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LongJohn
recumbent guru

China
581 Posts

Posted - 04/07/2010 :  07:30:11  Show Profile  Visit LongJohn's Homepage  Reply with Quote
Rick,

Awesome looking Velomobile.
You have done this in a record time (my "baby" took 9 months...). And its a "bute"!

I hope to get my Velomobile to the painter before summer.

But first; I can pick up my Nazca Gaucho highracer this saturday!!!

Thomas
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vhclbldr
New Member

USA
58 Posts

Posted - 04/07/2010 :  08:51:22  Show Profile  Visit vhclbldr's Homepage  Reply with Quote
wow... I mean.. WOW!
Dude, that design totally rocks. I may be following your example to the letter when I build the body for my velo, too.

I especially like how you planned for entry/exit with stepping in front of the axle (my tadbent will require the same entry/exit plan, too).

What were the dimensions (contact patch) of your tadpole? (wheelbase and track)

Again, fantastic job!

Jamieson
Builder of Tadpole Recumbent w/ Electric-assist
Bel Air, MD (USA)

Edited by - vhclbldr on 04/07/2010 08:52:45
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/07/2010 :  11:57:55  Show Profile  Reply with Quote
Thomas

Thanks for the comment. I have a long way to go before it will be finished, 9 mo. does not seam all that long for a project like yours. I am not even thinking about sanding and paint. You know the 8-20 rule, it just looks like I am getting somewhere.

So what color are you going to paint the "brute"

Rick W
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/07/2010 :  12:08:19  Show Profile  Reply with Quote
Jamieson
Thanks for the complement. I went through a lot of iterations to get the design to where it was buildable with the mold-less method. I will be posting the patterns and templates when Warren and I(mostly I, Warren has been waiting)create a page for the complete build.

The trike has a 27 in. track and a 50 in. wheelbase.

Rick W

Edited by - rickmantoo on 04/07/2010 18:04:40
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jpsantell
Starting Member

USA
2 Posts

Posted - 04/08/2010 :  03:11:28  Show Profile  Reply with Quote
Rick, I read somewhere that you are big, like 6' 6" is this going to be a tight fit for you?
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LongJohn
recumbent guru

China
581 Posts

Posted - 04/08/2010 :  03:48:08  Show Profile  Visit LongJohn's Homepage  Reply with Quote
quote:
Originally posted by jpsantell

Rick, I read somewhere that you are big, like 6' 6" is this going to be a tight fit for you?



BRING IT TO BATTLE MOUNTAIN!!!!!

Thomas (6' 6" 6mm)
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/08/2010 :  06:03:48  Show Profile  Reply with Quote
Jpsantell

You have me confused with Thomas. I am a tad under 5'-10" and getting shorter.

Thomas
BM maybe? Got to geter done first.

Rick W
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raymondg
recumbent guru

865 Posts

Posted - 04/08/2010 :  08:35:22  Show Profile  Reply with Quote
Rick, if you are worried about getting it done in time for Battle Mountain, then cover it with a tarp, don't touch it until Aug, and then work 24/7 for a month. That's how the rest of us do it

Very nice work by the way. This is my new favorite thread.

Raymond
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/08/2010 :  08:51:51  Show Profile  Reply with Quote
Raymond

I am glad you like the project. It is moving allong nicely.

Now that I have the frame almost mounted in the bottom of the shell, I am thinking about what you said earler about the trailing edge of the wheel well. With the wheel in the wheel well, I can see the shape of the wheel well and it neesd to be a little smoother on the trailing edge. I may want to modify he rear edge like you sugested by adding some foam on the inside and reshaping the body. It is only time and a little foam and fiberglass. Do you have any reference pictures of what the modified shape you sugested would look like?

Rick W
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OleBent1
Starting Member

USA
4 Posts

Posted - 04/08/2010 :  13:15:51  Show Profile  Reply with Quote
Rick,

I've been lurking around (occasionally) for a while on this forum, but I've been actively watching this thread for a while now, and now feel compelled to join in. Way cool job on the trike and shell! Very impressive!

I agree with Raymond's observation on the wheel well detail. I think what he's suggesting is a lot like what is done on the insides of open aircraft cavities (like internal weapons bays) to reduce both cavity pressure oscillations (that low frequency drumming sound you hear on some cars when just the back windows are open) as well as extra drag due to the air trying to decide whether it wants to go into or out of the open cavity. By rounding the back edge of the wheel well, it helps entrain the air within the well into the "freestream" air flowing just beyond the wheel well. The same effect can be accomplished with a sloped or ramped rear edge. In the most aggressive cases, rear bay walls have a ramp that extends inward to about half the cavity depth, but I don't think you'll need anything that severe to see benefit in your application. I'm guessing that if you radius the back edge to about 1/4 to 1/3 the depth of the wheel well, that ought to do it.

