4 – Wheel Bicycle for Playa

[Elliot]

BAS:
I must confess I don't know much about Atomic Zombie. Somebody gave me their "Bicycle Builder's Bonanza" book, and I was impressed enough that I wanted to make my adapters available to any of those guys who might want them. In other words, they seemed like "my kind of people", but I have enough projects and hobbies already, thank you very much.
A flexing frame could indeed serve as suspension -- ask any heavy-haul trucker.

I have noticed quite a bit of talk about disk brakes on the A.Z. forum. In fact, a couple of those gents have asked me about adding a disk brake flange to my adapter. I may or may not be able to get that made in the future. But I believe some of those guys are also on that trail.

All my own pedal vehicles have "stage coach brakes" -- basically a stick that rubs on the tire. Simple and effective.

The Ackerman Principle should not scare you. Stop by any hardware store or such, and look at the front of a lawn tractor. Notice the steering arms -- the lever that is welded to the spindle. Notice that the steering arms are not parallell to the vehicle centerline, but are angled a little bit. With your eyes, continue the lines of the steering arms to the rear of the tractor. You will find that those lines meet in the middle of the rear axle. That's all there is to it. It does not even matter if the steering arms are behind the front axle, or in front of it. The line goes thru the spindle and thru the link-end, extended to the middle of the rear axle.

Fishy:
P.M. me if you are interested in a hand cycle. A friend of mine builds them.

[BAS]

Elliot-- Well, I got a little confused by some of what was being discussed with regard to disk brakes-- probably from coming in late on the conversations. Actually, there seems to be some talk about how the Street Fox and the Street Fighter for the most part share the same front end, so that is probably what I should be looking at.

I thought with the Ackerman Principle there was some sort of calculation involved for what sort of angle...?

IIRC the Street Fighter's frame is designed to flex something like an inch or so to keep the wheels connected with the ground.

So, you have "enough projects"-- would that mean that asking you to build the vehicle for me is out of the question?

Anyway, I think I am more likely to actually build something (especially something that works) if I am following (mostly) someone else's plans... at least for the first few projects. (And I still need tools and a work space... ) I'm debating whether to try the Street Fighter or Street Fox first.

Well, work really wore me out today (lots of calls for us custodial folks to take care of... whew!)

[gyre]

It's spelled 'disc', unless you're living in the 17th century or count the slang use for hard drives.


Ideal steering geometry is still being debated.

I drove a car once with such peculiar settings that it would not track in a straight line, except under full throttle.
It would try to pitch into the ditch at steady speeds.
Under hard throttle, braking or cornering it was remarkably easy to drive.

[Elliot]

BAS:
I don't doubt that it is possible to calculate one's way to suitable Ackerman, and General Motors probably needs to do that. We don't. Just look down on the king pin and the tie rod end, and extend that line to the center of the rear axle.

Correct... I will not be building your machine for you.


Gyre:
Thanks! I can never keep disc and disk straight. Now I wrote it on a post-it and stuck it on the monitor.

That car sounds like a race car all right! I can probably understand most aspects of steering geometry if I sit down and study it again, but it’s been 30 years since I learned it, so it would take me all day now. And there are many forms of racing, and countless thousands of individual race cars.
But full power and hard braking means suspension travel at the extremes, and the steering linkage can be arranged so you get toe-in at the extremes when directional stability is needed most. Then, in the middle of the suspension travel, the toe will be slightly out, which helps with turn-in.
Old Mr. Ackerman is very much part of a race car’s turn-in. Remember that the tires must be toed out in the turn. And for straightway stability, they must be toed in. The transition from toe-in to toe-out must necessarily cause a jolt in the system -- from everything being in tension to everything being in compression (or vice versa). That sudden transition is trivial in a grocery-getter, but is undesirable in a race car where the tires are already at the limit of traction, and any kind of upset in the forces will slow the car down.
The camber angle is also part of the suspension travel equation. The common system of short upper suspension links and long lower ones... is specifically intended to change camber to maximum negative (contact patches as far apart as possible) for stability under extreme conditions. And the camber of a tire affects which way it wants to go, so camber set for going fast around corners can also make a car squirrelly on the straights.
Keeping a squirrelly car going smoothly straight... is one of the key skills of a racing driver.

Right, there is probably no such thing as ideal steering geometry. Mass-produced cars are full of compromises for various reasons of cost-cutting, manufacturing, tire wear etc. My Dodge Dakota violates most of the basic “rulesâ€

[gyre]

There are a couple of books on suspension design that come with software for setup.
One of my cars was done with one of these.
They are available from sae.org and maybe Bentley.
You could always use adjustable pieces and play around or just ask Elliot to get settings close enough for a bike.

[BAS]

The design(s) I bought from Atomic Zombie have a template for the connection I plan on using, and I haven't seen any complaints about it on their forums, since I don't plan on changing the design (much).

