Hi All,
I’ve done around 300 roasts on my R1V2. I posted recently about a couple of problems. One is solved but the other one remains. You can see that the result of the drum moving towards the rear is scoring of the aluminum pulley. I had attributed squeaking during the roast to the belt, but I now believe it’s this metal-to-metal contact. No beans ever drop out the front during the roast, and I can complete roasts without problems other than noted. What would cause this, and more importantly, what’s the solution? Do I need a shim at the rear bearing?
Thanks in advance for the help.
Eric
Definitely looks like scraping. If you are still under warranty, check with tech support about what you should do. Just so you don’t do anything to void the warranty.
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Well, usually, you just push it back into place. If it won’t go back, you’ve had some kind of problem putting the face plate back on. Either a cable is creating an obstacle, or it’s not aligned and tightened as it should be. If you push on the drum shaft from the front, does it bounce back into place? If not, you have a problem, if yes, you should be able to just push the pulley back in place.
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Do you do this everytime you take off the face plate?
I generally check the clearance, and do a “press test” (as per the manual guidance for initial setup) after the plate is on.
What are you pushing?
Yes, as a matter of fact, I do that every time. Personally, I think that the laws of physics would impede the removal and reassembly of the face plate without moving the back pulley. As you will see, the drum will immediately sag, once you remove the face plate. When you’re putting it back on, you must raise the drum a bit and also screw it back into place.
As for what I’m pushing, again it’s the back pulley. The round thing in the picture above with a belt around it.
The last two responses brought up good points and prompted me to reevaluate the situation. I had assumed that the drum was moving backwards and contacting the pulley during roasting, but when I push the shaft from the front bearing as described in the manual, it moves back about 1mm and returns to the front position, just as it’s supposed to. When it’s pushed to the most rearward position it does not contact the pulley as I had assumed. I wondered if the “latching mechanism” of the rear cover was somehow moving forward to contact the pulley since it seems to correspond to the scored area on the pulley, but I can’t get it to move in that direction. I’m totally at a loss to understand what’s going on, so any suggestions, theories, or snide remarks would be appreciated.
Thanks!
Press test…sounds like I should be at the gun range. 
BTW, I’ve never had any problems with removal/replacement of the front cover and I pay particular attention to correct drum and shaft placement, knowing that it can be a problem. As far as I can see, they’re in their normal position and as mentioned, behave as per the manual.
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Please excuse me for asking this question:
Did you check to make sure that the set screw on the side of the pulley and the cap screw on the end of the shaft are tight?
If they are not tight, the pulley might be sliding on the axle shaft for the drum.
You can take a screwdriver and gently try to pry the pulley away from the drum. You should be able to observe the pulley move about 1mm from the spring action, but it should not make contact with the framework for the squirrel cage.
The pulley should be fixed rigidly to the axle shaft for the drum.
Here is a photo of the end of the drum after removal.
In the photo the bearing is pushed most of the way to the end of the shaft. The pulley compresses the spring. The socket head cap screw on the end of the shaft and the side set screw should hold the pulley in place.
The spring is to compensate for the thermal expansion of the axle due to heat.
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Not only do I excuse you for asking the questions, I can’t thank you enough! I was unaware of both the set screws and the socket head cap screw. I pried with a screwdriver and sure enough, the pulley does contact the squirrel cage and doesn’t retract back. The drum doesn’t move when I do this, so I believe that the pulley is, in fact, sliding on the axle shaft as you suggested. The problem is that I don’t see set screws in either of the holes on the side of the pulley. In the area you highlighted, I only see the threaded holes which appear empty. I wonder if they were ever there. It seems unlikely that they both would have fallen out and if they had, that I wouldn’t have noticed them. In any case, I’ll try to order replacement screws from Sweet Maria’s. Do you think there is a need to also address the head cap screw on the end of the shaft that you mentioned? It seems to me that the fact that the drum moves backwards and springs forward normally when pushed from the front bearing means that I don’t, but I would defer to your opinion.
Again, thank you for taking the time to help me with this problem. I’ll post again with a follow up.
Eric
Hey Eric,
I just checked my Bullet and there are definitely set screws in the two threaded holes that are 90 degrees apart…
I was mistaken about the cap screw. It only holds the keyway in place and keeps it from sliding out. (That is an unusual method for keeping the keyway from sliding out)
If I get a chance later, I will check the set screws and determine what size they are.
While I am thinking about it, After you get the set screws in place and tightened. You should check the alignment of the motor that is driving the pulley that is loose. From your photos, it looks like the belt is making contact with one side of the pulley. On my Bullet the belt is centered.
(Loctite would probably be a good thing to keep the set screws from falling out again. On the other hand the set screws are going to be cheap and you will probably have extra set screws. You’ll know what to look for if it happens again.)
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OK, you asked for it…how do I adjust motor alignment? 
BTW, I just wrote to SM to ask if they can sell me the set screws. With the holidays, I’m not anticipating a quick response.
The set screws are 4mm diameter and 4mm long.
Amazon has them in stock and depending on where you are at, you might be able to get them by Dec 24th.
There are only 50 pieces 
, 
I’ll try to dig out the information for aligning the motor and belt, but just getting the set screws in place, should allow you to roast.
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Wow, I can’t tell you how much I appreciate you walking me through this!
I had to get my flashlight to look again…nope no set screws. That is plain weird.
I just placed my Amazon order. Even though they just built an Amazon fulfillment center about 10 miles away from my house, the screws won’t get here until the 28th. I’m not complaining though. I bet if I had to go through SM it would have been weeks.
You the man!
There is a short tutorial on adjusting the pulley in the manual on page 27
Here is a link to the manual:
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Once again, thanks!
Sorry, I didn’t mean to make you go through the manual for me. I had read this, but I thought it was just to correct position in the x-y axis. I guess I didn’t realize that this was how to correct pulley alignment (even though I now see that it clearly states drum or pulley is not aligned…oops).
Anyway, once I get all this done I’ll report back.
Happy holidays!
Hey Eric,
Somewhere in a thread on the forum, I read that they originally used 2 set screws, but have changed that to using just one set screw. The concern was that 2 set screws might damage the surface of the shaft.
Also please keep in mind that the pulley on the motor shaft also has set screws holding it in place. It is probably worth disassembling the sheet metal to get to the motor shaft and check for tightness.
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Hi all,
You can follow this guide to disassemble and reassemble the Drum (or Drum Motor):
Best regards,
Kevin
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Thanks Kevin,
Much appreciated!
I don’t really understand why 2 screws would be more likely to damage the shaft than 1, but add that to a long list of things I don’t understand. With 50 screws on the way, I have plenty to spare, but I suppose I’ll use just one if that’s what’s currently recommended.
Thanks for the heads up about the motor shaft pulley.
They are suggesting that we use the screw hole that is NOT in line with the keyway.
Normally, the steel keys are softer metal than a shaft. It might be that they have experienced deformation to the key which caused the key to wallow out the keyway and then damage the shaft. I am just guessing. I haven’t experienced any issues with the set screws, shaft or keys or keyway.
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