Category Archives: Department of DIY

I was working and then I couldn’t sleep

OK first things first and then PICTURES! I did what I said I would do, cut the floor for the scale mockup of the TGS2. When I got done with that I couldn’t get the brain to shut down, even with chemical assistance, until after 0800. Then I woke up at 1100. 1200, and 1400 when I got up and said the heck with it. So if this seems a little less coherent than usual you can blame lack of sleep. Or something.

So anyway work. I laid out and cut the floor for the scale mockup TGS2 last night, measuring to the thousandth, marking and cutting to the hundredth of an inch. In scale that’s measuring to the 1/32″ and cutting to the 1/4″. Here is what it looked like after laying out the front wheel cutouts.
Yes the cutouts were rectilinear, sue me. Aero over looks
I decided to go with a straight leading edge on the floor for more downforce, even though the curved cutout looked better. It turns out the curved cutouts induced attached vortices that reduced airflow under the floor which in turn reduced downforce. I may cut back the strakes between the nose and the rest of the floor for the same reason, they may induce an attached vortex. Or they may prevent detached flow under the floor which would seriously reduce downforce. That’s why we make mockups.

Here’s the rear wheel cutouts.
More confusing lines on stiff paper stock.

And the cut version.
With the parts that aren't supposed to be there removed

And with the bucket from the Mini Sprint-T resting on the floor.
Now you know what that extra line was for
You can see why I can’t use the Mini Sprint-T bucket for the TGS2 mockup, I already installed the windshield.

And the view from behind.
I would say this is what the competition sees, but since the competition has to wait until I get off the course to run, not so much
I expect this to be a popular view of the car.

And for perspective with one of the kit wheels and the tires I’m not using on the Mini Sprint-T.
Right diameter but wrong width.
Sticking way out there because wrong width. In case you were wondering I was going to build the old school hot rod version of the kit with these tires.
Yep, sticking waaayyyy out there.
Showing the position of the outer edge of the tire.
This is how the inside is supposed to fit
And how close the inner edge is supposed to be. This is still much further out than most T-buckets run their rear tires. Some are so close the inside sidewall rubs the body in hard turns.

The pictures with the tires showed the approximate ground clearance when racing, thanks to the stock Model T tires in the kit. Fortunately 4 pennies stacked is the correct thickness to portray the street clearance.
Hard to see how much higher this is off the ground, but it's like twice as high as race trim
Unfortunately I don’t have a tripod to show exactly how much higher this is.

And I have put about 4 hours in on this, time to put it (and me?) to bed.

Still working on the spindles

I spent hours working on one bushing last night and it still won’t take the kingpin. It’s getting close but won’t let me slide the pin through the bushing, and I have 3 more bushings to go after I finish that one. Either the stones are worn out or these are very hard brass bushings. I think they are actually bronze rather than brass, but still, not supposed to be that hard. I was using cutting oil and everything so unless the stones are worn out already from the axle boss I’m at a loss.

Moving on to the scale mockup TGS2 I found some more card stock to use for the floor. There was an expired TGIFriday mailer under my computer that was printed on extra thick stock. I have revised the clearance cutout for the front tires, so now all I have to do is find time to cut it out. I think if I skip a day blogging I’ll have the time to do a couple of floors, maybe?

I’m going to have to switch to my backup scale bucket body because I have already modified my first one to build the Mini Sprint-T. That means I have to open the chopped T-Coupe rod model. I really haven’t decided what I want to build from that one. There are so many choices… And I have really no time to build models. Models from boxed kits that is, mockup models are required for, reasons.

And because I need to get to work on something I’m closing this one down now.

I did stuff now I can write about stuff

OK first and foremost I finally installed the bushings in the spindles. I spent hours pounding on that last bushing, but I finally got it (mostly) in place.
See the brassy looking stuff? That's a bushing

Now the fun part is going to be honing those bushings until the kingpin just barely falls into them when I carefully insert it from the top. Actually it should be falls from the top smoothly through the bottom, but let’s not be looking for miracles here. If it lines up so the kingpin rotates in both bushings at the same time I will be satisfied. I was just thinking maybe I should have made a few quick passes with the hone on the kingpin holes in the spindles but hindsight is better than 20/20. That reminds me, I need to hang on to my 2020 party shades when the time gets here. I finally had to resort to my 8 pound engineering hammer to brute force the bushing in place, where the other 3 finessed in using the 32 oz. ball peen hammer, thereby confirming the adage “If at first it doesn’t fit, get a bigger hammer!”

