Backhoe Design Ideas

[JoelD]

Can you give me more details on what you did? Did you hook up to the rear or the mid PTO? I've been looking on Surplus Center's website. I can see pumps that I think would work, but I haven't found anything to adapt from the PTO to the pump. My mid PTO is a 1 inch 15 spline. My rear PTO is a standard 540 PTO.

There's this that matches the PTO output shaft, but the other end doesn't match any of the pumps that I've found in the price range on thier website.

I found an adapter from standard 6 spline to 1/2 keyed. My tractor had a 31/32 10 spline rear PTO shaft (LONG story) I found an adapter to standard 6 spline, then slipped the six spline adapter over that and put the 1/2 inch keyed pump into the other end of the adapter.

Here's some examples.

http://www.hubcityinc.com/media/q.pdf

Just slip the adapter over your six spline rear PTO then slip the pump into the other end and use a key and a couple of set screws and you are good to go.

Sorry my pictures don't make it all that clear, I've sold the machine otherwise I'd send you more pictures, but it's fairly straight forward.

Nice being able to use any pump, rather than PTO pump.

Joel

 

[dfkrug]

i've never heard of restrictions in work lines to get smooth controls.. The official solution is to change the valves for ones with slots in the edges, so they cheat some oil before they fully open... You can also grind them yourself, we've done that on payloaders that needed more precise tilt control when used with a 20 meter hoist boom on the quicktach.

A more efficient way to decrease jekiness is to reduce the speed by decreasing engine rpm, instead of wasting power by restrictions.

Well the speed of the cyl movement is an issue mostly for the swing cyl(s)
on these small hoe attachments. Much less for the boom, and not all all
for the curl cyl. Lots on TBN about damping the swing circuit. The
restrictions on my JD FEL were for the curl only.

As for cheating some oil around the lands in the spools, that makes sense.
I wonder if any of these hoe attachments have that. My current hoe's
valves have a very noticable position mid-stroke of each lever which cuts
off flow to/from each work port, as well as blocks the valve center. It
is less apparent on other stack valves I have used. Maybe I could use
some valve customization....

 

[Renze]

Well the speed of the cyl movement is an issue mostly for the swing cyl(s) on these small hoe attachments. Much less for the boom, and not all all
for the curl cyl. Lots on TBN about damping the swing circuit.

That makes sense..

 

[Iplayfarmer]

Well the speed of the cyl movement is an issue mostly for the swing cyl(s) on these small hoe attachments.

I guess that answers my next question. I have two 3" cylinders for the swing. I was wondering whether to plumb them as single acting or double acting. Double acting has a lot more force and may be smoother, but single acting requires less flow (i.e. Faster). If swing speed is frequently an issue with these smaller hoes, then I will plumb them as dual acting cylinders. I suppose that worst case I can always go back in and plumb them single acting later if I want more swing speed.

 

[charlz]

Mine has a 'cushion valve 1000psi' on the SA swing cylinders... is this to 'slow start' the swing and take some of the jerk out of it?


As for a PTO to pump adapter the p/n for mine is 70020-00786 but TractorSmart shows the price as $92.56 It is just at PTO coupler welded onto a keyed piece with a couple set screws that slides over the pump shaft. Seems easy enough but maybe not so easy to make yourself?

 

[Iplayfarmer]

Mine has a 'cushion valve 1000psi' on the SA swing cylinders... is this to 'slow start' the swing and take some of the jerk out of it?


As for a PTO to pump adapter the p/n for mine is 70020-00786 but TractorSmart shows the price as $92.56 It is just at PTO coupler welded onto a keyed piece with a couple set screws that slides over the pump shaft. Seems easy enough but maybe not so easy to make yourself?

I went back and looked at hydraulic pumps at Surplus Center. To get a pump that would put out enough volume at 540 RPM would cost over twice as much as a pump that I'd run at 2000 RPM (i.e. belly mount).

I'm really spending too much time on the hydraulics. I'm going to connect to the tractor hydraulics at least initially to see how it works. I need to get my 4 point mounting mechanism figured out for now.

 

[JoelD]

I don't know what tractor you are hooking up to (GPM of tractor). I've got my surplus center catalog #282

My tractor had three PTO settings (older Kubota), 540, 700+ and then 1250 I think it was.

My current tractor, Kioti LK has two settings 540 and 1000.

If you've got a faster setting than 540 that would permit a smaller pump.

Pump 9-7154 is rated at 12.24 GPM at 2000 rpm, that would give you 6 PGM at 1000, which should work fine depending on the size of the backhoe you are building. I ran this pump at 540 and it worked find on my 5 foot hoe on my little Kubota B6000 (the tractor's pump was somewhere aroung 2 gpm, little tractor). The pump costs $99.

The adapter I spoke about is on page 110, with the quick connect to the tractor and the female end ready for the pump shaft with key way.

There's a number of ways to come up with a combination that would work.

Page 32 has spline shafted pumps with higher outputs, which max out in price at $199.

Good luck,

Great fun when it all comes together.

Sincerely,
Joel

 

[Iplayfarmer]

I don't know what tractor you are hooking up to (GPM of tractor). I've got my surplus center catalog #282

My tractor had three PTO settings (older Kubota), 540, 700+ and then 1250 I think it was.

My current tractor, Kioti LK has two settings 540 and 1000.

If you've got a faster setting than 540 that would permit a smaller pump.

Pump 9-7154 is rated at 12.24 GPM at 2000 rpm, that would give you 6 PGM at 1000, which should work fine depending on the size of the backhoe you are building. I ran this pump at 540 and it worked find on my 5 foot hoe on my little Kubota B6000 (the tractor's pump was somewhere aroung 2 gpm, little tractor). The pump costs $99.

The adapter I spoke about is on page 110, with the quick connect to the tractor and the female end ready for the pump shaft with key way.

There's a number of ways to come up with a combination that would work.

Page 32 has spline shafted pumps with higher outputs, which max out in price at $199.

Good luck,

Great fun when it all comes together.

Sincerely,
Joel

I just got the newest SC catalog out of the mailbox about an hour ago. I think I see the adapters you are talking about. I only have 540 RPM on the rear, so I'd need a pretty big pump to get better flow. I keep thinking there has to be a way to use the 2000 RPM Belly PTO. The pump I'd need for 2000 RPM is under $100; but I'd have to adapt from my 1" 15 spline shaft and move it forward and to the side a bit so I can tuck it up above the subframe. The parts to move it add up pretty quick.

For now I'm keeping my eyes on E-bay for a pre-fab PTO pump.

 

[Iplayfarmer]

I just bought a PTO "Hydrolic" pump off e-bay.

Here's the item... Charlynn PTO Drive Hydrolic Pump - eBay (item 170314394646 end time Mar-30-09 18:41:14 PDT)

If you are the seller, thanks. If I was bidding against you, neener neener...uh... I mean sorry you didn't win.

I really don't know any of the specs on this pump. Feel free to chime in now and tell me if it's not going to work. The sooner I know, the easier it will be to take.

 

[JoelD]

How big is the return hose fitting? Not sure that's gonna flow enough oil? Nothing to loose for that price. Only one way to find out, if it doesn't work swap out for another. No big deal in the end.

Certain there is someone on this forum who would know something about that pump.

Good luck,
Joel