The Contraption 2010

[LeChatNoir]

Doggy, I’m starting to get really excited for this year. We’ve worked hard for two years, six to seven days a week, without a vacation. Looking forward to the day we head out.

The next two big steps are getting the exhaust hooked up and then the lighting. I’ve got a few cool ideas for some other small surprises too, so hopefully there will be enough time. The muffler shop says they might have the pipes done tomorrow. If so, I know what I’ll be dong this weekend.

[bigbluedoggy]

Where will you guys be camping this year? I'm having a different experience this year since we're not doing the lounge. I intend to get out and about and see as much as I can!

[LeChatNoir]

Not completely sure yet, but I'll keep you posted. I bet it'll be nice change to get out and see stuff, rather than have to be the one putting it on.

[LeChatNoir]

Update


I really like to test things out as much as necessary or at least as much as time will allow. I’ve been wanting to see how well the cooling system will work in the high heat of the day and haven’t really been able to give it a good watch yet. Today seemed like the hottest of the year so far for us, and as good a time as any. After letting the engine run at low/mid range for a while, driving both the alternator and the flywheel, the temperature gauge started to climb up.

The cooling system is strictly thermo siphon with a 190 degree thermostat located at the top of the engine block. In the back of my mind I’ve been a little unsure of how well it will move the water around the circuit and if it will do it fast enough. Things looked good in theory, but…

As the temperature climbed up to just above 190 degrees, the thermostat opened and I watched it drop quickly to 180. After letting it run a while longer, it leveled off and hovered just below 190. Granted, this is not under motive load, but I think it performed very well. Nice.

And a package with two Cree headlamps arrived in the mailbox today. Three cheers for Oscillator!

Hip Hip… Rust Bucket!

Hip Hip… Rust Bucket!

Hip Hip… Rust Bucket!

Looks like they’re gong to work perfectly and be easy to work into a cool looking headlight assembly. I can’t wait to play with them after dark and see how well they shine!

[motskyroonmatick]

Right ON!

[bigbluedoggy]

The excitement builds... !!!!

[Elliot]

All right. I just got home from a wondermuss trip in Millicent (The Bus) and I promptly celebrated by having two beers for lunch, so....

I've been designing something the whole way home from Camarrillo. See... I am now the custodian of yet another Kinetic pedal vehicle, and this one is definitely going to Burning Man with me this year. It has a couple of mechanical "issues", which is why the owner let me take it home to see what I might be able to do with it.

Well, it's another four-wheel vehicle with no suspension. Gull dommit, even Henry Ford, the fool, figured out that a four-legged dining table would rock on two legs if the floor was uneven, but a three-legged milking stool always leveled itself.

So I'm considering the standard fix: Turn the #$%^&* thing into a trike.

This chassis happens to have a lot of ground clearance in the middle of the front -- perfect for a single front wheel.

Mounting it is a different matter. I would like to avoid permanent alterations (or butchering) to the professionally fabricated aluminum frame. So I'm thinking "use the existing mounting points".

Now.... Eventually, I'm going to take photos of what I have to work with. But meanwhile, we can simply think back to the "hub-less" motorcycle wheels that some of us posted photos of on this thread (or previous years' editions). The front spindles on this Thing (The Beach Party Buggy, actually) are bolted on. I'm thinking of fabricating a cross-member that bolts to these hard points. Then the cross-member would have a pivot point for the steering in the middle -- a king pin.

The problem, of course, is that with the steering spindle attached on both sides, there is no place for wheel spokes to go. So the wheel bearing(s) need to go around the outside of the steering mechanism. A "Lazy Susan" kind'a bearing, sort'a. In fact, I could probably rig up a rolling prototype with a $5 Lazy Susan bearing or two from the nearest hardware store.

But for a week on the Playa, and a career in Kinetic Sculpture Racing, we need something better.

Naturally ( ) I have it all designed in my mind. A ball bearing, where one of the races is split in half for assembly and servicing. The inner race attaches to the hub, and the outer race attaches to the wheel. Diameter... somewhere around 10 inches. Tons of machine work, then tempering of the races.

Or.... Maybe something exists that can be adapted? On the cheap, I mean?


Edit: Add photo:

[gyre]

Aside from the dirt, the issue is usually speed with those wheels.
May not be an issue in this case.

Call a bearing manufacturer.

They have engineers just for idiots like us.

The issue with steering bearings is low speed and lubrication.
This type of wheel has the opposite issue.

I always liked that wheel design.

[LeChatNoir]

Sounds like you need a gigantic thrust bearing, but I'm not exactly clear on how you're approaching this. Photos could give me a better idea, but I can't guarantee it.

On the contraption front, I got the pieces back from the muffler shop and assembled the header this evening...





There's a long straight pipe that couples with the end of this piece to run up the smokestack.

And now I have a question for you motorheads. I want to incorporate the muffler back into the tailpipe and am thinking that, to be effective, it needs to be closer to the end of the exhaust run than it does the engine, but this is not my field of expertise (if I could be accused of having such a thing). It would be easier to incorporate nearer the engine, but it seems that the long run of pipe afterwards would sort of defeat the purpose and encourage a *frap frap*, robot-burping-down-a-digeridoo sort of sound.