The other thing you could consider is to install wheel discs on the outside of the front wheels. This "should" help avoid disturbing the nearby airflow as is goes over the wheel well. Hard to say how well the two will work in combination, mainly because of how the bottom side of the open well may interact with the air flowing under the velo. I'm guessing the combination will both reduce drag and may actually make a slightly quieter ride. As I think was pointed out earlier in the thread, the shell probably makes a pretty good acoustic transmitter.

Keep up the great work...looking forward to more posted progress!



Mike

Cruzbike Sofrider V2.1
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Dreamer
recumbent guru

USA
619 Posts

Posted - 04/08/2010 :  17:05:54  Show Profile  Reply with Quote
Rick,

I'll second what Raymond said. If you wait till you get it "done" you might not make it to Battle Mountain for 3 or 4 years or more. Read Raymond's story about his first trip to B.M. with his machine. I suspect that experience has been instrumental in his current success.

If you need more encouragement check out the pictures of the first Spectre we took to B.M. She had coroplast fairings held together with packaging tape and the gaps were covered with cloth and duct tape. We worked on her every day, fine tuning, learning, experimenting and creating but at the end of the week, we had run and that is what this exciting, crazy sport is really all about.

For what it's worth, we learned so much that we scrapped the first machine and started over with the results that we weren't finished with the Specter 2 when we took her to B.M. last year.

Do the best you can. If she's road worthy don't be afraid to bring what you build.

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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/08/2010 :  17:30:10  Show Profile  Reply with Quote
Raymond and Mike
If I understand you guys correctly I should cut in to the trailing side of the wheel well and add a 2-3 inch radius curve in the area marked in red on the attached picture and then blend it back into the body curve 6-8 inches back.


Rick W
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/08/2010 :  17:32:34  Show Profile  Reply with Quote
Dreamer

Thanks for the encouragement Garrie Hill has been after me to get out to BM this year also.

Rick W
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Upright Mike
human power expert

USA
3800 Posts

Posted - 04/08/2010 :  18:04:05  Show Profile  Reply with Quote
quote:
Originally posted by jpsantell

Rick, I read somewhere that you are big, like 6' 6" is this going to be a tight fit for you?

quote:
Originally posted by rickmantoo

Jpsantell
You have me confused with Thomas. I am a tad under 5'-10" and getting shorter.
Thomas
BM maybe? Got to geter done first.
Rick W


The 6'6" person is Frank Geyer (actually he's about 6'4") whom Rick built his last streamliner for...

Frank


Here is Rick... pictured in center with arms raised in triumph!

Edited by - Upright Mike on 04/08/2010 18:07:15
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Upright Mike
human power expert

USA
3800 Posts

Posted - 04/08/2010 :  18:15:49  Show Profile  Reply with Quote
And then there are some REAL giants in this group! I don't know how they fit in streamliners! Thomas on Right.

From BATTLE MOUNTAIN 2008 ALBUM: Some really really tall folks: (left to right) Chuck Royalty, new Trike WORLD RECORD holder; Gordon - a cyclist from Canada who came down to join the Varna crew; Warren Beauchamp - Cuda-W pilot and webmaster; Hans Wessels - SpeedHawk rider who went 73.5 mph during the week; and Thomas van Schaik - who went a personal best 62 mph on his one trial run in the SpeedHawk he says his height is about 6'6" 6 mm.


Carol Leone jumps in the picture with some really really tall people!

Edited by - Upright Mike on 04/08/2010 18:27:41
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Upright Mike
human power expert

USA
3800 Posts

Posted - 04/08/2010 :  18:25:55  Show Profile  Reply with Quote
quote:
Originally posted by rickmantoo

Dreamer
Thanks for the encouragement Garrie Hill has been after me to get out to BM this year also.
Rick W


Rick - if you need a driving companion from our Great state of Michigan to Battle Mountain, let me know! With a stop-over in Iowa Sept 11-12 for the HPRA races there, then its another 1500 miles to Battle Moutain.
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raymondg
recumbent guru

865 Posts

Posted - 04/08/2010 :  20:45:39  Show Profile  Reply with Quote
Rick,
I was thinking something like the pix below. The renderings would be of the starboard side. Rather than a simple radius, I was thinking a 2:1 ellipse to allow a cleaner transition of flow along the side (and bottom) of the vehicle in the vicinity of the wheel well:

-Raymond




Edited by - raymondg on 04/08/2010 20:52:29
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LongJohn
recumbent guru

China
581 Posts

Posted - 04/09/2010 :  01:14:43  Show Profile  Visit LongJohn's Homepage  Reply with Quote
Raymond,

Allert tried to do something similar with the STRADA:

http://2.bp.blogspot.com/_PUYDavQs6vc/S1eFpXRvBfI/AAAAAAAAABQ/vTW5_Ol3vAw/s1600-h/DSC00928.JPG

If you make the "arc" to extreme you get alot of spray when riding in the rain...

