COBRA Hydraulic Jack

Has anyone replaced the scissors jack on a late 90s vintage COBRA trailer with a COBRA Hydraulic Jack. If so I would appreciate it if you would share any details about the switch.

Thanks,

Bill

On Friday, November 20, 2020 at 2:42:35 PM UTC-5, wrote:
Has anyone replaced the scissors jack on a late 90s vintage COBRA trailer with a COBRA Hydraulic Jack. If so I would appreciate it if you would share any details about the switch.

Thanks,

Bill

Hi Bill,

Not what you asked, but this is R.A.S. after all...

If the reason you are replacing is frustration with the cheap scissors jack and ungainly handle, consider a ratchet-driven scissors jack like this one. https://modernspare.com/product/3000...contact-point/

I got one of these in a spare tire kit for my tow vehicle, and it's a pretty slick piece of kit. It still suffers from the geometry issue inherent with the scissors design, but this one is very easy to to crank and could easily be made with a clip to hold the handle on the frame of the ramp.

Otherwise, I'd just write Spindelberger. They're super responsive and helpful and deal just fine in English.

P3

On Friday, November 20, 2020 at 11:42:35 AM UTC-8, wrote:
Has anyone replaced the scissors jack on a late 90s vintage COBRA trailer with a COBRA Hydraulic Jack. If so I would appreciate it if you would share any details about the switch.

Thanks,

Bill
Ours came installed with a Hydraulic Jack, I suspect it is Cobra. We have no problem with it. Not much help to your question but this is R.A.S. after all...
Heinz

This is an aside (but this is RAS after all) but I had to replace my (original?) leaky hydraulic jack and found that the bottle in the small floor jack from Harbor Freight is IDENTICAL. Wonders never cease.

On Saturday, November 21, 2020 at 12:53:27 AM UTC-5, John DeRosa OHM Ω http://aviation.derosaweb.net wrote:
This is an aside (but this is RAS after all) but I had to replace my (original?) leaky hydraulic jack and found that the bottle in the small floor jack from Harbor Freight is IDENTICAL. Wonders never cease.
I made a complete hydraulic system for my Cobra from off-the-shelf parts from McMaster Carr. If interested, I can send a parts list and photos to your e mail address. Mine is listed above. You will need a drill press and other aluminum metal-working tools (I have a band saw, but a hack saw will do the work too) and some mechanical building experience. If you have those, the total cost will be about $200 and a day's worth of labor. But then you will have a hydraulic jack for your Cobra trailer.

On Saturday, November 21, 2020 at 8:37:40 AM UTC-6, wrote:
I made a complete hydraulic system for my Cobra from off-the-shelf parts from McMaster Carr. If interested, I can send a parts list and photos to your e mail address. Mine is listed above. You will need a drill press and other aluminum metal-working tools (I have a band saw, but a hack saw will do the work too) and some mechanical building experience. If you have those, the total cost will be about $200 and a day's worth of labor. But then you will have a hydraulic jack for your Cobra trailer.

I would very much like to see this parts list. Thanks.

PS - I cannot see your email address "above" in Google Groups version of RAS.

On Saturday, November 21, 2020 at 6:36:14 PM UTC-5, John DeRosa OHM Ω
On Saturday, November 21, 2020 at 8:37:40 AM UTC-6, Jay Campbell wrote:
I made a complete hydraulic system for my Cobra from off-the-shelf parts from McMaster Carr. If interested, I can send a parts list and photos to your e mail address. Mine is listed above. You will need a drill press and other aluminum metal-working tools (I have a band saw, but a hack saw will do the work too) and some mechanical building experience. If you have those, the total cost will be about $200 and a day's worth of labor. But then you will have a hydraulic jack for your Cobra trailer.
I would very much like to see this parts list. Thanks.

I've already tried to post this once so apologies if this is a duplicate. With Jay Campbell's permission, I've put the photos and BOM for his intriguing DIY hyraulic fuselage jack up on a shared drive.

https://drive.google.com/drive/folde...On?usp=sharing

Chip Bearden
JB

Which small floor jack at Harbor Freight? There are a whole bunch of them. I would love to replace the bottle on mine.

On Tuesday, November 24, 2020 at 12:00:24 AM UTC-6, wrote:
Which small floor jack at Harbor Freight? There are a whole bunch of them. I would love to replace the bottle on mine.

I believe that it is the $30 cheapest 2 Ton floor jack that I used the bottle from. Lots of spare parts now left over in the junk bin.
https://www.harborfreight.com/2-ton-...ack-64874.html

I have seen the same bottle in cheap jacks at Walmart and other big box stores.

That being said it is always best to take your old bottle with you, plus a ruler, to compare old with new before purchase.

My $0.02,
John (OHM)

I should add a couple of things on this topic.

- While the bottle jack approach is just as good as the scissors jack's when making fine UPWARD rigging adjustments (and great for fast coarse raising the fuselage), but is very much inferior when trying to make fine DOWNWARD rigging adjustments. IMHO.
- The foot actuator on the original "Cobra" hydaulic jack fits nicely onto the replacement bottle.
- The original jack has a cleverly bent lever attached to the release valve so that you can use your fingers to open and close it. The replacement bottle's valve is basically a short bolt with the head cut off and a slot cut into the end. You then use the pipe (used to pump the jack up/down) to open/close the valve by rotating the bolt. I use a large screwdriver instead.. Not quite as easy to use as the original bent lever. I was unsure about moving the original lever to the replacement bottle. Same threads? Same ability to close the release valve properly? That all comes down to the machining in the factory which, I fear, is pretty "iffy". Anyone re-invent this?

My $0.02,
John (OHM)