Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


postage stamp mounting - Page 3 Babe_b10
Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Cox Engine of The Month
May-2020
Levent Suberk's

"Medallion .049"



PAST WINNERS
CEF Traveling Engine

Win This Engine!
Gallery


postage stamp mounting - Page 3 Empty

postage stamp mounting

Page 3 of 3 Previous  1, 2, 3

Go down

Happy Re: postage stamp mounting

Post  roddie on Fri Aug 29, 2014 8:49 pm

getback wrote:my Best run for today    my God some one left the window open there at first lol!

I can't wipe the grin off my face Eric!!!!!!!!!
roddie
roddie
Top Poster
Top Poster

Posts : 6861
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Happy Re: postage stamp mounting

Post  roddie on Mon Sep 01, 2014 1:57 pm

Another advantage to this mount.. is that the clearance between the venturi and the firewall is such, that you can "choke" the engine by using a strip of wide rubber-band. Slip it between the mounts and "stretch it thin" to slip between the intake and the firewall. when released, it will expand "thicker".. and seal the intake. Flip the prop while watching for fuel in the line.. then stretch the rubber-band again, to remove it. Smile
roddie
roddie
Top Poster
Top Poster

Posts : 6861
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Happy Re: postage stamp mounting

Post  getback on Mon Sep 01, 2014 2:48 pm

Such it is , I have not feeler gaged it but looks like .020 to me ?? I still want to try and learn the bladder did find some plastic hemi-stats that i didn't even know I had Embarassed . I would still like to have one of those large syringes.......Roddie did Mike or Kim report in to U?? Eric
getback
getback
Top Poster
Top Poster

2019 Supporter

2020 Supporter

Posts : 6953
Join date : 2013-01-18
Age : 62
Location : julian

Back to top Go down

Happy Re: postage stamp mounting

Post  Oldenginerod on Wed Sep 03, 2014 2:33 am

roddie wrote:
Oldenginerod wrote:Just managed to score one of these original Goldberg engine mount kits, including a fuel bladder.  
postage stamp mounting - Page 3 Pictur12
I guess after all this time the balloon mighty be perished, but I'm keen to be able to utilise one of my "postage stamp" engines without messing around making up mounts.  Problem is the postage cost more than the kit (& probably more that what I paid on average for the engines).

Rod.

That's a COOL find Rod! Now you'll at least be able to mount and run those engines!  Thumbs Up 

Goldberg mount arrived today.  If anyone's interested, the seller has listed another the same.
http://www.ebay.com/itm/151395997050
Oldenginerod
Oldenginerod
Top Poster
Top Poster

Posts : 3000
Join date : 2012-06-15
Age : 57
Location : Victoria, Australia

Back to top Go down

Happy Re: postage stamp mounting

Post  JPvelo on Wed Sep 03, 2014 7:35 am

JPvelo
JPvelo
Diamond Member
Diamond Member

Posts : 1962
Join date : 2011-12-02
Age : 52
Location : Phoenix

Back to top Go down

Happy Re: postage stamp mounting

Post  getback on Wed Sep 03, 2014 3:41 pm

25- +- to the US man that's hi in my book when u have good friends willing to help just to see there product on a airplane and will that works for -O- Thanks again Roddie!!!  Eric Very Happy Very Happy Small Cox Logo................. I am Definitely trying to do too many things at once !!! didn't even see the engine with it MY BAD!! Eric


Last edited by getback on Wed Sep 03, 2014 5:33 pm; edited 1 time in total
getback
getback
Top Poster
Top Poster

2019 Supporter

2020 Supporter

Posts : 6953
Join date : 2013-01-18
Age : 62
Location : julian

Back to top Go down

Happy Re: postage stamp mounting

Post  roddie on Wed Sep 03, 2014 5:31 pm

getback wrote:25- +- to the US man that's hi in my book when u have good friends willing to help just to see there product on a airplane and will that works for -O- Thanks again Roddie!!!  Eric Very Happy Very Happy Small Cox Logo

