DoorK

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Sep 14, 2013
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Bradley Illinoiz
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After chillin' with the family all day I snuck home to put a couple hours in on the DoorK. Got 2 of 4 planned braces for the attachment points started. Looks different with the door out of the way...
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GC.
 
Mar 26, 2012
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Maplewood, MN
Man, you really are going 'all in' on this one Carl! Some impressive work going on.

And, only a kid from our era would use the term 'husky' as an adjective. :grin: I was kind of a skinny kid, so I always had to have the 'slim' jeans. But these days I'm really thankful for my favorite brand, LEE jeans, and their Extreme Motion straight fit tapered leg style. Biking in jeans has never been so much fun!

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And now back to your regularly scheduled build off thread....
 
Sep 14, 2013
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Bradley Illinoiz
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Yeah... I wouldn't be caught dead with hair that short.
Anywho... I've been thinking about the center of gravity and the 10 1/2" clearance height of the subframe and the narrow track at 16". Also there's plenty of clearance for the handlebars to turn. I think I'm going to have to make the two halves lean together, or this beast is going to want to tip over. As far as the precision needed I'm wondering about a ball and socket...
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I could temp weld it solid and go for a pedal powered spin but if I can source the heim? joints (ball and socket), I should probably just do it. More lean to the right and less but still some to the left. I also just thought of this... Putting the battery under the door frame in its own cage would lower the center of gravity too.

Carl.
 
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Sep 14, 2013
6,641
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Bradley Illinoiz
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Posed the bike next to an 8' ladder
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While I'm waiting for the heim joints to arrive I got a couple of the stickers I've been saving mounted on the wing.
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But no real progress while waiting for parts.

GC.
 
Posed the bike next to an 8' ladder
View attachment 160529
While I'm waiting for the heim joints to arrive I got a couple of the stickers I've been saving mounted on the wing.
View attachment 160530
View attachment 160531
View attachment 160532
But no real progress while waiting for parts.

GC.
Awesome frame!

This last picture gave me an idea: Can you mount the door behind the left wheel? I like that utilitarian ratrod look, with the wheel next to the door.
For the doors to open you probably have to cut or build "lambo doors" :grin:

And with the battery you can probably wire a loud horn.

Just throwing ideas here, love the build and direction so far!
 
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Sep 14, 2013
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Bradley Illinoiz
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Door is not going to be an operator...
I'm still waiting on parts and I've got to get going on the battery. It's one of the things I'm missing and I've never played with an eBike before so this will be a learning experience fo sho. If I can source some battery parts and build my own I can save a couple bucks. But I may just buy one and save some time. With battery in hand I can 1. fire up the motor &2. build the battery tray. 1/2" Heim joints are on the way. When they show up swing arms will be assembled and then I'll have to figure out some struts to keep it vertical. I'm thinking the gutted door can't be any heavier than a hatchback, so a couple struts might do but I'm mentally prepared to use 4 if I need to.

GC.
 
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Sep 14, 2013
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Bradley Illinoiz
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So does this make sense to you guys?
DoorK struts.jpg

From the rear view, bike and door are two vertical lines. visualize the swing arms in a row along the bottom edge of the door and back half of the bike as a horizontal line. Now we have a squared off U shape (from the rear view) that is going to want to fall over, one way or the other. Struts are attached in an X shape, top of one side to the bottom of the other. There needs to be enough give to allow the bike and door to lean together, left or right, but enough strut action to help keep it vertical. I'm thinking the struts will need to be partially extended when attached in the neutral / vertical position to allow the lines to lean one way or the other. I wonder how that will effect the struts?

Carl.
 
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kingfish254

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Aug 31, 2009
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Historic Savannah
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Something about that makes me think there are too many connections and it will bind up or be rigid.
Seams like it should be treated like a flexible sidecar. Try searching around on sidecar flex geometry and see if you can find any details on how they work it all out.



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May 30, 2021
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So does this make sense to you guys?
View attachment 160658
From the rear view, bike and door are two vertical lines. visualize the swing arms in a row along the bottom edge of the door and back half of the bike as a horizontal line. Now we have a squared off U shape (from the rear view) that is going to want to fall over, one way or the other. Struts are attached in an X shape, top of one side to the bottom of the other. There needs to be enough give to allow the bike and door to lean together, left or right, but enough strut action to help keep it vertical. I'm thinking the struts will need to be partially extended when attached in the neutral / vertical position to allow the lines to lean one way or the other. I wonder how that will effect the struts?

Carl.
In theory that should work, but… it won’t. You are relying on the struts to off set each other partially loaded, which sitting still might work. But once you start moving the door top out or in while you’re riding the weight from being off center will overcome the struts. I can’t see how leaning the bike will force the side car to lean the same way. If you were to use a upper and lower a-arm like on a car, both would react the same (leaning left, right or straight up). Think of a parallelogram .
 
Sep 14, 2013
6,641
14,340
61
Bradley Illinoiz
www.instagram.com
Something about that makes me think there are too many connections and it will bind up or be rigid.
Seams like it should be treated like a flexible sidecar. Try searching around on sidecar flex geometry and see if you can find any details on how they work it all out.
Yeah it seems like maybe all I need is to be able to lean the bike... Although the last pic looks pretty cool and complicated, rolling the sidecar over and tilting the wheel while staying flat and low. Probably not an option for me.
In theory that should work, but… it won’t. You are relying on the struts to off set each other partially loaded, which sitting still might work. But once you start moving the door top out or in while you’re riding the weight from being off center will overcome the struts. I can’t see how leaning the bike will force the side car to lean the same way. If you were to use a upper and lower a-arm like on a car, both would react the same (leaning left, right or straight up). Think of a parallelogram .
Yes this is exactly what I needed another viewpoint. Thank you @Oldbiscuit I can see where you're coming from and seems right to me, especially the upper and lower arms. A parallelogram is exactly what's needed. There has been one planned for a while, without thinking of it as one and I didn't realize the importance either. I had an idea for an upper arm from the top hinge on the leading edge of the door to the headtube area. My concern with it is the different length. I think the lean would be constant left or right, so the arms need to be horizontally parallel to each other for sure. But what will different lengths of arms do to the geometry? I suppose I'll find out. on the rear half of the frames it will be easy to use an upper and a lower arm of the same length. Once the parallelogram is in place I still think I'll need something like struts in place to help the bike to stay vertical, maybe only from the middle of the door to the lower half of the bike frame to help counter the left turn lean. Now I'm wondering if I need to attach the swing arms from the center lines of each half of the frames? For example an arm attached to the chain stay will drop in relative height from the ground as it leans to the left and raise in relative height on a right turn lean. Maybe the pivot points need to be the same distances from the centerlines to counter each other? Man my head is spinning around trying to visualize it...

Carl.
 
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May 30, 2021
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Carl, the easiest way for you to see your results would be to get 4 pieces of card board strips and put thumb tacks in the corners to make a square. Start shifting like a parallelogram to see how different lengths will affect it. There are computer programs that engineers use to figure these things, but you’re not building a race bike, I’m sure you’ll see the results easier if you play with it on the table with cardboard before you start welding arms on the bike.
 
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