Author Topic: Treadmill Dyno  (Read 127623 times)

0 Members and 1 Guest are viewing this topic.

SparWeb

  • SuperHero Member
  • ******
  • Posts: 3388
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Treadmill Dyno
« Reply #330 on: October 29, 2012, 12:44:44 PM »
Else, the mini starter motor was mounted, tested and broken   :-\.   

And the warranty was voided.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #331 on: October 30, 2012, 06:01:55 AM »
With the new shaft and the doc wattson inline, it peaked at 115 amps and 1400 W   ;D  But the tiny set screws connecting the bell of the motor to the shaft couldn't handle the torque and failed.  I guess the next thing to do is put a pin through the shaft and the bell housing.  I'm really impressed by the speed controller at this point, since it's only rated for 50A continuous, but I guess that's what you get when you buy nice American made products  :)

« Last Edit: October 30, 2012, 06:10:50 AM by taylorp035 »

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno Pink Foam Edition Week 4
« Reply #332 on: November 03, 2012, 04:35:18 PM »
We had about 8 hours on the CNC machine yesterday so lots got cut.  I think we cut 22 cross sections in that time.





Later on, we discovered that our foam board adhesive wasn't drying (~3 hours after applying it).  We then read the label and it said not to use on 'non porous' surfaces.... which the foam is closed cell and there is no plywood as there normally would be.  Hopefully 48 hours will let the stuff dry.  Next week we hope to start applying drywall compound on the front pieces since it will take ~100+ man-hours to make it perfectly smooth to our satisfaction.


The mini starter motor was yet again reinforced, but after running it too often/long, we let out some of the factory smoke.  It was probably just some of the insulation burning off the coils.  The magnet bell wasn't too hot.   Also, setting the ESC to a 80A max wasn't getting the job done, so we removed the current limiting.  Peak power was recorded at 1000W.

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #333 on: November 06, 2012, 06:27:23 PM »
After letting the foam board adhesive sit for ~72 hours, it hasn't dried one bit   :(   So today, we bought some construction adhesive, which the label looks like it will be good for non-porous surfaces and foam.  Does anyone have experience with this?  We are going to try it out tomorrow and if all goes well, it will be applied to all ~35 cross sections on Thursday and be dry by Friday, which then we can start adding drywall compound.




SparWeb

  • SuperHero Member
  • ******
  • Posts: 3388
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Treadmill Dyno
« Reply #334 on: November 07, 2012, 01:12:20 PM »
Some types of construction adhesive do get used for bonding insulating foam to walls, so you are okay there.  Gotta pick the right one though:

IS             http://lepageproducts.com/ProductDetail.aspx?pid=72

ISN'T        http://lepageproducts.com/ProductDetail.aspx?pid=77

It's also very viscous, IIRC so applying just enough to keep the bond-line thin will be tough.  Or you can let the car get 10% longer...

No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #335 on: November 07, 2012, 03:40:05 PM »
Today we looked at the glue we used before and saw that it was not recommended for foam to foam applications.... too bad we didn't read that earlier.  The new stuff we got is almost dry after ~4 hours, so things are looking good.  The downside is now we can't seem to separate the foam mold anymore... so maybe the glue dried???  If it stays stuck together, I don't really care what happens.



taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #336 on: November 10, 2012, 10:28:55 AM »
The body is finally done being cut out  :D   I think the total cutting time was about 20 hours on the cnc router.






Gluing the whole thing in the vertical position was a challenge since the aluminum bars in the center were 12' total in length.... we eventually tied the car to the ceiling to make sure it wasn't going to fall over.

Work was also done to measure the pressure drop over the intake and exhaust valves using a vacuum cleaner, an air flow rate meter and a pressure gauge.


taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #337 on: November 14, 2012, 08:02:12 PM »
We found that our second type of glue (the construction adhesive) isn't drying either..... so when we went to put the car in the horizontal position, it broke in 3 places  :/   But after a quick test today, we found that hot glue works really, really well, so it looks like we have finally solved our problem.

