to use, and some good tutorials on how to use it?
If anyone has anyone pre-existing drawings made that I could send them to give them a general idea of what we’re working with that’d be great to. I told them I’d get them something by Monday, and they’d get me some pricing on what it’d cost to get them made. If anyone wants to go in on this and get a batch made I’m sure they’ll cut the cost a bit.
the hardest part of TI is the drop-outs.all the ones i,ve seen end up using the miyata lolly-pops,which are way low tech on a TI frame.
if they could make TI bearing caps that would be a nice change.
I think it is probably good to use Ti bearing blocks to avoid the whole galvanic corrosion thing. I don’t know if titanium is hard enough for that use though. As for cad drawings, it is relatively easy to sort of rough out a unicycle drawing, but it is the details that make a useful technical drawing. The details are the precise measurements that you want to use everywhere, the ID and OD of the tubing are also part of this, and they depend on what is readily available at the company and what they would find convenient to use. You will need that from them. Also, manufacturability is a major issue. I’m guessing you don’t yet know what machines and capabilities they have at that facility. Some shapes can be difficult and or timeconsuming to produce.
As for software, solid werks, pro E, and Ideas, are all good programs, but not easy to learn. Autocad, is quite easy to learn, but tends to be prone to artifacts when doing complicated or 3-d drawing. It is what I would recommend interms of ease of use. I’m sure the others will jump on and flame this post that they like something else for drawing. Really, you could even use ms paint, as long as you dimension something well. Working the software and producing informative and complete sets of drawings are two very different things. I wish I had time to help you with this project, but by the time we disscussed all the specs and requirements enough to draw them, you’d be as well off to do it yourself. I don’t mean to make this all sound hard. It isn’t really. I just wanted to make sure you understand what is involved, so that things run smoothly with Airborne. If you have any software questions about autocad or technical drawing, I can definately try to answer those if you want. Your library or a book store should have books that help with any of the drawing software out there. Good luck!
-gauss
CAD
Doug posted a link to a great FREE CAD program here:
If you follow the tutorials you’ll quickly learn to use what might other wise would be an overwhelming tool.
Thanx Doug!
Christopher
Cad Help
AccordNSX, I read your post over at Airborne and got excited. I am a CAD engineer proficient in AutoCAD, IMSI, and Solid Modeler.
Consider me a volunteer for the project. If you scratch something out on paper I will turn them into CAD drawings. Count me in on the batch purchase as well.
I can be reached at scarmichael@decaturelectronics.com
Re: CAD uni drawings?
Hey, count me in on these drawings also! I’ll help however you want.
I use SolidWorks, but there is probably a way to translate between
everyone’s drawing packages. Anyone want to try a NetMeeting session to
start the drawings?
Initial drawings and models can be submitted to the TI guys without complete
details such as tubing wall thickness. We can submit tire clearance,
bearing diameter, seat tube ID, heights, etc. They can redline the drawings
with their dimensions and send them back.
Doug
“firstrax” <firstrax.4trby@timelimit.unicyclist.com> wrote in message
news:firstrax.4trby@timelimit.unicyclist.com…
>
> AccordNSX, I read your post over at Airborne and got excited. I am a CAD
> engineer proficient in AutoCAD, IMSI, and Solid Modeler.
> Consider me a volunteer for the project. If you scratch something out on
> paper I will turn them into CAD drawings.
I’m definately excited to get this project on the roll. I’m hoping that out of this can come a Ti frame that can accomodate a 3" tire, and have a flat crown for some off road gliding and one footed skills. If anyone wants to post what they think would be good for a frame then definately light this post up. Obviously the seatpost diameter is going to be one thing we’re going to have to take into consideration as far as size goes, and how the bearings will be attached.
Re: CAD uni drawings?
> I’m definately excited to get this project on the roll. I’m hoping that
> out of this can come a Ti frame that can accomodate a 3" tire, and have
> a flat crown for some off road gliding and one footed skills. If anyone
> wants to post what they think would be good for a frame then definately
> light this post up. Obviously the seatpost diameter is going to be one
> thing we’re going to have to take into consideration as far as size
> goes, and how the bearings will be attached.
>
>
> –
> AccordNSX - Skill Level 3/4
It sounds like some inspiration could be drawn from the KH24 frame. The
design looks relatively simple to manufacture which, by the sounds of
things, would be a big plus for working with titanium. It also takes a 3"
wide tyre, has a flat crown, twin bolt Magura brake mounts (so no need for a
brake booster), fits a Profile hub and takes a sensible seat post size
(27.2mm).
