Too many moving parts on these machines.

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cold front

Member
Mar 3, 2009
137
western,NY
Arrrrrr! now I have to replace the convection fan. There is two sealed bearing on the spindle and one of them is making noise (enough to bother me). No wonder people sell these after a season or 2. Good thing I don't mind getting my hands dirty because I have put a lot of time into cleaning, tightening down loose parts, adjusting parts, Replacing a combustion fan and now this!

The convection fan comes apart very easily into its component part..pulled the squirrel cages off and unbolt the engine from the frame. The sealed bearing must be press onto the spindle some how...too bad I don't know much about this because I bet all I have to do is pop the bearing off and somehow replace them by pressing them onto the spindle. I wish I took a shop class in high school..it would come in handy now. So I guess I'll have to buy the whole damn unit from the dealer $$$.
 
Shop class what's that?

Folks here might be able to cross reference it if we are provided the numbers on the makers plate starting with the makers name.
 
Oh...also I'm back to burning oil tonight till I can get this fixed......somewhere out there, there is an oil man laughing his butt off!
 
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SmokeyTheBear said:
Shop class what's that?

Folks here might be able to cross reference it if we are provided the numbers on the makers plate starting with the makers name.
Hi Smokey, The St. Croix part number for the convection fan unit is 80P20003-R. I might be able to get the bearing part numbers if it's stamped into the side?
 
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cold front said:
SmokeyTheBear said:
Shop class what's that?

Folks here might be able to cross reference it if we are provided the numbers on the makers plate starting with the makers name.
Hi Smokey, The St. Croix part number for the convection fan unit is 80P20003-R. I might be able to get the bearing part numbers if it's stamped into the side?

Sorry, I'm looking for what is on the blower makers plate, cross referencing a possibly missing number because the stove maker tells the actual part maker he can't show it in any cross reference list is usually a losing proposition.

My blowers were like that even though they fit the blower makers numbering scheme.

ETA: Also the bearings may be fine and the fan became unbalanced due to buildup.
 
Try some Teflon spray lube on the bearings, may save the day.
 
The Motor part number is J238-200-2040 (115v 60hz 1.6A) (T.P.L CL.F) (RU)

Bearings: Thailand NMB 608S

The problem may be with the motor armature, It looks a bit beat up and the bearings feel smooth when I spin them by hand.
 

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Even if you get a new fan, suggest you try replacing the bearings and keep the fan as a backup. My bixby convection fan is prone to bearing noise. Replace them and life is good. The bearings seemed fine, but were the noise source.
 
Granger carries a pile of bearings they should be able to cross that NMB 608S bearing into the line they carry.

There are also a large number of places on line that sell bearings and it is a common bearing size.

That doesn't look all that banged up. I'd get the bearings and do a replacement.

That particular setup is very difficult to cross.

ETA: For no shop class you did a good job getting it apart.
 
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If the bearing is pressed on you can remove them by slightly reducing the shaft size and increasing the bearing size.

Usually if you apply cold temps to the shaft alone it will shrink slightly.
Dry Ice or Liquid nitrogen should work.
You can get Nitrogen in one of those freeze cans at an electronics supplier.
If you hold the can upside down the liquid should be cold enough to shrink the shaft.
Try to not get the bearing cold.
The bearing should pull right off.

Replacement bearings are available almost anywhere
Here is one place (there are many)
http://www.mcmaster.com/#standard-ball-and-roller-bearings/=g1n6w6

Replacement is easy.
Heat bearing with hair dryer and slide it onto shaft.

Good Luck,
---Nailer---
 
Does the wear on the armature look ok? I am really not sure if the sound is coming from the bearings...you can't spin them fast enough by hand or drill. The is coming from the unit though.
 

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cold front said:
Does the wear on the armature look ok? I am really not sure if the sound is coming from the bearings...you can't spin them fast enough by hand or drill. The is coming from the unit though.

That shinny side looks like it might be rubing against something. Looks uneven to me. Not that it helps at all but you may be right. Might not be the bearings.
 
