RCCrawler Forums

cembom · 08-10-2007, 07:34 PM

I said something about not seeing the gain. What I meant was, for me I dont even compete, so A 200 oz mediocre servo is fine. Also correct me if I am wrong but isnt the 300 oz good enough most of the time? I would think that the hydro set up would be another thing to worry about tuning and setting up and also another thing to go wrong therefore since the servo alone isnt bad, the cons out weigh the pros.

Moving on from showing my noobness. I think its awesome. One thing I would like to see though is it working front and rear steer with one master cyl. Again about the bad, it would have to be mounted somewhere. In theory I guess it could work though right? Oh wait that master would have to be huge to hold enough fluid for those drones. Nevermind

Krawlin · 08-10-2007, 07:35 PM

WOW! I am very impressed! Looks awsome man! Also... about the hydraulic thing... maybe be wrong but, what if you had a bit fatter master (or whichever one is controlled by the servo) to hold a bit more fluild... A little more power coming out of the slave? Maybe not?

Bronco · 08-10-2007, 07:54 PM

SCREAMING AMAZING

. im extremely impressed dude!

KSCrawler · 08-10-2007, 08:40 PM

Okay, this has got me thinking (I know, scary...). Instead of a master cylinder driving the slave cylinders, what about a gear pump that is driven by a winch modded servo. This wouldn't give you proportional steering yet, but stay with me. Time to mod the modded servo! Pull the pot out of the servo and extend the pot wires enough to reach one of the steering knuckles. Affix the pot to the top of the knuckle such that the rotating knuckle rotates the pot. Now when a steering input is given, the pump kicks in and moves the slave piston in the desired direction until the feedback from the pot matches the steering input to the servo channel (much like a stock servo works) resulting in proportional steering. Definitely violates the Keep It Simple, Stupid! rule, but I think this just might work!

KSCrawler · 08-10-2007, 08:49 PM

Here's a cool animation of how a gear pump works... http://www.mekanizmalar.com/gearpump.shtml
Haven't found one small enough for this application on the web, so started looking for alternatives. Drawing a blank, I just happened to notice an old hand crank nitro fuel pump hanging on the hobby wall. Eureka! Would likely take some serious modding, like removing the gru and letting the winch servo drive the rollers directly. Now if I only had this guys mad fab skills for that kickass slave setup...

ColquittCustom405 · 08-10-2007, 10:51 PM

Well it looks cool and seems like it could be better than a servo mounted on the axle.Nice work man.Could we get a video of it up against a rock or wall,then it pushing itself off.I also would like to see how fast it could go bak and forth.Again nice work man! Awesome!

CCFBERG · 08-11-2007, 02:01 AM

Quote:

Originally Posted by Krawlin

WOW! I am very impressed! Looks awsome man! Also... about the hydraulic thing... maybe be wrong but, what if you had a bit fatter master (or whichever one is controlled by the servo) to hold a bit more fluild... A little more power coming out of the slave? Maybe not?

Well I tried that knowing that it most likely wouldnt work and it took a $H1t load of force to get it to move, not because of the desighn or binding or anything like that but because of the simple physics of hydraulics basicaly you reverse Pascals law when you try that.

here is some pics of that failed atempt Note how much bigger the master piston is comp to the slave outer diameter a total reversal of my completed system

CCFBERG · 08-11-2007, 02:03 AM

Quote:

Originally Posted by ColquittCustom405

Well it looks cool and seems like it could be better than a servo mounted on the axle.Nice work man.Could we get a video of it up against a rock or wall,then it pushing itself off.I also would like to see how fast it could go bak and forth.Again nice work man! Awesome!

as soon as I can but gotta finnish the rig first so might be a while!

thanx for the comment!

CCFBERG · 08-11-2007, 02:17 AM

Quote:

Originally Posted by KSCrawler

Here's a cool animation of how a gear pump works... http://www.mekanizmalar.com/gearpump.shtml
Haven't found one small enough for this application on the web, so started looking for alternatives. Drawing a blank, I just happened to notice an old hand crank nitro fuel pump hanging on the hobby wall. Eureka! Would likely take some serious modding, like removing the gru and letting the winch servo drive the rollers directly. Now if I only had this guys mad fab skills for that kickass slave setup...

