Hydraulic cylinder
 

Hey guys
I'm planning to add a cylinder to operate my 3 pt independent of my deck lift. The plan is to put the cylinder where the lift rod goes, between the trans and frame. There is 2 1/4" of space in there and I am shooting for 4" of stroke. I could use another quiet line cylinder but it's 1 3/4" OD (1.5" bore), feel like I'm wasting a perfectly good half inch! :biggrin2: I'm looking to stuff the largest diameter cylinder I can in there (F=P•A). When I look up cylinders online, they list bore and stroke but rarely outside diameter. Got any ideas? Cylinders from other models or equipment?
Thanks

Bill

QL cylinder is your best bet. Unless you mount the cylinder on the outside on the back.....

What model of tractor are we working on?

Do you intend to use the a different pump and reservoir, or the ported pump and rear end?

Without knowing some more about the particulars, it's hard to give an opinion, a larger diameter cylinder will use more fluid and be slower (if you use the ported pump) and unless you intend to lift something really heavy, the factory cylinder would easily lift all the "approved" implements, do you need more power than that?

Just some thoughts...

Sorry, it's for a 1450. I picked up a 3 spool valve to replace the single valve under the dash. My plan is to make it a tri-stick; 1 for the deck, 1 for 3 pt, and one split to front/rear hyd outlets. I know larger dia will be slower, but I'm increasing bore dia 1/4"-1/2" over stock cylinder, didn't think it would slow much. A 1/4" increase (according to my math) is good for an extra 115 lb at the end of the lift arm. Do I need more power? No, but more power is always just right!:biggrin2: I'm just curious, and with everyone else's knowledge of other equipment, if someone knew of a cylinder that might give a little extra power and still fit. Just exploring all options. :beerchug:

Jonathan, a ql cylinder is my fallback, I don't want to have it mounted outside on the back.

Thanks
Bill

Thanks for the update, this sounds like a fun project.

While I agree that more power is almost always better, I can tell you from experience that my hydraulic lift Wide Frame tractors (factory set-up) have enough lifting power to cause the front end to "float" when carrying a full load. No to say that this is a problem that can't be overcome, just a point of reference. An extra 115 lbs of power would surly require a front weight bar if used at full capacity.

Being an "Only Cub Cadet kind of guy" I can't help with what parts from other equipment will meet your needs. Hopefully someone who has contemplated this before, will be along shortly to offer some advice and opinions.

Please keep us posted.

Bill,
I did some math on this a little while back also. I don't know how you got 115lbs, but it sounds right. I did a quick figure and going from a 1.5" bore cylinder to a 1.75" bore at 600PSI would take the cylinder from exerting 1060 lbs to exerting 1443 lbs. So, yeah.... 1/4" makes a BIG difference! Anyway, I was running numbers the other day for this 582D project I'm working on and planning on doing something similar, and I found that even if I ran 2 QL cylinders for the 3PT it wouldn't exert the same pressure as 1 '82 series cylinder. Now, we both know you can do a lot with leverage, after all, I'm not sure there is much lifting difference between the QL's and the '82 series, they just used a longer arm with the smaller bore cylinder. In all the research I've done, it seems all the GT manufacturers used that cylinder off the '82 series in their tractors. (JD, Bolens, CCC even some of Jacobson and Ransomes) So finding a cylinder bigger than that will be tough. Finding one between the two..... I haven't yet. So, I think the best bet (and my plan) is to try and use either 2 QL cylinders, or 1 '82 series. You just have to adjust the rockshaft arm that attaches to the cylinder to compensate for the bore and stroke difference. Or, you could go to a hydraulic shop and have them make you a cylinder...... :bigthink: I have a shop that does that. It's not as bad as you might think ($$$ wise). But still will be FAR more than using one already in production. Just my :TwoCents:

Johnathan
I started with the 1060 and 1443 numbers also. Multiply by 3.5" input arm on the "rock shaft", divide by 4.5" output arm. Multiply again by 7.5" lifting point on the lift arm and divide by 18" long lift arm gave me 343 and 468 lbs. So it's 125 lbs haha couldn't do the subtraction. :biggrin2:

I've been playing with the linkages, changing lift points and lift bar trying to find a balance between power and travel. I think my best bet is to make the 3 pt rock shaft 1 to 1 and move my lift links to 7.5". 1060*7.5/18=441 lbs of lift force with the ql cylinder.

I changed the Liftbar on my 3 pt to a straight bar connected to the float link on the deck rock shaft instead of the "wing" I welded on to get more force. Math tells me it's almost doubling the force to over 400 lbs, but it still struggles at the end of the stroke to lift my tiller. Part of that is the rock shaft arm flattens out and I lose some of the mechanical advantage. I'm wondering is the 600 psi number we are using correct? How sensitive is the pump pressure to rpm, is half throttle 300 psi?

Attachment 50174
Sorry lousy cellphone pic


A custom hydraulic cylinder eh? This sounds like a job for Jeff in PA! I'm thinking oval shape to maximize use of the space. LoL I did notice in my search you could get the ql/power king cylinder or the 82 series/jd/case/etc. I've seen the newer mower lift cylinders for sale, but not all sellers are responsive when you ask for overall dimensions.

Sam, I'll definitely post the outcomes. I'm just in the gathering stages now, there will be more questions, particularly the crash course in making hydraulic hard lines I'll need. :bigeyes: HaHa

Thanks guys
Bill

Well geewizz. I just did a bunch of calcapations and never new this threat existed.

Yeah, the cylinder on an 82 series, iirc, is a 2.5" cylinder and at 625 psi is roughly 3,068 lbs of lifting force. WOW! Got that by doing 1.25×1.25xπ= 4.91x625= 3,068. I believe the stroke on said cylinder is only 2.5" tho compared to 4.75" on a ql cylinder.

Just imagine the damage you could do with a 2.5" cylinder on a 5" stroke! You would have it all!!

You found me out! :biggrin2: As you can see I had been doing the same math you are. The '82 cylinders put out a lot of force.

I've settled on finding a QL cylinder, just haven't moved forward on this project. Since my 1450 is both right hand lift control and right hand direction control I want to split them up so I can operate both at once. My plan is to move the lift controls to the left side and add the 3 spool valve, or add foot controls, leave the right side lift and add the new valve. I'm mocking up the foot controls now to see if I like them, after that this project will come around again.

I would love to have room inside the frame for a 2.5"x5" cylinder.....means I could keep the skin on my knuckles.

Bill

I'm wanting to do the same to my 128... maybe this year

here is a site that has hydro stuff cheap
http://www.surpluscenter.com/Hydraul...ers/?page_no=8