Noob: Bicycle spoke drawing or mating 2

[steinmini]

I searched everywhere, asked, but so far there is no correct answer to this question.

I have designed a specific one-side mount front hub for a recumbent tricycle (that is what I do for living - designing & building HumanPowered trikes) and as it appears, there is absolutely no way to get a spoke into proper position except by moving it, rotating it and getting it into desired position with free "move/rotate part" command. There is a whole list of problems during the process and so far, the least painful was to connect (coincident mate) the threaded end of the spoke with the spoke hole on the rim and jerk and joke it around until I managed to fit the bent end to the hole on the hub. Once I did manage it, created a circular pattern for the next 8 spokes and struggled with the next one, attached the next 8 spokes the other way on the same flange, and once I finished, did a mirror to the other flange (opposite hub side), moved it by the required offset angle (in this case 11.25 degrees) and saved the assembly file. Next time I opened the file, to continue the assembly process (to fit the axle, disc brake rotor etc), SW2010 informed me that there are rebuild errors, said ok, and the spokes were all over the place. Nothing I tried did any good. Back to beginning. So, I thought there might be someone who knows something I'm obviously missing here.

On the hub flange, the spoke holes are not allowing concentric mates which would make my life much easier and the same on the rim...

Since I'm new, I'll skip attaching the files, but will be glad if anyone wants to look into it.

Thanks in advance,

Robert Stein

 

[CorBlimeyLimey]

Zipping and attaching the files will be the simplest and quickest way to review what you have, and offer suggestions.

 

[steinmini]

Ok, here it is. However, there is no spoke inside it. Sending anything would be useless. The spoke body is 2mm, length for this rim/hub around 155m. The end result is to find out is there a way to solve the issue... Ignore the rebuild error on the disc brake text (suppressing it helps)

One of the problems I'm completely aware of is the fact that in real world conditions the spokes don't act as rigid bodies even though are solid.

Anyway, I'll see what someone else may be able to suggest.

Of course, anyone downloading and opening the files may freely modify them for non-commercial purposes

 

[FreddyB]

There are of course many ways of doing this but I can only suggest what I would do.

If I understand right, you are having problems locating a spoke such that it is mated properly in the hub end and rim end. Because you are not locating properly, when you open the file it has gone haywire.

I would add some reference geometry and use that for the necessary mates. For example, I would add a point (Insert/ reference geometry/ point) on the spoke axis (mate it to the axis) and then dimension it at a point along the spoke so that it is pretty near to where the spoke will pass through the rim. You should then be able to mate the point to the hole as a concentric mate.

You could probably do something similar at the hooked end. On some more abstract component profiles I sometimes find it necessary to cheat a little and add a flat feature to a component simply so I have a flat surface or an edge to mate with. The feature can be a minute cut extrude either on the surface of else buried in the part.

Does that help??

 

[CorBlimeyLimey]

See if this helps. The spokes are probably in the wrong holes but should show the concept.

 

[steinmini]

Sure it helps (every little does )

So, I can say thanks for the help!

OTOH, you're right, you laced the wheel in the opposite direction (the LH flange should be connected to the LH side of the rim, but I was not asking anyone to do it for me, I was asking for help to understand what I have to do to make it work at least easier if not perfect

I will not do stress-force-pressure test on the wheels but need to understand how to get the job done. I know more about wheels than about using all the possibilities that SW offers, and this is just a tiny step in the learning process.

If it was this single wheel, I wouldn't even bother to nag anyone, however, the range of rim sizes used for recumbents spreads from tiny 16x1.75 (305mm bead) through 349, 355, 406 up to standard MTB size 559 (26") ... There will be different widths, rim profiles, sectioned, double wall rims... And understanding the way it can be done is crucial.

The rest of the design should involve more math in moving parts, kingpin inclinations, caster, camber... Mainly automotive issues, but with a lot of downloadable libraries and available models/3D parts it shouldn't make much problems. So far, the conflict between the way SW treats the spoke and the way a wheel spoke acts in reality resulted with my need to ask for help.

As I believe there might be others who might have the same sort of problem, I will upload the final result to share the knowledge

Thanks one more time!

Robert Stein