[gyre]

More effective closer to the engine.
Less back pressure near the end.

[LeChatNoir]

Ah... perfect!

I can put it right between the two weld joints visible on the first straight section after the 180 degree bend.

[gyre]

If the muffler isn't adequate, there are other things that can be done.

[Elliot]

I did a bit of experimenting on a hot rod roadster many years ago, and it seemed that a longer tail pipe helped reduce the sound. Even better, in that case, it may be that the longer pipe lowered the pitch of the sound (Johann Sebastian Bach organ technology), which I perceived as cozier.
Now... it is possible that the longer tail pipe simply moved the outlet of the sound further from my ears.

What I'm more sure of, is that the diameter of the pipe affects the tone. Organ technology, again. The surest way to ruin the rumble of a good-old 'Merican V-8 engine is to run very small diameter pipes, like some of the "lowriders" do. Some guys do the same with Harleys.

So I'm thinking you may want to run the largest possible diameter pipe up that stack.

[LeChatNoir]

The straight piece to run up the smokestack is of that same diameter as the header. However...

The original smokestack had a piece of PVC drain pipe in it to keep it rigid. Knowing this would not hold up to the heat of an exhaust pipe, I replaced it with aluminum of the same diameter. Basically it's a double wall pipe, what with the outer thin sheet metal pipe over the inner rigid core. Roughly 3/8" air space between the two.

My original idea was to then run the exhaust pipe up this inner core, creating another airspace to dissipate heat. But now that you mention a bigger pipe, I wonder if it'd stay cool enough by just using the inner aluminum piece as the last section of tailpipe?

Perhaps a test is in order.

[LeChatNoir]

After getting down and looking at it, I decided to change where the muffler goes, so it would tuck underneath everything a bit better.



Pics of it off and on the machine:












Now I've got to come up with some sort of crafty, neato looking heat shield for that pipe.

P.S. I stuck the long straight piece on to see how it sounded and it was surprisingly quiet. No *Poing Poing* sounds. I should have a test run with just the header feeding into the larger aluminium pipe/smokestack soon, perhaps by the end of the day.

[Token]

You can use the heat shield as a second can. Look at motorcycle mufflers. They run a perforated pipe the same diameter as the headder through the can and pack the space with fiberglass. The fiberglass is the dense kind like the stuff you pack a portable propane forge with.

This type of muffler reduces the noise a bit but mostly just clips the pops and putts down to a mellower tone.

[LeChatNoir]

Ah... forge lining. Interesting. I've got lots of kaowool ceramic blanket in the back of the shop. So I could perforate the existing pipe, say... on the first straight section, then wrap that with another larger pipe. Seal the ends off, of course, and pack the in between with the kaowool?

Hmmm....

[gyre]

See if it's needed first.

[Token]

Gyre is wise.

If the blanket is solid woven type, you need to shred it. Just put some catnip juice in it and let the cat at it.

[unjonharley]

releaving the pipe before the muffler may defeat the muffler. you need enough presure to push through the muffler

[LeChatNoir]

So I got it hook up and tested it two ways. First with just the pipe feeding into the 3 inch diameter aluminum and it made a very deep *Thump Thump* that was actually so pronounced that it was a bit much pressure on the ears. So then tried again with the tailpipe run all the way up and out the top nd it performed much better. All you hear is the diesel banging trough the block, which is still pronounced, but you can have a conversation beside it so that's good enough for me. I think there's no need to pursue further sound reductions.

Here's an image of the final exhaust mounting:




And then a video with sound. Not sure if it sound all that different than before really, but...

[youtube]http://www.youtube.com/watch?v=6fl1hRCmOqc[/youtube]

[LeChatNoir]

And Happy Fourth of July!!!!!

[gyre]

I'm glad it works okay.
There's more that can be done, but once it's lower than the block noise...

You might consider a flex joint in the system.
You'll have to judge if it would help.

Some glass packing or a light muffler near the end can help with any remaining harshness, if worth the trouble.

There is a design for breaking up the pulses that you can make, which is very slim too.

[LeChatNoir]

At this point it seems adequate and I'm going to call the exhaust done, I think. A nice balance between putt putt and clack clack.

[Elorrum]

beautiful LCN!!! So looking forward to seeing it rolling along.

[wraith]

That is indeed a thing of beauty. Makes me sad I'm not going to make the Playa this year.

[LeChatNoir]

Thanks!

Elorrum, be sure to flag us down if you see us. And wraith, it's a bummer that you won't make it this year, but I know that's how it goes sometimes. Think you'll try for 2011? We hope to be there then as well, and 2012 seems like a "must make it" year. We have plans to continue bringing the old rust bucket for as many years as the DMV will have us and we can swing it.

I imaging that there will be little additions here and there in the future, but what it is evolving into, I'm getting the feeling, will be more or less the final version.



Though the right piece of rusty junk could change all that.

[LeChatNoir]

And speaking of the current version...

The CCFL's and LED's showed up today. That means it's time to get ready to mount some lighting!

[theCryptofishist]

That means it's time to get ready to mount some lighting!

I love it when you mew dirty at me!

[unjonharley]

And speaking of the current version...

The CCFL's and LED's showed up today. That means it's time to get ready to mount some lighting!

Time to get that pile of junk on the road?????