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[Ryaly2dogs]

I recently acquired a 20-inch HP R-1 saw that came to me completely disassembled and grungy.  In cleaning/putting it back together, I am noticing the ring gear and worm drive are about 3 mm too far apart to engage (see photo); so no power feed until this gets figured out.  I checked and double checked and there is no adjustment possible that would bring these two components closer together without bending the rod.  Question, over time, since these are mechanical, it seems they may wear down.  Of the two components the worm gear seems to be made of a softer metal, and thus would possibly be the culprit to wear out (also ring drive part number and diameter spec checked out).  Has anyone out there encountered a similar situation and was a worn worm gear the culprit?  I am aware of replacements on the HP website but wanted to check with this group first as to whether or not I am on the right track, or possibly missing something before I start ordering replacement parts.

Thanks all.

[Ryaly2dogs]

Sorry, the photo posted upside down; my bad.

[Slabbercabber]

The gear should be bronze and the worm steel.  That would cause the worm to wear out first.  It sounds counterintuitive but the bronze embeds grit and the grit wears the steel.  Absolute worst case of wear would leave the two just rubbing each other.  They cannot get actual separation from wear.  I would unbolt the drive shaft and make sure it cannot be aligned to work properly.  If that doesn't give you any solution, call the new company and ask for the OD or number of teeth in the gear they are using.  Divide the number of teeth by the pitch to get the pitch diameter.  Pitch diameter is the center of contact, not the outside diameter.  It is possible that the original gear was replaced by one of the wrong size.

[jakesrocks]

One thing I noticed is signs of welding on the tank behind the bronze gear. It's possible that some time in the past the tank cracked out. Could it be that when rewelded, it was placed too far from the worm gear ?

[catmandewe]

check the bushing on the drive shaft at the back of the saw, if it is egged out then the shaft will be lower which will raise the gear in the front. If that is it then just replace the bushing and it should line up again.
Diamond Pacific also carries those parts since they bought the company that used to own Highland Park.

[catmandewe]

Oh I just saw that your photo is upside down so check the bushing in the front of the saw then.

[Ryaly2dogs]

Thanks for the feedback, I have a few directions I can go with this based on your guidance.  I will follow up and hopefully be reporting back out with success.

[Ryaly2dogs]

Well, after ticking off the above items, the result was a success.  In the end, after the process of elimination, it came down to disassembly and reassembly.  Tank weld idea was a gasket mark (tough call since my photo sucked); the wear on the drive shaft bushings was checked but surprisingly nil.  I appreciate the detail on bronze vs steel wear, and the thought about worst case wear would only have worn out to the point of detachment but not beyond that (my DUH! moment)....which got me thinking.  The cradle drive shaft was connected to the pulley shaft running the ring gear; so what if that moved?

Earlier in the day, when I checked the motor for functionality, the motor pulley belt torqued loose the nut affixing the drive shaft bracket to the saw body.  This effectively moved the rod (which terminates in the worm gear) upwards just a few millimeters which was enough separate the ring gear from the worm drive.  Right then the light bulb shined brightly, and about 15 seconds later, 2 nuts were loosened, the rod repositioned as I saw the ring gear intermesh with the worm drive, and nut tightened...problem fixed.

Your insights and tips are appreciated! I learned more about this cool, new-to-me saw and gained a new appreciation for all the components and degrees of freedom involved.  Saw is fixed, extra parts were not purchased, and I thank you all.

Cheers.