Catatonic Posted August 24 Report Share Posted August 24 I have a 1975-built Shimpo RK-2 that has been doing pottery far longer than I have. I acquired it in 2020 from a relative who taught pottery for 45 years at a fire sale price ($150 and came with 300lbs of dried stoneware clay). It was very well maintained during his time and it's still a workhorse, but.....the pedal. The pedal is super stiff and doesn't allow me to moderate the speed of the wheel at need without really leaning on that pedal or using the lever (with my messy slip-saturated hands.) As a learner, it makes it hard to manage a pull on the clay. I tried applying some WD-40 to the place outside the housing where the pedal is attached, but no dice. I am somewhat mechanically inclined but the manual for this machine shows NOTHING about the pedal assembly. Does anyone have any advice on how to deal with this? Or must I begin saving my nickels for a newer machine? Quote Link to comment Share on other sites More sharing options...
Hulk Posted August 24 Report Share Posted August 24 (edited) The "Power Adjustment" section (page 7) may apply: SHIMPO_West_RK-2.pdf (shopify.com) Where "...to a point where the variable speed control will not work." suggests that moving in the decrease power direction may also decrease the pressure. When looking at the machine per "DRAW. No. 4 [sic]" most if not all the linkage between the pedal and the Cone/Ring is exposed, and hence you may see where there is some binding to be eased by lubrication, cleaning and lubrication, cleaning, polishing/restoring and lubrication... *** see here *** ah, see this doc, where grease is recommended, and several parts/locations identified: RK-2B-FULL.pdf (shopify.com) *** as you were... *** WD-40 is useful for many things, however, it is not a particularly good lubricant. Disassemble, clean, and grease could be a good choice. Light machine oil where disassembly isn't an option? Flushing with the WD-40 and then following up with something else could be a good choice. Disassemble, clean, polish as necessary - if there's any galling, lube with good grease, reassemble. Hope that helps! Please do report back on your findings/results. Added: my friend who transitioned from ceramics to glassware (oh, forty five years ago or so) had a large sponge with a hole in the middle that he'd push over the knob on the "gearshift" lever - it would rest against a larger knob he'd installed just below the end there - and so the sponge caught most all the hand muck that would otherwise ooze down and drip all over the pedal, his foot, the floor... Edited August 24 by Hulk added Catatonic, Rae Reich and Hyn Patty 3 Quote Link to comment Share on other sites More sharing options...
Catatonic Posted August 24 Author Report Share Posted August 24 24 minutes ago, Hulk said: WD-40 is useful for many things, however, it is not a particularly good lubricant. Disassemble, clean, and grease could be a good choice. Light machine oil where disassembly isn't an option? Flushing with the WD-40 and then following up with something else could be a good choice. Disassemble, clean, polish as necessary - if there's any galling, lube with good grease, reassemble. "a large sponge with a hole in the middle that he'd push over the knob on the "gearshift" lever " Yeah. Sigh. That disassembly stuff. 😵💫 That rather intimidates me, honestly. What light machine oil would you recommend? I have chain lubricant for my bike... and what does "galling" mean, other than as it applies to watching news reports of the coming election? The sponge on the pedal lever is a great idea! Bill Kielb and Hulk 2 Quote Link to comment Share on other sites More sharing options...
PeterH Posted August 24 Report Share Posted August 24 2 minutes ago, Catatonic said: and what does "galling" mean It's a new one to me as well ... https://en.wikipedia.org/wiki/Galling Bill Kielb, Catatonic and Hulk 3 Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted August 24 Report Share Posted August 24 (edited) 3 hours ago, Catatonic said: Yeah. Sigh. That disassembly stuff. 😵💫 That rather intimidates me, honestly. What light machine oil would you recommend I think I would first try what is posted in the manual that @Hulk linked. Light general purpose grease would be fine. Also known as All purpose, Multi purpose, and many times white lithium grease. Pivot point A (2 points) and glide B. If you want to use a thin even coat of your chain lube it may remedy this for awhile but likely will not last as long as the grease. If any of these points (A&B) have accumulated what looks like sticky gunk ( non technical term) clean then lubricate. That WD 40 mentioned would likely be a decent cleaner. I believe the manufacture suggest yearly. BTW little to no disassembly appears to be required. Edited August 24 by Bill Kielb Hulk, Catatonic and Rae Reich 3 Quote Link to comment Share on other sites More sharing options...
Catatonic Posted August 24 Author Report Share Posted August 24 (edited) Update-- Those schematics are helpful, especially the one with the lube points. I used PPL-1 grease by ParkTool but I still get to a point where there is distinct resistance and then it kind of "thunks" past it--right about the time the guide bar moves just past the halfway point through the whatever-you-call-that-thing-it-slides-through. I can't see anything on the guide bar that would account for it and the other linkages, including the roller wheel, move freely enough. When I push to the highest speed, the wheel head actually slows down, and then picks up when I back off a little, but that may be a separate problem. Could the guide bar actually have a slight bend, not readily visible to the eye? (I guess now I am asking for a physics lesson. 😬) Edited August 24 by Catatonic new thought Quote Link to comment Share on other sites More sharing options...
Hulk Posted August 25 Report Share Posted August 25 Chain lube likely an upgrade over light machine oil, depending on which chain lube, hah! I'd go with grease, as possible, but that could mean disassembly... "Galling" - where metal surfaces that move against each other are messed up: Galling - Wikipedia Where there is wear, but the metals are still smooth, usually not as bad as galling. ...oh, PeterH already posted a galling wiki, err, wiki about galling. How the cone is engaging the ring when the "pedal is to the metal" might explain the speed anomaly. Perhaps someone familiar with the RK-2 can answer regarding the guide bar. Rae Reich and Catatonic 2 Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted August 25 Report Share Posted August 25 Sorry no ideas here. Maybe post a short video showing the operation of the assembly for some ideas, else you will need to go through maintenance and adjustment by the manual. Catatonic 1 Quote Link to comment Share on other sites More sharing options...
Mark C. Posted August 25 Report Share Posted August 25 Cone drives are less responsive than pedal wheels in my opinion. This is one Dino talking to another Catatonic 1 Quote Link to comment Share on other sites More sharing options...
Catatonic Posted August 25 Author Report Share Posted August 25 2 hours ago, Mark C. said: This is one Dino talking to another I searched high and low on YouTube for videos of people making repairs on RK2's and I have only found one person working on my specific model (other RK models have a different configuration). Considering of the investment of time, not to mention the cost of tools and parts, I'm thinking I want to just go full princess and get myself a new wheel. 😁. Ready to step out of the dinosaur life (at least in my pottery). Hulk 1 Quote Link to comment Share on other sites More sharing options...
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