Tag Archives: building model cars

My steering box is on indefinite backorder

AFAIK Speedway Motors is having similar problems with China as I am in that what used to be a Sure Thing is now Vaporware. My steering box can no longer be considered a viable option, and the people I used to work for no longer have a working web site. E-mails sent to them come back as undeliverable and there is no solid date on stocking my steering box either. Both of us are up the proverbial unsanitary tributary.

Which means I can stop sweating about my bank balance getting below the amount due for the steering box order because it won’t be due any time soon. The good news is Speedway will honor the price I placed the order at including discounts in effect at the time of the order. The bad news is they have to get a new supplier and won’t be able to ship my order until they get the parts from the new supplier.

In other good news (really good, not sarcastic “good”) I got in contact with the person I got the LS7 I’m using to make the Mini Sprint-T to purchase another and a scale Powerglide transmission to build the A/Mod SCCA Solo Racer. I think I might have mentioned the LS/Powerglide combo a few weeks back when I was thinking about how to balance my weight against the powertrain weight from side to side with my legs in a pretty narrow footwell next to the engine and letting my shoulders hang out over the transmission so the total polar moment was as low as possible. Anywho, I decided to build a model because I’ll never be able to build the full-scale version while I’m building the Sprint-T. The plan so far is to have the left side exhaust run over the driver’s legs like the right side of a supermodified. And also to have insulating blankets between the manifold and the driver’s legs, like in the supermodifieds. With the short runs in SCCA Solo Racing that’s probably overkill, but it doesn’t weigh much and it increases the safety margin over just wrapping the pipes with exhaust wrap which I was going to do anyway because of the performance benefit.

Last thing before I drop this on you, the remnants of the hurricane passed far enough to the east that we only got one brief shower here that was dried up before I finished. The walk was dry when I went to get the mail, that’s how brief the shower was. Also someone dropped this link on me and I liked it, so I think I will pass it along.

Still thinking about… things

Not to sound ominous or anything, just that I have been letting my ADD do its thing and letting my mind wander around a bit.

One thing I have been thinking about is I used a wrong number in the sitting beside the engine SCCA A/Mod car. The engine extends 9″ to the left of center on the left, not the 8″ I used to figure my offset, so y=x-16 rather than 15, and the 7″ comes from the fact that I have room left over in my 14″ wide racing seat. And before anyone else can say anything yes I have a narrow butt. Anywho, I was also thinking that I could use 3 pedals if I sit next to the engine because I basically have as much room as I want to the left, and 14″ is plenty of room for a 3 pedal footbox. With the linked pedal set the brakes and clutch pedal could be mounted in the 7″ to the left leaving lots of room for the linkage to the gas pedal to the right.

Odd as it might seem the car that has the driver to the left of the engine has more room for the pedals than the Sprint-T because of the body limitations being 34″ wide at the floor in the middle of the car and the firewall only being 26″ wide. This limits the engine offset to 13-(engine width to the right) inches, or about 3″ for the LS engines, leaving just 16-9 or just 7 inches of space for heels with no room for the right foot to lean to the right. Sure feet will fit there but there isn’t much room to shift from side to side to keep your legs from cramping on long trips like the trips to the races planned for the Sprint-T. It will work, I have tested it by sitting with my foot in one spot while working on the computer for a few hours, but it is uncomfortable as all get-out. The seating position is really better for autocross racing or SCCA Solo racing than it is for long highway trips. For racing the seating position holds the driver in position directly on the controls, but for long trips that is a liability because the driver can’t move without moving the gas or brake pedals, which means that long trips will require frequent stops for driver comfort.

Something else I have been thinking about is building myself a trike I can get in and out of so I can start riding again. The easiest thing to make would be a tadpole trike, or reverse trike as some call them, 2 wheels in front, and a regular bicycle rear triangle in the back for the rear wheel. One thing I have been thinking about for this vehicle is how to make the pedal reach adjustable for different riders without having to alter the chain to fit each rider, because I know that I’m not going to be the only person to ride this trike. Something like this will invite other people of limited mobility to want to ride, for the same reason I want to build it, wanting to ride still or again but can’t get on or off a regular bike any more. So what I came up with is having a regular bike driveline mounted to a boom that has a pivot concentric to the rear cluster so that the pedals can be moved fore and aft in an arc while the tension on the chain to the rear wheels stays the same. All the fiddly bits are in a small space that is easy to get to on the front of the trike, and it can be removed for extensive maintenance or repair. The chain to the rear wheel can be fully enclosed to only need annual or biannual maintenance and also not transfer grease to the rider’s legs if inadvertently touched.

