Sorry to take so long but I finally got a decent picture saved someplace I can use to post it to the blog.
There’s a wrinkle that doesn’t show well in the picture because of the angle, but is glaringly obvious IRL. So this part is Just Practice while I perfect my technique. Also I have been looking at pictures in catalogs and online of turnouts that used this method and they have egg-shaped openings, not teardrops. That means I have to work on my technique even more to get the opening right every time.
Since I spent so much time trying to get a good picture today after trying to get a good turnout yesterday I’m up past my bedtime and I really need to be awake when the stormdoor installation team shows up in the morning, I’m putting this to bed and then myself. Hasta la Friday. Which I know is ungrammatical Spanglish, but anyway, Mañana
Last night I did the bender again and started trying to do the “sliced tangent to the inner radius” exhaust tip. Now while I was building my tool and practicing bending the raw stock I was listening to YT Music on my phone, which ran the battery down so I couldn’t take pictures after I was done. But I promise pictures for tomorrow after the phone gets charged.
The tricky part is the heating of the raw stock to make it soft enough to bend without causing the tube to collapse. I ruined many bends because I overheated the tube and collapsed it. I also discovered that heating the stainless steel bolt I’m using as a bending post doesn’t work for tubing at all, unlike solid rod. If the post is warm enough to soften the plastic, the wall of the tube next to the post collapses before the outer radius starts to bend. In retrospect I should have expected that, but I was thinking in metalworker mode not plastic model builder mode. The way to go for the plastic tube is to spin the tube on its long axis with the intended bend area in the heat source (butane torch flame) until it gets soft but not floppy, then put it in the bender and make the bend. This has to be done extremely fast because the temperature spread between floppy and rigid is very small and soft enough to bend and too cold to bend smoothly is even smaller.
Anyway I discovered another reason for using the sliced bend exhaust tip, it leaves a delightful teardrop shaped opening besides directing exhaust away from the car, similar, shorter, but not exactly like when the reverse technique is used for side-exit exhaust. But I wasn’t expecting this shape from the inside bend, I was expecting a more oval shape opening. Maybe when I get a better quality bend the shape of the opening will be more oval than this attempt. But better quality requires more practice and there is a limit on how much raw stock I can waste on practice. I really need to reserve one stick of tailpipe material for the final build so I have enough length. But I will get a picture of the pretty practice tailpipe for tomorrow’s post
This is a technique I haven’t used since the last time I was building models for/with my son when he was a child, who will be 42 next birthday. So to say I was out of practice would be a gross understatement. So I decided some practice on some of the raw stock I’m using for the exhaust would be in order. I decided to start on the hardest exhaust end first because if I could a decent job on that the others would be a piece of cake.
Well the pictures didn’t turn out so good because the new phone doesn’t do macro very good, the old phone used to do macro real good, but this one stinks. Also it’s all white plastic so while I can see it, the camera just doesn’t pick it up well at all. But given the limitations of the technology here’s a before pic. Actually the other end of the tube that hasn’t been worked yet, but you get the idea.
And after, notice the thin edge looks like the whole tube is really thin.
On a different background and lighting to make the difference more noticeable.
And before really needs a contrasting color on the edge but the tube wall is still discernible.
So this was the straight-cut tip, the tip I’m going to be emulating in plastic is the turn-out tip, where the tube is bent around a radius and then cut tangent to the inside of the bend right where the bend begins. This is a classic hot rod design motif that forces the exhaust in a different direction without enlarging the width of the exhaust in tight confines. The normal use is to turn the exhaust down in front of the rear axle when a combination of no ground clearance and not enough floorpan clearance when the axle is at full bump prevents routing the pipe over or under the rear axle. Or like I’m doing putting a side exit exhaust where there isn’t a lot of room to the side and you don’t want to hang a sharp edge out on the side of the car.
And if a picture is worth a thousand words then I have posted enough for today. Next step is to fire up the bender and make that turn-out tip.
And then found out one of my tools had made like Elvis and left the building. Or maybe it would be more accurate to say needed another tool to maintain the one tool, as everything came to a grinding halt because I didn’t have anything resembling a sharp pencil to make lines with.
