12” gauge DRGW Inspired RR

Discuss park gauge trains and large scale miniature railways having track gauges from 8" to 24" gauge and designed at scales of 2" to the foot or greater - whether modeled for personal use, or purpose built for amusement park operation or private railroading.

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0351
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Re: 12” gauge DRGW Inspired RR

Post by 0351 » Sat Jun 05, 2021 5:03 pm

ERIE S-1 BERKSHIRES wrote:
Sat Jun 05, 2021 3:04 pm
I built a Alco FA-2 with a Kohler 8 HP coupled to a Eaton 11 hydrostatic pump with a chair Lynn 5.9 cubic inch motor on each truck in series, 3 gallon oil tank for cooling! The Eaton 11 pump has acceleration valves for forward and reverse for smooth starting and stopping, never had a problem heating up the oil pulling a heavy load. Also one of my on hold projects is a 2 1/2 Little Giant X1 also same hydraulic drive as the Alco FA-2 I highly recommend the 11 hydrostatic pump!
Thanks for your input. How is your Eaton 11 connected to your hydro pump?
Would you be willing to share pictures of your truck setup?
I was told that there are some pumps that will bolt to the Eaton 11. Think the John Deere Big Green Mowers used an Eaton 11 with a bolt on pump for powering hydro motors.

Happy to hear someone else is building a Little Giant! I’ve got some drawings, GE-folio, and plenty of photos, if you ever need some for reference.
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ERIE S-1 BERKSHIRES
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Re: 12” gauge DRGW Inspired RR

Post by ERIE S-1 BERKSHIRES » Sat Jun 05, 2021 6:40 pm

The Eaton 11 is a hydrostatic pump it connects directly to the hydraulic lines, the one that you thinking about using with Drive shafts is called the Eaton 11 hydrostatic transmission. I went downstairs and took a picture of mine laying over on its side the top of it is facing the picture the bottom is away from us
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0351
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Re: 12” gauge DRGW Inspired RR

Post by 0351 » Sun Jun 06, 2021 10:57 pm

ERIE S-1 BERKSHIRES wrote:
Sat Jun 05, 2021 6:40 pm
The Eaton 11 is a hydrostatic pump it connects directly to the hydraulic lines, the one that you thinking about using with Drive shafts is called the Eaton 11 hydrostatic transmission. I went downstairs and took a picture of mine laying over on its side the top of it is facing the picture the bottom is away from us
Thanks for the picture. Is that pump a model 1120-011? Do you possibly have a photo of your truck motors are setup?


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Colossians 1-14
“ In whom we have redemption through his blood, even the forgiveness of sins:”

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BigDumbDinosaur
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Re: 12” gauge DRGW Inspired RR

Post by BigDumbDinosaur » Mon Jun 07, 2021 1:05 am

0351 wrote:
Sat Jun 05, 2021 12:08 am
Sorry, I meant problems with the model 6/7 overheating. Haven’t read anything about the 11s having problems. The Eaton 11 manual has the shows the option of using a reservoir and cooler for some applications.
The Eaton series of pumps of which the model 11 is a member, are, like all hydraulic pumps with aluminum housings, not very efficient as loading nears maximum ratings. Ergo they have a natural tendency to run hot. They are mostly intended for moderate loading, with occasional peaks. Gear pumps with iron housings are considerably more efficient under heavy loading.

If you use an Eaton 11, I highly recommend you include a radiator of some sort in the return line to the reservoir. Continuous oil temperature should not exceed 150º F, and short-term temperature should not exceed 200º F, even if using a synthetic. The problem has less to do with heating the oil and more to do with what happens to the pump when it gets too hot. Seals can fail and the difference in expansion rate between the steel pump components and the aluminum housing will produce internal blow-by and a marked loss of efficiency.

In determining oil reservoir capacity, one gallon for every three horsepower applied to the pump is the minimum ratio I use. In your application, that would work out to a four gallon reservoir. The reservoir should be filled to no more than 85 percent capacity to allow for expansion and to discourage aeration that can lead to damaging pump inlet cavitation. A bigger reservoir won't necessarily aid cooling, since it will be enclosed by the locomotive's carbody and thus not able to freely radiate to the air. The reservoir's primary role in any hydrostatic power transmission is to prevent pump starvation under any condition, not to dissipate heat.