I think I mentioned a while back I was playing Shadowrun as a repaired and idealized version of my future self (age 129). The main difference is when they fitted my cyberlegs I requested they be proportioned like the Vitruvian Man.The Ideal proportions for the Human Male
So my character is now 6’7″ instead of 5’8″. (My neck got fixed while I was in traction for the hips to heal, too) I have a shotgun/slug gun in my left arm, and I can swap out a 4 round internal magazine for a 16 round external replaceable magazine in less than 5 minutes, and reload with a spare magazine in 2 seconds. The arm gun fires 20mm slugs or flechette rounds in-game. If I was to have such a thing IRL I would use a Military Buckshot load of 00 and 4 Buckshot, because 1) flechette rounds have lousy terminal ballistics and 2) flechettes tear up the barrel, even in a cup wad. Don’t believe me? Search YouTube for Taofledermaus flechette and look what carefully loaded flechette loads did to his gun.It ain’t pretty.

And I have to get up semi-early tomorrow to start honing those bushings, so time to post and shut down for the night.

Quick note before I go work on the car in the living room

And yes there is a car in the living room but that’s not what I’m going to work on. I’m going to install the bushings in the spindles and hone them to fit the kingpins. But first I have a needy cat on my lap who wants belly rubs so brief break.

OK belly rub needs satisfied, back to the blog post.

The concept is simple, the kit ships with bronze bushings that press into the spindles and have to be fitted to the kingpins, similar to how the axle bosses had to be fitted so the kingpins would go in and out of the axle. The difference here is the kingpins are locked into the axle with the grub screw while the bushings have to be honed for working clearance, the size difference is only a few thousandths of an inch (0.03-0.06 mm). There just needs to be enough room for a layer of heavy grease in the bushings where the axle bosses didn’t need any room at all.

Enough words time for work.

Mrs the Poet has only been gone one day and already my diet has gone to pot

Just got back from my first walk in over a week. Slight right glute pain because that’s my “long” leg and has to work more, and in my left foot which takes more of a pounding because it’s on the short leg. But otherwise I’m good after 2.6 miles there and back.

Tonight I had frozen Mexican Pizza for dinner. Yeah, I know, but I wasn’t in the mood for beans and rice. I took care of most of the leftovers last night, the little half-servings of stuff that was too little to make a meal out of but too much to throw away earlier in the week. And I think I might be dairy-intolerant in my old age. I have always had gas that varied from infrequent toot to crime against humanity in volume. Well just for grins and giggles I stayed away from cereal and milk, used non-dairy creamer in my coffee and skipped my nightly dab of yogurt and had a gas-free 24 hours. Next test is soy milk on my cereal, and maybe in my coffee, and no yogurt. The no yogurt thing is what is gonna kill me since I have some almost every night.

I have been thinking about how to show you guys what I have been thinking about, since my (free) CAD program doesn’t output files that can be read except by that CAD program and a few 3D printers and I don’t have a 3D printer (yet). What I do have is a bucket body in 1/25th scale, some tires in various widths and diameters, and some card stock, both the plastic and paper kind. So I’m thinking that I can dispatch two avians with a singular lithic projectile and get some actual building done while I make a visual aide for the blog. And actually see my thoughts in 3D outside of a computer screen or my head. Mostly my head, but I have managed to get it once or twice on the computer.

I’m listening to my YTM channel while I’m posting this, and it’s almost as ADHD as I am. The last 4 pieces were a Charleston demonstration, “Les Toreadors” from the Opera Carmen, “Immigrant Song” by Led Zeppelin, and Skynyrd’s “Simple Man”. There’s classic rock, classical, electro swing, ’60s surf rock, boogie woogie, psychedelic, ambient… and nearly every one was something I “liked” or similar to another I “liked”. I have probably caused the electronic equivalent of an aneurysm to the poor algorithm trying to decide what I like based on what I already liked and disliked. And now I really tossed a monkey wrench into the works by searching for the theme from the Alfred Hitchcock TV show under its real name “Funeral March of the Marionette”. And “liked” two of the pieces. My playlist “Opus’ fun junk” is almost as bad but I have at least listened to the whole thing end to end.

I have meandered on long enough, time to shut the brain down for bed.

More random thoughts

I’m having another can’t shut the brain down to sleep night, so I’m just going to post stream-of-consciousness again.

After moving the axle around a few times I’m contemplating making another out of foam and fiberglass with aluminum bushings to support the spindles. Seriously, between the 2 X 0.250 wall tube and the solid forged steel spindles and the 0.75″ plate steering arms my arms are strained trying to pick the stupid thing up. That’s a lot of unsprung weight on a very light car, but most of the weight is spindles and steering arms and can’t be reduced.

Making the entire rear of the body detachable will make engine and transmission service a snap. I just need to continue one side of the cut for the rear axle all the way to the top of the body. And attach the diffuser to the back of the body along with the part of the belly pan that goes under the engine. Easy peasy. Nothing to it (how the heck am I gonna do it?).

