ram design question

[turnkey4099]

"
As far as a strap to keep the cylinder in check in relation to the beam, that is what the pusher is for. If something breaks, it tells you that it wasn't strong enough.

My $0.04 worth!
-Pat

Sorry but what happens is the nose of the cylinder lifts after the rod has extended somewhat and then the rod bends. The more power you have and the longer the cylinder, the more likely it is to happen. It isn't a question of anything breaking, it is just basic physics - power exceeds the ability of the rod to stay straight when you get into a really hard piece to split - as in almost stalling. A simple loop of 1/4 iron over the nose of the cylinder is cheap insurance.

Harry K

 

[mga]

i'll be adding a large U bolt to the end of the cylinder. as i stated earlier, i saw a rod bent because there was inadequate support in the front of a cylinder. too bad too...the rod was brand new. but, you're right...it is cheap insurance.

as for the wings on the wedge....i could just weld angle iron to it...right?

 

[turnkey4099]

i'll be adding a large U bolt to the end of the cylinder. as i stated earlier, i saw a rod bent because there was inadequate support in the front of a cylinder. too bad too...the rod was brand new. but, you're right...it is cheap insurance.

as for the wings on the wedge....i could just weld angle iron to it...right?

Just anything to add some additonal angle. Once the block hits the wings, it is forced apart faster and splits faster. On the easy stuff I am splitting, except for knots, they finish the split very shortly after hitting the wing ramps.

There is another point about the wings. They add a -lot- more bracing to the wedge and give a lot more welding bead. Our first splitter we built in that shop with this design we pushed the wedge right out the end of the tube. That was before we added the wings.

My wedge is 9" high. On knots and stringy stuff, I wish I had a simple knife extension above that. Maybe a 6" long by 4 or 5" high wedge with no wings. As it is, it isn't unusual for me to have to turn the block over so the strings and such that were on the top get cut.

I don't think, however, you can use 'wings' and still have removeable 4 or 6 way slip on adapters.

Just throwing a shot of the full splitter FWIW (if it works)

Can someone on here tell me a simple way of copying the URL to insert? I do a "highlight - copy" on photobucket but then come over here an all I have is the little box "insert URL" with no way to "Paste". Having to manually type it in is a PIA.

Harry K

 

[mga]

i was looking at the wedges at northern tool. they offer an 8 inch and a 12 inch. for 4 bucks more i think i'll go with the 12 inch.

i believe i got the ram/slide designed pretty good, but i'll have to order a couple more pieces of steel. i found the best prices at onlinesteel.com

when done i'll post a picture.

 

[cord arrow]

Can someone on here tell me a simple way of copying the URL to insert? I do a "highlight - copy" on photobucket but then come over here an all I have is the little box "insert URL" with no way to "Paste". Having to manually type it in is a PIA.

i'm not sure exactly what you're trying to do, but i copied a photobucket image here as a test. here's what i did.

.....right clicked on the photobucket image.

.....clicked on properties.

.....expanded the box to see all info.

.....cut & pasted the LOCATION (not address) to "upload file from a url", find this by clicking the "manage attachments" link beneath the dialog box, not by using the icon at the top of the dialog box.

 

[cord arrow]

it's just my avatar, but it looks like this:

 

[cord arrow]

of course, this works with ANY image.

great for swiping.............

 

[woodchop]

This is on my splitter. I don't think it would be possible to make a removable 4 or 6 way head to slip on it. As I said in my prior, I would start the wings back further were I to re-do it.

Harry K[/QUOTE]


I made a 4 way out of two 1/2" plates that follow the contour of the original wedge.

 

[turnkey4099]

i'm not sure exactly what you're trying to do, but i copied a photobucket image here as a test. here's what i did.

.....right clicked on the photobucket image.

.....clicked on properties.

.....expanded the box to see all info.

.....cut & pasted the LOCATION (not address) to "upload file from a url", find this by clicking the "manage attachments" link beneath the dialog box, not by using the icon at the top of the dialog box.

Aha, thanks. Saved and printed for my next attempt.

Harry K

 

[turnkey4099]

Durn it! I keep forgetting to add this to my replies:

On the ram/wedge design. Plan it out so the push plate does not contact the wedge. Avoids damage. I don't remember the specifics on mine (built back in early 80s) but I planned it so it came to about 4" from the wedge as I was working with only a 15" cylinder. I was aiming for IIRC 21 or 22" throat but something slipped in my figures and I came out with a 19"

Very few rounds need to be pushed all the way through (some knots and stringy stuff). For those that do, I just back off the slide and drop a chunk of wood behind the block being split.

Harry K

 

[Butch(OH)]

sorry if i was unable to make myself clear, this is basically what i was trying to say.

if i appeared to jump bad, it was unintended. long day, late night.

Accepted and same here, bad day, late night, I should know better.

