Critique this velomobile body

[The Toecutter]

I haven't progressed on this project since the hurricane hit. I've been working 12 to 16 hours without a day off.

[Stubby79]

Originally Posted by The Toecutter

I haven't progressed on this project since the hurricane hit. I've been working 12 to 16 hours without a day off.

There are more important things than one's side projects. Occasionally.

[Ecky]

Originally Posted by The Toecutter

I haven't progressed on this project since the hurricane hit. I've been working 12 to 16 hours without a day off.

That's me as well. Half of the technicians in my area are in Texas for disaster recovery, leaving me covering lots of other calls / shifts.

[freebeard]

You've gotta have priorities.

[Grant-53]

Fatigue makes for mistakes; stay safe. We'll all be here when you need us.

[The Toecutter]

I will have my first day off in roughly 1 month this Saturday. I'm hoping to get at least a tailbox ready. I am in the process of a re-design and have discovered that for my chassis dimensions, steering requirements, seat and boom position, and other variables, I will not be able to make a perfect NACA0026 teardrop work from the top-down perspective, but the shape will be close.

I hope to have the next drawing ready to post this weekend.

[The Toecutter]

I never did get the opportunity to scan my drawing and the camera on my phone broke, but I did manage to test a tailbox some weeks back. The right steering spindle failed at about 25 mph. It required noticeably less effort to push at speed, but my speedometer was broken and I was guessing the speed at which it broke based on cadence and selected gear, but I was no where near topped out. I was only a few blocks from home when it happened, fortunately, and was able to very slowly ride back.

Last weekend I got the trike back on the road. I had to have my suspension blocks modified to fit the dimensions of the new redesigned spindle, and it sat for 2 weeks because of that as well as waiting for the replacement spindles to arrive. I replaced the left one as well; it had cracks across the welds. I was running the gas shocks at 80 psi and have reduced them to 60 psi.

I haven't done anything with my body pieces since that test, but I spent a portion of time after work yesterday carrying about 50 feet of 1-inch pvc pipe cut into 5 foot sections on my lap along with pvc elbows(90 degree and 45 degree) and T-s back home. I'm building a roll cage structure out of it before I mount the front pieces to the tailbox that compose the rearmost 70% of the vehicle dimensions, as well as allowing the body shell to have more permanent and safe mounting points. I'm taking advantage of the 4-day weekend for this and hope to have something more substantial than a tailbox usable before I return to work on Monday. I dont expect to have the hood piece ready, but everything else is a possibility.

Once I have that working, I can build the pieces needed to seal my chainline from the elements and then go about replacing my crankarms, front and rear gearsets, upgrade to trigger shifters, and install a torque-sensing bottom bracket/instrumentation. I want the drivetrain sealed so that the parts get tens of thousands of miles with minimal maintenance, like some commercial velos.

A butterfly-style steering wheel and rack/pinion system may be in its future as well, which the next body will have to be designed around. I might be able to make a NACA0018 layout fit a top cross section of the vehicle perfectly and shape the whole thing with compound curves, which may allow an area around 0.4 m^2 from the reduced width a steering wheel will allow and who knows how low drag coefficient can go on an open wheel design(low 0.2s are possible with open/exposed wheels, but can better be done?), but I will need some software to analyze it and shape it accordingly to my needs BEFORE I go through all the effort to make a plug and lay glass down or try carbon fiber.

[freebeard]

Any chance you know someone with a phone that has a working camera?

...the next body...

PVC is brittle, nasty stuff. I collected a few of these:



Wakeboard control arms. They're 1 1/4" aluminum tubing bent and tempered.

[The Toecutter]

I had to disassemble it again today to make replicas of some of the pieces to help add more rigidity. While doing so, I had a friend take the following picture now attached to this post.

That is the tailbox as I tested it last month(minus a few minor pieces designed to keep it from wobbling around without the front assembled to it). I still have a lot of work to do before the whole shell is usable, but the tailbox is solid.

[aerohead]

Years ago,at the International Human-Powered Vehicle Speed Trials,at Battle Mountain,Georgi,who'd designed the then,fastest bike,told us that the 1/4-inch gap between the wheels and wheel fairings was responsible for half the drag of the bike; which has around Cd 0.11.
I' don't have much data on exposed-wheel rigs,so I'm not much help to you.