I’m still having fun building parts for the Milan SL. My last piece was the head out lid and shade cap. After building these pieces, I realized that I should be able to stow the cap inside the Milan. The single piece cap assembled with its pillars doesn’t fit in the available space in the Milan. Stealing some ideas from Wim Schermer’s splittable Quest hood, I came up with a quick way to remove the pillars and split the cap into 2 pieces without tools.
Here is the unpainted hood – split down the middle. At this stage, it still had the pillars mounted with screws.
One of the problems I had to solve was to come up with a quick way to join the halves without using tools. I settled on using 3M Dual Lock. The idea was to fabricate a flange or lip on the underside of one half of the cap, for the full length of the split. The lip would have enough depth to allow 2 thicknesses of Dual Lock. Here’s a cross section to show what I mean.
Laying up the flange didn’t sound like a lot of fun so I came up with an easier but less optimal way to accomplish the same thing by 3D printing something similar. Rather that printing a flange for the whole length of the split and trying to get the curvature right. I decided to print some 1″ long sections of flange, using carbon fiber/PETG filament, and epoxy them on one half of the cap along the split. Here’s the design of the piece. Also shown is the underside of the cap.
The next item to address was getting rid of the screws holding the pillars to the cap. I ended up using a slightly re-designed flange piece to attach the pillars using Dual Lock. Lastly, I wanted to get rid or the 2 allen screws on the clamps holding the lower pillars to the lid. I redesigned the clamp to use only a single M6 thumb screw. Here are some photos…
There’s a problem with the approach I’ve taken though. The split is not entirely sealed against the elements since there lip doesn’t run the whole length of the cap. If, over time, I find that this splittable cap is worth keeping, I’ll replace the one inch flange pieces with a full length carbon fiber flange.
After finishing the head out lid for the Milan SL, I thought about those sunny days that I need the added air flow of the lid, but also want some shade. I looked back at the shade cap that I made for my WAW. It worked well and I liked the way that it looked. So I decided that I should make a similar removable shade cap to use with the head out lid of the Milan.
Here’s my WAW shade cap from a few years ago. The WAW has some nice clamps installed on the inside of the lid near the cockpit edge. These were great for mounting the clear plexiglas posts shown below. It only took a few seconds to loosen the clamps to remove the cap.
I already had a scrap piece of a hood from my Milan’s one piece hood mold. I just needed to come up with the plexiglas posts and some clamps similar to those used in the WAW.
Here is the Milan shade cap. Notice in the head on view below, how much open space there is for air to pass through.
Here’s the clamp that I designed to mount the clear plexiglass posts. I printed them with carbon fiber / nylon filament and embedded metal M5 threaded inserts.
By the way… I’m aware that the Milan’s aerodynamics are most likely compromised with this cap, but its only purpose to keep me comfortable on warm days.
The stock Milan opening is enclosed by 2 pieces – the lid which covers most of the opening and a small hood which attaches to the lid.
It’s nice to be able to ride without the hood on hot days. To do so, you remove the hood from the lid and ride with just the lid.
The problem that I have with riding head out with this setup is that the opening in the lid is so small that the front of the opening feels like it’s right in my face. So I decided to make my own lid to be used exclusively for head out riding. It provides a larger opening for a less confined feeling.
To build the lid, I started by laying up a hood from my own Milan race hood mold. I cut away the overhead portion of the hood, leaving a larger opening than the stock lid’s opening. There is also more of a lip on the front edge of the opening, forming a bit of a windscreen. Notice that I’ve added the same NACA duct and mirror covers as I used on my full hood.
The lid is held in place by the usual Milan cable housing hinge at the front. Also at the front is a single bungee that extends from the bridge up to a hook on the underside of the lid. Magnets are attached at the back 2 corners of the lid to mate up with magnets taped to the inside of the body shell.
I’m used to riding with the full hood, so riding head out is quite different. A lot more air flows past my face and around my neck and shoulders. That is the point of building this lid so this is a good thing. Vision out front and to the sides is excellent. The amount of air flowing through the NACA duct is not as noticeable with the open lid as it is with the full hood. I think that it probably isn’t worth the effort to add the NACA duct in any future lids that I may make.
As for performance… I didn’t take any time to do any actual testing. I’m not able to feel a slow down due to adverse change in the aerodynamics, but I’ll assume that the lid will slow me down a bit. Overall, I’m pleased with the effort. The fit of the lid is decent and the added airflow will be appreciated on warm days.
I’ve been tinkering with my Milan hood, making some minor improvements so I thought I’d do a quick update.
Closable flush NACA duct flap
I really like having a closable NACA duct on my DF – enough so that I’ve added one to my Milan SL.
The flap is adjusted using a lever mechanism similar to the one I used on my DF NACA duct.
Side Window moldings
I 3D printed these moldings in flexible TPU filament to hold the side windows in place. Formerly the side windows were just hot glued to the interior surface of the hood. It looked pretty messy.
Added Snoek-inspired Mirrors
I originally came up with these for the DF. They actually fit the Milan hood better on the flat sides of the knee humps. These mirrors replace the smaller Spin mirrors that were located closer to the visor where the plastic white plugs now fill the holes.
I’ve used various tools over the years to adjust toe in on my race cars, trikes and velomobiles. Mostly, I’ve used various forms of trammels like this nice one built for me by my friend Bill (A2naut on Bentrider).
or this gizmo that I put together using 80-20 T-slot profiles.
There are a couple of problems using these on velomobiles. You have to slide them under the velomobile which has minimal ground clearance. With the trammel, you’ve got to keep sliding the tool in and out to measure in front of and behind the wheesl. The other problem is that some velomobiles have enclosed front wheels so very little of the wheel is exposed below the bodywork.