This Friday, I will put my windmill blade carving skills to the test by doing the front side of the rear wheel skirt.  We decided to keep the edges of the bottoms of the wheel skirts "sharp" instead of rounded over, because we think the airflow will be better.  Some teams have edges that are very sloped, which we think would push air down towards the ground instead of neatly around the wheel skirt.  The world leading supermileage cars all seem to have a different answer to the shape of the bottom of the wheel skirts.  Even the multi-million dollar solar cars have different designs, some have rounded edges and others have sharp edges... and many of those cars spend some serious time in the wind tunnel (oh what I wish I could do with our car mould, some modeling clay and about a whole day in a giant wind tunnel   ;)  )

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #338 on: November 17, 2012, 06:09:37 PM »
Progress:  Pink mold is now covered in drywall compound.




Trying to give the shape of the car justice with a camera is near impossible... it really takes a minimum of a minute and a walk around the car to absorb the whole thing.  You really start to appreciate the preciseness of a cnc machine in the ability to make the curves perfect..... especially after building last year's car by carving the whole thing by hand.

 

Frank S

  • Hero Member
  • *****
  • Posts: 1620
  • Country: us
Re: Treadmill Dyno
« Reply #339 on: November 18, 2012, 02:19:31 AM »
It looks like it is almost time for the fun to start with all of the hours of meticulous hand sanding before you make the outer mold. it would be nice if you could lay your hands on a portable coordinate measuring machine  like this
I live so far outside of the box, when I die they will stretch my carcass over the coffin

DamonHD

  • Administrator
  • SuperHero Member
  • *****
  • Posts: 3622
  • Country: gb
    • Earth Notes
Re: Treadmill Dyno
« Reply #340 on: November 18, 2012, 02:51:22 AM »
Ha!  At least one person here who shall be nameless (OK then, Ghurd), already KNOWS that hot glue is the solution to all the world's structural problems, and probably financial and energy problems too if we could just work out how to do it right!  B^>

Rgds

Damon

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #341 on: November 18, 2012, 07:50:49 AM »
Quote
it would be nice if you could lay your hands on a portable coordinate measuring machine  like this

We do have one of those, but it's probably only good for a ~15" radius working envelope.  There are other ways to get the mold back into a digital format, including some newer software that takes pictures and meshes them together to make a 3D model.

Ha!  At least one person here who shall be nameless (OK then, Ghurd), already KNOWS that hot glue is the solution to all the world's structural problems, and probably financial and energy problems too if we could just work out how to do it right!  B^>

Rgds

Damon

My adviser feels the same way about hot glue.   We even bought different grade of hot glue sticks, including some high strength stuff, that actually does seem to be stronger.

ghurd

  • Super Hero Member Plus
  • *******
  • Posts: 8057
Re: Treadmill Dyno
« Reply #342 on: November 18, 2012, 07:11:25 PM »
My adviser feels the same way about hot glue.   We even bought different grade of hot glue sticks, including some high strength stuff, that actually does seem to be stronger.

I am not trying to be an X-Purt on the stuff I love...

but usually,
Hi Temp 'sticks' better to normal, and strange, stuff.
Lo Temp might be a little faster to work with, but that is the only advantage I see.
Multi Temp is fine, but only after the gun is 5 minutes past completely heated up, and IMHO it works best with a hi temp gun.

I feel the biggest difference is in the gun itself.
If you can see daylight through, from the stick spot to the hot spot, then forget it.

And you get what you pay for.
No more 99-cent or $2.99 guns for me.  Those seemingly over-priced mini-guns are worth it for someone serious.

Last few years I have been using the 5/16" Ad Tech Project Pro (with the needle tip instead of a funnel tip), and hi or multi temp sticks from wally.

