Still stuck on imagi-building that A-MOD car

I have a mind that must chew on problems to solve, not social problems, physically solvable problems like bicycles or race cars. And the one that’s occupying my mind is the A-MOD car. Like all good engineering problems it has a simple premise: Make the quickest car possible on an autocross course within these constraints; 72″ minimum wheelbase, 42″ minimum tread, 900 pounds minimum weight with driver and full fluids, and 10″ minimum wheel diameter. There are safety rules common to every car in the series, and because having a really stiff suspension is a huge advantage you have to have sprung suspension, not that actual springs are required, there are cars that are riding around on actual hockey pucks between the suspension and the frame, but something that isn’t a solid piece of metal against another non-moving piece of metal.

Anywho, working through those minor strictures I have evolved literally thousands of cars with uncountable variations of “suspension” over the last few weeks. But what I keep coming back to is a single-pivot rear suspension with a solid axle and a single disk brake halting the axle. It’s simple, strong, and fairly lightweight. And relatively easy to adapt to a chain drive. Another thing is it works extremely well with a common trope in cars this size, mounting the engine on the rear suspension. Basically this is done to simplify the drivetrain and shorten the chain on chain drives. It’s really bad for unsprung weight so I’m only doing the designs as due diligence to make sure I’m covering all the bases, and because researching this adds to the knowledge base for other designers, and what I learned to pass on to other designers is the unsprung weight is pretty close to zero if the Center of Mass of the engine is mounted right at the pivot point of the suspension which is physically impossible unless the rear swing arm is mounted in such a way as to create a virtual pivot point in or near the CG of the engine, which kinda negates the purpose of mounting the engine on the swingarm in the first place, simplifying the rear suspension and drivetrain.

Another suspension I have been looking at is the classic 4 link and panhard rod with the forward pivot of the 4 link even with the front drive sprocket of the chain drive and the rear pivot right on the centerline of the rear axle so the chain and the suspension swing through very close to the same arc and making having the same chain tension through the suspension travel simple.

Another thing I have been looking at is mounting the rear part of the chain drive solidly to the rest of the frame and using CV axles to run the power to the wheels as shown in a book I bought, How to Build Motorcycle-Engined Race Cars by Tony Pashley. and in this video by Vasily Builds where he modifies his swingarm buggy into IRS. Way more complex to build but less unsprung weight than almost anything else, but the 4 link is lighter overall, allowing weight to be added where it will do the most good, making the final decision a tossup or a painstaking virtual build of both to see which would be better. I have the time but not the software to do the virtual build, and the 4 link is both cheaper and easier. And since I have more time than money, cheaper is the way to go on this one.

But I would still rather be building the Sprint-T. This is just something to keep my mind occupied so I don’t build a doomsday device and just destroy everything. Speaking of which, I can’t find my yellowcake, I have the lemon and the cinnamon, but not the yellowcake. (Mad scientist in-joke, you don’t have to laugh if you don’t get it, but if you don’t get it and want to get it google “Nigerian yellowcake” for the source of the joke.)

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My electronics are dying

My phone will only work by plugging in the charger and unplugging it because the on-off switch is busted. My laptop refuses to charge and only works when plugged in. Now I can almost understand the laptop getting creaky, I bought it back in 2013. In laptop years that makes it almost pre-historic. And my 2½ YO phone is equally ancient in an industry that cycles through another generation every 9 months. But that doesn’t mean I have to like it.

What really pisses me off about the phone is I was getting out of memory messages about my apps, so I spent almost as much as the initial cost of the phone before rebate tripling the capacity, going from 8GB to 24GB with a 16GB card. And I still get out of memory errors with more than 15GB free space in the card. I really don’t get that. Stupid phone, you wanted memory, I bought as much memory as you can hold, and you still say “out of memory” with almost twice the free space as when I bought you. Stupid phone. Who designs a system that puts everything in working memory and refuses to use free storage even for things like saving pictures unless you move each picture there manually one at a time? It is storage, dangit, store things in it. Like updates and texts and pictures, and other things that need storing for later use. But for some reason I don’t have anything to tell the phone to do that and to download updates to the card then run the update from the card. It almost looks like the phone was designed to use up its operating memory and then get replaced every year…

And I can’t seem to be able to cut a straight line lately, making cutting a new floor for the TGS2 scale mockup mostly an exercise in frustration and spoiled materials. I’m back to getting lots of good stiff card stock as junk mail so this isn’t actually costing me money, but it is still frustrating to not be able to get stuff done so I can see progress. And this particular thing is so simple, I literally need to cut one piece of paper to shape and tack-glue it to something else and paint it so everything is the same color, then cut, paint and glue another piece of paper so I can take a picture and post it here so you can see what the finished car is supposed to look like, more or less.

I should mention that I decided to move the engine/transmission forward rather than stretch the body back, so the wheelbase went from the Speedway kit’s 102″ to 90″, helping the balance just a scosh. It is only a percent or two depending on the fuel load and driver weight, but at this point every little bit helps. I think one of the things I’m going to do on Monday is pick up another set of stones for the hone so I can get the kingpins finished before the turn of the next century. The ones that came with the tool seem to have given their all honing the chrome-moly axle boss to fit the kingpins.

And I think it is probably a good time to hit the hay.

Design is getting down to brass tacks

That is a very archaic turn of phrase in the headline, it means discussing the ornamentation on a custom saddle and dates from at least as far back as the 17th century. Today it means getting to the fine details of a deal or design. As of this point the front end is approaching brass tack territory.

