Bungee Material for Landing Gear and Engine Bay Doors

Try West Marine, years ago I purchased bungee for my ASH26, worked perfect and I just found some of the same stuff in a box of old glider parts, still acts as if new.

On Sunday, December 3, 2017 at 10:56:09 AM UTC-8, Craig Funston wrote:

Many hiking / climbing / outdoor stores will carry bungee cord in bulk. If you're in the US, try REI, or one of the big box stores with lots of guns and dead animals in it. ;-)

Craig
7Q

On 12/03/2017 08:44 AM, wrote:
On Sunday, December 3, 2017 at 9:35:33 AM UTC-6, wrote:
On Sunday, December 3, 2017 at 7:38:05 AM UTC-6, wrote:
I am looking for a source for bungee material for my landing gear and engine bay doors (ASH-26E). The original (German-sourced?) bungee is about 5 mm diameter and stretches to about twice the rested length. The 3/16 inch USA-sourced material I have been able to find (McMaster-Carr, etc.) doesn't stretch quite as much, about 75% rested length. Since the adjustment on the '26's engine bay doors is quite critical, I really would like to find the original (German-sourced?) bungee material with more stretch. Anyone know where I can get some?

Thanks,
Jim

Thanks, guys, good input....

No joy on Amazon (searching from the USA), but I'll keep checking.

I have an eBay purchase on the way, from China, real cheap. The best "specifications" I can find are comments like "100% stretch" and "Capable of stretching under load to about twice it's untensioned length". I am not real confident of getting decent quality, life, or performance, we'll see what I get. Here are two links:

https://www.ebay.com/itm/112044223163
https://www.ebay.com/itm/322860613155

I did find a German eBay supplier, but they are out of stock on 5 mm:

https://www.ebay.com/itm/Bungee-Cord...1N1H KIs7sdsA

I've checked Aircraft Spruce also, "shock cord", but they don't stock 5 mm (3/16 inch). Their material is MIL-C-5651D spec'ed, greater than 100% elongation, so that is good. If I don't like the 5 mm stuff I get from eBay, I might try their 1/4 inch or 1/8 inch material.

But the best would be to find the original (German-sourced?) material.... This may be it:

https://www.schnurhaus-onlineshop.de...5-GL-PESGw-020

But 20 meters is way more than I need, and they want 30 Euros to ship Germany to USA.

We'll see what I get from China. But I still would like to get a meter or two of the original stuff if I can.

Cheers,
Jim


Source for 3/16 inch MIL-C-5651D Type 1 shock cord, 500 ft rolls, that's a lot of gear doors, haha!

http://www.theecwcorp.com/braided-el...e-i-p-317.html

Cheers,
Jim


On my 26E, I measured factory original cord as .160 inch (light
pressure with a caliper), so I took that as 4 mm. Real close to 5/32.

On Sunday, December 3, 2017 at 5:38:05 AM UTC-8, wrote:
I am looking for a source for bungee material for my landing gear and engine bay doors (ASH-26E). The original (German-sourced?) bungee is about 5 mm diameter and stretches to about twice the rested length. The 3/16 inch USA-sourced material I have been able to find (McMaster-Carr, etc.) doesn't stretch quite as much, about 75% rested length. Since the adjustment on the '26's engine bay doors is quite critical, I really would like to find the original (German-sourced?) bungee material with more stretch. Anyone know where I can get some?

Thanks,
Jim

This has been well discussed on the ASH-26E owners list.

I have had no problem using McMaster Carr 3/16 (~5mm) bungee cord on my ASH26E, and I've replaced engine bay door bungees several times. It is not rocket science, but you have to not over tighten the cord.

On Monday, December 4, 2017 at 1:03:26 AM UTC-5, Darryl Ramm wrote:
...I have had no problem using McMaster Carr 3/16 (~5mm) bungee cord on
my ASH26E, and I've replaced engine bay door bungees several times...

Um, if you've had no problem, why do you need to keep replacing bungees???

On Monday, December 4, 2017 at 8:00:06 AM UTC-6, Dave Nadler wrote:
On Monday, December 4, 2017 at 1:03:26 AM UTC-5, Darryl Ramm wrote:
...I have had no problem using McMaster Carr 3/16 (~5mm) bungee cord on
my ASH26E, and I've replaced engine bay door bungees several times...

Um, if you've had no problem, why do you need to keep replacing bungees???

I have replaced the gear door bungees on my gliders every few years, usually once they begin to get sucked open in a slip. I get about three years out of aviation bungees, and got one or two years out of commercial (Chinese) cord.
The seemingly short life I attribute to a very light installation preload, to minimize wear on the door surfaces, and constant stretched pressure. either with the doors closed or open. The correct tension therefore falls into a narrow range, which goes away within a few years.
I found it interesting that the aviation cords have a color code for the date of manufacture braided into the jacket.
cheers,
Scott, SHK & Std Cirrus

On Monday, December 4, 2017 at 6:00:06 AM UTC-8, Dave Nadler wrote:
On Monday, December 4, 2017 at 1:03:26 AM UTC-5, Darryl Ramm wrote:
...I have had no problem using McMaster Carr 3/16 (~5mm) bungee cord on
my ASH26E, and I've replaced engine bay door bungees several times...

Um, if you've had no problem, why do you need to keep replacing bungees???

Jeez, the ever enquiring mind of Dave Nadler :-) The rear bungee may gets cut off when you remove the doors. (or if you have enough pairs of hand/your act together you take both doors off at once. And the front bungee wears out after many years.. You might also replace them to improve the style of fastening clip attached to the front bungees. Are those enough reasons? :-)

A common problem is people over tightening bungees on Schleicher motorgliders. The doors can bang around sometimes in flight with the mast extended, overtightening the bungees to try to stop that is not a solution, besides that a reminder to fly more coordinated.

On Sunday, December 3, 2017 at 8:56:37 PM UTC-6, Jonathan St. Cloud wrote:
Try West Marine, years ago I purchased bungee for my ASH26, worked perfect and I just found some of the same stuff in a box of old glider parts, still acts as if new.

Ditto suggestion on West Marine. As it is intended for marine use it holds up very well. And it comes in multiple colors! Be wild and crazy with your bungee!

On Monday, December 4, 2017 at 4:57:19 PM UTC-8, OHM Ω http://aviation.derosaweb.net wrote:
On Sunday, December 3, 2017 at 8:56:37 PM UTC-6, Jonathan St. Cloud wrote:
Try West Marine, years ago I purchased bungee for my ASH26, worked perfect and I just found some of the same stuff in a box of old glider parts, still acts as if new.

Ditto suggestion on West Marine. As it is intended for marine use it holds up very well. And it comes in multiple colors! Be wild and crazy with your bungee!

https://www.westmarine.com/buy/new-e...52?recordNum=3

I have 25 year old west marine bungee cord that is still good. Safe bet it was not made in China!

On Monday, December 4, 2017 at 8:54:27 PM UTC-8, 2G wrote:
On Monday, December 4, 2017 at 4:57:19 PM UTC-8, OHM Ω http://aviation.derosaweb.net wrote:
On Sunday, December 3, 2017 at 8:56:37 PM UTC-6, Jonathan St. Cloud wrote:
Try West Marine, years ago I purchased bungee for my ASH26, worked perfect and I just found some of the same stuff in a box of old glider parts, still acts as if new.

Ditto suggestion on West Marine. As it is intended for marine use it holds up very well. And it comes in multiple colors! Be wild and crazy with your bungee!

https://www.westmarine.com/buy/new-e...52?recordNum=3