#5

[GeorgeDS]

With high density foam, do you mean something like evazote ?

Just a thought, might epoxy glued and finished 1/4 inch rolled cork be a little sitffer than the foam ?

Hope you will post some picture of the framing in the floor.

I am thinking about a solar trailer combined with a possible sleeping arangment for my diy folding ebike conversion, of which i yesterday smoked the controller

 

[ghcoe]

With high density foam, do you mean something like evazote ?

Just a thought, might epoxy glued and finished 1/4 inch rolled cork be a little sitffer than the foam ?

Hope you will post some picture of the framing in the floor.

I am thinking about a solar trailer combined with a possible sleeping arangment for my diy folding ebike conversion, of which i yesterday smoked the controller

The high density foam I use on the floors I pick up at Harbor Freight. It is foam that locks together to be put on hard floors to alleviate foot and leg discomfort.

Not sure about the cork. Have not played with that idea, but I do tend to stay away from epoxies. I don't particularly like working with them.

The framing will be under the floor and will run from the hitch to the axle. Not sure of the material at this point could be wood or aluminum or a combination of the two. I will post up pictures here when I get to that point of the build.

 

[skyl4rk]

Make sure that the hitch bar is stiff enough and strong enough not to break. I used 1" square tube aluminum and it is too flexible. I think I can reinforce it but I have only used my trailer to sleep in the back yard, so I don't tow it much.

 

[ghcoe]

Make sure that the hitch bar is stiff enough and strong enough not to break. I used 1" square tube aluminum and it is too flexible. I think I can reinforce it but I have only used my trailer to sleep in the back yard, so I don't tow it much.

Well I was thinking a 2"x2" or 1" aluminum tube. The aluminum did seem to flex a bit when I was testing it at the store, but I think it should be ok for this build. A foamie is quite rigid when it is all glued together like a unibody. With the 2" canvas covered floor with a span of only 40", the aluminum would be more for pulling forces than for load bearing. Of course that is just a theory at this point.

You have a picture of your build?

 

[twisted lines]

Is that Hot wire cut ?

 

[ghcoe]

Is that Hot wire cut ?

Yes, all the cuts in the foam are hot wired.

 

[skyl4rk]

Make sure that the hitch bar is stiff enough and strong enough not to break. I used 1" square tube aluminum and it is too flexible. I think I can reinforce it but I have only used my trailer to sleep in the back yard, so I don't tow it much.

Well I was thinking a 2"x2" or 1" aluminum tube. The aluminum did seem to flex a bit when I was testing it at the store, but I think it should be ok for this build. A foamie is quite rigid when it is all glued together like a unibody. With the 2" canvas covered floor with a span of only 40", the aluminum would be more for pulling forces than for load bearing. Of course that is just a theory at this point.

You have a picture of your build?

viewtopic.php?f=24&t=72251&start=15#p1256891

 

[ghcoe]

Ah! Yes I think I stumbled upon this build in my researching.

 

[Terra6]

Looking good.
This is great exploratory work for developing a small lightweight trailer with aspects that can be incorporated into a larger yet small teardrop for max lightweight.

Sub 50lb, maybe even 40 or 35 are great targets for a cycle trailer. What are the euro bike trailer weight ranges?

Thoughts
Narrower wedge shape?
PMF necessary to save weight?
Minimize walls and roof weight with 1/2 inch xps and light canvas for PMF?

On this build since it is for a cycle trailer, everything needs to be assessed for max lightweight/ minimal size to reduce drag and weight.
My thoughts are minimal overall size. In other words not built to space convenience or roominess but more custom sized exactly to owner physical size.
From my experience having used a 24 inch bed travelling in a minivan for 4 yrs, the width of the trailer can be narrower reducing weight. Thinking 30 to 36 wide external. Length equivalent to maybe 6 inches longer than owner. Storage on shelves on side in top corners.
Height again 2 to 6 inches taller than situp height. Possibly angled low at front up to back. Basically a wedge coffin.

Even though this is for an electric bike, they are very limited in range without adding extra weight and aerodynamic drag. That article about the electric bike race with solar to China still highlights that they still required 50% human power even with electric and solar panels telling me that weight and drag still major restrictions.
Weight and size are enemies to human powered (and even electric assist) and it's a great engineering challenge to build max light and yet sufficiently strong to accomplish the task.

Realize that this is a contract job for you, yet interesting engineering challenge.

 

[ghcoe]

Looking good.
This is great exploratory work for developing a small lightweight trailer with aspects that can be incorporated into a larger yet small teardrop for max lightweight.

Sub 50lb, maybe even 40 or 35 are great targets for a cycle trailer. What are the euro bike trailer weight ranges?

Thoughts
Narrower wedge shape?
PMF necessary to save weight?
Minimize walls and roof weight with 1/2 inch xps and light canvas for PMF?