An accessory automatic transmission radiator suitable for a full-sized pickup truck or an SUV of a Chevy Suburban's size makes for a good radiator—bigger here is definitely better. The radiator should be inserted in the return line upstream of the filter. You might also want to consider fan-cooling the radiator.
I realize that by using right angle gear box’s I’ll be loosing some power.
Any type of power transmission device will have parasitic losses. As geared devices go, the efficiency of the Tolomatic product is fair to good, depending on speed and load. Tolomatic right-angle units use intersecting helical gears that are cut with a 45 degree helix, resulting in a lot of sliding action between meshed teeth. I've seen 75-80 percent efficiency quoted for these gearboxes under full load, although I haven't personally used them in anything. Just for perspective, helical gears operated on parallel shafts typically exceed 90 percent efficiency under full load, since they are cut with smaller helix angles and have true conjugal action that minimizes sliding between teeth.

Under ideal circumstances, a hydrostatic power transmission system consisting of a fixed-displacement pump, fixed-displacement motor, and required flow-control valving, will achieve a maximum efficiency of around 70 percent if most of the plumbing is done in tubing instead of hoses. Hoses greatly hurt efficiency, and thus tend to make the system run hotter. The only places you will find hose in my F-unit's propulsion system is at the trucks—and these are short hoses, at that. Everything else is plumbed in steel tubing.

Efficiency with common variable-displacement pumps may reach the 70 percent level with the pump operating at maximum displacement, but will quickly deteriorate at lower displacements. YMMV, of course.

Something to consider in driving the trucks through shafts and gearing from a chassis-mounted source is the torque reaction that will be generated. Under heavy loads, torque reaction will cause the locomotive to roll to one side, same way a rear-wheel-drive automobile rolls to the right under acceleration. You may find this to be undesirable. This behavior won't occur with hydraulic motors mounted in the trucks and geared to the axles (geared meaning a roller chain drive—actual gearing would be unneeded extravagance, in my opinion). The torque reaction will be absorbed within the truck itself.
Hydro motors in the truck aren’t out of the question. I would need to come up with a way to connect a pump to the HST the route hoses to the motors? My commercial zero-turn diesel mower uses a 28hp cat that powers a hst and hydro motors at the wheels.
I would go that route, but as I said above, keep the hose to an absolute minimum.
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Re: 12” gauge DRGW Inspired RR

Post by rkcarguy » Mon Jun 07, 2021 2:03 pm

^^^
I think if you go this route, you'll find the cost comparable or less than the 4 right angle gear boxes, and be able to hydraulically attain your "gear reduction" while having tougher hydraulic motors capable of much more torque.
The 5.9 cu/in Char- Lynn motors Erie E-1 Berkshires spoke of are cross compatible with the Brevini motors I'm using, as well as Dynamic brand and several others. The ~5.9 cu/in range is a pretty common size. The threads and locations for connecting the hoses/lines can vary across them so you have to watch that. The Brevini motors are actually ~6.1cu/in, and as a result have a bit higher torque ratings, plus they were only $110 each when I bought them.

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Re: 12” gauge DRGW Inspired RR

Post by ERIE S-1 BERKSHIRES » Mon Jun 07, 2021 6:27 pm

I currently don't have a picture of the trucks, they are standard rail systems Alco trucks .I can take a picture Sunday, also Cheryl Lynn 5.9 Motors can flow 16.5 gallons per minute ! before purchasing other hydraulic motors check the flow rates?? the Eaton 11 well flow about 16 and 1/2 gallons a minute under low pressure

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Re: 12” gauge DRGW Inspired RR

Post by BigDumbDinosaur » Mon Jun 07, 2021 6:47 pm

ERIE S-1 BERKSHIRES wrote:
Mon Jun 07, 2021 6:27 pm
I currently don't have a picture of the trucks, they are standard rail systems Alco trucks .I can take a picture Sunday, also Cheryl Lynn 5.9 Motors can flow 16.5 gallons per minute ! before purchasing other hydraulic motors check the flow rates?? the Eaton 11 well flow about 16 and 1/2 gallons a minute under low pressure
Absolute flow rate is not as important as the ratio between the pump's displacement and the motors' displacement. That is what determines the amount of "gear reduction" that will be produced and hence the loco's speed and theoretical tractive force as a function of prime mover RPM. Flow rate matters in terms of power transmission capacity, and in sizing plumbing and valves. Going overboard with flow will result in a sluggish and inefficient system due to high pumping losses. Match the pump's displacement to the available engine horsepower and RPM, and then match the motors to the selected pump.
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Re: 12” gauge DRGW Inspired RR

Post by ERIE S-1 BERKSHIRES » Mon Jun 07, 2021 6:56 pm

Yeah but if you put too much oil through a motor that will not take that flow you're creating Heat!!! The ratio is perfect for a 1.6 engine 1 to 1 ratio from motor to axles with 5.9 cubic inch motor, does not create heat at all

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Re: 12” gauge DRGW Inspired RR