Well, heck, the weather has turned foul, and probably won't improve significantly for the next few months, so I am not going to start building any time soon, unless I find somewhere indoors to work.

Ugh. My car decided it didn't need its exhaust system any more and dropped the entire tailpipe and muffler in a grocery store parking lot (so now its lying on the backseat...). The manifold and a short piece of pipe are dragging on the ground, which makes backing up difficult. I am back to taking my bicycle to work until I can get it worked on-- Friday at the earliest. (I can't really fit under the car-- the last time I was that small was when I was twelve or younger, the Saturn is that low to the ground. Even if I could, I couldn't feel anywhere to tie the manifold to under there-- which might be why that was a weak spot in the first place.) I don't yet know how this will effect my funds for my project-- which is supposed to be a substitute for the car in the first place!

I suppose that last bit really belonged under the FUCK! thread, but I am a little short on time and it kind of fit under this thread, too.

[gyre]

Some of us might be able to guide you through a temporary repair.
You can use your jack to raise it, but you must block it with something stable and/or have something under it to protect you if it falls, such as wheel rims.

Is anything left of your exhaust?

[Captain Goddammit]

You can also just drive a wheel or two up onto a curb to get some safe working room.
For a cheap do-it-yourself patch job that doesn't require anything more than a hacksaw and wrenches, you can go to any car parts store and get little metal sleeves that fit over your pipes, and clamps to go over them to hold 'em on. You can also get short lengths of pipe to clamp in to replace a section that is gone or unuseable, and you can get those with pre-flared ends that slip over your pipes to make them easy to install. They've also got "flex-pipe" sections of easily bendable patch pipe you can stick in there.

None of this is "pro quality" but it's cheap and will get you on the road and you can do it yourself even if you're not a mechanic.

[gyre]

I've repaired with devcon epoxy steel.
It can be cheaper to go to a reasonable muffler shop if you can find one.
Depends on what needs to be done.

I think I have a saturn system around here less cat if it's worth shipping to you.

Worn out motor mounts are a common cause of stress failure of exhaust systems, esp with fwd.

[BAS]

I think I'll probably just take it to a muffler place. The predicted weather for the rest of the week doesn't look so good.

I didn't really look too closely at the tailpipe, so I am not certain what sort of condition it is in. (It was dark and the temperature had started to drop-- and I was more interested in seeing if I could secure the manifold so I could drive home. [I got a nasty cut on my right hand middle finger for the effort.])

Thanks for the info-- I was wondering if there was a way I could fix it on my own before I saw the weather forecast.

In theory, the engine mounts shouldn't be worn out. The car had a rebuilt engine put into it while my brother still owned it four or five years ago, and I would think Saturn would have examined the mounts...? (Of course, I may be placing too much faith in them.)

[BAS]

Well, I still haven't got my car fixed, so I have been biking it for all work days save for two. Those two days the temp.s were lower than I wanted to bike in (and one of them I wasn't feeling too good, anyway.)

However, I just found out that the third shift supervisor has a welder, and, since he mentioned it to me, I am hopeful that means he will let me use it! (Even if only so I can prove to him I really will build myself a quadcycle.) It sounds like he has other metal working tools, so maybe I will build the body out of metal, once I figure out some "minor" details (namely, the whole body...!) I'm going to bring the plans I downloaded to work tomorrow and show them to him.

So, maybe I will get my velomobile this season, after all!

[BAS]

Well, all signs are that I am getting a welder for Christmas, since my dad had to ask me questions about welders, and whether or not I really needed an auto-tinting helmet. (My Dad said that they take five minutes to darken/adjust-- that doesn't sound at all right to me...?)

Today I went to the university's surplus store and bought 5 junked bicycles at $5 each-- and got a friend help me get them back to my apartment. I am planing on using my dad's workshop to do the building.

I still need a lot of parts, and to decide how I want to build the shell. Oh, and since one of the bikes I got has a rear suspension, I think I will build the StreetFox as well as the StreetFighter, and probably enclose both of them.

[gyre]

A friend of mine hates them.
Of course he also hates to wear fire protection when welding and occasionally does the spark dance.

I gather the helmets vary in efficacy and visor size.
I think you get what you pay for, sort of.
I love the idea of them myself, but a bad one is probably worse than one that has a fixed tint.
Seems I was told you need a different tint for different jobs, so different lenses maybe.

[BAS]

I plan on not having any bare skin when I weld-- bare skin tempts skin cancer, from what I understand.

The auto-tinting is supposed to eliminate the need for different lenses, I think. I told my dad to shop around..., maybe I should tell him not to worry about the helmet and I will look for it myself...? (Of course, my parents are leaving any day now for Hawaii-- taking advantage of the low air fares, so I am probably too late.)

