Friday, August 24, 2012

Rib Bonded In

 
The did a quick hand layup of the rib yesterday using some carbon and basalt.  It ended up weighing 178g and should be tough enough to stand on.  I couldn't get any deflection by pressing on it in the middle, supporting one end on the bench.  I didn't try really hard as this wouldn't be a good test as once its bonded in the shell, the shell will add more stiffness. Another reason I didn't try too hard is that the rib was not even close to fully cured.   
 
 

I glued the rib in and could check out it's effectiveness today.   First I put the part on the floor on some foam and stood on it.  Definitely strong enough.  Then I supported it on some blocks on either end and stood on the middle and jumped around carefully.  My conclusion is that it is a bit overbuilt.  It took about 50g to bond in so ultimately with a bit better layup using vaccum, just slightly less material the finished weight bonded in could under 200g.  Now just to make at plug and mould so I can do one for the other side.   Looking down on it from above.

Wednesday, August 22, 2012

Shell stiffener

Managed to get the part I was worried about out of the mould without it sticking like the last one.  The left side bottom section of the shell is an experimental part to test the mould and planned laminate.  The test in the laminate is to use some Kevlar as the reinforcing bits instead of glass in a glass part. Kevlar will add some impact resistance and it's lighter than glass, being less dense so it builds thickness with less weight.  Kevlar seems to reduce transmission of noise through the shell.  If it proves its worth I will use it in the standard glass laminate.  Not adding it due to the extra cost would be short sighted provided it works. 

After examining the stiffness in the floor I decided that a stiffening rib as the best way to stiffen it up.  The other option I considered was adding a foam or honeycomb core.  The core is more work and may not be lighter.  The stiffening rib would go from the back edge of the wheel housing to where the rear suspension pivot is mounted.  The rib along with the very stiff corner at the bottom edge of the shell should act as a frame on either side of the shell.  If it works as well as I think it will the drivetrain should be very stiff.  This should help with climbing as there will be no losses due to flexing. Here is a picture of the pattern I am developing for the stiffening rib.

Another one with the rear suspension taped about where it mounts.
 


Other velos seem to have an aluminium frame member running under the seat (Mango) or an aluminium extrusion running in the chain trough (Quest).   Hopefully my solution works better than either of these methods.  If the stiffening rib is strong enough to step on beside the seat you will have some options for getting in and out by not being limited with only putting weight on the the bridge between the wheel housings.  There will be another rib bonded to the side of the shell from the bottom corner to where the crossmember from the fender ties in with the sides. 

Monday, August 20, 2012

Stuck


It finally happened.  I stuck a part in a new mould.  This hasn't happend for a few years and it is always a suprise when it does.

I did manage to get the part out of the mould after a long struggle.  You can see where the gel pulled off the part and stuck to the mould.  I had to cut and break up the part some to get it free.  I was even  able to chip the stuck gel off the mould without damaging it.  I only have a small bit to sand off.  It's only about the size of my thumb nail.  Luckily it didn't stick where the suspension strut fastens at the top of the wheel well.  There is a bit more to sand around the edge of the mould where the vinyl ester resin really stuck.  This was on the flange where there was no gelcoat.  Vinyl ester does stick much better than polyester gel coat.  It the future I will use PVA in new moulds until they are broken in.  I thought lots of coats of wax would do the trick but I guess not.

I have another mould sprayed up which I am hoping will release well.  This mould was treated the same as the one I stuck the part in.  I am keeping my fingers crossed that it comes out OK.   

Monday, August 13, 2012

Surprise, not riding velo much

There is a reason for not riding one of my velomobiles much.  I have a high racer that I am trying to get down to under one dollar per kilometer.  It has taken quite a while to get to this point where I am close to the goal as I have had the high racer for three or four years.  Obviously I have not ridden it much opting to use a velomobile instead.   It is a Bacchetta Strada that I bought from Cambie Cycles for a good price.   I do have some criteria for doing this, it has to warm enough to ride with short sleeves, it has to be dry, there have to be some hills and the ride can't be too far.   Riding to the post office or store on the island fits these conditions but at only 10 km for the round trip you don't knock off very many kilometers.

Last week end I went for a longer ride catching the ferry over to Vancouver Island.  It was a nice warm sunny day and I rode too far without eating and drinking enough so the last bit of the ride wasn't as pleasant as it should have been.  The last steep hill after getting off the ferry to Quadra Island was tough.  Had I been in my velomobile I would most likely have stopped and rested very briefly on the hill or gone at a very slow pace in low gear.  On the high racer I don't have the option of stopping without getting off(walking is uncool but can be necessary) and it is geared a bit high to go slow enough.  If I rode much slower balance becomes my main issue.  I did the same ride just a couple of days ago and felt much better.  A bit more liquids and some food did the trick.  I did have a good tail wind for the first part of the ride and was holding 38-40 kph which was great except I would have to ride back against it. 

