CEF speed contest Design Discussions (2014)

KariFS wrote:

rogermharris wrote:Gosh!  Now I have this running through my head.
I hate to say it but this sort of thing is what I have done for a living for nearly thirty years. Take an idea and bring it to life.  

Thinking about it more today I am wondering if a very narrow wheel would bee better?
Something that would cut through the grass rather than a wider tire that would tend to float on top and pushing the grass down. I'm thinking the thin wheel would ride more on the ground and bee a smoother ride.

CDs maybe?

http://old.solar-active.com/carcd.htm

For those of us who don't have access to a laser cutter

actually one of the things i was thinking of. my son had a wind powered vehicle science project last year. we used cd's for wheels and a block of Styrofoam. that thing would roll forever

Yea.. thin discs would be better for smooth pavement I think. On grass.. thin wheels could bounce.. and the struts are more susceptible to snagging. I suppose a CD-wheel's diameter would prevent the latter.

Rog, did you make hubs for the CD-wheels on the wind-powered model? With your machines at work, you could cut a small .750" diameter disc with your axle size's bore, and form a raised boss to fit inside the CD's .590" center-hole . Maybe make that part from 10mil or something thick enough for a hub. You could try gluing it directly to the disc.. or cut a collar to fit around the boss which would "sandwich" the disc between a hub assembly.

Here's a pic of a spinner-adapter having a raised boss that I made on the CNC router a while back. I think I used 6mil PVC.



I like the wheels you've made Rog. The "Harris" on the tire's sidewall is classic!

Here's some wheels I've made on the CNC.



My Rare Bear's wheels are 3/16" GatorPlast. I filled the radial hole/spoke pattern with hot-melt glue to strengthen/streamline them. The tires are o-rings.



You don't need a CNC machine to make cool wheels though. This tail-wheel (also my Rare Bear's) is a small rubber grommet with it's center-hole bushed with alloy tubing for a .062" wire axle.. and has an o-ring fitted for a tire.




I made the plastic washers (hubcaps) from common clear packaging material. I drilled random axle-holes in the sheet near the edge.. and cut them out with a standard paper-punch by centering the hole in the eye of the punch. This works great when you need a small precision ID non-metallic washer. You can punch .005" brass/tin sheet for soldering.. but it's tough on a paper punch. Sig doesn't sell those coil-spring wheel retainers anymore. Goldberg used to furnish them in their 1/2A kits as standard hardware. I bought several packages years ago and don't have too many left.. so I figured I'd try to make my own. I hand-wound .015" music wire in a tight coil around a slightly smaller mandrel using locking-pliers. You could also clamp the coil-wire horizontally in a vise, chuck the other end with the mandrel in a VS hand drill held perpendicular and slowly wind the coil under tension.

those are really nice roddie! i use to use a lot of that pvc at my last job. i will have to pick some up to play with. the ones i'm making are derin so they are plenty strong and very light since they are cut from 1/8" sheet. i did make a hub like the white one pictured but they were made from 1/8" lexan and we used wood shish- kebob skewers for axles though a straw. was supposed to be all recycled materials.

That grommet and O-ring tire is just brilliant...

rogermharris wrote:those are really nice roddie!  i use to use a lot of that pvc at my last job. i will have to pick some up to play with.  the ones i'm making are derin so they are plenty strong and very light since they are cut from 1/8" sheet.  i did make a hub like the white one pictured but they were made from 1/8" lexan and we used wood shish- kebob skewers for axles though a straw. was supposed to be all recycled materials.

Rog, I'm all about re-using stuff.. and it's a great lesson for a youngster! Do you have any pics of that craft that the two of built? You mentioned it being wind-powered.. did it have a conventional sail with rigging?

Mike, Thanks man! Some of my modeling ideas work.. and some of them languish in the depths of what looked good on paper... (as witnessed here more than once..)

roddie wrote:

rogermharris wrote:those are really nice roddie!  i use to use a lot of that pvc at my last job. i will have to pick some up to play with.  the ones i'm making are derin so they are plenty strong and very light since they are cut from 1/8" sheet.  i did make a hub like the white one pictured but they were made from 1/8" lexan and we used wood shish- kebob skewers for axles though a straw. was supposed to be all recycled materials.

Rog, I'm all about re-using stuff.. and it's a great lesson for a youngster! Do you have any pics of that craft that the two of built? You mentioned it being wind-powered.. did it have a conventional sail with rigging?

Mike, Thanks man! Some of my modeling ideas work.. and some of them languish in the depths of what looked good on paper...   (as witnessed here more than once..)

I meant to take a couple pics tonight but forgot. He is in bed going to sleep at the moment so I can't get a pic right now. It caught the wind using an orange juice carton cut and flaired out to catch the wind. I will try to remember to take a pic of it tomorrow. He did win the contest with it.

OVERLORD wrote:

ian1954 wrote:Has no one else started building yet?