[Elliot]

I have a Miller auto darkening helmet and I don't know how I ever welded without it. It is adjustable for darkness and two or three other adjustments -- read the booklet until you understand it. Granted this one cost over 300, but wow... it's the way to go in my book.

Five minutes? He's thinking about eye glasses that darken when you walk from the house out into the sun. Welding helmets flip from clear to dark in a fraction of a second.

[gyre]

You might want to at least do the research for him.
There seem to be a wide range in size, speed, durability (a big issue).
Some seem quite expensive.
I've seen one recommended on forums, but I don't remember the brand.
Might have been the Miller.

[BAS]

I suspect he must have been thinking about the eyeglasses, too. I am guessing that the helmets use liquid crystals or something similar.

Well, if he is getting one for me, he has probably already bought it at this stage. I believe he and my mom are supposed to leave Sunday (or Monday?), and will be getting back right before Christmas.

Thanks.

[Toolmaker]

Well, all signs are that I am getting a welder for Christmas, since my dad had to ask me questions about welders, and whether or not I really needed an auto-tinting helmet. (My Dad said that they take five minutes to darken/adjust-- that doesn't sound at all right to me...?)

Auto darkening helmets are damn near instantaneous.
(1/12000 second to 1/20000 second give or take depending on quality)

This also allows for better welds start since you don't have to worry about moving off of the optimal mark and angle when you jerk your head down to close your old school headgear.

The more expensive helmets tend to be better for the larger views and the ability to go dark with low amp tig etc. Miller and Speedglas are the best but very expensive.

Try to get Miller gear if you can, you'll be much happier in the long run. As far as helmets go try to get one with a big view whether its auto or fixed shade.

Be sure to share your exp. in the Welding thread too!

[BAS]

Yeah, Toolmaker, what you say is what other people have told me. Unfortunately, my Dad didn't ask me until shortly before he and my mom left for a trip to Hawaii (they are taking advantage of the low air fares), and I didn't post right away... so I'll just have to see what I get. If I don't like it, I suppose I can always cut some corners elsewhere and scrap together the money for a better one. (I did send him back an email right away telling him that the helmet shouldn't take that long to darken and about the advantage of auto-darkening helmets.)

Well, since I have never welded before, I am almost certain to show up on that thread, with questions and/or stories.

Gotta go-- got a call on the radio!

[Captain Goddammit]

Auto-dark helmets are the shit, specifically because you don't lose your place in between when you flip the lens down and start welding.
For me that was the single hardest problem to overcome when learning to weld.
I think even the cheap ones are better that old-school manual ones.

[BAS]

That's what everyone has been saying! One way or another, I am going to get an auto-darkening helmet.

[Captain Goddammit]

Harbor Freight Tools usually has them starting around $60. And they work.

[unjonharley]

Harbor Freight Tools usually has them starting around $60. And they work.

This is from one that must wear a helmet. Or is not allowed out of the home.

[BAS]

Yah! Farm & Fleet screwed up and only charged me a little over a hundred dollars to put an exhaust system into my car!

Boo! We got hit by a blizzard and so I am going to have to wait until Sunday to get my welding stuff.... (oh, well. It isn't like I would get to use it right away or anything... )

I still need to get to St. Vincent dePaul and a few other places to find raw material. The idea is to get this done as cheap as possible.

[gyre]

I'm glad it's working again.

[BAS]

I wouldn't mind taking a look at the repair job, but the weather is still too nasty. (I was supposed to go down to my brother's house for Christmas Eve, but the snow was heavy enough in the morning so we canceled the trip.) My brother's house has a garage (about one-and-a-half car sized), so I might have been able to peek underneath.

[evernew]

Because I (a) have a sort-of similar question but the only thread treating it was from 2004 and (b) am a newb and do not dare post a new thread yet, I'll use this vehicle here to ask:

I read (in that thread from 2004) that the playa is pretty skate-able on a longboard. The description of the ground sounds like the dust would kill the bearings in a flash, though, and the wheels wouldn't turn that greatly on it.

So my idea was to make a mountain board. A longboard with rubber tires instead of polyurethane wheels. Would that work? What is the ground really like?

[BetaBox]

imagine trying to push through a couple inches of baby powder or flour. There are hard spots, but if it is going to be anything like last year.....forget it. Bicycles can have a hard enough time by themselves. I don't want to discourage you, but be prepared for absolute crap conditions, especially at the end of the week.

[Captain Goddammit]

Evernew, the answer is it depends...
Some years, the surface is great, some years it's horrible. It depends mostly on what the weather over the winter is like.
Even when the surface is in decent shape (which is still marginal for a 'board) the streets get rutted and bumpy.

[ripvansparky]

Hi, we have a girl in our camp with a mountain board that she rides quite a bit while being pulled behind our art car.

I have the $60 harbor freight helmet and it works great.