I dont see why this wouldnt work, I thought about it as well but just decided that I didnt want to do it that way this time. I actualy have a Positive displacment gear pump I made myself about a year ago that is about the size of a Nickle is going on another hydraulic setup on an airplane im building so you can make them very small!!!. Also the other thing you may want to think about is there may be a slight delay in the steer when you make an imput to your controller, reason is.....it will take maybe OH.....wait wait wait.................ok positive displacement gear pumps creat flow on one end and a low pressure or on thier (what we call sucktion side) the require speed so they have to spin pretty fast to do what they do. Im not sure a modded servo would work but you could use a small elec motor of some kind, might have to be the size of a 540 or so though because you have to have enough umphhhh or when your tires hit the rocks it will stall the pump or cavatate it, then you get into heat buildup, airation of your oil, all kinds of probs! But check it out, its been done before with a pump, JasoninAgusta has the scorpion with 4weel steer the system costed $800 but it will move rocks if it has to!

cembom · 08-11-2007, 10:23 AM

Hey JIA dont you have a hydraulic rc? Is it steering or suspension? I know someone does and I think its a scorpion. Guess I will be doing some searching.
I see now ^

That cylinder is huge. I think it could be munted under the hood area of a tuber or something. Recess it into the cowl now that would be cool. I think it would hold enough to do front and rear steering but they would be together. no independant yet. There are a multitude of rc airplane fuel tanks that would work. only thing is that the ram would have to be square. So what kind of rig are you building with those axles?

JasonInAugusta · 08-11-2007, 10:36 AM

Quote:

Originally Posted by cembom

Hey JIA dont you have a hydraulic rc? Is it steering or suspension? I know someone does and I think its a scorpion. Guess I will be doing some searching.

Not to derail the thread, but I built the hydraulic Scorpion.

http://projecttwin.com/files/Hydraulics.mpg

http://projecttwin.com/files/hydraulics31.mpg

Here's one of the first basic diagrams of my system. The pump is rated at 200cc/min at 100psi. Actual pressures seen during operation are dependent on the load on the system and the max pressure is adjustable.

Krawlin · 08-11-2007, 11:52 AM

Hey JIA, how many in.,oz. of torque do you get out of that system? And does the 7.2 volt battery power the pump and such or does the Lipo take care of that?

JasonInAugusta · 08-11-2007, 12:56 PM

Li-Poly powers the motor/pump.

There is no in.,oz measurement, hydraulics produce a linear movement. There is no rotating motion so there's no torque measurement as you'd have with a servo.

I don't know what my setup would equate to with regard to a standard servo measurement, but I have yet to see a servo that can do what this system does.

STEW<CO> · 08-11-2007, 01:22 PM

Damn, some of you guys are just too freakin smart, nice craftsmanship fellas.

Krawlin · 08-11-2007, 01:28 PM

Quote:

Originally Posted by JasonInAugusta

Li-Poly powers the motor/pump.

There is no in.,oz measurement, hydraulics produce a linear movement. There is no rotating motion so there's no torque measurement as you'd have with a servo.

I don't know what my setup would equate to with regard to a standard servo measurement, but I have yet to see a servo that can do what this system does.

Ohh... I didnt know you couldnt measure hydraulics that way.. oh well. Anyway, maybe measure it in the amount of pounds it can push or lift. PSI maybe? maybe not?

JasonInAugusta · 08-12-2007, 11:02 AM

Quote:

Originally Posted by CCFBERG

You know both ways are correct and fine in my mind, I wont knock guys with servo's on thier axles and I wont say my way is the best way I just wanted to introduce something new that doesnt requir a pump or $800 (no disrespect Jason if you happen to read this)!!!! your **** is way cool and it inspired me to keep working on this months ago!!! But if you have the talent to do things other than type........tear it up in your shop and lets see it .......lets make this the coolest thing ever together.

I actually get paid to type and trust me-I have the talent, I just don't have the time.

When will we see video of this in action on the rocks? I'm liking how your system should respond nearly as fast as the servo you're using.

Crawln Coles · 08-12-2007, 11:14 AM

Quote:

Originally Posted by CCFBERG

as soon as I can but gotta finnish the rig first so might be a while!

thanx for the comment!

Forget the rig...!

Make a few of theese and buy a blue star so I can buy one from you

Red Rockcrawler · 08-12-2007, 11:42 AM

Dang Dave gets deployed and we don't here from you in a while and this what you come up with. Nice work I can't wait to see this in person.

Get that rig finished we are planing a comp in Spokane soon.

Let me know if you need more tlt shocks I got some you can have.

Cory

RCJunkie80 · 08-12-2007, 12:02 PM

Copyright that sh!t and make some $$$.

aggressivellc · 08-12-2007, 01:59 PM

Stuff like this is why r/c rock is the fastest growing segment of the hobby. We all suffer from CLSA (cant leave sh** alone) Keep up the good work man and if you decide to get that star let me know.

08-10-2007, 07:34 PM	#41
cembom Rock Crawler Join Date: Jun 2007 Location: Flint/Mt. Morris Posts: 570	I said something about not seeing the gain. What I meant was, for me I dont even compete, so A 200 oz mediocre servo is fine. Also correct me if I am wrong but isnt the 300 oz good enough most of the time? I would think that the hydro set up would be another thing to worry about tuning and setting up and also another thing to go wrong therefore since the servo alone isnt bad, the cons out weigh the pros. Moving on from showing my noobness. I think its awesome. One thing I would like to see though is it working front and rear steer with one master cyl. Again about the bad, it would have to be mounted somewhere. In theory I guess it could work though right? Oh wait that master would have to be huge to hold enough fluid for those drones. Nevermind

08-10-2007, 07:35 PM	#42
Krawlin Quarry Creeper Join Date: Jul 2007 Location: Sierra Vista, Arizona Posts: 271	WOW! I am very impressed! Looks awsome man! Also... about the hydraulic thing... maybe be wrong but, what if you had a bit fatter master (or whichever one is controlled by the servo) to hold a bit more fluild... A little more power coming out of the slave? Maybe not?