Your welcome Eric! It was a real treat to see the vid of you "running" yours!!! You asked if I'd heard back from "Mike and Kim". Mike didn't have a postage-stamp back-plate yet.. so I didn't send him a set of mounts. I sent them to you, Mark McRiley (batjac) and Kim. Mark PM'd me that he got his. I haven't heard from Kim yet.. but I know he was looking forward to trying a set on one his "famous" birds... Time will tell... Smile
roddie
roddie
Top Poster
Top Poster

Posts : 6861
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Happy Re: postage stamp mounting

Post  getback on Wed Sep 03, 2014 5:39 pm

I am excited about getting it on a plane and testing the run Very Happy Just need to get some stuff behind me so I can build something?!?!?!! Wee will see if there is enough space in there once it gets wound up Very Happy Very Happy Eric Babe Bee
getback
getback
Top Poster
Top Poster

2019 Supporter

2020 Supporter

Posts : 6953
Join date : 2013-01-18
Age : 62
Location : julian

Back to top Go down

Happy Re: postage stamp mounting

Post  roddie on Tue Nov 11, 2014 11:32 pm

Some useful info on my custom mounts.

postage stamp mounting - Page 3 11-11-20

As you can see.. the distance from/to the firewall is the same as a horseshoe production back-plate, using my latest design. They have a firewall mount-spacing of 17/32" x 1-1/16" and an overall size of 13/16" x 1-5/16".

I'm glad I made a handful of these.. because I no longer have access to the router machine/CAD program I used to make them.

I'm using this postage-stamp mount on my "Phred's Phault" 50% scale version of a VooDoo, and using a balloon belly-tank.

roddie
roddie
Top Poster
Top Poster

Posts : 6861
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Happy Re: postage stamp mounting

Post  roddie on Wed Dec 10, 2014 8:43 pm

Eric (Getback) recently informed me of a failure in one of the mounts I sent to him. He had run his engine on the bench and also flew it on one of his airplanes. The aluminum separated/cracked on one of the 90 degree bends, which he noticed while swapping-out the engine with another. I really hope that this is an isolated incident.. otherwise the aluminum might not be able to take the stresses of engine vibration at the bend points. The mounts shown on the "290 Special" plan at the beginning of this thread, are made of sheet-steel.. by comparison.

I sent out a few sets to people here.. and will replace any that have broken. Just send me a PM.

roddie
roddie
Top Poster
Top Poster

Posts : 6861
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Happy Re: postage stamp mounting

Post  schiada96 on Sat Dec 27, 2014 7:16 pm

[url=postage stamp mounting - Page 3 Getatt15://www.servimg.com/view/19086392/9]postage stamp mounting - Page 3 Getatt14[/url]


This is how we did it a long time ago, hope it helps.

On forming aluminum the aircraft materials 2024-T3 ,6061-T6 , 7075-T7 all need to be formed with a specific minimum inside radius or they will all crack. 5052-H32 and the lesser materials should form on a sharp inside radius.
schiada96
schiada96
Moderate Poster
Moderate Poster

Posts : 16
Join date : 2014-11-23

Back to top Go down

Happy Re: postage stamp mounting

Post  dckrsn on Sat Dec 27, 2014 8:41 pm

Hey schiada96, welcome to the forum. Didn't see
you sneak in.
That mount is a thing of beauty. The idea of beam
mounting a Cox reedy has always facinated me, and
I'm a big fan of the 290 engine with it's 128tpi needle assy.
Thanks for sharing that.
Bob
dckrsn
dckrsn
Diamond Member
Diamond Member

2019 Supporter

2020 Supporter

Posts : 2181
Join date : 2010-10-21
Age : 67
Location : Long Island, New York

Back to top Go down

Happy Re: postage stamp mounting

Post  getback on Sun Dec 28, 2014 9:31 am

Yes I Like that too , never seen it done that way ! Good idea , Thanks , Eric
getback
getback
Top Poster
Top Poster

2019 Supporter

2020 Supporter

Posts : 6953
Join date : 2013-01-18
Age : 62
Location : julian

Back to top Go down

Happy Re: postage stamp mounting

Post  roddie on Tue Mar 29, 2016 7:22 pm

I had sent Eric (getback) a set of the mounts I made a while back.. and one of them broke. I'm making-up a new set for him. Actually.. I'm making two sets using different bending-methods and will identify them with etchings.