I went back to earlier drawings of the front end and found a couple that placed the crossmember above the front axle, but not as high as the one I discussed yesterday. So I went back to that and moved it higher, and also added the radiator mounts and body supports in front and hung the rack off the backside. I dropped the MD3 nose from the design in favor of making less drag and downforce with a nose made from the same HDPE panels the rest of the body is going to be made from. The right side of the rack might protrude from the body at full left lock but I don’t care at this point. That is a minor aesthetic point that is overridden by making the damned thing work right. There is nothing for it to interfere with on that side.

At this point I have started thinking about the cockpit design, specifically protecting the instrument cluster from the environment while parked outside, and making the cockpit tolerable at highway speed. Putting a roof on took care of most of protecting the instruments from condensation, rain, and bird poop. Further enclosing the environment with some kind of side windows will do a better job of preventing condensation and blown rain from getting to the instruments. I don’t know if that would be enough to allow driving in the rain, but it will probably do a lot for making the interior livable at highway speeds by reducing cockpit wind and turbulence. The original cockpit had no windshield or side windows with the driver wearing a helmet with a face shield all the time, even on the street. That was back when the car had a V8 in the front and the driver sitting on the left side of the cockpit. Now I’m even thinking about heat and AC 😇. There are races in FL during the winter that might be fun to run in, which means driving in winter, which means a heater. Driving in the rain means a fogged windshield which means a defogger which means AC of some kind.

I even looked up what sender to use on the gas tank so the gas gauge works right (10-90 ohm). Really this started when I discovered the entire instrument cluster came out as a unit. And that the engine and transmission controllers expected to find the instrument cluster before they would let the car run. Since I need a tach and speedometer and the computers know how to use the ones in the cluster and everything will need to be “unconfused” L8r, why not use the OE cluster? It saves having to buy those instruments later and figuring out how to make everything work together which is even a bigger hassle than telling the computer it isn’t in a minivan any more.

And now it is about time for my walk, so more thinking about random things.

Opus the Unkillable

Mrs. the Poet’s retirement has made for her keeping me from working, and the Feed

I love my wife, I really do. BUUUT (very long “uh” sound there) she refuses to acknowledge what I do as “work” and is constantly telling me to stop “playing on the computer” and do what she wants me to do, basically denying the validity of what I do. I do not know what to say about this, especially at the time she says it because of my aphasia not leaving me with the vocabulary to respond. Sure I sound all glib and insightful in the blog, because I have the time to stop and think about it, lower my stress levels by meditating, and allow the words to flow out of my fingers bypassing my mouth. The process in and of itself is much less stressful than trying to actually speak with my wife making a rejoinder to a comment she made. As a result I’m frequently unable to respond with anything more cogent to her “playing on the computer” remarks with anything more than “Go away, I’m working here!”

Up first, the lowlife scum that hit a Miami cyclist with his vehicle so hard that the roof was collapsed around the driver’s head and then left claiming he “didn’t know” he had hit anyone violated his parole. Driver in Fatal Hit-and-Run Crash on the Rickenbacker Causeway Heading to Prison After Probation Violation and Driver Guilty In Cyclist’s Death Sentenced To Prison For Probation Violation When I saw one link I was thinking they were really looking to violate this guy, but then I read another link that said he had been checking in with Foursquare at bars and clubs, places he was not supposed to be and in violation of his parole, so he basically violated himself on this one. I hope he has a life-affirming moment in prison and never drives again. I was going to type something else, but then I stopped to think “Is what I want vengeance against this one idiot, or do I want a cultural change that keeps idiots like this from being able to hurt people because they lack the means to hurt people?” And I have to say that while vengeance against that idiot would make me feel better for a little while, making it so that idiots like him can’t hurt people would make me feel a lot better in the long run.

Next a little lifestyle from a little south of the Beautiful Suburbs of Hell. Round Rock memorial bike ride honors avid cyclist Killed in a wreck very much like mine in many respects, just trying to get where he was going and make a living.

Our Daily Ted. Morning Links: Awkward cycle track in Marina, PCH closed at Point Magu, fight North Fig parking at City Hall

Trying to change the legal infrastructure in the land of the automobile. California Bicycle Coalition Announces Its 2015 Legislative Agenda

CA riders remember a fellow rider killed on an epic ride in OR. Riders finish avid cyclist’s last journey

Still in CA, I would love to see drivers held to the same standards as cyclists when motor vehicle infrastructure is discussed. Dick Spotswood: Marin bike lobby’s political clout is slipping Really, not another freeway or even a pothole filled until drivers stop speeding, running red lights, turning right on red through crowded crosswalks, driving on sidewalks to get around people stopped a red lights…

So, what about people who don’t have smart phones, like me? Tech solution for “dead red” lights

Bicycle advocacy in America’s Amsterdam. Guest Article: Four things BikeLoudPDX has learned in their campaign for SE Clinton

They’re starting to learn lessons from the Netherlands. Cycling reduces the death toll on our roads…

OK I don’t know if you will be able to read this or not, but if you can’t copy and paste the headline into a Google search and read it from there. There is at least one city determined to not kill it’s citizens. A Plan to Limit Cars in Paris Collides With French Politics

Another e-assist article. Bultaco Brinco Is a Really Interesting E-Bike, but Not Exactly Cheap I used to have a ‘taco motor in my shifter kart… I don’t think this one would work the same. I like that the pedelec mode has a 100 km range, but I’m thinking there isn’t much assist in that mode. I built a bike with a lot smaller battery that had almost that range but used a constant pedal cadence mode and powered cranks. It is somewhere in the garage which means archeologists will be the next people to see it. At least I hope it’s in the garage. If it isn’t that means I had another bike stolen and I won’t even be able to give the police an exact year, much less a time of day…

And those were all the links I could find today, enjoy!

Billed @€0.02, Opus the unkillable badass Poet