So I looked at various commercially available toe-in gauges to get some ideas. Most are meant for use with race cars and involve lasers or measuring against an elevated string rectangle. Then I came across a simple type of product called Toe Plates. These are just 2 plates that are bolted onto the front wheels of the car. They use simple tape measures across the plates in front of and behind the wheels to determine the actual toe setting. These wouldn’t work with the velomobiles for a lot of reasons, but I liked the idea.
Looking around the garage, I found some 8020 T-slot profiles and some 8020 90 deg threaded nubs. Using these pieces, I concocted this low slung toe gauge. It’s similar to one that I had seen on The Velomobile Observer blog a long time ago. Each bar is placed along a front wheel. The 2 nubs on each bar hold M8 bolts which are screwed into the nub at the same length to form pointers to be pressed against the rim. Using these pointers eliminates any interference from the tires. The ends of the bars are pulled together by the bungee straps that run under the velomobile. These are adjusted with just enough tension to keep the pointers pressed against the rims. The tape measures are used to measure the distance across the bars at the same distance in front of and behind the wheels. So for example, if the wheels are pointed straight ahead, the bars would be parallel and the measurements would be identical and so on. The 4 red plastic pieces are just supports to keep the bars flat on the ground. I’ll probably replace those with some 8020 aluminum pieces that would be more robust.
Here you see the tool used on the Milan SL with its enclosed front wheels.
I used the tool today to check the toe-in on the DF and the Milan. I was pretty happy with the ease of use and the repeatability of the measurements. The 80-20 products are very precisely machined so once I had all of the pieces bolted together, I had a tool with no slop and very straight edges.
I’ve decided not to update the steering plates on the DF to the newer geometry plates. These plates really improve the straight line stability in cross winds. However, they increase the turning radius noticeably.
Recently, I was riding in some gusty winds and was reminded how easily the DF can be pushed around. Even though I’m not crazy about the aesthetics, I decided to add a tail extension. I had added one to my DFXL in the past so I knew how well it works. Here is the DF with its new tail extension:
I’ve since added a column of red LEDs along the trailing edge behind a cast resin lens and some single yellow LED turn indicators.
This is not exciting news but it may be of interest to a few people. I was looking at a photo of a DF seat mount built by Garrie Hill, when I thought that I saw a bag fitted to the back side of the DF seat. It turned out that it was not a bag. But I liked the idea of using that space for a lightweight bag.
This is the bag that I came up with. The material is a nylon mesh fabric that I bought on eBay. I don’t have a proper sewing machine so it’s put together with contact cement and held in place with velcro. It’s about 9 inches wide at the top, 12 inches wide at the bottom and 14″ from top to bottom.
When I sold my red DFXL, I included my shade cap in the sale. It was a copy that I made of the factory part sold by ICB. It worked OK, but I never really liked the way it mounted with the 2 straight struts holding up the front (shown below).
With spring around the corner, I need to replace that shade cap. But I want something that looks a little better than my previous shade cap. So I came up with a hood, popped out of my aero hood mold, that has a little more structure. It maintains the sections that interface with the cockpit so no straight struts are needed. I opened up the visor area and side windows quite a bit to promote airflow. The sides and visor area openings are contiguous so the cap area looks like it’s floating without any structure holding it up. It did require some interior bracing to stabilize the cap area. (By the way… I’m not sure I like the white cap paint job…)
I haven’t tried the cap out in warm weather yet. I think that there’s enough open area to allow air in, but may need some exit vents to allow that air to flow through the cockpit.
Update: After a short test, I noticed that as the speed increases, less air enters the cockpit through the front NACA duct. This may be due to chaotic air flow inside the cockpit. With that in mind, I’ve added a new air exit duct to see if that can improve the air flow out of the cockpit.
After spending a fair bit of time composing this response, I thought that I might as well capture it for this site as an FAQ. You can see my Velomobile FAQ here.
I also get a lot of questions about my velomobiles while stopped at an intersection or while taking a rest stop. I wanted a quick way to point the curious person to more information. So I’ve added a QR code sticker to the side of my velomobiles. I generated the QR code that points to my FAQ on a free site at http://qrcode-monkey.com and then laser printed that code on sticker paper. Anyone who’s curious and knows what a QR code is can use their smart phone to snap a photo of the side of my velomobile and let the QR code navigate them to my Velomobile FAQ page.
If you are interested in pointing to a velomobile FAQ, I’d suggest pointing to The Velomobile Knowledge Base. This is a much more comprehensive source of information than my bare-bones page.
A word of caution… Some people are rightly reluctant to use a QR code to navigate to a website. There are stories out there of phishing scams that involve QR codes. I’ve looked into http://qrcode-monkey.com (which I used to generate my QR code) and it seems to be a popular and safe QR code generator. Do your own research.
With the addition of the NACA duct and fans, I seem to be getting enough air flowing through the cockpit that I can leave my Lexan visor installed during a ride without overheating. Up until recently, I still left my side windows open so there was an easy path for air to exit the cockpit. Then I decided to install some Lexan lenses over the side windows to improve the aerodynamics (at least in my head). This seemed to choke off the flow of air coming from the fans and the NACA duct.
Then I remembered the small exit vent that I constructed for the aero hood that I made for Peter B’s DF. That hood had no side windows so it needed to provide a way for air to exit the cockpit. Here is that vent under construction…
Fortunately, I made a small mold from that vent so that I could reproduce it easily. So I thought it was worth a shot to try installing a copy of that vent on my own homegrown hood. Here, you can see the progression of grafting the vent into the hood.
It seems to noticeably increase the air flow through the cockpit. However, without proper testing, I don’t know if it has any negative effect on the aerodynamics. My list of features to test continues to grow.