I finally rode the velo to the post office the other day.  The big surprise was that I was faster than with the high racer.  The trip ended up being 25:38 minutes compared to around 28-30 on the high racer.  I had assumed that I would be faster on the high racer as it is a bit hilly.  The reason the velo was faster is that I could carry a bit more speed from the downhills to the uphill.  The hills are fairly short but terrain is not would I would call velomobile friendly.  Not enough rolling hills just some short steep bits.  Curious to see if the Milan GT will be even quicker as I should have a bit more speed coming into the uphill bits.  Even just a few more kph cresting the hills would make a big difference.

Wednesday, August 8, 2012

Last Mould

I am presently working on the last mould--not really the last mould but the last needed to make the first Milan GT.  



Here you can see a trial fit of the door plug into the mould before making the return flange.  I am a bit worried that I may have to redo this mould if it does not fit well enough.  Having to press the plug into the mould I made it off of is not a good sign.  It may well work just fine but there is no way of telling until I make an actual part and fit it to the shell.  Progress has now sped up a bit as I finished the kayaks I had on order.  Here is a picture of them and the Milan GT plug.  If the Milans come out as nice as these kayaks I would be very pleased.

I have been walking by the Milan plug a few times every day for a while now.  The shape is growing on me.  When I first saw it on the internet I was doubtful about liking the shape.  This was until I saw it in person during ROAM.  It really does look much better in person than on a flat screen.  While some may like a simpler shape, the nice flowing curves remind me a bit of shapes found in classic old sports cars.  Depending on how the light hits it, it always looks a bit different.  My biggest decision will be what colour to build mine.  I am leaning towards the blue that is in the kayaks.  My second choice is white as it very visible and dresses up really well with a contrasting coloured stripe.  A distant third is a dark green much like British Racing Green.  The reason I won't go with the green is that it shows every little scratch.  Yellow is out as we build about 40% of our kayaks in it and while I like the colour I see too much of it.   








Thursday, July 12, 2012

Three More Moulds to Go!!!

I now have three more moulds to make before I am ready to start on building the first Milan GT.

The one of the left is the storage tray that mounts in front of the left side wheel housing.  There isn't one available for the right side but if I find it really useful I will make one for that side too.  The down side of this is that you end up with more stuff as once its in there you do tend to forget about it.  Both of these storage areas together are about the volume of a mid size pannier.  The middle one is the hood.  It should be fairly straight forward to make once we have the mould with a flange on it.  The right one is the door.  It will need to be a two part mould as it has some undercuts.  There are three different sizes of door but I am starting with the one with the biggest bumps.  The others can follow later.   Same applies to the small mouldings used to mount the side stick steering and electrics.

It seems to have taken forever to get to this point.  There is still a lot to do before the moulds are ready to use but that is just sanding and polishing.  I will be quite happy to see the end of the sanding as its boring to do but you do need to be careful to do it properly.  More skill required than you would think at first glance.  I can only sand for a while each session as my hands an elbows can only take so much.  It's not so bad if you are outside on a sunny day.

Tuesday, July 10, 2012

Best seat at the Movie



I arrived early and had to wait a while until the movie started.  The velomobile was a big hit with the kids.  


Testing the system and waiting for it to get dark.  I took a picture in the dark but it didn't turn out very well.  The carbon top just disappears in the dark.

We had the chance to go see a movie at the Blenkin Park next to the community centre on Quadra Island.  I ended up with the best seat in the park.  Being inside the velomobile was quite an advantage as it cooled off after dark.  Folks sitting in chairs were wrapped up in blankets and wore toques ontheir heads.  I was OK with just a sweater on and my jacket draped over me.  I actually nodded off for a few minutes so I couldn't have been too cold.    I would not recommend sleeping in the velomobile but it is possible in a pinch. 

The screen is an inflated structure about three stories tall.  It only takes a few hours to setup.  The Coastal Cummunity Credit Union is the main sponsor for the event.  Luckily the weather co-operated --the week before it had been raining and a few degrees colder. 

The ride home was interesting as my lights failed to function properly.  I had forgotten to plug a battery into the E-werk and it doesn't work properly without it.  I have a Son dynamo which normally charges a battery and then runs the lights.  I had tested to be sure I had lights before I left as I had charged a battery and turned them on.  The lights would come on and then turn themselves off after about five seconds.  Luckily it was clear night and the moon was just rising.  I did have the flashing rear taillight working so cars could see me from behind.   In the last half on the ride no cars passed me and I could smell the honeysuckle that is in bloom all over the island.  One does go rather slowly downhill when you can't see too well.  Some spots where the forest was tight on both sides of the road were pretty dark.  A mini adventure not to be repeated.