Posted 2011-11-12 9:00 PM (#138901) Subject: Hydraulic jack
Member
Posts: 26 Location: East Texas
I'm too old to keep cranking on my trailer jack; Too cheap to buy a hydraulic, so I'm gonna build one. However I need a little information to get started. Can anyone tell me the stroke length and diameter of the cylinder on a factory unit?
How about pump GPM and pressure?
Thanks,
Posted 2011-11-13 7:53 AM (#138905 - in reply to #138903) Subject: RE: Hydraulic jack
Member
Posts: 26 Location: East Texas
Originally written by gard on 2011-11-12 10:47 PM
Here's some manuf specs. 12V pump means a low pressure sysytem
Have you considered a heavy duty electric drill?
No.
Anything electric would have to incorporate a gear motor to produce the torque required to operate the jack under load. For the cost of a DC or AC gear motor I can buy a DC hydraulic pump, valve and cylinder.
Posted 2011-11-13 5:00 PM (#138911 - in reply to #138901) Subject: RE: Hydraulic jack
Extreme Veteran
Posts: 379 Location: Missouri
I don't have any specs to help you but here's a good source for hydraulic parts. I've been thinking of doing the same thing as you, and believe I can buy all the parts from here for half the cost of a factory jack.
Posted 2011-11-13 7:36 PM (#138913 - in reply to #138911) Subject: RE: Hydraulic jack
Member
Posts: 26 Location: East Texas
Originally written by hornet on 2011-11-13 5:00 PM
I don't have any specs to help you but here's a good source for hydraulic parts. I've been thinking of doing the same thing as you, and believe I can buy all the parts from here for half the cost of a factory jack.
Posted 2011-11-14 5:49 AM (#138916 - in reply to #138901) Subject: RE: Hydraulic jack
Extreme Veteran
Posts: 379 Location: Missouri
I've seen many folks carry 6x6 blocks and lower the jacks onto them. I do that even with manual jacks to keep the foot off the ground. The problem I think you'll run into with only 8 inch travel is if you're using the jack to level your trailer, you could easily run out of lift. Most of the jacks I've seen look to be about 2 foot long.
Posted 2011-11-14 7:43 PM (#138921 - in reply to #138901) Subject: RE: Hydraulic jack
New User
Posts: 1
Location: Farmington, MO 63640
Before you go to all that trouble, I have a brand new, still in the crate I-Drive trailer drive system I need to sell. Don't know if you are familiar with these or not but it is the cadillac of hydraulic jacks. 10,000 lb lift capacity and it has the caterpillar drive system so you can move your trailer without hooking it up to your truck. These jacks were selling for around 2800 to 3000 and I'll sell this one for $1000 bucks. This no joke or scam, you can pay for it when you pick it up. It's taking up space in my garage and I need it gone. If you would like to see pictures I can email them to you. My address is jay.sheets@twisted-creek.com or you can call me at 573-631-8970
Posted 2011-11-14 9:42 PM (#138925 - in reply to #138905) Subject: RE: Hydraulic jack
Expert
Posts: 3853 Location: Vermont
Originally written by ellisor on 2011-11-13 7:53 AM
Originally written by gard on 2011-11-12 10:47 PM
Here's some manuf specs. 12V pump means a low pressure sysytem
Have you considered a heavy duty electric drill?
No. Anything electric would have to incorporate a gear motor to produce the torque required to operate the jack under load. For the cost of a DC or AC gear motor I can buy a DC hydraulic pump, valve and cylinder.
How big must a cylinder be if the available pump produces 2500 psi and a lifting force of at least 17,000 pounds is needed. Force 17,000 Formula: Area = --------- = --------- = 6.8 square inches psi 2500 Area = 3.14 X R X R 6.8 sq.in. R X R = ------------- = 2.17 3.14 R = Square root of 2.17 = 1.47 inch radius cylinder Diameter = 1.47 X 2 Diameter = 2.94 inches A 3-inch diameter cylinder will be sufficient.
Posted 2011-11-14 9:49 PM (#138926 - in reply to #138901) Subject: RE: Hydraulic jack
Expert
Posts: 3853 Location: Vermont
Originally written by ellisor on 2011-11-12 9:00 PM
I'm too old to keep cranking on my trailer jack; Too cheap to buy a hydraulic, so I'm gonna build one. However I need a little information to get started. Can anyone tell me the stroke length and diameter of the cylinder on a factory unit? How about pump GPM and pressure?Thanks,
How big must a cylinder be if the available pump produces 2500 psi and a lifting force of at least 17,000 pounds is needed. Force 17,000 Formula: Area = Force/psi = 17000/2500 = 6.8 square inches Area = 3.14 X R X R ........ R X R = 6.8 sq in/ 3.14 = 2.17 R = Square root of 2.17 = 1.47 inch radius cylinder Diameter = 1.47 X 2 Diameter = 2.94 inches A 3-inch diameter cylinder will be sufficient.
Hydraulic jack
