Starting to Design my velomobile

To build the plug for this creation I’ve decided to use polystyrene insulation board, commonly found in home improvement stores. This is different than the polyisocyanurate foam I have worked with in the past. Using this material will bring up a couple things that are new to me.

First is that auto body filler (ABF) and the resins that I’ll be using are not compatible with polystyrene, and will cause the polystyrene to melt. So I will need to add a separation layer on the shaped foam plug before smoothing out with ABF or applying gel coat.

Also, the best way to sculpt this material apparently is by using a hot wire. So, I have to figure out some type of tool and process to do that.

And since I’m already dealing with lower back issues, I want to make a work-stand or rotisserie to hold this plug at a height that keeps me standing up rather than crouched low to the floor. I saw an auto body rotisserie offered in an auto body supplier catalog, but $1,400 would be a lot of cash for what I need!

I spent some time walking around a tool supply store looking for ideas, and found these: Manual tire changing station.

Manual Tire changing stand, to be used for my work stand.

These bolt together surprisingly snug and tight, to shape that bottom “X”. There were a couple parts that I put in my metal scrap bin, a couple hitch pins and clips that I’ll keep, and I’m going to re-purpose the other parts.

For my work stand I purchased some 80/20 metal, in 1″ square aluminum bars, 12′ long. I will use one piece as the spindle for my plug, and use other pieces to create a gauge so I can insure left and right sides are symmetrical.

To start with I notched and bent over the middle of this re-purposed part, it will be used to support the 80/20 arbor.

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Cut a notch and bent the tab down as best I could
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A length of 80/20 material resting in the notch.

This got flipped around and welded onto the top of the assembled stand:

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Welding the parts together; the round cylinder I’m welding onto is threaded internally, so this completed tower can be rotated a bit if needed.

I added some wood feet to each support, and installed a board that is attached to the base of the two uprights. Keeps the posts in place and help to stabilize it all. My final design will be about the length of the Milan; I will probably shorten up that bottom board when the foam plug is all together.

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My design will be about as long as the Milan GT. I will shorten that lower board when the foam is ready on the spindle.

The nice feature of the 80/20 material is the clamping and assembly options available. This is the first time I’m using it, but it seems very nice quality stuff. On one end of my spindle I installed 2 locking bolts so that the spindle wouldn’t slide off the stand.

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The 2 bolts thread into a backer plate which can slide in the slot ; tighten up and very secure.

OK, so my work-stand is set up, need to gather supplies.

Foam: purchased in 4′ x 8′ sheets, 2″ thick. My rough calculations were that I would need 10 sheets, but it’s easier to have a bit extra on hand if needed, and I can return undamaged pieces. Purchased 12 sheets.

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12 sheets 2″ thick

Here and there gathering up more supplies,… discount on a dented gallon can of gray gel-coat? Sure! send it to me…. more Tyvek suits…. long knife and extra blades for foam cutting…. nitrile gloves…. already purchased a 500 count case of paper cups a few months back….

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A couple more Tyvek jackets, discounted dented can of gray tool gel coat, paper towels, knife…..

Since I will be using the exact same drive system/steering components as the WAW, I will design things like front boom attachment points top and bottom, front suspension attachment points, steering points, things like that to the exact dimensions as my WAW.

I figured it would be very handy to have a very large caliper to quickly and accurately take measurements. I recognize I am very fortunate to have two different velomobiles here as I design and create, to be able to measure things out rather easily. I know that others who have built their own velomobiles had to decipher and estimate based off photos or estimates.

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X-Kaliper from Oregon Rule Co.

I purchased these from Oregon Rule Co, called their X-Kaliper. You select your desired arm length and spine length.

I ordered 22″ long caliper arms, and there is an additional measuring spine that can be attached to the right side of the caliper as seen, so I can measure out to 64″. The arms slide along the spine in grooves, easily clamped in place with the two thumb screws. Rock solid and consistent measuring. Very nice!

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But I didn’t realize they could also be very helpful at this stage; measuring the widest point on the WAW, just forward of the front wheels. I’m measuring here just to determine what size foam blocks I need to cut for my plug.

PB150044

I wanted to get something figured out for a hot wire foam cutting tool. Haven’t done anything like this before….

I have a variable amperage battery charger in the workshop so that will be my power supply. I cut a simple C shape out of some scrap plywood, added a handle and a couple bolts for the wire. I didn’t anticipate how much the wire stretches when it gets hot (and news flash, guitar strings don’t work well for this… ). I had to keep grabbing a screwdriver and adjusting tension, then snapping the wire. That wasn’t working…

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My first try on the right; on the left is my improved version, hooked to my battery charger

A friend on BROL mentioned that I needed nichrome wire, so I ordered a spool of that. Another friend discussed making something resembling a bucksaw when he did wire cutting before. That got me to thinking some more, wandering around the shop and pondering more, and….

Came up with this! I took a Quick Grip clamp, removed a roll pin from the end of the metal spine, removed the handle and reversed it, and then re-installed on the metal spine. Drilled and installed a screw eye on either end, wire strung between them. So now when you manipulate the clamp handle it moves the clamping arms away from each other. And the arms are made out of some reinforced polymer that is not electrically conductive. I added tape to the right side as an added precaution, since that will end up being a handle.

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Limited cutting depth of about 3″, but if I feel I need more depth I can add wooden extensions.

I should point out here that I’m using the “old school” process… I know that one could put things into a 3D design program, cut and splice a design into 2″ thick segments or something like that, but I’m going with this process. As my wife (the 34 year Art teacher veteran) says, it’s my version of sculpting.

I’ll accept that! OK, I think I’m ready….

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