How not to make a pretzel out of your exh. fan paddle

The exhaust fan motor and related parts are subject to a lot of heat and the shaft end and the paddle (Blade) are subject to some nasty nasty abuse with the heat and corrosive nature of the ash and soot, especially if you live in a humid area.

As most of you know I have been dealing with a draft motor issue of late. (Not a terrible deal, but requiring attention)

Many sites that sell the new motors will mention "Simply remove your old fan and reuse on the new motor"

Haaaaaaaaaaaaa, yeah right.

Other outfits got it straight.
The odds are real good that the fan paddle is going to be stuck on the shaft tighter than a bulls A$$ in fly time ! ! ! ! !

Even the set screw can be a pita.

Soaking the set screw with some good penetrant can help and it will not hurt the shaft area either.

Sadly it will take some good "REEFING" to get that little sucker off.

Now then comes the rub.

If you intend to reuse the fan it can't be looking like a pretzel when you get done with it.

IF ANY of the blades are bent, tweaked or otherwise out of phase with their mates the likelihood of the thing setting up BAD VIBES is almost 100% assured and if this happens, not only will it not be quiet, but will vibrate the motor and shorten its life span A LOT

OK
I had a motor I wanted the fan off and did not want to ruin the fan as it turned very very true.

Soooo, what to do ???

MAKE A TOOL

Here is a cute little gizmo that slips over the fan hub and has a hole on one side that a longer version of the set screw that holds the fan on with can be threaded through and into the hub (hole has a bit of clearance on the set screw) and directly across is another threaded hole to allow a second set screw to thread in and grip the hubs outer diameter.

In the end is a square headed long threaded screw to "push" on the shaft and remove the hub from the shaft, leaving the blades pristine.

Reusing the fan is fine.

Always apply never seaze compound to the set screw threads and the shaft
(makes next time far easier)

Never seaze is a silver high temp lube compound that will help a lot to keep the threads free

Took me a bit to whip this little critter up, but the fan slid off with a very minimum of effort using a 4 inch adjustable wrench on the push screw and a slightly larger wrench holding the tool by two flats I milled on it.

Here are some pix

 

That's country folk jargon C'Mon

Translated loosely, REEEEEEEEAL TIGHT

 

I must confess, these tools are used by HVAC guys to get the fan blades off AC condenser units after they been in the weather for a few years.

I decided to just make a special one to fit the need.

 

Another is "tighter than a bullfrog's a** underwater".

 

Handy tool for anyone's tool kit. Thumbs up again!

 

Too bad this tool is not available at Harbor freight

The ones made to do AC condenser fans is $$$$$$$$$$$$$$$$$$$$$

I had the round stock and only needed to buy the little extra set screws.

I might also add, that a tap of the correct size and thread pitch to run through and clean the threads is a great item to have in the tool box as well.

The threads tend to corrode from the caustic environment.

Always use a set screw that it slightly longer than the depth of the hole in the hub.

This will prevent the top couple threads from getting all fouled up.

Use a Q tip to swab the Never Seaze into the set screw hole and down inside the hub before installing the fan paddle.


Carry on troops.

Yess, the Frog would get waterlogged and sink.

 

Nice dude.
Normally on the older stoves I can't get the grub screw loose and end up drilling it out.
Then just just spot mig the blade on the new motor. Just a matter of grindin off the weld next time. THe grinder heat is usually enough to unfreeze the fan collar.
Our new stoves have a lefthand thread motor shaft with the nut holding against the blade. Super easy to change. The draw back is if some idiot in the factory doesn't tighten them in the factory we end up needing to pull apart the stove to do it. 5 seconds for them in fabrication, 10 minutes for me in testing. I get up em for that but they still stuff it up occasionally.

 

Always been "just one of the boys" most of my life

No worries mate.

Most of the girls are not spinning the handles on the machine tools.

Me, I avoid the kitchen like the plague (Except if I get hungry)

More fun in the shop making stuff.

 

Yup, never seize is the key to that never being a problem again. Might even use Hi Temp version.

 

Pretty cool tool! We run into the stuck fan issue with our Harman units as well, but usually we just cant get the dang set screws out...cant get them turning. Sadly in a service situation, we dont often have the luxury of time waiting for penetrating oil to un-seize the set screw. We try some lube, try to turn the screw out with a socket/allen combo, but after that, the shaft gets cut off, and the fan and motor is replaced

 

I'll bet if Snowy designed a tool to remove stuck auger motors, a few service techs would want to get their hands on one.

 

Flame wrench works dandy

 

Put a split collar just above the auger coupler and use a small "pickle fork" (Auto steering gear tool) to wedge the motor off.

 

If the manuf's would just use a touch of never seaze on the screws, no worries.

Heat the hub with a propane torch til its hot to the touch, then add a good wicking penetrant, let sit a bit and likely it will budge.

Should only take 10-15 minutes to wick in the Skunk pizz

 

Strewth, how much can a koala bear? Dudes are non gender specific downunder.
Sorry....

 

That little gadget is slicker than goose $hit! Should copy write that bad boy and get it into production.

 

Yuppers. Put the high temp copper any seize on the 50F I've been working on. Hope that avoids smashed knuckles and the use of curse words come spring clean up!