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Posted

Hoping for someone with one of these hammers to be around here. Could be even a different vintage of same machine could be different, or maybe it doesn't matter either way?

I just picked up and got running a 75KG (165lb.) Striker C41-75 hammer the other day. Pretty sure it's 2000 vintage (11/2000). Pretty happy with it. There are a couple details that I'm disappointed about, but easy workaround and shouldn't affect proper operation.

First up though, the belt guard sheet metal on the back just happens to be missing the little plate showing correct flywheel rotation direction. The old rivets are there and witness mark of where the plate used to be, but plate is long gone.

The more I think about it, it seems like the rotation direction really shouldn't matter and even if it spun backward from what the plate used to say. I mean the crank just raises the air piston up&down in a linear fashion at whatever rpm the motor spins, so functionally it should operate identically either way. Am I mistaken here?

The only reference to similar is is a page showing lots of info on a Striker STC-88 hammer (88lb. not 88Kg I presume). This hammer has a different model number and appears different vintage, so not sure if his plate is what mine was or backward, but photo below is what his had:

88DirectionOfRotationDetail.jpg.c07b41adabdcefcd60111e1755e363c7.jpg

His motor is mounted underneath and on the left (looking at it from the back) and mine is mounted low and on the right looking from same perspective. This motor mounting location alone might change motor direction maybe. I don't know. It's close, but not an exact match to my hammer for sure.

Here's the quote from this website:

Quote

"Check direction of flywheel rotation. Rotation must match the direction of the arrow placard that is riveted to the top of the flywheel cover. See the photo at right. The rotation direction must be corrected if it does not match the arrow placard. For more about this task, see problem #3 in the Troubleshooting section further down this page."

And later mentions this

Quote

"No harm done if it is backwards when first starting the hammer, but excess wear of compressor cylinder may occur if allowed to continue."

Is it even true that excess wear of compressor cylinder may occur" I can't understand why that would be the case, but I could certainly be mistaken.

Sorry so verbose, but details might be important for proper assessment.

In short, if somebody has a 75KG Striker like this one, if you could tell me what your label says for direction, I'd appreciate a reply.

Could be that Anyang and other similar makes & clones all rotate the same direction by design, so if you know this is the case that would be helpful as well.

Maybe there's a general rule of thumb that simple analysis just makes the proper direction of rotation evident?

For reference, here's a photo of my machine in case that matters:

1f1.thumb.jpg.915f53bdcc4ff2f73f0178d5c9e1bace.jpg.9b1be1904be389956f0a60d835d21697.jpg

Thanks a lot for any advice.

Posted

Have you contacted Striker for manuals? A company selling them came right up, remember to include "forging hammer" in the search terms. 

As to why the direction of rotation matters and how it could cause excess wear of the compressor piston and cylinder is pretty easy. Lube oil is pumped to bearings, cylinders, etc. turning an oil pump backwards won't move oil. 

Are there any sight glasses that let you look into the machine's works? I'd be surprised if there wasn't a way to check if it's getting lube oil while in operation. Lubrication is pretty important and there are probably ways to check.

Probably need the manuals though. 

Frosty The Lucky.

Posted

I have the manual for the machine (miracle!) but it does not mention flywheel rotation direction unfortunately.

The grease lube (crank & con rod) is via zerks so that should be pretty straightforward. The oil lube is via vacuum oiler which functions fine in either direction (yes, I tried both). Since the piston draws the vacuum by simply oscillating up & down, the flywheel direction essentially has no difference on the function of the oiler, I mean it moves it up & down the same way no matter which direction the crank rotates. That's why I'm confused.

The only possibility I can think of is that pulling to, say, the left on the downward stroke and the right on upward stroke, might mean something if reversed. In other words, the only difference I can think of is the direction vectors of force on the bearings/crank might mean something, but I'm not sure what that would be. Maybe the bearings are more likely to spin in one direction vs. the other due to bearing design? I dunno what that difference might be.

It's too bad the darned thing came to me in pretty good shape other than the direction placard being torn off. Typical Piffle for me I say. Just my luck.

Anyway Frosty, thanks for the suggestion to contact Striker. I've read that local (USA) sources are now all defunct so IF there is any hope of contacting anyone, it would be direct to China I guess. I'll give it a stab in the next few days though and see if anything good comes from it.

Posted

Ran out of time to edit in a couple more thoughts, so FWIW...

All I can imagine regarding wear due to direction is maybe a "spun bearing" situation is more likely in one direction vs. the other due to bearing design? Of course this would really only apply to a plain (i.e. babbit) bearing and not a roller bearing as far as I can guess. I dunno.

Such a simple thing and without the dang label I'm a quivering, ignorant meat bag.

Just to be clear, I'm not skeptical about the correct flywheel direction being important and I would like to spin it in the recommended direction. I mention this since my thoughts on this so far seem to paint me as doubting that the direction matters, which isn't really the case. I simply can't visualize why the direction should matter because of some undoubtedly erroneous mental block that my brain has erected. I can't seem to work it out.

What would be neat to find out is that Striker hammers all had the same flywheel direction no matter the size or vintage. If that were true, I'd be golden. But I have no idea if that is true or not.

Thanks again, and in advance for additional advice.

Posted

Is there an indication of direction on the motor? Belt wear might tell you something as well. 

The company I found searching and forgot to PM you the link, sorry about that, seems to sell lots of machinery and list a lot of Striker hammers.

Getting a look at other Striker hammers direction of rotation might be enough to make a safe "guess." If they all rotate the same direction the odds would be very good.  

Without taking it apart and playing with the parts it's hard to imagine how the innards work and the significance of the oiler. 

Frosty The Lucky.

Posted

The only thing that would matter, is if there is a splash paddle on the bottom of the connecting rod of the compressor. One direction would splash the oil toward ????, the other direction would splash the oil the incorrect way.

Neil

Posted

Thanks Neil. I'll open it up and check that out. I'm fairly sure but not positive that this machine hasn't had the covers off since it was purchased, so it's probably in dire need of a greasing anyway. I've was told that the machine possibly has less than 100 hours on it. I have been near humans before though so I'm sure that's at least an exaggeration, however it's probably not got a lot of wear due to lack of lube (sure sounds decent at least). But I'll feel a lot better after it gets a proper greasing. So I'll see what else I can glean from an interior inspection.

Having said that, the crank and con rod are not greased by oil but rather just grease zerks, so a splash paddle is probably not on the menu. Sure won't hurt to see what I can learn by studying the insides a bit.

Posted

I would say if that is the original motor, it more than likely is rotating in the correct direction. My experience with machinery that is belt driven the belt will be tight at the bottom of the motor pulley and slack at the top while running.

I can't control the wind, all I can do is adjust my sail’s.~ Semper Paratus

Posted

I could be all wet here, but I'm imagining a crank driving a piston rod that pushes a piston.  If so, the geometry would mean that the rod puts a significant side force on the piston during the compression stroke.  And the direction of that side force would depend on the crank rotation.  If there were a port on one side of the cylinder, for example, you'd probably want the rod pushing the piston toward the opposite side.

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