Small pieces of pellets or such sometimes can get into the works, I'd clean it all up reassemble it checking all clearances as I went and take it for a test drive on the bench first.
 
cleaned everything put in back in and same problem. I took it apart again and I'm pretty sure its the right bearing. Talk to the dealer, he's a real good guy. He told me they just replace the whole unit and never break in down like I did. You need a press to get the bearing off, you can cool it down but it's hard to keep it to the shaft only he said.

The only way I could tell which bearing it was, was to hold the spindle in one hand and pinch the bearing in the other hand between my thumb and index finger then, turn the spindle back and forth. This way you can actually feel the little balls catching on the bad bearing.

In a way this stove machine has been like a shop teacher to me (along with this board of course). I have learned a lot. I think a shop class or two should be mandatory in high school even if you're not going into the skilled trades you would gain skills that could help you the rest of your life.

Smokey, Thanks for the heads up on the coolant. I was wondering what the copper tubes were for on the motor.

Thanks to all.
 
cold front said:
cleaned everything put in back in and same problem. I took it apart again and I'm pretty sure its the right bearing. Talk to the dealer, he's a real good guy. He told me they just replace the whole unit and never break in down like I did. You need a press to get the bearing off, you can cool it down but it's hard to keep it to the shaft only he said.

The only way I could tell which bearing it was, was to hold the spindle in one hand and pinch the bearing in the other hand between my thumb and index finger then, turn the spindle back and forth. This way you can actually feel the little balls catching on the bad bearing.

In a way this stove machine has been like a shop teacher to me (along with this board of course). I have learned a lot. I think a shop class or two should be mandatory in high school even if you're not going into the skilled trades you would gain skills that could help you the rest of your life.

Smokey, Thanks for the heads up on the coolant. I was wondering what the copper tubes were for on the motor.

Thanks to all.

The coolant I was concerned about was what nailer was suggesting would shrink the shaft so you could get the bearing off easier. That stuff is down right flesh freezing cold.

Spending a lot of time with a good millwright beats any dozen high school shop classes and a lot of college engineering programs.
 
sometimes using a small pick/awl
you can lift out the side seal on the bearing and add grease
then snap the seal back in
at this point you have nothing to loose

get a replacement coming and this might keep it going until the replacement arrives

when my combustion blower failed after 15 years
I added drops of oil daily until my replacement arrived

you can also cut off the old bearing with a dremel and cut off wheel
then probably tap the new one on using a piece of pipe over the shaft to keep it square

there is more than one way to skin a cat
 
Cat skinning is a capital crime in this household, that is what his royal majesty has decreed so be very careful.
 
Yup, the Dremel with cut off wheel made very short work of it. I think the Dremel might replace the crowbar as my most favorite tool.

So, now i'll order up the bearings and figure out how to press them on...I'm thinking a small cooper pipe to fit over the spindle and a vice.
 
If your not comfortable replacing the bearings yourself, take it to the local tech center or high school that has a program that relates to relacing the bearings, I'm sure they would do it for you. I've had my local tech center do many things for me. Another option, take it to a local machine shop. Heck of a lot less expensive replacing both bearings vs a brand new blower.

EDIT: Now that you got the bearings off, make sure when the new bearings are installed, the pipe that is used only touches the inner race of the bearing, not the seal or outer race.
 
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Put the armature into your freezer for a few hours... it will shrink the shaft and allow you to get the bearing on easier.
 
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How old is this fan assembly?

You can use a pick to remove the rubber seals to see what went bad with the bearing. Probably a little dust worked in past the seals. Adding grease will get you by for a limited amount of time. The problem is at this point the bearing is really done and will make a lot of noise.

Replacing with a loose tolerance (heat expansion), low noise bearing is the best bet. At $3 each from an NMB source is best. Don't put in the low grade Ebay or other source bearing. It will be noisy and probably won't last in this application.......and they also do a 3x markup on price of a lower quality than NMB bearing.

Apline Bearing sells the NMB 608S for $3 each but there is a min. of $15 purchase. Try contacting them and let them know what the application is.
 
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