Even 35 years ago, higher end cabnitry was assembled with hot glue.
G-
www.ghurd.info<<<-----Information on my Controller

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #343 on: November 25, 2012, 07:49:07 PM »
We got word today that we will be able to obtain some of the coveted radial tubeless tires that we have been trying so hard to get for the last 3+ years.  In theory, these tires could reduce the rolling resistance of our car by a factor of 3, which is super important if we want to break the North American record  :)

Now for some more CFD.   I was able to set up the model with hollow wheel skirts and a spinning tire in one of the front side skirts and the other empty.  I was interested to see roughly just how fast the air is actually moving inside and maybe what we could do to make it better.  The analysis was pretty intensive (transient with motion and a high mesh density), which is now possible with my black friday purchase of  8gb of ram for my thinkpad w500 laptop.  It took me about 3 hours to get the whole thing setup and drawn the way I wanted it.

The first one is the one without the tire and an opening in the bottom of the skirt.
Full size:    http://i45.tinypic.com/25gw75z.png



The second one has the tire.  It's not very good, since there seems to be a massive leak  in the bottom of the skirt.... probably due to the mesh not recognizing the thin parts.

Full size :   http://i49.tinypic.com/349cwa8.png




Also note the lack of the tire touching the ground.... I have yet to solve this issue, so for now the model can only get to within ~1" of the ground.  The block-ish shape to the inside of the car is a result of not being able to make a shell out of my cad model... so I had to extrude the volume out.  It should be close enough to get the general idea.


Some inspiration for my CFD work from the world of solar car aerodynamics:
http://www.nuonsolarteam.nl/nieuws/inside-the-wheel-cover/?lang=en

It's too bad they don't actually show more of their results/conclusion other than an effort to minimize the air gap between the wheel and the skirt.  This is something we have a solution for that we hope to implement on the new car.

Frank S

  • Hero Member
  • *****
  • Posts: 1620
  • Country: us
Re: Treadmill Dyno
« Reply #344 on: November 26, 2012, 03:36:20 AM »
Taylor could your have used a revolve to cut feature to remove the interior volume? by creating a geometric plane 90 deg to the axis
I live so far outside of the box, when I die they will stretch my carcass over the coffin

SparWeb

  • SuperHero Member
  • ******
  • Posts: 3388
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Treadmill Dyno
« Reply #345 on: November 26, 2012, 01:03:13 PM »
I fear the 3D profile will have a lot to say about what happens in the wheel-well, not just a 2D profile.
Flow through spokes, (or is it on a solid disk) brake disks and calipers, that sort of stuff.
Not saying it isn't important - I'm worried about the amount of work needed to get a useful result.

Those sacrificial skirts (in your linked article) look like a funny thing to try, though.  You would rather have the main skirt come down as close to the ground as you dare.  Maybe a lower 1/2" of paper/foam/nomex that will scrape off during trials runs, leaving whatever maximum material condition can exist without scraping any more.

No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #346 on: November 26, 2012, 07:51:03 PM »
Taylor could your have used a revolve to cut feature to remove the interior volume? by creating a geometric plane 90 deg to the axis

That would of been a smarter idea for sure.... at least for the top part.  The bottom still needed to be flat to represent the actual shape.

Quote
I fear the 3D profile will have a lot to say about what happens in the wheel-well, not just a 2D profile.
Flow through spokes, (or is it on a solid disk) brake disks and calipers, that sort of stuff.
Not saying it isn't important - I'm worried about the amount of work needed to get a useful result.

The question is "what is useful?"....  getting a drag force isn't really on top of my list... especially since I can't set the car up properly and my original drag numbers from a month ago are all about a factor of 2 too high....      And yes, 2D airflows really don't serve the problem justice..... time to start wishing for a 3D hologram monitor for my laptop  ;D

Quote
Those sacrificial skirts (in your linked article) look like a funny thing to try, though.  You would rather have the main skirt come down as close to the ground as you dare.
I agree that their solution is not what we really want/need.  Our wheel skirt is only 1/2" - 1" off the ground, depending on the tire used, inflation pressure and how much the frame decides to bend..... you can't really go any lower than 1", especially since the skirts are so long.... I can't count the number of times the car beached itself on a bump in the road/sidewalk.  We have an idea where you take their secondary mini skirt frame idea/location and then take some stretchy material and cover the gap between it and the main skirt.  This is something I have never seen before used on a SMV car or solar car, and I hope to prototype it in the coming weeks.  The hard part is rigidly attaching the 2nd skirt/frame to the axle, which is made of carbon fiber and there is literally no clearance room for it.