All right, all right, I have

As already mentioned in February,I started building a V1 for the contest. The model is almost finished. below some pictures of the build:













I still have to fix the tail wing, belcrank , control horn and linkage, lead outs and do the fuel proofing.

Lieven

Lieven,

Very creative approach, I like it!

Jim

A novel idea for the competition Lieven, but is that a cockpit I see? That would make every flight a suicide mission.
It would be great to see it with a pulse-jet installed.

Rod.

https://en.wikipedia.org/wiki/V-1_flying_bomb

mate you better watch out   my SPITFIRE    will catch that v1 flying bomb and shoot it up till cinders and ashes

Oldenginerod wrote:A novel idea for the competition Lieven, but is that a cockpit I see?  That would make every flight a suicide mission.

Some V1's were built with a cockpit, like the Japanese Kamikaze bombs. Not sure if they were ever used, it was one of those desperate things they did just before the end.

I bet after half an hour of listening the pulse jet behind your head you'd be ready to crash the thing just to get some silence.

KariFS wrote:
I bet after half an hour of listening to the pulse jet behind your head you'd be ready to crash the thing just to get some silence.

KariFS wrote:

Oldenginerod wrote:A novel idea for the competition Lieven, but is that a cockpit I see?  That would make every flight a suicide mission.

Some V1's were built with a cockpit, like the Japanese Kamikaze bombs. Not sure if they were ever used, it was one of those desperate things they did just before the end.

I bet after half an hour of listening the pulse jet behind your head you'd be ready to crash the thing just to get some silence.

OK, found one.
http://www.pbase.com/image/63767261
two...
http://www.itv.com/news/meridian/update/2013-03-04/reichenberg-restored/

pkrankow wrote:

KariFS wrote:

Oldenginerod wrote:A novel idea for the competition Lieven, but is that a cockpit I see?  That would make every flight a suicide mission.

Some V1's were built with a cockpit, like the Japanese Kamikaze bombs. Not sure if they were ever used, it was one of those desperate things they did just before the end.

I bet after half an hour of listening the pulse jet behind your head you'd be ready to crash the thing just to get some silence.

OK, found one.
http://www.pbase.com/image/63767261
two...
http://www.itv.com/news/meridian/update/2013-03-04/reichenberg-restored/

Hanna Reitsch did some flight in V1... I prefer when she was in a Habicht...

Thanks foryour comments. Glad you like it. The Reichenbergs were only tested. The idea was that pilots should bail out of the craft after aiming at the target. They were never launched from a ramp but were dropped from a flying Heinkel.

Not only entertaining, but educational too! Thanks for the information on. Stuff I never knew

Lieven, How were you able to source info on the finish? I'm guessing that color/pattern made the V1 less visible from both above or below while flying over the English channel? Young "Greg" knows his history! The Spitfires and other allied fighters were also known to "knock" these unmanned flying bombs off-course by flying close enough to "tip" a wing.. and offset the V1's gyro-heading. It was extremely dangerous.. but it worked if you ran out ammo.

roddie wrote:Lieven, How were you able to source info on the finish? I'm guessing that color/pattern made the V1 less visible from both above or below while flying over the English channel? Young "Greg" knows his history! The Spitfires and other allied fighters were also known to "knock" these unmanned flying bombs off-course by flying close enough to "tip" a wing.. and offset the V1's gyro-heading. It was extremely dangerous.. but it worked if you ran out ammo.

Phil's wiki link shows this.

Bob

roddie wrote:Lieven, How were you able to source info on the finish? I'm guessing that color/pattern made the V1 less visible from both above or below while flying over the English channel? Young "Greg" knows his history! The Spitfires and other allied fighters were also known to "knock" these unmanned flying bombs off-course by flying close enough to "tip" a wing.. and offset the V1's gyro-heading. It was extremely dangerous.. but it worked if you ran out ammo.

doodlebugs spitfires tempests mosquitoes could catch and destroy those horrible things my nana was in the tube tunnels and she got hit by a v1 and she was very lucky and lived to tell the tail but her dad was'nt lucky enough he's saved a lot of people who had no legs (they where blown off) etc etc

and this is what se remembers of it and told me
"they would buzzzz and then suddenly stop and you heard a whistling sound and you had to cross your fingers and hope that it wouldn't land on you ".

she was only 3

this is my favorite pic of a hurricane manned by a poles of the 303 squadron
the 303 squadron shot down the most aircraft during the battle of britain
here is a video on them

https://www.youtube.com/watch?v=ptijNcDanVw

Roddie, I got the idea of such a pattern from a picture of a Stuka model and a German camouflage pattern on internet.





The colours and everything else is a result of my own imagination. V1s were couloured green/brown on top only as in the picture with the Heinkel.




My grand parents and my dad, an 8 year old boy in '44, saw V1's flying over their house on the way to the UK. They lived in the province of Eastern Flanders, Belgium.The first time they saw one, they were very afraid as something flying with a flame on the tail meant to them it could immediately explode. They knew later that NO flame at the back was dangerous!!