Seriously, I needed to mark out the placement of parts on the bottom level of the practice structure because part of “practice” was putting parts where they would be in a plan, and without something capable of making accurate, repeatable marks,that was not in the plan. Well that was exactly the plan but the inability to make those marks threw the plan out the window.
I also tried cold-forming the styrene rods I’m using to represent the frame tubes, and I’m getting good bends as far as radius and roundness are concerned, but they don’t retain their shape. I actually bent one in a 180°+ loop and in about an hour it had straightened out so much it wasn’t even a full 90°. So I’m making the trip to Harbor Freight for that butane torch to replace the one that was “put away” after I already put it away where I thought it belonged, and picking up a few more things while I’m there. I also need to pick up a replacement Christmas gift for one of my RPG group, the guy who sometimes gives me rides home when it gets too dangerous to walk on the streets near where we play because there are no sidewalks and the speed limit is “50% of pedestrians struck at this speed will die within 30 days” which I know does not apply to me, but “not dying” doesn’t mean it doesn’t hurt (there is a character who uses that quote in “Dan and Mab’s Furry Adventures”, but I can’t find the page it appears on). So we bought him some sword fighting gloves for his Renny job, but they were ridiculously small on his hands and too small even for my hands which were Medium/Small glove size when I was in the Army back in the ’80s.
That was a sidetrack. So, Harbor Freight, butane torch, other things like gloves and batteries. And a pencil sharpener if they have one. And if they don’t I get a mechanical pencil with really small “lead” someplace on the return trip.
OK this is just here to have an actual daily “something” here to attract attention from the bots that eventually read and classify everything on this blog for search engines. What I’m going to do after I finish this place-holding post is make a structure from the rods to get more practice with the file method of generating a cope in the plastic rod, more practice in getting a decent close-up from my phone camera (I should probably invest in a macro lens for said camera), and see just how rigid a structure I can build using the styrene rods and sheet.
OK now off to practice creating things from plastic shapes.
OK I got some more raw stock for the Mini Sprint-T yesterday. Basically I got 0.040″ thick styrene for making brackets and steering arms and the spindle backing plate where it connects to the axle. The amusing part is the minimum order was 4 sheets of which I will use maybe half a sheet if I’m profligate in my layouts, and when they packed it they included an extra 2 sheets to “protect” the actual material I paid for. So I needed less than ½ of a sheet, bought 4 and got 6, for a total of 12 times as much material as I need. The other funny part is unlike the rest of the raw stock I got this was sent in a padded envelope instead of a cardboard box stuffed with crumpled paper.
This sheet material is going to model structures that will be fabricated box structures on the real car like the engine and transmission mounts, or actual parts that are just that heavy because of the stresses involved and the critical nature of the part like steering arms. A major part of model building is “representation” rather than actually reproducing something in miniature. The exhaust system will be a good example of that for the Mini Sprint-T. The 1:1 version will have what is called a “tri-Y” or 4-2-1 exhaust system that improves torque below the torque peak but doesn’t change peak power much. It doesn’t get every last HP at peak though, so drag racers don’t use them much, but road racers, short-track oval racers, and autocross racers spend more time well below the torque peak and the tri-Y manifold is popular in those applications. Well this is a type of manifold that requires a large amount of fabrication for smooth flow, and ditto on the fabrication level for the scale version, and because of the difference in materials is actually easier to build full-scale than in miniature. Well to get around that I’m going to use the fact that the exhaust is going to be wrapped in insulating material to hide the fact that I’m just going to butt-join the rods representing the tubes of the manifold and not build the streamlined joints. The work would have been hidden by the wrap anyway and this saves a lot of work that will never be seen. The real tricky part will be the wrap, I’m still experimenting with stuff for that. My thoughts are whatever I use will require a paint wash to get the color right so it will have to be something that takes paint well. But that is something that comes much later in the build, so I have time to figure that one out. The current leader for that is hypoallergenic bandage tape, but I still need to do the paint test. And like I wrote, the actual wrapping will be in the future.
