Noisy Shaft mounted fans on Fimec & HSD spindles

[Gerald_D]

Received two HSD spindles today - except for the colour and cable connector, they are identical to the Fimec. These photos show the the fan arrangement before any modifications:

http://www.mechmate.com/Forum/messages/47/1840.jpg

Air entry is through the grille on the back

http://www.mechmate.com/Forum/messages/47/1841.jpg
http://www.mechmate.com/Forum/messages/47/1842.jpg

The fan is exactly like a typical water pump - sucks in through the center and flings out around the perimeter

http://www.mechmate.com/Forum/messages/47/1843.jpg

The alu body of the spindle is an extrusion with 4 colling holes. All the air just goes straight through the long holes. Nothing exotic.

http://www.mechmate.com/Forum/messages/47/1844.jpg

If you have ever seen a siren, you'll notice that this is the same construction . . .

http://www.mechmate.com/Forum/messages/47/1845.jpg


Easiest option? Remove fan and blow compressed air into the grille area of the cover...... (seal the grille so that no cold air escapes out that end)

[dan sutula]

Gerald,
I noticed that the fan on this FIMEC/HSD spindle is of the radial-vane type. I recall from past experience that fans with "backwardly-inclined" vanes are typically quieter. Although - I doubt that the difference would be significant enough in this application, it is perhaps another "angle" to explore.

PS - Outstanding job on the MechMate Project - sharing your knowledge experience and design is a wonderful gift to fellow enthusiasts. Thanks!

[Gerald_D]

The really quiet fan is a separate Pabst 3656 fan mounted on the back (same as used by some Colombo spindles) Spec Sheet (http://www.ebmpapst.us/allpdfs/3000.PDF). This range of fans has a choice of Sintec bushes or ball bearings - the Colombo guys have discovered that the bushes don't work too well.

With my first Fimec, I removed the standard plastic fan off the shaft (it broke in the process) and replaced it with the Pabst. A small duct/adapter was needed.

[Kobus_Joubert]

These spindles or the water cooled ones, can they work upside down ? Like on a router table
11086

[Gerald D]

I see no reason why they cannot be used "upside down."

[Kobus_Joubert]

Thank's Gerald, so there are no limitation on the bearings by turning it around.

[Gerald D]

The moving part of the spindle (rotor/armature) weighs much less than the cutting forces, so the main bearing loads are not created by gravity. I don't see that dust ingress should be a worry on a properly sealed spindle. I have seen some spindles in tables that way around (direct drive spindle moulders)