08-10-2007, 07:54 PM	#43
Bronco I joined the Band! Join Date: Sep 2006 Location: ... Posts: 515	SCREAMING AMAZING . im extremely impressed dude!

08-10-2007, 08:40 PM	#44
KSCrawler Quarry Creeper Join Date: Jul 2007 Location: Mac Posts: 377	Okay, this has got me thinking (I know, scary...). Instead of a master cylinder driving the slave cylinders, what about a gear pump that is driven by a winch modded servo. This wouldn't give you proportional steering yet, but stay with me. Time to mod the modded servo! Pull the pot out of the servo and extend the pot wires enough to reach one of the steering knuckles. Affix the pot to the top of the knuckle such that the rotating knuckle rotates the pot. Now when a steering input is given, the pump kicks in and moves the slave piston in the desired direction until the feedback from the pot matches the steering input to the servo channel (much like a stock servo works) resulting in proportional steering. Definitely violates the Keep It Simple, Stupid! rule, but I think this just might work!

08-10-2007, 08:49 PM	#45
KSCrawler Quarry Creeper Join Date: Jul 2007 Location: Mac Posts: 377	Here's a cool animation of how a gear pump works... http://www.mekanizmalar.com/gearpump.shtml Haven't found one small enough for this application on the web, so started looking for alternatives. Drawing a blank, I just happened to notice an old hand crank nitro fuel pump hanging on the hobby wall. Eureka! Would likely take some serious modding, like removing the gru and letting the winch servo drive the rollers directly. Now if I only had this guys mad fab skills for that kickass slave setup...

08-10-2007, 10:51 PM	#46
ColquittCustom405 I wanna be Dave Join Date: Dec 2005 Location: Orlando Posts: 7,420	Well it looks cool and seems like it could be better than a servo mounted on the axle.Nice work man.Could we get a video of it up against a rock or wall,then it pushing itself off.I also would like to see how fast it could go bak and forth.Again nice work man! Awesome!

08-11-2007, 10:23 AM	#50
cembom Rock Crawler Join Date: Jun 2007 Location: Flint/Mt. Morris Posts: 570	Hey JIA dont you have a hydraulic rc? Is it steering or suspension? I know someone does and I think its a scorpion. Guess I will be doing some searching. I see now ^ That cylinder is huge. I think it could be munted under the hood area of a tuber or something. Recess it into the cowl now that would be cool. I think it would hold enough to do front and rear steering but they would be together. no independant yet. There are a multitude of rc airplane fuel tanks that would work. only thing is that the ram would have to be square. So what kind of rig are you building with those axles?

08-11-2007, 11:52 AM	#52
Krawlin Quarry Creeper Join Date: Jul 2007 Location: Sierra Vista, Arizona Posts: 271	Hey JIA, how many in.,oz. of torque do you get out of that system? And does the 7.2 volt battery power the pump and such or does the Lipo take care of that?

08-11-2007, 12:56 PM	#53
JasonInAugusta 06 Super National Champ Join Date: Jun 2004 Location: Stark Industries Bar and Grill Posts: 11,361	Li-Poly powers the motor/pump. There is no in.,oz measurement, hydraulics produce a linear movement. There is no rotating motion so there's no torque measurement as you'd have with a servo. I don't know what my setup would equate to with regard to a standard servo measurement, but I have yet to see a servo that can do what this system does.

08-11-2007, 01:22 PM	#54
STEW<CO> Rock Crawler Join Date: Mar 2007 Location: Man Cave! Posts: 892	Damn, some of you guys are just too freakin smart, nice craftsmanship fellas.

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08-12-2007, 11:42 AM	#58
Red Rockcrawler Trying to have Fun Again Join Date: Apr 2006 Location: In your fridge stealing a beer Posts: 2,923	Dang Dave gets deployed and we don't here from you in a while and this what you come up with. Nice work I can't wait to see this in person. Get that rig finished we are planing a comp in Spokane soon. Let me know if you need more tlt shocks I got some you can have. Cory

08-12-2007, 12:02 PM	#59
RCJunkie80 Rock Stacker Join Date: Jun 2007 Location: at the river Posts: 50	Copyright that sh!t and make some $$$.

08-12-2007, 01:59 PM	#60
aggressivellc Quarry Creeper Join Date: Jul 2007 Location: Racking my Brain Posts: 424	Stuff like this is why r/c rock is the fastest growing segment of the hobby. We all suffer from CLSA (cant leave sh** alone) Keep up the good work man and if you decide to get that star let me know.

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Thread: Hydro steer made easy