And I have been thinking about all this stuff in a vain attempt to not think about other stuff like BLM and COVID-19. I can’t for the life of me figure out why any of this is controversial. Police shouldn’t predate on unarmed black men, and when there is a virus that is spread by breathing covering your mouth and nose to keep virus-laden particles from getting out or in. You prevent yourself from getting sick, but more importantly if you are pre-symptomatic or asymptomatic you don’t get other people sick. So stay home when you can, and wear a mask when you can’t stay home. The life you save may be mine!

I’m not dead again yet

And that is one convoluted headline that wraps up my life in a sentence. I’m just reading and doing stuff, practicing making exhaust tips and things. I haven’t made any real good tips yet because I keep collapsing the tubing against the bending post, because the differences between soft enough to bend and soft enough to collapse are this much (holding fingers almost touching) and I haven’t got the touch down yet. I need to get the spatial relationship between the heat source and the bending post better, but ATM I have zero idea what that should be. What I’m looking for is close enough to get the soft tube to the bending post while it’s still soft and so I don’t have to let it get too saggy and stretch it out and make it too small. There are literally thousands of ways to screw this up and I’m finding most of them.

Mrs. the Poet wants me to be in bed at the same time she is, and so do I. It’s getting close to the time she gets up, so I’m putting this to bed now and me shortly after.

A little late, but here it is

Sorry to take so long but I finally got a decent picture saved someplace I can use to post it to the blog.
See that teardrop opening?
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

I spent hours practicing

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

I have been practicing on raw stock

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.
that's a thick-wall tube if I'm trying to emulate exhaust tubing
And after, notice the thin edge looks like the whole tube is really thin.can you see how much thinner the tubewall looks now?
On a different background and lighting to make the difference more noticeable.That's really thin now
And before really needs a contrasting color on the edge but the tube wall is still discernible.needs better lighting and a better photographer

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.

Waiting on the door installation people

OK I have selected storm doors to replace the ones installed when the house was originally built in 1985, now I’m waiting for the installers to arrive and measure the door to get the right size storm frame. As this is one of the few standard size things on the house, I don’t expect too much hassle getting it installed.

One thing I have to say, it’s easy to get through the door once it’s open, the frame is 3′ x 6′. Looking through the Lowe’s listings this is the largest standard door available. There are taller doors, but they are only available by special order. There are lots of doors that come narrower, but I didn’t see anything wider. So 3 by 6 is as big as you can get without spending buttloads of money. But the installation people have to verify that in person so they get the right thing.

I have been practicing with the bender for the plastic stock of the frame and exhaust for the Mini Sprint-T, as the exhaust in particular requires lots of work to get right and there is a bend for the muffler/tailpipe in particular that really needs to be done right. To simulate the thin wall exhaust tubing of the 1:1 scale vehicle the end of the exhaust tip needs to be filed to a knife edge from the inside and the inside painted matte black or matte silver. That’s something I’m going to have to research, does E85 leave a carbon deposit when tuned for best power? I already know that the highway mileage tune for 87 octane won’t, as it is about as lean as the engine will run right with, emulating a tune that let a ZO6 Corvette get just over 38 MPG in a real-world highway test. For airplane drivers this is the car equivalent of tuning 150° lean-of-peak on the EGT. And for people not aware this is over 40 MPG steady-state from an engine that displaces 427 in3 (7 liters) and put out ~500 HP at the rear wheels back in the day. But anyway the highway tune will not remove carbon deposits at the end of the exhaust, so if the tune for E85 carbons up the exhaust then I need to emulate that in the model. And I just checked the E85 forum and there are 3 posts that say they don’t get any carbon from running E85, and one that said he still has carbon in his tailpipe from the 87 octane the dealer put in when he first bought it, but nothing more than that in 5000+miles since he bought the car, so I’m going with the matte silver for the inside of the tube.

The fuel map is going to look really strange when I get this tune done, because most of the map will be slightly rich except for the RPM block and throttle setting for steady-state freeway cruise at 60 MPH which will have a “hole” that leans the engine as far as it will go and still run right. On 87 octane this will be leaner than the max NOx point so low CO, CO2 and middling NOx.

And I have been sitting here writing for about 3 hours waiting to hear from these people, and it’s about 1630 CST so I’m going to assume they aren’t going to answer today. And this is a good word count to stop at, because I don’t want to bore anyone today. So, I have to go out again tomorrow to deposit a check, which means going on the bus again. But not as bad as Black Friday in the rain.

More parts arrived

The parts I bought this January finally arrived today. The backgrounds are the business cards for the company I bought the parts from, to give you an idea of scale for these parts, and I’m using “scale” in two forms for this. The parts are for the Mini Sprint-T in 1/25 scale.