But at any rate what I have now will fill in for complicated fabrications that would be a nightmare to produce in scale and not be discernible from cutting it from a single piece of heavy sheet. End of the current chapter. Next will be actually building the frame, which is like 80% of the build for this model. There are a few dimensions I’m not entirely positive about, some of which need to be hashed out during the model build because I can’t import the parts to my CAD program. The other ones are because I have to build to a rulebook that’s a bit vague about certain things like roll cages, and another rulebook that is more than a bit vague about the same things, and doesn’t mention anything about it except that for my car it’s required without any dimensions or tubing sizes. That is a really big help GoodGuys. “All Roadsters must have a roll cage.” That is verbatim everything printed in the rule book about roll cages. So what I’m doing is using the SCCA Solo rule book for roll bars and applying the rules to the rear hoop, and treating the car like it weighs 2500+ pounds, when I’m looking at maybe 1800 if I run iron heads on the SBC engine and something along the lines of a 4l60E transmission and the Ford 9″. Now if I get a quick change I can get the TH350 and take about 45 pounds off the car because I can change the gears to something really tall for the freeway and gas mileage without having to compromise to get the right gearing for racing. Just jack it up to unload the gears, pop the rear cover off, and swap the race spur set for the highway spur set and refill the rear end then go. And the car will be slightly quicker racing because the race gear doesn’t have to be compromised because of 9″ gear availability or having to get good highway mileage. But the other side of that is quick changes are much more expensive than the common 9″, and other junkyard rear axles are even cheaper and “close enough” on the gear ratio. But in the model I will be using the quick change, because I have 4 of them and no 9″ Ford in that scale. I have 2 of the V8 size housings and 2 of the 10″ ring gear size housings, but no 9″ Fords 😐. And you can see how decisions for the 1:1 car affect the 1:25 model.
And it’s getting late and I should be going to bed soon.
As the saying goes, fair warning. I am thinking about the Mini Sprint-T again. I realize this does not carry the same imminent danger to life and limb as its larger counterpart, unless you are the guy with the scalpel-sharp knife cutting plastic to bring the thoughts to fruition. Then fingers might be at renewed risk, but only mine. I did almost lose the end off one about 50 years ago while building a plastic model. But that is a tale for and from a different time.
One of the things I need to think about is stuff connecting the front and rear axle to the frame. In most kits this is usually molded as a single piece that gets glued to the frame and axle(s), but I have to build mine from raw stock and sometimes from hardware from a 3rd party like Ted’s Modeling Marketplace or Dirt Modeler . But mostly it is a matter of putting the axle in place and then figuring out where is a good place on the frame to tie in the locating links. And possibly adding more uprights and diagonals to the frame to prevent flexing IRL because we are trying to “model” something to make IRL. This is just “old school” 3D modeling, with actual physical pieces getting cut and built in actual physical space. And also because I like cutting material and gluing stuff together. So, indirectly thinking about the Mini Sprint-T is actually thinking about the full-size Sprint-T, just thinking in more achievable circumstances. I have the skills to make a presentable engineering model, but it might not be a display quality model. And what I really want is a display quality engineering model. But I will accept an ugly engineering model in lieu of a display quality engineering model if it means I have a representation of the Sprint-T in physical form.
Along those lines I bought new model-building tools as I can’t use the tools I did have because age has hampered my abilities and the new ones will fit my hands better (I hope). At any rate what I have now are jury-rigged from tools made for other things, or just flat out never intended to use for making models but can be forced into the role if you have the physical dexterity, which I don’t anymore. As an example there’s this one cut I need to make that requires rolling your wrist just right while holding the razor blade to get the desired curve, and my wrist no longer moves that way while imparting enough force to make the cut. When the tools get here I’m hoping I can make that cut. That’s the thing I’m dealing with because of my accumulated damages over the last 60 years. It’s not the tools, it’s the fact that I can’t make the tools do the thing any more. And this is why I’m sad/angry, sadgry? What is the word for that emotion. And Amazon was of no help in finding equivalent bits that I can spend my gift cards on…
And I just got a box the size of a shoebox containing a few plastic rods and sheets and lots of paper padding. Which was the first of the many packages I’m getting from the same order. I guess this is to prevent damage to the rods from bending as they can develop a permanent set if held in a flexed position. And now I need to find my butane torch and a can of fuel to use it so I can bend the rods without breaking them. This seems like a good place to stop writing and maybe start doing again.