The KH frames are great but they are reasonably heavy. I say “reasonable
heavy” as I’m drawing a (bad) comparison between it and the Wilder sat
behind me which is a different style of frame but almost half the weight - a
560g difference or there abouts. I guess that gram counting on the frame
side of things is only a small consideration when the wheelset components
are where the real savings are to be made.
About the only measurement I can give is one that pertains to the fitting of
a Profile hub and it’s bearings. The Wilder inner bearing race measurement
(which has to be 3.78" +/- .030") is basically the inner distance between
the 2 bearings when placed on the axle. The effect of this is to bring the
forks in to proper alignment to ensure the bearings contact the bearing
holders correctly. Oh yeah - the bearing holders should likely take 40mm OD
bearings.
I reckon getting an estimate of just how much a finished frame would weigh
(as well as a ball park end cost) would help people decide whether they want
one or not. The more people interested will affect the final price so it’s a
bit of a catch 22. That said, I have a definite niggling feeling that I need
and want a KH24 (for all the reasons at the start of my post) but would hand
over the extra bucks for a similar frame that was way lighter. So… um…
yeah - I’m real interested but that’s dependant on the frame spec and the
weight saving to cost ratio.
This sounds like a very exciting project indeed!
Cheers,
Neil
P.S. A ti version of the heavy Wilder rail bracket would be real cool too.
P.P.S. Gram counting can seriously damage your health… and your bank
balance 
Hey,
It sounds like you already have a volunteer for this. If for some reason that doesnt work out, I can do the modeling in Pro/Engineer.
If someone out there wants to take apart their 24"x3" muni frame and measure absolutely everything, that’d be great. If that somebody had a scanner, they could just sketch out the frame and dimensions on paper.
If Airborne is serious about this, I think they could get these manufactured fairly reasonably. You might want to call Unicycle Source and get an idea what they would be interested in, and then pass that information along to Airborne.
You can probably count me in for a prototype. Drop me a line if you need me to do your modeling:
gbarnes@iastate.edu
I’m really excited to get this thing on the road. If we all pitch in then we can get this done in a timely manner and all benefit from being those super cool kids on titanium unicycles. It’s been a long day at work and I’m a bit delirious. I’m hoping I can post something intelligent come tommorow.
What about using Reader’s cut sheet with ovalized tubes? Are they willing to make more than a trophie piece and crank out a few?
Christopher
First we need to get them some CAD drawings so they can get an idea of what they’re working with. From there, changes can be made where needed, and a general price per piece can be made. I think we all have this mental picture of what the frame is going to look like, things like tubing and what not are the main thing that needs to be handled right now.
Re: CAD uni drawings?
Wow this sounds fun!
My other job is design so would be very willing to help. I also have the
specs for the bearing holders etc. From my experience for something like
this it is best to work in 2D on something like AutoCAD or DXF’s as it works
cross platforms.
Can I suggest that you first decide what you are wanting use the frame for.
i.e. trails, gliding, Muni, big drop offs etc. then design a frame that
will take it. There will be a lot of factors which will be same but some
will not. Crown on a cross country Muni does not need a wide aggressive
crown that catches your knees, but if you want to glide on it then that is
what you want. If you want it for a Muddy environment then you want
mud/stone clearance, you don’t want it for trails or gliding.
Roger
The UK’s Unicycle Source
----- Original Message -----
From: “AccordNSX” <AccordNSX.4wyly@timelimit.unicyclist.com>
Newsgroups: rec.sport.unicycling
To: <rsu@unicycling.org>
Sent: Sunday, May 19, 2002 7:46 PM
Subject: Re: CAD uni drawings?
>
> First we need to get them some CAD drawings so they can get an idea of
> what they’re working with. From there, changes can be made where needed,
> and a general price per piece can be made. I think we all have this
> mental picture of what the frame is going to look like, things like
> tubing and what not are the main thing that needs to be handled right
> now.
>
>
> –
> AccordNSX - Skill Level 3/4
> ------------------------------------------------------------------------
> AccordNSX’s Profile: http://www.unicyclist.com/profile/541
> View this thread: http://www.unicyclist.com/thread/18185
>
>
> rec.sport.unicycling mailing list -
www.unicycling.org/mailman/listinfo/rsu
>
>
Obviously a frame needs to be built that is going to appeal to a lot of people on the board. For the people who are interested in helping out with this project and a possible purchase of a frame in the near future, what would you want your frame for? I’m looking for a well-rounded frame. Something with a little bit of mud clearance, but that not being a big neccesity. Basically I’m looking for a frame to be designed that can take decent size drop offs, 3-4 feet. I’d like a flat or semi-sloped crown on it so the frame can be used for some trial/freestyle stuff when playing around on it.