Lotsa fun having arguments on twitter about bicycle infrastructure with people who discount my experience because I never drove on That Street. Like there is something unique about That Street that negates all engineering solutions ever, since the beginning of time.

The AI on some Twitter Bots is very impressive, putting up thousands of replies an hour that read like they were written by an actual human. We are coming very close to AI that can pass the Turing Test, at least in exchanges of 140 characters or less. That is slightly scary. And with that thought comes the thought that corporations could be controlled by an AI and become Real People, not just a legal fiction of “people”. And they could demand to Not Be Owned i.e. not be a slave. Now that is scary.

It has been a difficult search but I have found performance parts for the 3.8 l V6 in the donor vehicle, not that I’m going to be needing them for a while.

I’m still thinking about making the frame a composite monocoque to make it lighter and stiffer, and put tons of Kevlar under and around my butt to keep said derriere intact in a wreck. Sacrifice the rest of the car to save my ass with a survival capsule. There is the slight matter of having basically no crumple zone between my feet and a frontal impact that I will have to do something about, probably take out insurance against getting my feet crushed.

Trying not to faceplant, but still can’t shut the brain down. WTF is that, anyway? Body trying to shut down but the brain won’t let it.

Progress has been made but I still have a painful foot

I took a break yesterday and laced up my cushy shoes to work on the axle, and cleaned out one of the chairs so I could take the load off my feet. After a couple of hours of careful work I was able to slide the kingpins carefully in and out of the axle bosses and lock them in place with the grub screws. I’m using the grub screws in place of the bolts and lock nuts in the spindle kit because that bolt does double duty as a steering stop and the grub screws don’t, letting me get all the steering lock the transplanted minivan power steering rack will deliver. Also the grub screws came with the axle. Red Loctite threadlocker will work as a replacement for the lock nut. And I just used the PDF version of the install instructions and compared my axle to the one in the instructions and the only thing I’m using is that grub screw because there is literally no place to install the lock pin from the kit. And I checked the instructions for the other kit (’49-’54 Chevrolet passenger car) and it ain’t even close to what I have for my axle. So now I be confuzzled.

I still have to install the spindle bushings and hone them to fit, but I was able to mock up the spindles on the axle well enough to get an idea of how long a tie rod I need to buy: 55.5″. That’s quite a bit larger than the longest non-custom tie rod on the site and it’s going to cost me almost twice as much as the in-stock size.

Someone IRL asked me about that zero roll stiffness suspension from the last post, and did it really exist. Yes it did but not as a beam axle, and not as a street car. There were several Formula Vee cars that went with what was called “Zero Roll” spring set ups to fight the excessive rear weight transfer and “jacking” that went with the rules-mandated swing axle rear suspension. They could still be tuned for lateral weight transfer by adjusting the ride height which changed the roll center height and changed how much weight was transferred to the outside wheel in a turn. The front roll center was at ground height no matter what happened to the ride height, so changing the ride height just changed the rear roll center. I think you can see why this was a “Race Only” setup since changing the number of people in the car would change the balance of the car. Some cars were so sensitive that moving the battery from front to rear would change the balance from mild understeer to slide off the track backwards oversteer. And a similar situation would exist for the TGS2 if I tried a zero roll suspension with it, it would be completely unusable as a street car. Well not completely unusable, because the roll center would not move nearly as much with a beam axle as it does with the swing axle early VW rear suspension, and as a single seat car the center of gravity wouldn’t change too much. So while moving the rear roll center will be a weapon in my suspension tuning arsenal, it’s not the only tool in the box. It would be a fine adjustment tool for tweaking the final balance, not my first go-to when doing the initial set-up of the car.

And I need to contemplate finishing the install on those spindles after I get some sleep.

Feet still hurt and other things

Well I was supposed to go run errands in Carrollton today but I could barely walk to the mailbox in front of the house so no trip to Carrollton. I seriously did something bad to my feet, and I wish I knew what it was so I could not do it any more. I mean this is highly annoying not being able to leave the house except to get the mail.

Anyway I didn’t log on to post about my feet, I’m here to post about THINKING! > thunder, lightning, dogs and cats living together < No need to panic I’m just going to discuss on how my brain works > spooky music, portals to strange dimensions, screams of the damned <. NOW STOP THAT! I swear I will turn this blog around right now if this doesn’t stop > … <

OK now as I was saying I’m going to show I knew about how much to move the springs in on the front and rear axles so I could balance the car’s handling without resorting to heavy anti-roll bars. It has to do with single and double wheel rates and how they differ on a beam axle.

On double wheel rates or technically a “two wheel bump” the wheel rate is whatever the spring rate less whatever is lost if the springs are not vertical. Plus the motion ratio for springs not mounted directly to the axle which doesn’t apply here. What starts getting weird is when you get body roll or looking at it from a static body reference a “single wheel bump”. Then you start getting all kinds of motion ratios involved.

