Need advice on extending out a segmented boattail ( I have no idea how to word that )

[Cd]

So i have this crazy idea that I thought up several years ago.
I'm using two 24 " drawer slides attached to each other to extend out a 70 " segmented boattail.

On the end will be a pulley, with a cable leading to a crank inside the car .
When I need to retract the tail, I will rotate the crank, and reel in the cable that pulls in the drawer slides ( like a fishing rod setup )

I'd like to have it motorized, but thst can come later if the idea even works.

So how would I EXTEND it though ?

The only thing I can think of is to use gearing, but then I would have to find a way to create the teeth all along the bottom of the drawer slides.

What I need is something that is capable of pushing forward the 70 inches that the slides go out to.

Something like a power antenna motor, but one that extends out 70".

It also has to be dirt cheap and still allow me to use the back seat in the car. ( So a broomstick pushed out the back would not be a good solution. )

Until I find a solution, I guess I would just pull over on the side of the road and pull out the tail by hand.

Currently, i just have the drawer slides, and some cardboard aided design testing done.

Will i actually build this ? Probably not, but just maybe.

[Piotrsko]

Perhaps the lift shafts that are used in pop top camper shells gotten from a scrap yard? About 3ft worth of up and down movement but they end up 6ft long. The only other would be slip fit plastic pipe running air pressure or hydraulics. See homemade pipe squirt guns.

[Cd]

That's a great idea. Thinking outside the box for sure !
Unfortunately, those pistons are very strong and hard to push back in ( I found this out when I went to fix the ones on my hatchback.)
Thank you for the tip though.

[Cd]

Somerhing like this, but just with the shaft and crank might work
https://reverb.com/p/hercules-ss710b...ash-ez-adapter

[freebeard]

Quoth DDG:

https://usbellows.com › resources › faqs › what-is-meant-by-pantographic-linkage-
What is meant by pantographic linkage? | US Bellows
Pantographic linkage is an accessory that is used to distribute axial movement between two bellows, allow lateral motion and support the weight of the center pipe section between the bellows. Expansion Joint with Pantographic Linkage

https://www.freepatentsonline.com › 4437635.html
Pantograph linkage system - National Research Development Corporation
A pantograph linkage system for use in a manipulating tool comprises a pair of pantographs linked together in parallel. Each pantograph consists of a pair of arms held in a fixed relative orientation and the two arms comprise components of parallel linkages.

[Cd]

If I am doing this right, I think I have a pulley system that pushes, instead of pulling.
I THINK this may work.
Thanks for the advice everyone.

[aerohead]

One option would have to do with my brother's 50-foot, self-erecting, HAMM radio antenna, which uses cable/pulleys for both functions.
On a boat-tail application, the cable would pass from the winch, to a caged pulley at the 'rear' of the 1st 'drawer' ( like a sideways gin-pole ), then pass back forwards, to the 'inner' face of the 2nd drawer.
As the cable is clutched, and tensioned, it forces the second drawer out of it's nesting position, until fully extended ( like an elevator car cabled from below ).
If counter-rotating spools share the same shaft location, the 'retraction' cable is paid out during 'erection,' then for 'collapsing', clutching operations reverse, with the winch now 'reeling the tail back in.'

[Cd]

Aerohead, I think you described my setup.
The center pulley "pushes", while the side pulleys act as the anchor.
I was all set to start building on the boattail this weekend, but then re-read Darin's thread on that 'ginormous' cardboard tail he made.
It ended up only resulting in a 1MPG gain.
I think I pretty much gave up after reading that.

[aerohead]

Originally Posted by Cd

Aerohead, I think you described my setup.
The center pulley "pushes", while the side pulleys act as the anchor.
I was all set to start building on the boattail this weekend, but then re-read Darin's thread on that 'ginormous' cardboard tail he made.
It ended up only resulting in a 1MPG gain.
I think I pretty much gave up after reading that.

I think Darin tests at relatively low velocity, compared to, especially Austin, where one can drive at 85-mph between there and San Antonio.
Do you remember which car Darin got the 1-mpg with?

[Cd]

Originally Posted by aerohead

I think Darin tests at relatively low velocity, compared to, especially Austin, where one can drive at 85-mpg between there and San Antonio.
Do you remember which car Darin got the 1-mpg with?

This one : https://ecomodder.com/forum/showthre...n-31498-6.html