On this build since it is for a cycle trailer, everything needs to be assessed for max lightweight/ minimal size to reduce drag and weight.
My thoughts are minimal overall size. In other words not built to space convenience or roominess but more custom sized exactly to owner physical size.
From my experience having used a 24 inch bed travelling in a minivan for 4 yrs, the width of the trailer can be narrower reducing weight. Thinking 30 to 36 wide external. Length equivalent to maybe 6 inches longer than owner. Storage on shelves on side in top corners.
Height again 2 to 6 inches taller than situp height. Possibly angled low at front up to back. Basically a wedge coffin.

Even though this is for an electric bike, they are very limited in range without adding extra weight and aerodynamic drag. That article about the electric bike race with solar to China still highlights that they still required 50% human power even with electric and solar panels telling me that weight and drag still major restrictions.
Weight and size are enemies to human powered (and even electric assist) and it's a great engineering challenge to build max light and yet sufficiently strong to accomplish the task.

Realize that this is a contract job for you, yet interesting engineering challenge.

Yeah the European trailers don't share their weights in most cases. The only one that gave me a idea was this one https://scout-camper.de/en/home/ showing 47kgs (103lbs.) If that one weighs that much I would venture to say this one is https://widepathcamper.com/bicycle-camper/ in the 150lbs range easy. The person that wanted me to build this one wanted it 100lbs or lighter so I gave up at first once I knew I was under 100lbs. Now it is a challenge to see how low I can go and still make a comfortable trailer. There is a teardrop style bicycle trailer being built too http://mody-plast.de/produkte/fahrradwohnwagen/ . I see on another site that it weighs 92-110lbs depending on options. So I believe I am in a good spot weight wise.

My dimensions are pretty close to what is being built in Europe, as well as DIY builds, although there does not seem to be a standard by any means. I came up with the wedge shape for a couple of reasons. First a boat goes through the water pretty good so flip it over to cut through the air. No front wall to hit something that would throw you over the handlebars, also to deflect impacts to the sides making it easier to recover. If you have a head wind the front will cut through the wind. If you have a tail wind the back flat wall will act as a sail to help push you along. Not sure about side winds at this point. Here is another similar sized trailer like I am building http://www.bicyclecaravan.com/bicycle-c ... trailer-2/.

I am making the sidewalls out of 1" and the floor at this point with 2". PMF will have to applied to add the strength and protection to the foam.

The client wanted something fairly large. I do believe this trailer will be close to the size they would like since they referenced the trailers above as a guide for me. They wanted something to be able to sit comfortably in and store some items for travel. We also talked about solar and extra battery in the trailer. Basically one battery can be charging while they used the other. This is planned to be pulled behind a high dollar cargo e-bike so I am not sure of it's capabilities.

I hope to get the walls up tomorrow.

 

[GPW]

For more weight savings , a lighter Linen canvas is much stronger than a heavier cotton canvas…

 

[printer-TNT]

For more weight savings , a lighter Linen canvas is much stronger than a heavier cotton canvas…

Now he tells me.

 

[ghcoe]

Progress this week.

I was able to finish priming the floor and attach the canvas to both sides. Since I was not intending to canvas the floor I did not order enough canvas so I had to use a Harbor Freight drop cloth for this process.

 

[ghcoe]

Getting a bit behind here I see. Well here is the progress since last time.

The walls come to a point in the front so I used duct tape to hold the pieces together on the outside. I then applied Gorilla Glue along the seam on the inside before I bent the walls together back together.

I added some spacers on the edge to hold the walls up from the bottom of the floor dado.

Then the walls are set up to get ready to glue to the floor.

 

[ghcoe]

First I run glue along the inside edge of the wall dado.

Then I set the nose down into the dado and then bend the walls along the floor profile. I use clamps to hold the walls in place on the back and then check to make sure the nose is slid back all the way. Luckily my measurements all came in so I must of done something right...

Now that the walls are where I want them I apply glue into the crevasse that the shims provided for me.

 

[ghcoe]

A few shots of the walls after the glue up.

I had a couple places where the walls did not want to butt up to the floor properly so I had to add a few finishing nails to hold the walls in place as the glue dried.

 

[ghcoe]

After the walls were dry it was time to raise the roof...

I applied some 1"x2" to hold the roof in place as I installed it and as the glue dried.

Usually I set the roof on top of the walls, but I on this build I decided to install between the walls. This will help hold the curve of the walls at the top since the foam does want to go straight.

 

[ghcoe]

Once the roof was in place I applied glue and then clamped it all together.

Here is a shot of the temporary roof supports once the roof is installed. They will hold everything even as the glue dries.

And then I popped the shelves into the shelf dados. They fit perfect! They will also give a lot of extra strength to the front section of the build.

 

[Bezoar]

Looking good! Been waiting for an update, can't wait to see the finished product and its final weight!

 

[GPW]