EDIT:

Airflow picture near the nose.  Looks like we did a fine job at getting the nose at the right height.

http://i47.tinypic.com/1zn39mw.png



« Last Edit: November 26, 2012, 08:49:12 PM by taylorp035 »

Frank S

  • Hero Member
  • *****
  • Posts: 1620
  • Country: us
Re: Treadmill Dyno
« Reply #347 on: November 27, 2012, 05:08:00 AM »
Quote
I fear the 3D profile will have a lot to say about what happens in the wheel-well, not just a 2D profile.
Flow through spokes, (or is it on a solid disk) brake disks and calipers, that sort of stuff.
Not saying it isn't important - I'm worried about the amount of work needed to get a useful result.
The question is "what is useful?"....  getting a drag force isn't really on top of my list... especially since I can't set the car up properly and my original drag numbers from a month ago are all about a factor of 2 too high....      And yes, 2D airflows really don't serve the problem justice..... time to start wishing for a 3D hologram monitor for my laptop  ;D

[/quote]

Don't we all dream for a set up like the one in the ironman movies LOL to include the robot helper
I live so far outside of the box, when I die they will stretch my carcass over the coffin

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #348 on: December 01, 2012, 05:19:40 PM »
Some engine testing of the high compression head at ~1300 rpm.
http://youtu.be/9osDzvURCIk

Note the "Chill BRAH!" sign.... it has nothing to do with the fire alarm, but more of a reminder not to rev the engine to 6k rpm.... later on, we decided to build a blast shield on the front of the dyno stand to protect us in the event of a failure.

The bottom was dry-walled last night.  It took 8 or so people a good 2+ hours to apply the compound.  We should be on track for having it done by next Friday and then we can prepare for doing carbon fiber the next week.





zap

  • Hero Member
  • *****
  • Posts: 1107
  • There's an app for that
Re: Treadmill Dyno
« Reply #349 on: December 08, 2012, 10:53:39 PM »
Cool... it almost looks like an orca on it's back!  Nature always knows best.

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #350 on: December 09, 2012, 11:58:07 AM »
Finished the new flywheel!   It has a timing pulley cut into the center hub, along with the tapered hole and key slot.  The cross bar has the fancy engraved letters and has been polished for several hours with metal polish and clear coated to prevent any corrosion.  The new flywheel cuts about .35 lbs from the cross bar while only slightly lowering the moment of inertia.






A nice shot with last year's car in the background.  We are estimating a 40% reduction in air drag for the new car, even though the cars look rather alike.  Initial measurements shows the new car being about 2.5" narrower  The first round of carbon fiber should be applied next Friday.


taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #351 on: December 16, 2012, 02:24:58 PM »


We went fairly conservative on the carbon this time around.  Many areas are only there for aerodynamic purposes (actually, nothing will be structural).  Over the whole night, we had about 24 people show up, and in total, it took about 60 man-hours to get the car from it's drywall state to getting vacuum pumps running.  It took about 1.5 hours with ~12 people to lay and glue the carbon fiber on.   In a few weeks, we will do the bottom half, which will be significantly more difficult.



If you are interested in some photos of the wet layup, I have those too.
« Last Edit: December 16, 2012, 03:27:27 PM by taylorp035 »

SparWeb

  • SuperHero Member
  • ******
  • Posts: 3388
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Treadmill Dyno
« Reply #352 on: December 16, 2012, 09:59:21 PM »
I get the picture, but then I've vacuum bagged CF before.  Had an autoclave to play with too, heehee.

The bottom will definitely be tricky, so I would like to see how you manage that.  Does it have to be carbon fibre?  Why not glass, which is often easier to drape?  May also be easier to work the resin into glass cloth than cf? 

