Thursday, December 20, 2012

Keeping the Rain Out

This is the part that will keep the rain that runs in along the door edge off of me.  This will fix one of the only criticisms I have come across of the Milan.  There are still the usual ones of cost and weight but they also apply to all other velomobiles.

The flange the door closes on slants inward so any water getting to it will run inside the velo.  The above part has three purposes:  the first to direct water into the bottom of the velomobile, the second to round off the otherwise sharp edge of the door lip and the third to stiffen up the door edge.  One could make the edge thicker but this will add more weight than the above part.   The other choice would be to use a soft gasket the door closes down onto.  For my experience with gaskets in kayaks, this was not the way I wanted to go.  Besides, the finished look of the Milan is nicer without the gasket sticking out. There is a small gap between the front of the hood and the door just above my shoulder.  This lets most of the rain in.  Now with the gutter it can no longer drip down onto me. 

The rain gutter is two layers of carbon fibre with a third layer on the inside edge. Weight of the part is less than 50 grams. If you cost it out based on weight and the time it takes to make it, it might be one of the most expensive bits in the Milan.  At first I thought I could get away with a contact laminated part, but it needs to be vaccuum bagged as the material doesn't always stay in the sharp contours. 

Wednesday, December 12, 2012

Milan Handle

The retracting hand hold on the back of the Milan is easy to install.  Installation on other velomobiles would be similiar. 
Here you can see the two holes drilled in the back of the shell.  I first drill a small hole with a 3/16" bit,  follow this up with a countersink to carefully bevel the gel coat slightly wider than the finished hole.  The reason to bevel the hole is to prevent chipping of the gel coat when drilling the final sized hole.  Then I drill the hole to the final size, in this case 1/4".   
What it looks like on the inisde.  I glassed on the anchor point but you could also bolt the "p" clip in place.  There is a 30" piece of 5 mm rope and a 22" piece of shock cord.  The reason for this much lenght is so you can reach it after the rear fender is in place and replace the cord and shock cord if necessary.  The top of the Milan is permanently bonded to the bottom so there is limited access.   Reaching around the fender is difficult as I discovered putting the first handle on the first Milan GT. 
 
The finished result with the rope pulled snugly against the back of the shell.  The distance between the holes is 8.5cm.  The previous one was a bit longer but I like the new lenght better.  



Thursday, December 6, 2012

Heat and hold down jigs

Now that the heating season is here I have had a pellet stove put in the shop.  So far I am quite pleased with its performance.   One does notice how much fuel it uses as you need to fill it manually.  The big advantage over just a wood stove is that to light it you only press a button.   It also burns very cleanly as you do not see smoke coming out of the chimney only some shimmering from the hot combustion air going out.   My other choice here for heat other than wood is to use electricity.  The vast majority of the electricity used in BC comes from hydro power but some is from coal fired power plants in Alberta and some from burning natural gas.  Using  electricity is much more expensive and not the greatest choice for being carbon neutral.  I do have some baseboard electric heaters as backup heat.  They will be used a bit when I have specific areas that need more heat.  Luckily, for the most part, I only need the extra heat for short periods.
 
A side benefit of having bags of pellets is that I have found another use for them.  Some of the moulds are odd shapes and hard to hold in place when you are working on them.  Partial bags of pellets make good weights to hold them in place. Here is an example of a couple in use.
 


Wednesday, December 5, 2012

Weight


Here I am weighing the left side bottom part to see how much lighter the carbon/Kevlar part is than the glass part.  This part ended up weighing 2300g with a saving of 1160g.  There is still some potential for a bit less weight maybe 100-200g but that would have to be done carefully after seeing how this laminate works out.  The other two shell parts were a bit lighter with all three weighing in at 6.7 kg (14.74 lbs).

I have made the other major parts and the total weight saving is going to end up around 4 kg.  This will mean a finished weight of around 26-27 kg(57-59lbs) when equiped with 70 mm drum brakes and the lighter rims and tires. 

Monday, November 26, 2012

Progress on the next Milan

 
 
The first seat and carbon wheel well.
 
 I finally finished off the seat mould and made one.  This one will go into the first Milan GT and I will take the seat from it and put it in the carbon/Kevlar one I have started building for myself.  This seat is a bit on the heavy side as I made it out of glass with one layer of basalt/carbon on the front side and in the ribs down the back.  Can drop at least 200g off the weight just by using less layers and it will still be strong enough. 

The carbon wheel well came out quite well.  There is a reasonable weight saving from the glass/Kevlar version.  This part takes me a long time do as all the material needs to be glued in place before I put the bag on.  Being a fairly complex shape the carbon is in relatively small pieces which each need to be handled separtely.   The bag ends up with lots of wrinlkes in it which makes finding and fixing a leak a real challenge.  This of all the parts for the Milan is the one we will have the highest failure rate with.  I would much rather make a top or side of the shell as they seem to go quicker.  The shell parts do actually take quite a bit longer and I like to have two people when we wet out the part.  Much more satisfying when you demould a large part.

I am making up all the small parts for the next Milan so I can assemble the next one without being held up waiting for these parts.   This is also a good way to check that all the moulds are ready to use.  I anticipate that the first Milan GT for sale will be built in January. 

Sunday, November 18, 2012

Two Hoods

This is the new larger hood I can comfortably wear a helmet in. 
What it looks like from behind.  I have some thin foam attached with Velro to the back edge of the hood to add a bit of ventilation.  They are removeable so I can experiment with what works best.

Close up of the slots that control the shape and position of the visor.  To open it you just push it up with your finger.  It stays in place quite nicely at whatever position it is set at.  To close it I have a short cord attached at the bottom edge that hangs down inside.  Just pull the cord toward you and that side closes.  Pull the other side and it is closed.  The cords are still a bit of a work in process.   Maybe a small hole in the middle of the visor at the bottom edge so you just use your finger to close the visor.  The other idea is a lexan loop bolted on the bottom edge instead of the hole.  The hole even if it is small will let a fair bit on water in at speed.   
The two hoods  in an end on view.  the original hod is on the left.  The new Milan GT XL hood is on the right.

Wednesday, November 14, 2012

New Hood

I have decided to build a slightly larger hood so I can comfortably wear a helmet while riding.   Here in this part of Canada riding with a helmet is a legal requirement.  I have been riding with a helmet for a long time now and it just doesn't feel right without.  The other consideration is that if you were involved in a serious accident the insurance award can be reduced by estimated protection the helmet might have provided.
 
I ended up making two different front visors as the shape of the new hood is a bit different.  The original is the top one in the photo.  It seemed to take forever to get the right shape as I had to make the first one by hand and then transfer it into a CAD program.  I then used that to create the file for my CNC router.  A couple of revisions later and we have visors.  The advantage of cutting them on the CNC router is that they will all be the same so replacement is straight forward.   Besides, making the slots freehand was no fun.