Rod ends in 1/25 scale, the color is because there was a brass lamp bouncing light from the camera flash

The seat in scale. This is actually much nicer than the actual seat in the car that I showed a few weeks ago, but if I had the $ this is exactly the seat I would install

Again, the backgrounds in the picture, the dark part, is the business card of the company that I bought these from. They literally get lost on a standard size business card. And there was a note inside the delivery envelope saying the guy that runs the whole show for this company just got out of the hospital after 2 months. And those thin pins coming off the top row of rod ends fit snugly in the stainless steel tubes I bought to make the links for the 4-link, and the plan is to add a tiny drop of solder to the end of the tube to hold the rod end and jam nut in place. The jam nuts are those hex-shaped things above the rod ends.

And I need to get to bed, so the blog post needs to, too.

Shopping take two

I didn’t get out to buy butane and bolts today because Mrs. the Poet got a call to go to lunch with a friend and I had already started a pot of beans and couldn’t leave them unattended for the hours and hours they need to assume their beany goodness. So she went out and I stayed with the beans, and I will go shopping on Friday. NBD.

I’m sitting at my desk eating my last meal of the day, which is usually the sandwich and veggies Mrs. the Poet makes for lunch, but because she went out for lunch I had to scrounge up my own food today, after spending hours slaving over a CrockPot full of beans and ham bone. In such a situation my goto meal is usually something in the ramen family or cup noodles, this time microwave ramen bowl with veggies. It is just a constant source of amazement that that tiny packet of dehydrated veggies fills so much of the plastic bowl the noodles ship in. I mean the package is barely as big as two matchbooks, but after cooking there is about a third of the bowl full of veggies. The noodles hardly change at all, but when the veggies are rehydrated suddenly there is a bowl full of food in front of me. I don’t care what others say to me this is one of the miracles of the modern age.

So anyway while I was making sure nothing bad happened to the beans I had some time to think about the reason for the shopping trip. One thing I came up with was spending the extra money for a second 5/16” bolt to make the jig for the roll hoops, since they are going to be identical now. And with the jig I could theoretically make a kit for converting the AMT T roadster kits into a Mini Sprint-T if that seemed like it was a good idea. Right now it isn’t, but that might change in the future, who can say? Certainly not me. My prognostication abilities aren’t that precise. When I was asked to look at the possible outcomes of Bush v Gore I saw battles and chaos and interpreted that as possible civil war or riots in the streets, not the Iran /Afghan wars.

Anyway, back to the car model, if I can find some good wood in the garage I can drill a couple of holes in it to put the bolts into that would be the right distance apart. Then after making the first bend I could use the second bolt as a jig and make the second bend to make the hoop the exact right size for the frame, using guide marks on the jig to get the angles right, which is almost a pun, because both hoops need to have their legs bent to a right angle to the top bar of the hoop. The design has gone through some iterations where this was not a true statement, but for the time being it is true. Both hoops are the same, same width and same angles, and when the frame is finished and painted the internal bracing for the rear hoop gets bolted into the 1:1 Sprint-T after the painted and wired body gets slipped inside the frame and roll cage. Technically that should be a slash (/) instead of the word “and” because the frame rails go around the roll cage which forms structural bulkheads in the frame and the roll hoop bracing becomes part of the triangulation of the frame. As I pointed out years ago now, frame stiffness is a function of d4 where in this case d is the average distance from the bottom of the bottom rail to the top of the top rail, and running the top rail over the roll cage increases d to the max it can be without making either the top or bottom disconnected from the rest of the frame. And it’s much easier to build the frame with removable sections than it is to either spray the body inside the frame a different color, or build the frame around the body without causing damage to the body or getting overspray on the frame or body or both. The tricky part for the model is getting that same effect without messing up the paint when gluing the braces in the frame. I think I might need to use cyanoacrylate for these joints instead of my usual Testors solvent cement because “assembled after paint” so these joints will require a bit more patience fitting together than the ones for the solvent cement. And it’s starting to get to be time to hit the sheets, so I’m cutting this one short here.

Progress, but without pictures

I know, pics or it didn’t happen, but I forgot to take pictures. I still haven’t gotten any butane for the bender, but I’m working on making diagonals to fit smoothly to look like both crossing diagonals are one continuous piece. It’s tricky, and kind of a cut and try thing to get both halves to match up. Many mistakes were made and discarded.

I have been so busy with this I forgot to take pictures, forgot to watch the Formula E race I recorded, and would have forgotten to eat if Mrs. the Poet hadn’t made dinner and yelled at me to come eat after I checked to see if the meat was done enough. I have been seriously spaced about this.

And now I need to check e-mails and get caught up on the day.