I sort-of recall that bagging can be done with multiple pieces - hard to describe in words.  It looks like you did the body today with just one big bag, which would have left a lot of empty space underneath between the front wheel fairings.  I think I can see that in the photo.  The key is the way to bag around the mold, because areas where the bag "tents" over a corner will not be compressed, so I think the trick is to assemble a bag with many sections...  Literally cut the bag, letting a long free edge hang, then stick on the next piece to the free edge, which will wrap onto the next side.  Like, one for every major face, with lots of free edge.  Join the edges with putty.  Slowly apply the vacuum, and if it becomes obvious that the bag doesn't fit, don't proceed, rather rip off the bag and put in a new section with slack where it tented up before.  Be prepared with the materials ready just in case.

It was all pretty thoroughly planned in advance when I did those projects (long ago!).  I think you'll be improvising as you go with the one-off project, and from what I've seen so far, it will go swimmingly.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno Carbon Fiber pics
« Reply #353 on: December 17, 2012, 02:02:20 PM »
Well, we took off the vacuum bag today and unfortunately, it seems like we have the same exactly problem as last year, only a little bit better.  Now were are close to 100% certain that the wrinkles are caused by the vacuum bag it's self (exact same pattern as the vacuum bag).  So we have decided that this top layer is going to be thrown out and we will re-surface the mold.  Then, we plan on doing a wet layup with no vacuum bag, since we know that will work.  We also noted that we were very close to the minimum amount of glue needed to get all of the fibers wet (the vacuum pulled it all out).  Total weight felt like about 3-4 lbs, so not too bad.

There are even micro wrinkles in between the large wrinkles that you can see with the camera.  The inside surface was better, but there were valleys where the wrinkles were.

Larger Version:  http://i45.tinypic.com/21alpgy.jpg


« Last Edit: December 17, 2012, 02:09:51 PM by taylorp035 »

SparWeb

  • SuperHero Member
  • ******
  • Posts: 3388
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Treadmill Dyno
« Reply #354 on: December 17, 2012, 10:04:16 PM »
Oh, no!  I suppose the inside is silky smooth instead...

Where did you apply the vacuum?  I have a few thoughts about what may have happened... but just guessing until I can think about it a bit.

I didn't look at this critically before, but maybe I can help you compare the layup stack you used with the recommended practices that tend to get better results.  I've got several composites books stashed away in PDF on this hard drive.  Getting a "male" part surface to look nice from a male mold is not the easiest thing to do.

A cold wet-layup with no vacuum will be heavier, and ultimately even more work than a bagged mold (done correctly) because you will be sanding sanding sanding anyway.
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

Frank S

  • Hero Member
  • *****
  • Posts: 1620
  • Country: us
Re: Treadmill Dyno
« Reply #355 on: December 18, 2012, 05:51:56 AM »
  Could you now take this shell before removing from the mold and ad some support ribbing and framework.
 then use it as an outer female mold the inside of it should be smooth if not add some fill and sand until the desired smoothness is achieved. Laying up a male part in a female mold is 100s of times easier plus it allows for the addition if internal ribs or supports as needed. Much easier to make a second or 3rd body shell if needed.
 Or before attempting to make another male part on your male mold get some white shrink wrap like they use to wrap boats and escalators for shipment bag your bare male mold then heat shrink until the desired smoothness is achieved with some vacuum to create a glove. slit open the glove along a non critical area remove, then lay up your fiber & resin then slip the glove over this the plastic will have enough stretch to pull over the product seal the seam and apply your vacuum again this time your glove already has the basic contours as a start point and should offer much better results.
 I personally like to use a female mold to make a male part whenever possible
 Just a thought 
I live so far outside of the box, when I die they will stretch my carcass over the coffin

Frank S

  • Hero Member
  • *****
  • Posts: 1620
  • Country: us
Re: Treadmill Dyno
« Reply #356 on: December 18, 2012, 05:55:25 AM »
by using the existing shell that you have you can also spray you gel coat or color coat in the mold before applying the resin & fiber. 
I live so far outside of the box, when I die they will stretch my carcass over the coffin

taylorp035

  • Hero Member
  • *****
  • Posts: 1005
  • Country: us
  • Stressed spelled backwards is Desserts
Re: Treadmill Dyno
« Reply #357 on: December 18, 2012, 10:39:33 AM »
The top part of the mold is completely un-usable at this point... dimensionally, it is stretched out and could never be used as a female mold.  We really need the carbon to be the exact shape of the mold, else the tires and engine will not fit.  To put this into perspective, you can see the picture below for how we got the carbon off... this was after 2 hours of trying to peel it off.