 

[Patrick62]

Sorry but what happens is the nose of the cylinder lifts after the rod has extended somewhat and then the rod bends. The more power you have and the longer the cylinder, the more likely it is to happen. It isn't a question of anything breaking, it is just basic physics - power exceeds the ability of the rod to stay straight when you get into a really hard piece to split - as in almost stalling. A simple loop of 1/4 iron over the nose of the cylinder is cheap insurance.

Harry K

I would have to see this to believe it. I have heard of the rods getting bent on cylinders, and I suppose that man isn't capable of making a rod that is actually straight. However, ( I am not picking nits here, much...) I am under the impression that Prince Hydraulics that build my cylinder and rated it at 2500 PSI assume that the 2 inch diameter rod is sufficient for the forces involved.

I could be wrong.

Hydraulic cylinders work in a straight line. I also really doubt that a 1/4 inch strap is going to contain the many tons of force that could be released due to a bent rod. My little splitter uses a 18" cylinder with a really small looking rod, and it has functioned well enough, but I could actually see that one bending if something really went sour.

-Pat

 

[NELOG]

A small strap over the front of the cylinder seems like a good insurance policy. Also, because the way the cylinder applies its force, it should never have to contain the full force that the hydraulic cylinder is capable of producing. One problem that I've run into is the ram flexing towards the beam. Although I've only observed this rarely, the defelction is significant, to the extent that I thought I had bent the rod a few times. I don't know if this is an illusinog because the beam is flewing towards the cylinder or if the cylinder is doing most of the flewing. In any case, I saw a pretty cool splitter where the builder had placed an aluminum block between the beam and the cylinder to prevent this deflection. I never saw this machine in action, but I imgaine that the flex in the beam might actually be transfered through the block and casue the ram to bend upwards.

On another topic, has anyone given much thought to where the hydraulic cylinder should be attached to the push plate, relative to the front and back of the push plate, to minimize binding on the beam?

 

[turnkey4099]

A small strap over the front of the cylinder seems like a good insurance policy. Also, because the way the cylinder applies its force, it should never have to contain the full force that the hydraulic cylinder is capable of producing. One problem that I've run into is the ram flexing towards the beam. Although I've only observed this rarely, the defelction is significant, to the extent that I thought I had bent the rod a few times. I don't know if this is an illusinog because the beam is flewing towards the cylinder or if the cylinder is doing most of the flewing. In any case, I saw a pretty cool splitter where the builder had placed an aluminum block between the beam and the cylinder to prevent this deflection. I never saw this machine in action, but I imgaine that the flex in the beam might actually be transfered through the block and casue the ram to bend upwards.

On another topic, has anyone given much thought to where the hydraulic cylinder should be attached to the push plate, relative to the front and back of the push plate, to minimize binding on the beam?

I first saw the 'strap' thing in a how to build a splitter article back in the 70s. The rod I saw bent was in the shop I was working in. I was there watching as it was the first test of a new tool we built to push a stiffener inside a 4" square tube. Quite amazine to see. Yes, the nose of the cylinder for insurance should be restrained so it can't go very far in any direction.
The tensile strength of a 1/4" x 1 1/2" strap should be more than sufficient to keep the nose from rising. The vector of the bending force will be almost parrallel with the rod at first so the force causing the nose to rise isn't that high until the angle increases.

Position of the rod connection: I, too, have pondered this. I can't recall seeing any design that doesn't have the push plate flush with the front edge of the slide and the rod attached right to the ack of it. If it is placed there, then it doesn't matter how far back from it the cylinder is attached as that is where the force will transfer to. The only other way is to extend the slide in front of the push plate and that doesn't seem such a good idea to me. No real reason, it just wouldn't look right. Hmmm, now that I picture it, I guess you could have a long slide with the push plate at the the front but the ear for the cylinder attachment in the middle of the slide, that should keep the slide from trying to nose down or up better...

This is a very interesting thread.

Harry K

 

[mga]

as i stated earlier, i saw a bent rod on a 5" cylinder. the rod was only 1 3/4" but, when it tried to push thru a knotted chuck of wood...it bent. however, there were two other problems going on: first, the push/slide wasn't designed right and it allowed too much play. second, there wasn't a strap on the front of the cylinder. as it pushed against this piece of wood, you could actually see the cylinder rise in front and the rod bend down. that was a lesson learned.

so...i am putting a 1" thick hold down in the front of the cylinder and i intend to keep the rod as close to the beam as possible. since my new design has a smaller push plate, in theory there should be less forces trying to push it in different directions. the new cylinder is also a 5" diameter, but the stroke is now 24" with a 2" rod. keeping everything straight and secure is a priority with that distance.

i have to agree with an earlier post that keeping the push plate as small as possible is a wise decision...after all....you just want something to push the wood against the wedge. i should have it together in about two weeks.

the end of the rod will be right against the push plate, and, since the pin to hold it is only for drawing the slide back, there will be no force on the pin.