There is an event I want to attend near Casa de El Poeta, the Dallas event for the Hot Wheels 50th Anniversary Tour. Hot Wheels were first introduced in the fall of 1968, but didn’t make it to the rural TN town I lived near until spring of ’69, and my first one was a red 1968 Mustang from that first run. I was already an avid Matchbox car collector, but now I had a new obsession that was to be fed by Hot Wheels and Johnny Lightning cars, which were similar but made by Topper toys instead of Mattel. Anyway that event takes place between 8 and 11 AM on Saturday.
Given that I’m normally falling asleep when I would need to be catching the bus to get to the party that calls for some drastic sleep cycle reset on my part. Which is why this is going to be a long day, or technically Thursday is going to be a long day. Yep, I’m staying awake until after sunset instead of my usual about sunrise. Seriously I’m usually dropping into slumber between 0600 and 0700, and I need to catch the bus at 0651 to get to the opening ceremony featuring the monkeys from Gas Monkey Garage at 0800. There will be a small car show (small in number) and some potential Hot Wheels cars (small in size), and of course the Gas Monkeys. But to get there I have to not sleep until 2200 tonight, which is going to be difficult. One thing that will help is I have lots of caffeine in the form of iced coffee and 2 liters of diet cola, and iced tea. You might have noticed a common thread in the beverages beyond caffeine, they’re all cold drinks. Hot drinks and weather together make me sleepy, so no hot beverages until close to bed time. One thing I’m going to take care of is shaving and getting a haircut. I’m overdue for shearing the locks because no matter how much product I put in my hair it just won’t assume the correct flat surface of the classic flattop haircut.
Next post will be after the haircut.
Heat indexes have been off the charts lately, from what I can tell. I haven’t been able to go for my walks so I have been spending most of the time indoors and hardly check the weather, but it’s 86°F in my office as I type this with the AC going. So it can’t be anything but hot outside. But just FYI my phone says it is currently 98°F outside. At 1855. So by deduction it must have been over 100 at some point today, say like between 1400 and 1500. ETA the 2200 news weather report had a 100° high temperature. And the urban heat island effect keeps the nighttime temperatures up, too. And this is where today’s headline came from YouTube
I’m not happy with the way the floor came out for two reasons. Number one is I forgot to include the front support for the front fenders, and 2) I made the rear cutouts too wide, as shown in the pictures. Seriously I left enough room for a 16″ wide tire and the widest race tire I have been looking at seriously was 14″ with the street tires in the 12″ range. And I have plenty of raw stock for the floor, finally. So the floor will get a do-over. And that’s why those 9″ wide tires in the pictures looked so lost in there. Even the 10″ wide tires for the Mini Sprint-T would have been swallowed up.
While I am on the subject of the TGS2 I have been looking at a pull-rod spring instead of direct mounted springs for 2 reasons. One reason is I can change the spring rate just by changing 2 bolts, either a little or a lot, The second reason is the unsprung part of the pull-rod is much less than the direct mount spring because the entire spring and shock are moving with the car. Yes they move with the axle but they are entirely supported by the frame so they are sprung weight. The bellcrank and mount add a couple of pounds but it is all sprung weight. But the primary reason to go with the pull-rod springing is adjustability, I can change spring rate and ride height in just a few seconds and swapping a different length pull-rod is much cheaper than swapping different shocks and springs. Literally a dollars to donuts comparison, I can buy or make a custom pull-rod for about the price of a dozen donuts where a spring and shock absorber are $200-300 assembled. With my budget this is a cost-benefit ratio I can most definitely live with.
And I need to take a shower and hit the hay.
Well I had two pumps, one that failed somewhere in the piston and the other one that had a rotting hose from the pump to the chuck. I only have to send one back, so I put all the bad parts in the return box and assembled all the good parts into a working pump. I then used that pump to get my tires back up to the minimum 70 pounds per square inch to prevent pinch flats on potholes.
And after I did that I felt like Superman™ so I tried to mount the tires to the wheels I had just mocked up that afternoon. It was a struggle, but as you can see:
I got the front edge even with the bead on the tire, but I need to pump the tire so the back side matches the front.
It’s hard to see from that angle, so this is easier.
So what I do now is talk to my diabetic friends about getting some used needles and syringes to pump up the tires to meet the beads of the rim.
And there’s something good coming on Science Channel, so I have created enough with the words and pictures, Opus the Unkillable