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        MF 480 and Speed 480 question

#1 Sabrejock Dec 09, 2001 08:58 AM

MF 480 and Speed 480 question
I just got my first fan in the mail and need to know something.

I've tried to put the speed 480 BB Race (GR#6327) into the housing. The supplier says it should slip in and out. I've removed the sticker and cleaned off any residue. I can get the motor in about halfway to where it should be by really hard pressure. To go any farther I would need a press or rubber mallet. To get the motor backout from halfway in, I needed to use large slip-joint pliers to wiggle and pull the motor free. I have two of the motors, both brand new and they are the same. I even took a file and dressed the slight ridge in the case at the front end. No better.

This does not seem like a normal thing to have to do. If I did press the motor in all the way, there is no way that I can see I would ever get the motor out again.

All I need to know is what your experience with this settup is to see if mine is normal, or if it gets returned. Thanks in advance, Tex.

#2 Haldor Dec 09, 2001 10:07 AM

Mine were tight after the sticker was removed but not hard to assemble. Did you remove any of the sticker glue residue from the casing?


#3 Sabrejock Dec 09, 2001 11:11 AM

Glue Residue
Haldor, I removed all residue with solvent. Your motor will slide out again after you push it in? Mine certainly will not. Tex.

#4 hoser Dec 09, 2001 01:58 PM

I have had similar encounters with that also. even on the midi fan.

what I've done is sand the inside of the fan where the motor sits. put in one finger with coarse paper in the area where the motor goes and sand till it slips in.

I have also been thinking of cutting 1/4" slits between each of the stators all the way to the motor mount are where the screws go to help in cooling, I doubt that that would cause any structural damage to the fan.

#5 Haldor Dec 09, 2001 03:42 PM

Its been a while since I fitted one but my s480's did fit bit it was tight. It will not slide in or out without pressure. How about putting the motor in the freezer for an hour and try again?


#6 MicroRotors Dec 10, 2001 01:31 AM


If he does that, How would he get it out again?

He would have to freeze the whole unit. Then they would both contract at almost the same rate.


#7 Haldor Dec 10, 2001 03:10 AM


Originally posted by MicroRotors
If he does that, How would he get it out again?

He would have to freeze the whole unit. Then they would both contract at almost the same rate.

Maybe - but that wasnt an issue stricktly speaking as Tex wanted it in ;) When he wants it out again he can tap it with a dowel and hammer it out.

Perhaps freezing the unit works here aswell as metal and plastic not neccesarely share the same expansion/contraction properties.


#8 LJH Dec 10, 2001 10:14 AM

I had the same trouble. My brother has a small milling machine/ lathe and I turned the motor can down a little bit. Mine was not going in there with out taking material off of something.


#9 Sabrejock Dec 10, 2001 10:54 AM

Fan Faws
Wow, how can this a normal thing? It would be unacceptable in any other type of manufacturing. Perhaps somebody should pull the bratwurst out of his butt and do some quality contol. ;)

Thanks for all the replies, Tex.

#10 JasonJ Dec 10, 2001 03:09 PM

Yup, mine went in tight too, I took off the stickers, sanded the inside of the housing, put the motors in the freezer, I ground a bit of chamfor into the front of the case, this is where it seens to be widest, and then put heat sink compound on the motors to lube them up and help heat transfer, the lube is the most important thing, if they are tight and crook in there at all you will go nowhere. Putting the units in the freezer helps get them back out, the metal dose contract faster then the plastic and more so.
I dont know why they are so tight, maybe the speed race 480s have a bit larger case than a standard 480? Mine are Grumpuar or whatever "dont have the stickers anymore :) " So you figure German fans, German motors, but what ever, just easy on the bratwurst thing, you know they are pretty good units and Oliver "Wemotek" is a member and contributer on this board.

#11 Admiral_Red Dec 10, 2001 03:18 PM

I had a hard time getting mine in too, but I solved that by sanding too. I also had a problem with my rotor rubbing when I got in into my f-18. Free outside it, and a slight bind when placed inside the ducting. Robert at EJF kept me from my idea of butchering the rotor, to sanding the outside of the fan shroud to get the required clearance.


#12 Sabrejock Dec 10, 2001 07:03 PM

To all who responded, thanks. But we still have not not heard from Oliver, and any explaination for the above.

I know full well that you Americans on the post would not for one minute accept having to do a ring and valve job on your brand new Buick before you could drive it home. Tex.

#13 Bare Dec 11, 2001 12:18 PM

Obviously the Molds are wearing a bit, causing the motor hole to be a tiny bit smaller than it should be.
But what's the big deal ? it's easy enough to sand the tube enought to proerly fit the 480,
This ain't a Buick. it's a $50 toy part.

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