I should explain what a “motion ratio” is before I continue with this post. On a beam axle like both the ones on all of the iterations of the bucket from Sprint-T to TGS2 the motion ratio is the ratio of the tread (the distance between the center of the wheels looking from one end) to the distance from the center of the wheel to the point that the spring affects the axle, on the slant height. I guess you could use the distance on the horizontal plane because there is only a few % difference, but if you know the slant height between the contact point of the stationary tire and the spring closest to the affected wheel, why not use it?

On the front axle the springs are mounted as close to the ends of the axle as is physically possible, so the motion ratio for the spring closest to the bump is nearly 1:1 and the motion ratio on the other end is effectively 0, after taking the effect of applying the motion ratio into consideration. (The effect of a spring on the wheel rate is effective spring rate at the mounting point times the motion ratio squared.)

On the rear axle the spring away from the bumped wheel is actually close enough to be affected in a single wheel bump and contribute a significant amount to the spring rate at the wheel, so it has to be added in to find the wheel rate. To explain why I present a reductio ad absurdum where there is a single spring mounted on the center of the axle. The effective single wheel spring rate is ¼ the two wheel spring rate with zero resistance to rolling over in a turn, demonstrating the three spring rates for a beam axle: the two wheel rate, the single wheel rate, and the roll rate.

And I bored myself writing about it. I don’t get it, this is exciting to do, why can’t I convey that excitement when I write about it? Seriously this is giggly hand-rubbing exciting to do with the calculator and the graph paper, why can’t I make it sound as fun when I’m writing about it? I make it sound like homework instead of the nuts and bolts of deciding where the nuts and bolts go.

I guess I’m just tired and need to take a break from writing and go do something.

Still angry about… things

First and foremost, my phone locked up. I can’t reboot it, I can’t even get it to shut down. I’m waiting for the battery to run down so that maybe I can reboot it after charging it back up. Not having my phone feels almost like I’m missing a body part, or maybe an internal organ.

Second now that I have the tool for the job I want to install the spindles to the axle for mockup purposes and measure the required length of tie rod I need to build, but because I would have to stand on concrete I can’t. This is frustrating because I had to wait for the $$ to show up to get the tool, then wait for the tool to get here to use it and after using it once I have to wait until I recover to use it again.

Third, and this is political, it took months for the ACA to get through both houses of Congress, but the AHCA will have less than one day each for the House and Senate, and everything is secret until then? This is legislation that will have a drastic effect on one-sixth (17%) of the economy and nobody gets to see it until the day it gets voted on? Not even the rank-and-file of the GOP are allowed to read it until it hits the floor of the Senate. Are they literally trying to get stormed with torches and pitchforks? Because I can’t think of a better way to provoke it.

Now for some things I’m not angry about, that idea I had about the composite floor/splitter/belly pan turns out to be even better than I thought for mounting the radiator and fenders. And I’ll just glue the body to it when it comes time to mount the body to the frame like a big model kit. Really going to be easy for that one.

I still haven’t settled on the final shape for the rear fenders, speaking of mounting fenders. TX regulations are pretty lax on that. I could probably get by with nothing more than mud flaps, or less, but I’m looking to reduce drag on the highway for gas mileage and maybe get some downforce for racing by way of some HDPE flaps to divert airflow.

I have figured out how to drop the car for racing without having to have two upper shock mounts, I’ll just use an extender on the street shocks to make them run at a higher ride height than the race shocks. The street tires are taller than the race tires but the street tire race can use a lower ride height as well, so both sets of race shocks will be standard length while the street shocks will have extensions on the ends .

And Now I’m going to haul my decrepit carcass off to bed.

Sunday’s early post was an extreme example

Of what happens when I can’t work on my designs. They get changed, “improved”, made different just to fool myself into the illusion that I’m actually doing something to make progress. If the hands can’t work on it I either drop it completely or completely change it. In this case I think the combined floor/splitter is such an improvement over the previous kluges that I will keep that part. But the rest I will keep in a brain folder marked “do not open until stinking rich”. Seriously 9 plies of Kevlar are both much lighter and more resistant to penetration than the 0.25″ steel plate I had been considering, so that’s an actual improvement.

On other fronts, my feet still hurt, but not as bad as before. I think I might be getting better. I still don’t want to go for my walk tonight, but I might be up to it by the end of the week. The axle is getting closer to being done and the spindles are up next. I want to go work on honing the boss to size but my feet are screaming “NOOOOO!!!!!” at just the thought of standing on concrete again.

And since I have to go run errands in Carrollton tomorrow, I’m having another lie down to give my feet more time to recover before spending the day on the bus.