So it will be a weighing between aerodynamics and cleanliness of the bike and rider.

Thomas (My VM is really narrow <20", with the frontweheels sticking out. Allthough I have fenders on the front wheels I don't like the look, therefor planning on adding 1930's pick up type fenders).

Edited by - LongJohn on 04/09/2010 01:15:14
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alevand
human power expert

USA
2874 Posts

Posted - 04/09/2010 :  04:53:08  Show Profile  Visit alevand's Homepage  Reply with Quote
Watching the car next to you in the rain on the interstate give an idea why the radius reduces drag.

C:
Tony Levand
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OleBent1
Starting Member

USA
4 Posts

Posted - 04/09/2010 :  07:43:06  Show Profile  Reply with Quote
Rick,

Raymond's rendering above looks great. Consider applying the same kind of blending at the bottom edge/corner too. That should help clean up the flow a little more going under the flat bottom.

By comparison, keeping the "sharp" edges around the rear of the wheel well tends to make the flow enter and exit the well in a unsteady manner, then that unsteady flow just continues to cause issues downstream where you would ideally like the flow to stay attached and clean going around the back of the fairing. Attention to details like this tends to help clean up the flow over a larger part of the back end than you might think.


Mike

Cruzbike Sofrider V2.1
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raymondg
recumbent guru

865 Posts

Posted - 04/09/2010 :  08:07:05  Show Profile  Reply with Quote
Thomas,
Interesting, what is this "rain" you talk about? Seriously, it sounds like a fender might be good regardless. Of course, the fender could be integrated into the shape of the wheel well somehow, maybe by extruding a small section parallel to the ground straight out, starting at the 12 o'clock position and extending aft as far as necessary.

Mike,
I actually did that in the model, but it is hard to see in the two angles I rendered. My thought there was that the bottom transitions might not need to be as extreme as the sides, since the wheel is not steering in that plane.

-Raymond
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OleBent1
Starting Member

USA
4 Posts

Posted - 04/09/2010 :  09:40:46  Show Profile  Reply with Quote
Raymond,

Okay, I see it now that I know to look for it.

I'm thinking that 98% of the time, the wheel steering angle will be nearly zero, so steering angle is probably not a significant design consideration for this. Gut feel is that the bottom blend should be similar to the sides. Flow interactions between the belly and the ground can propagate aft from an open cavity in much the same way as the sides, although having a flat bottom all the way back (like Rick has) will result in fewer bad effects overall. It's probably more a "designer's choice" thing for Rick, based on how much internal volume he has in that area and how much effort he wants to apply to this.

I'm fairly certain I'm over-thinking and over-engineering this (but it's what I do...)



Mike
(Cruzbike Sofrider V2.1)
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/09/2010 :  09:49:35  Show Profile  Reply with Quote
Raymond/Thomas/Mike/Tony,Great information.

Raymond ,Very nice rendering.Thomas great tip about the rain thing, it has been doing that allot lately.

After I got the frame in the body and put the front wheels on I could see the problem with the shape. It has a lot to do with the foam wedge I added at the lower corner. So when I get back to working on the body I will remove the wedge and radius the corners like in the following picture.


Not very radical but this is a commuter vehicle not a racer. I will be adding wheel covers at lest on the outside of the front wheels.
Rick W
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/09/2010 :  10:05:33  Show Profile  Reply with Quote
Today I worked on making the body mounts. I decided that I will have one mount to the front



and a mount to the backside of the wheel wells and one up higher in the body just behind the rear seat mount.


The mounts are bent from 1/8"x1' 6061 aluminum with a nutsert added to provide the threads These brackets will be bonded into the body shell to provide attachment points for the aluminum struts coming from the frame.



Before I bond any of the aluminum parts I etch them to remove any oxidation to insure a strong bond. Here are the brackets etching away.



Next I will make the brackets that attach to the frame to connect to the aluminum struts

Rick W



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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 04/12/2010 :  09:40:42  Show Profile  Reply with Quote
Worked some more on mounting the frame to the body. The 3/4" square aluminum struts were attached with some rubber bushings to help reduce the vibrations.


I next worked on some chain management issues. The return chain tensioner had to be removed to fit the frame into the body so I made a bracket to attach a smaller idler to at the location of the power idler. I can rotate the bracket to get the right amount of tension on the chain.


Next I need to remove the frame from the body and attach the brackets to the frame that will bolt to the 3/4" struts. I need to cut the foot hole or holes in the front, reattach the body and the frame and take her out for a test ride before I finish up on the remainder of the fiberglass work.





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