Outer Limits 4x4 Board

just a quick one,

i have the set of mogs, and have scored a hydro ram, its 500mm compressed. its a single acting ram, though speaking to mick garner about wats on the mogrover, is has a 400mm compressed ram on it for the same diffs....

my question is, does it matter how long the ram is as long as its long enough and i can make it fit and its centred ok?
as i can use this one but it wont be fully compressed or fully extended on steering as its 100mm longer than the one the mogrover is running...

any help would be great.

screwy

Not 100% sure but once the steering had reached its stops wouldnt the ram keep pulling or pushing and break the stops off if you kept turning.

you can clamp stops to the shaft of the ram to fine adjust its travel.
ram will hit the stop and the over pressure valve in the pump will open

badger wrote:you can clamp stops to the shaft of the ram to fine adjust its travel.
ram will hit the stop and the over pressure valve in the pump will open

is that over pressure valve a standard thing in power steer pumps?

so i can run this long ram and just set it up without clamps and it will just open up the valve and stop it trying to turn? or no?

mine has something done to it internally that stops it getting full length. seems to work. no idea what tho!

im pretty sure thats the humming noise when u turn to full lock n hold it there.
bypass valve i think its commonly known as but im not an expert just looked ito this quickly once

You should be able to shorten it, pull it apart it should have a thread on the end with a nut that you can space the it to required size but I think 100mm you might be pushing it. buy the right size for a couple of hunG

It should be right, when you stop turning the wheel it stops getting pressure

yeh well thats my understanding is if i stop turning the wheel the ram will stop pushing, its hydroassist. if it were to keep going then its like push button lock to lock steering then isnt it which ofcourse is useless.

the ram will stop wherei turn teh wheel....my issue is that the ram will have extra travel than required both ways, is it ok to use the ram like that or does the ram specifically need to go full travel...

screwy

I used to work for Westralian HardChrome, we made hyd. cylinders for mining applications, It will work if the ram is not travelling to max-min lenghts of the bore. I haven't run hydro assit, or a hydrolic cyl. of a pwr. steer pump either but the cyl. itself will be fine to not travell the full lenght it's capable of.
The power steer pump does also have a by-pass valve in it so at full lock nothing (seals etc.) is under constant pressure

mattstar wrote:I used to work for Westralian HardChrome, we made hyd. cylinders for mining applications, It will work if the ram is not travelling to max-min lenghts of the bore. I haven't run hydro assit, or a hydrolic cyl. of a pwr. steer pump either but the cyl. itself will be fine to not travell the full lenght it's capable of.
The power steer pump does also have a by-pass valve in it so at full lock nothing (seals etc.) is under constant pressure

Just make sure that at full lock the force applied by the ram is no greater than the box itself as it may produce a lot more force before cut out pressure is released. f=pa. otherwise you may bend or break something.

4 choices..........

1/
Forget about it and fit it up as is .......

2/
pull the ram apart and fit a 100mm spacer ( or 2x50mm spacers either side of the piston)
(more weight)

3/
pull the ram apart and cut 100mm off of the tube
(less weight)

4/
get the right ram for the job




I've done all 4 'options' in the past for varying jobs.......
They all work 100% ........... cept number 1...... occasionally things go bump in the night and its on that odd occasion when the ram will extend that extra bit ( 100mmm ? ), but its only ya steering so keep an eye out for the odd tree

Usually options 3 or 4 are the right choice

Once the pump is at "full lock" i.e the pressure relief kicks in, I don't think it maintains pump pressure, so the ram wouldn't have anymore force behind it? I was under the impression once at full lock the pump releases pressure and it's a hydrolic lock that keeps the ram where it is, then when turning opposite the pump move's oil untill relief valve kicks in and ram "rests"
It's been awhile but this is my understanding. I will say I didn't have much to do with powersteer pumps though

Are you using the standard arms?
If you are, modify the cylinder (or buy another one) that has 9" of throw. Grind the steering stops on the arms dead flat. Sleeve the arms while you are playing with them, they are as weak as piss.
If your tyres will fit, this will give you just short of 45° of steering lock, and is the most you can get before the cardin joints start binding up against the inside of the knuckles. Make sure you have clearance for the little breather pipe that runs inside the knuckle.

If you are looking at connecting a large hydraulic cylinder to your steering you may want to consider buying an adjustable pressure relief valve = expensive, to be able to reduce the force acting on the cylinder or stopper

When you talk hydraulics it is very expensive. Most of the stuff is rated for industrial use and anything you use will usually be overkill. Consider adapting an old tractor or trucks steering system to your beast = cheap ?...

As the other guys have said, you need to make internal spacers for the ram to reduce the stroke.

But you said you had a "single acting ram". That'll only help you steer one way. You need two opposing single acting rams or a single double acting ram for a steering setup. Two single acting rams will work the same each way, but a double acting ram works with less force retracting than extending.

What screwy means is its single ended, double acting.

I vote spacers inside the cylinder, easier than cutting.

Also jeff, i forgot to tell you, the end fixed on the housing needs to be spherical, not pinned or it will rip itself off.