Post by rkcarguy » Tue Jun 08, 2021 10:52 am

When I calculated the hydraulic ratio between my pump and motors, I used the efficiency factor of both to calculate losses and come up with a desired axle speed, then purchased my pump to suit. I am geared "lower" (more torque-lower speed) than I need be because I will have some steep grades and want pulling power over the most speed I can get out of my available HP (per BDD's method of sizing the pump for the gas engine). My engine was realistically capable of 10-11GPM or about a 1.0-1.1 cu/in pump, but I opted for a .73 cu/in pump and a top speed of about 6mph instead of ~8.8 mph. FYI the 5.9 cu/in motors may flow up to 16GPM but their sweet spot on the flow graph is more like 8-10 GPM.
Both the pump and motors should have a flow chart available that shows gallons/min, pressure, RPM, and in some cases efficiency (mine did).
Regarding ERIE's and BDD's posts above, you're actually both right. If I remember correctly, the M11 pump doesn't run high pressures like a regular hydraulic system, and I think it will be "geared" different. We've had this discussion before on Chaski, but couldn't get anyone to post any useful information regarding their exact setup with the "low pressure" system.

0351
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Re: 12” gauge DRGW Inspired RR

Post by 0351 » Wed Jun 09, 2021 7:40 am

Thanks the input gentleman!

As BDD’s signature states, so am I.
-“Research is what I'm doing, when I don't know what I’m doing”- and there is a lot I’m still figuring out.

LOL! One thing I’ve found in my research, is that “Center drive vs truck motors” appear to be the subject of many debates on the Backyard RR page, as well as here on Chaski. Pros and cons on both sides.

I have in hand both the Eaton11 hst, plus 4 tolomatics, which I have very little invested, I’m still leaning towards a center drive. Just got to come up with the correct pto shafts.

That being said, if the opportunity presents itself to sell my parts, I may to go with hydrostatic pump and motors. Also my trucks are large in size, and will be assembled where they can be easily changed.

Monday, I had an opportunity to run down to the steel supply, and pick up metal for the 50tonner chassis and deck. Price of metal has definitely increased lately! $$$!!!

Got a 4’x8’ sheet of 1/4” for the deck, 3/8” plate for the pilots, and some 1.5”x3”
Channel for the frame.
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Re: 12” gauge DRGW Inspired RR

Post by rkcarguy » Wed Jun 09, 2021 1:59 pm

Looking good, except I hope you got a deal on that sheet its pretty rusty.
We were selling laser cut steel a year ago, for less per # than what the steel alone costs now, it's crazy.
Going hydraulic, and having the motors in the trucks frees up more space inside the body and allows you to move the diesel motor where you want it as long as the pump and motor fit. There is a lot of value in that, getting drive components away from your feet being you will be inside the cab, lining up the motors exhaust port with the prototypical exhaust of the model (if wanted), and so on.
My concern with the Tolomatic layout (like the one in the picture you posted-aside from the side torque already mentioned), is that the shafts connecting the pair of them in the truck are going to be subject to twisting forces in both directions as the wheelsets navigate turns and changes in track elevation. This could accelerate wear on the shafts and bearings. A chain "final drive" from a hydraulic motor allows some movement without any adverse effects, and you can also change the sprocket on the hydraulic motor pretty easily(provided you have a tensioner or slotted mount for the hydraulic motors) to fine tune your speed/torque output.
Another option would be to use a single, larger hydraulic motor for your ~4:1 reduction, and run that through some CV axles to your Tolomatics. If you are able to visit a transmission shop, might be able to get the female splines from their parts pile and get some adapters turned up so you can just use off the shelf front-drive axles.

0351
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Re: 12” gauge DRGW Inspired RR

Post by 0351 » Wed Jun 09, 2021 3:43 pm

No deals on steel in today’s market. That little pile of steel cost $425!!!
That rusty sheet cost me $240 by itself, plus a 1.5hr round trip. Checked at the local metal shop, they wanted around $360 for a 29”x 96” x 1/4” piece.

Got some new GE door handle samples on the way. Hopefully the new design will keep people form breaking off the glue on version.
This version is still nylon but instead of gluing on they will fit through an 8mm hole one the door, with a pin on the inside, allowing the to rotate when turned. Would prefer to have them printed in brass but not a $200 for 20 handles.
Picture below show how it will work. (PC board was used for demo because it’s roughly 16ga)

Also got an update from the printer on the headlights. There was an issue with gap fill using the material he had in hand. He’s gonna try printing the light housings in resin.
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Last edited by 0351 on Wed Jun 09, 2021 4:54 pm, edited 1 time in total.
Colossians 1-14
“ In whom we have redemption through his blood, even the forgiveness of sins:”

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