Here's a photo of two different bending jigs in a vise.

postage stamp mounting - Page 3 3-29-110

The blocks are PVC.. and I had previously experienced deformation on the design without the padded-slot, when making the 90-degree bends.

postage stamp mounting - Page 3 8-26-110

The "padded" block uses the same aluminum for the pads as the material to be bent. This forms a much sharper corner.

postage stamp mounting - Page 3 8-26-111

I don't know if forming the sharper corner may have caused the failure. More test-running may prove that theory. The mounts that I previously sent were formed with the sharp-cornered bends. It may have just been a "fluke".. but I'd like Eric to give them another try.
roddie
roddie
Top Poster
Top Poster

Posts : 6861
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Happy Re: postage stamp mounting

Post  roddie on Tue Mar 29, 2016 9:02 pm

Bending commences..

Without pads..

postage stamp mounting - Page 3 3-29-111
postage stamp mounting - Page 3 3-29-112
postage stamp mounting - Page 3 3-29-113
postage stamp mounting - Page 3 3-29-114

and with pads..

postage stamp mounting - Page 3 3-29-115

I etched the pairs; "B" for blunt-corner and "S" for sharp-corner. Note the slight difference in size between the two sets.

postage stamp mounting - Page 3 3-29-116
roddie
roddie
Top Poster
Top Poster

Posts : 6861
Join date : 2013-07-17
Age : 60
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

Happy Re: postage stamp mounting

Post  ian1954 on Wed Mar 30, 2016 4:47 am

Bending aluminium can be fraught but a lot depends on the alloy and how the sheet was produced.

With some sheets there is a definate "grain", for want of a better word, depending on how it was rolled. I have several sheets that bend easier one way than the other.

The best way to bend is perpendicular to the grain, so the grain lines cross the bend. Sounds strange - if I was using a sheet of aluminium to form a cylinder I would roll it with the grain as with would - but for a sharp bend this would produce stress and so I would form the bend across the grain.

The other thing to be wary of is the radius of the bend. For most aluminum sheet, the inside radius of the bend should at least be equal to the sheet thickness. If the alloy is higher strength and/or heat treated, the radius goes up to double the thickness (or more). Bending along the grain makes these radii even more important.

For sharpish bends I anneal the aluminimum - not pretty - rub a bar of soap on it and heat till the soap turns brown then let it cool slowly.

Sharp corners will contribute to fatigue failure but it does depend on the alloy itself to a large extent. Increasing the radius of the bend will reduce the stress and the larger the radius the less stress.

These mounts look wonderful but I would try and increase the radius a little more. Annealing helps but the finished result doesn't look as nice as the raw material.
ian1954
ian1954
Diamond Member
Diamond Member

Posts : 2682
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

Happy Re: postage stamp mounting

Post  getback on Wed Mar 30, 2016 9:24 am

bounce bounce bounce Roddie I will bee more than happy to test the mounts out , I think test stand for a few runs and go from there I will report of coarse . I wonder if Stainless Steel would work better I have a lot of this in 316 - 10 gage and the weight cant be off much considering the size ? If you can / would please send a blank that is ready to bend , I want to see what I can come up with and do some weight comparing. It may be to thick but that is what I have . Thank You for your efforts and work toward this project Thumbs Up I will get a engine ready in the mean time . Eric Eyebrows
getback
getback
Top Poster
Top Poster

2019 Supporter

2020 Supporter

Posts : 6953
Join date : 2013-01-18
Age : 62
Location : julian

Back to top Go down

Happy Re: postage stamp mounting

Post  Sponsored content


Sponsored content


Back to top Go down

Page 3 of 3 Previous  1, 2, 3

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum