Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by cold front, Jan 31, 2012.
For any automotive machine shop, pressing such a bearing on is a trivial task.
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After I cut the bearings off I inspected them the best I could. There was plenty of grease in both. There is a metal strip like part inside that hold or cradle the balls around the race of the bearing. One of the balls had somehow broke the metal strip cradling it. I think this is where the noise was coming from. If I can't press it on myself after putting it in the freezer a while I'll take it to a shop.
The fan assembly was in operation for 4 years. The stove is a work-horse, it heats the whole house about 1200 ft2. This may have something to do with all the parts failure I have had after the 3-4 year mark.
Here is a tid bit that you can think about.
If you can spin the shaft and the thing is quiet, then the likely cause of the noise is not the bearings.
Try wiring the fan up to a "patch cord" and plugging it directly into a 120V outlet.
Be careful with the live POWER
First blow out the squirrel cage fans and or better yet, wash them in a sink full of warm soapy water using a small brush to carefully clean all the blades.
Once done, try running it, and if its quiet, put it back in the stove.
Now, if the noise resumes, its not the bearings, but instead, harmonics that are setting up in the armature due to the power flow from the Triac speed controller.
If the Triac is not sending a perfect (or nearly so) "chopped" wave form to the motor, the armature will/can start to emit a whinning or some such noise.
As mentioned, out of ballance, due to dirt build up in the fan blade can also cause bad vibes.
If a bearing is bad, it will almost always feel rough and make noise when spun.
Packing more grease into the bearings and or changing the bearings may stop the noise, BUT this change can simply disguise or dampen the harmonics caused by a flakey Triac, and may return in a short while.
My Whitfield Advantage 2 has a "sweet spot" that the fan runs well and makes just air noises, if I move the speed controller very much away from that spot, it starts making noise in the form of a whinning, and is quite anoying.
This sort of noise can be very anoying, especially if the stove is in a room that you spend time in, watching TV or other things that you dont want to listen to some odd repetitious noise.
Give this a go and see what shakes.
The description of noise makes me think the bearings are the problem.
Did you get some 608S (low noise) replacements?
Got them installed yet?
What are the other failures you have had at the 4 yr mark?
Interesting. So the easy way to test the triac is to run the motor/fan assy without the triac and see if the whining noise disappears? And if so, replace the triac?
Triac speed controller. Thanks this is very good to know because I'm sure that will fail next if it has not already.
I replace the whole fan unit with a new one and I don't seem to have the noise problem anymore. I also got bearings replacements for the old unit and have not tried yet to pop them on the spindle. From what I can tell it's not easy.
Here is a list of things that have gone wrong with my St. Croix Prescott:
1) The decorative masonry brick fell apart in the second season.
2) The combustion blow failed at the end 3rd season.
3) The cam connector rod on the versa grate loosened up twice in the middle of the 3rd season. It made a clunking noise and the versa grate was only half working. Tightening down the inset screws on the rod with thread lock fixed it.
4) The screws holding the control board to the control board mount box came loose and the board fell into the box at the beginning of the 4th season. Screwing the board back into the mount with thread lock fixed the problem.
5) The convection fan unit failed in the middle of the 4th season (this season).
Older control boards have more primitive TRIAC designs that are more susceptible to making motor noise. What usually destroys a TRIAC is a stuck motor due to bad bearings. The bearings start to seize or seize completely. This causes the current to go up and destroy the TRIAC. A TRIAC rarely ever gets "worn out".
The best way to put the bearings on the shaft is to use a shop press. Next best is a large bench vise. You could also make a small press out of 2 pieces of threaded rod and angle iron. All you would need is a drill to make the threaded rod holes and hole to fit over the shaft.
I would use a piece of tubing.
Yes, all of the methods require a piece of tubing to place against the inner race so that the seal and outer race are untouched. Hit the seal at all and the bearing is junk....it will be loud. The 608S MT should have seals that are extremely quiet and don't touch anything internally.
I had an issue with my afton bay last night with a dry bearing, i took it all apart and olied the bearings and all is well once again. can anyone let me know if there is a cross reference # for the 608 replavement bearing at grainger?
"Too many moving parts on these things."
If you think "moving parts" is a problem, wait until them parts DON"T move! Now that's gunna be a bltch!
been there done that
The 608 is a very, very common bearing. Bring in to NAPA or good automotive supply, alternator or starter repair shop. Please do not use skateboard bearings.They do not have a very good load factor.(Probably no grease just light oil if lucky) You get what you pay for. Japanese or German bearings top quality. I won't put my time or life on less quality.
Just an observation. When you see scuff marks on the armature it is usually because one of the bearings is not holding the shaft on center. That happens either due to a failed race or the motor's end cap is loose.
If you don't have a press, I have successfully seating a bearing using the pipe method others have mentioned. It's a bit more medieval then using a press but it can be done. Find a pipe with the same diameter as the inner race that will fit over the spindle. Tap the pipe with a hammer. In a jam I have used brass rounds and tapped on the inner race moving around the race circumference. Need a steady hand though...don't want to hit the bearing seal.
People who don't learn the ropes might end up selling after a season or two...
The blowers need to be removed and cleaned and stove needs to be cleaned
properly. I learned the lesson the same way you did.
I'm in 8th year with my Prescott and it's a heat monster that works fantastic
with the right maintenance.
Original Bearings, 608SSD21. Interior Diameter – 0.315” (8 mm). Exterior Diameter – 0.8661” (22 mm). width – 0.276” (7 mm). Grease Lubrication
MATERIAL OF CONST
WHERE TO BUY
0 – 250 °F
High Temp Grease
0 – 250 °F
-40 – 300 °F
My choice is MacMaster Carr or Freud. Freud bearing is designed for router bit use, high speed and temperatures, tough use.
Do not buy roller skate bearing from ACE or you local hardware store unless you want to change bearing more often. And do not use Oil lube bearings, they are designed to have oil at all times.
Sorry, the table did not post right.
Here is as .pdf file
You guys rock. I read the post and every suggestion I had was talked about. The biggest thing is to not drive the bearing on by anything other than the inner race. The very best way would be to press them on with a hand press. I like the idea of putting the armature in the freezer and maybe heating the bearings up with a hair dryer. They may slip right on by hand. I use a neat tool called an induction heater at work. It amazes me every time I do bearings that bearings can be heated without heat
vid on cleaning sealed bearings
grease or oil?
Grease for low speed, oil for high speed.
They can feel smooth at a low rpm such as spinning by hand but it is a common problem on Bixbys and when you spin by hand they seem fine but put new ones in and it runs like new.
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