Andy

I still think it will be fine just as it is. the one's on the mog have more travel them what the steering has,

jav wrote:I still think it will be fine just as it is. the one's on the mog have more travel them what the steering has,

No you definitely need the stroke limiter inside the barrel, this is usually just a tube that fits over the rod and inside the bore with enough clearance for the oil to go around.

At full lock your steer valve will still be putting out full pressure to your assist cylinder, and will be strong enough (if not limited) to break something.

Yarno wrote:

jav wrote:I still think it will be fine just as it is. the one's on the mog have more travel them what the steering has,

No you definitely need the stroke limiter inside the barrel, this is usually just a tube that fits over the rod and inside the bore with enough clearance for the oil to go around.

At full lock your steer valve will still be putting out full pressure to your assist cylinder, and will be strong enough (if not limited) to break something.

Don't think he's going to break mog diffs with it.

im going to measure it all up and see how close it is.... i might be able to get away with it, if not i guess shortening it abit is the go?

can i just simply cut the shaft a little shorter and re thread the end?

screwy

You can give it a shot but it may be hardened steel (heat treated), if you cut some of the thread but leave some on it you may be able to use it still....

Screwy_ScrewBall wrote:im going to measure it all up and see how close it is.... i might be able to get away with it, if not i guess shortening it abit is the go?

can i just simply cut the shaft a little shorter and re thread the end?

screwy

No, don't do that.
That'll make the clevis (or whatever is on the end of the shaft) crush into the endcap. Buggering your shaft dust wiper and possibly the cap itself.

The ram neeeds pulled apart and spacers made. Both inside the tube and around the shaft between the piston and the topcap.

Alternatively, find a way to mount it with a longer arm so the stroke is used without trying to break the steering gear.

Screwy_ScrewBall wrote:can i just simply cut the shaft a little shorter and re thread the end?

screwy

the length of throw of the shaft is controlled by the available room within the ram's tube length......

If for example you have a eleventybillion metre long shaft and a tube thats only a metre long the maximum movement is .... just under 1 metre( the piston thickness comes into play here... )

If again you have the same shaft but the tube is only as long as ya pencil then the movement is only as long as ya pencil ( again minus the pistons length ).

It dont matter how big ya shaft is..... its the depth of the tube that matters
any chick can explain this for you

ok ive pulled the ram all down today as im sorted all the rest of the steering isuees..... ive unscrewed the screw on end where the shaft penetrates threw.... the easiest way i can see is to cut the end of the outer housing off ( where its welded ) and cut about an inch off it maybe an inch and a half and then re weld it up.

The thing with doing that is that the shaft will be poking out of the cylender the extra amount ive cut out, so the physical size of the ram will be exactly the same as before i modded it, though the shaft will now travel that inch less in and out...

is that correct?

the only other way i can see is to put a 15mm tube spacer on either side of the cylender inside to stop the shaft coming out all that way and in all the way.... with doing it this way.... does the spacer have to be a solid piece or can it just be a piece of tube that stops the travel, though will still have fluid in and around it?

cheers

Screwy

Screwy_ScrewBall wrote: the only other way i can see is to put a 15mm tube spacer on either side of the cylender inside to stop the shaft coming out all that way and in all the way....

with doing it this way.... does the spacer have to be a solid piece or can it just be a piece of tube that stops the travel, though will still have fluid in and around it?

cheers

Screwy

Yarno wrote: No you definitely need the stroke limiter inside the barrel, this is usually just a tube that fits over the rod and inside the bore with enough clearance for the oil to go around.

He sounds to me like he knows what hes talking about.

I wouldnt be cutting anything down.

Be carefull using spacers to limit travel the last thing you want is to damage the shaft when the ram is moving.

As mentioned earlier you can cut the tube to give you your desired stroke and leave the shaft length as is.

to work out the stroke measure from the bottom of the cyl to the botom of the head while fitted then take away the lenght of the piston . this gives you the stroke.

we have made many rams with spacers in them but we have always machined them to the shaft eg machine shaft fit spacer fit piston that way the spacer doesnt free float and maybe cause damage.

I would only use 1 spacer behind the piston not 1 in front and behind does the same thing but only 1 spacer to be made.

Thickness of the spacer only needs to be 6mm wall no need for any thicker

Internal spacers work fine if done right.
To do them right means they're solid, they seat squarely on the cap and piston and they don't mash up the bushing or seals in the topcap.

jav wrote:

Yarno wrote:

jav wrote:I still think it will be fine just as it is. the one's on the mog have more travel them what the steering has,

No you definitely need the stroke limiter inside the barrel, this is usually just a tube that fits over the rod and inside the bore with enough clearance for the oil to go around.

At full lock your steer valve will still be putting out full pressure to your assist cylinder, and will be strong enough (if not limited) to break something.

Don't think he's going to break mog diffs with it.

You obviously don't work with hydraulics then!!!

yeh i wouldnt cut it screwy because you will have to get the tread remachined into the end of it, if you dont and just cut out a section then weld it back together you will end up with a ruff surface on the inside where the seal runs on the end of the ram so you would have to get that remachined also.
spacers are the go for limiting travel,

cheers ben