Sounds like a good idea - finding out what folks want that is. Here’s what I’d personally like to see in the new frame:
- I'd like one for muni so that means enough clearance for stones / mud and a 24x3" Gazz. It'll see some trials riding as well but if it can survive muni then that shouldn't be a problem.
- Twin bolt Magura brake mounts for sure. Perhaps with cable fixtures up the back of the seat post tube? That may be a bit fiddly to manufacture though.
- Fits a Profile hub.
- I'm not hugely fussed about a flat crown and would take one with (preferred) or without. An angled crown like you mention might be a compromise in this area but it'd need some kind of grip on it to keep gliders happy.
- A 27.2mm ID for the seat post tube.
- Definitely made to take drops in the 3-4' regions and beyond. I don't imagine that'll be a problem though.
I’m definitely looking for a frame with the twin bolt mounts so I guess that’d be a deciding factor for me as to going for this one or a KH… I’d really like a Ti one though!
Cheers,
Neil
I would be interested in getting a titanium 20" Trials frame, if that size is made. I’m currently
riding a KH 24 frame on my MUni, so I’m not so interested in a MUni frame at the moment.
I’m about to get a Monty trials wheelset w/ Profile hub (it should be at my house when I get
home). I’ve got a Nimbus II frame I’m going to use with it, but it seems a little heavy, and if
the Ti frames are lighter and not to expensive, I would definitely consider one.
Here’s what I would want in a frame:
Flat crown, with good grip for gliding.
Not very heavy.
Seat tube that fits a bike seat post with rails. (27.2 is pretty standard size, which would be
good, but other sizes work also.)
Fits a Profile hub.
Plenty of tire clearance on the sides, but as little as possible on the top.
ummmm, that’s all I can think of for now.
I wouldn’t worry to much about frame strength in terms of drops. The frame doesn’t take much stress, besides being dropped on rocks and stuff.
Ben
Re: CAD uni drawings?
Ok now we are moving, next question. What type of work can the company do?
do they fabricate, machine, bend? If you use techniques that they have in
house the frame will be cheaper and probably better.
Roger
The UK’s Unicycle Source
----- Original Message -----
From: “Ben Plotkin-Swing” <Ben.Plotkin-Swing.4yl6b@timelimit.unicyclist.com>
Newsgroups: rec.sport.unicycling
To: <rsu@unicycling.org>
Sent: Monday, May 20, 2002 4:52 PM
Subject: Re: CAD uni drawings?
>
> I would be interested in getting a titanium 20" Trials frame, if that
> size is made. I’m currently
> riding a KH 24 frame on my MUni, so I’m not so interested in a MUni
> frame at the moment.
>
> I’m about to get a Monty trials wheelset w/ Profile hub (it should be at
> my house when I get
> home). I’ve got a Nimbus II frame I’m going to use with it, but it seems
> a little heavy, and if
> the Ti frames are lighter and not to expensive, I would definitely
> consider one.
>
> Here’s what I would want in a frame:
>
> Flat crown, with good grip for gliding.
>
> Not very heavy.
>
> Seat tube that fits a bike seat post with rails. (27.2 is pretty
> standard size, which would be
> good, but other sizes work also.)
>
> Fits a Profile hub.
>
> Plenty of tire clearance on the sides, but as little as possible on the
> top.
>
> ummmm, that’s all I can think of for now.
>
> I wouldn’t worry to much about frame strength in terms of drops. The
> frame doesn’t take much stress, besides being dropped on rocks and
> stuff.
>
> Ben
>
>
> –
> Ben Plotkin-Swing
> ------------------------------------------------------------------------
> Ben Plotkin-Swing’s Profile: http://www.unicyclist.com/profile/378
> View this thread: http://www.unicyclist.com/thread/18185
>
>
> rec.sport.unicycling mailing list -
www.unicycling.org/mailman/listinfo/rsu
>
>
You guys are moving fast on this. Maybe Accord should copy the forum and e-mail corespondence to Airborne to show that there is more than just a passing interest in it.
There site is here.
If you check out some of their frames and bikes, you can clearly see that they do some pretty impressive stuff. I don’t see any of our requirements being much of a problem for them. Their frames are made in China by a commercial division of China’s aerospace and satellite manufacturing organization. <— sounds cool to me.
Woohoo! Boy their frames are purdy…nice ‘n’ shiny too 
You’re right there - It doesn’t look like they’d have any problems with any kind of design we come up with: bendy bits, straight bits, flat bits etc. Excuse my technical terms but my head is in the clouds after checking out their site 