Quote
Where did you apply the vacuum?

On the bottom side of the the front right wheel fairing where there was no carbon.


Quote
A cold wet-layup with no vacuum will be heavier, and ultimately even more work than a bagged mold (done correctly) because you will be sanding sanding sanding anyway.

Right, the layers won't be very compacted, but we can use rollers and squeegees to make it half way decent.  We aren't too worried about the sanding..... if there are no wrinkles, sanding is actually quite easy.


Quote
Or before attempting to make another male part on your male mold get some white shrink wrap like they use to wrap boats and escalators for shipment bag your bare male mold then heat shrink until the desired smoothness is achieved

Yes, we have thought of this and would of done this.  Our theory for the wrinkles last year was that the glued was too dry before we pulled a vacuum... but it turns out that was not the case.  I think any future cars would have a female mold made and have a gel-coat surface for sure.  The hard part of a female mold is how to cut the sharp end of the wheels skirts and tail.  I guess you could add them in later if you wanted to.  Also, a female mold requires a lot more foam and depending how you make it, a bigger CNC machine.  This is definitely something that could be improved upon in the future (many local companies have this capability).  The gain might only be 5 lbs over our current method, but it might be worth it.  More use of a carbon fiber tube frame for the engine mounts and main support structure could yield another pound or two.  Then even rebuilding the engine block to make it lighter (carbon fiber bottom end, smaller and lighter crank shaft...) is another option.  Time, money and creativity.... luckily we have at least a medium amount of each to work with this year.

Frank S

  • Hero Member
  • *****
  • Posts: 1620
  • Country: us
Re: Treadmill Dyno
« Reply #358 on: December 18, 2012, 11:44:10 AM »
I may be looking at it from the wrong perspective. But consider this just as a penny farthings worth of thought
 You already have your master for a female mold
1/4 it end to end along girth at the widest point the  make the second slice end to end vertically straight down the center. Calculate the desired body outer dimensions. take the 2 top 1/4 pieces and place a thickness shim between them coat with a release agent then spray on a mold gel coat, now lay up several layers of fiberglass over this adding a  enough struts of wood to make a sturdy frame  glass them to the mold body.
 do this for the bottom 1/4 just as the top
 afterwards remove the shims and maybe have to cut some of the foam core to allow the master blanks to be removed.
 Now yo would have a top and bottom female mold  the 4 1/4 pieces become your Male cores without using the shims you now apply your release agent spray the gel coat lay in and roll the resin & carbon then insert the 1/4 mold male pieces wedge tightly then pull your vacuum the end result hopefully if you did everything correctly will be your 1 to 3 layer thick carbon body shell in an upper and a lower easily joined together
 It is possible the lower male master may have to be cut into as many as 4 pieces and shimmed accordingly
 If you can find a book or a video on how a Boston Whaler boat is constructed they are the absolute Gods of fiber-glassing  second wold be glass craft 
 A short step to this would be to forgo using the 1/4 molds in the final molding process and just vacuum press it like you did for the outer
 Like I said just a penny farthings worth
I live so far outside of the box, when I die they will stretch my carcass over the coffin

Frank S

  • Hero Member
  • *****
  • Posts: 1620
  • Country: us
Re: Treadmill Dyno
« Reply #359 on: December 18, 2012, 12:02:38 PM »
And no I was not referring the the high wheel bicycle in this case I and using it as a half cent LOL
I live so far outside of the box, when I die they will stretch my carcass over the coffin