Belt Up

Only if it is a good quality one! Mine definitely hasn't:-

In fact the whole thing is a lesson in mediocre engineering (see my review BDS 460 Belt Sander).

John

I've not noticed a crown on my belt sanders, maybe it's due to them all having tracking adjustment.

If you had a crown on your belt sander pulley the belt wouldn't run flat. Hence it needs (the added complication of) a tracking adjustment.

Rgds Simon

I think so too. I've got a Parkside cheapie belt sander from Lidl that clamps to a workbench and I use it for wood and ally flats and chamfering the edges. It hasn't got any crown I can see, the track adjustment works fine, and it's becoming one of my standard go-to tools.

It's a superb example of mediocre engineering at its very finest.

Both my belt sanders are older and British. Both have crowned pulleys and tracking.
Set up the tracking on a new belt and when I do some hard sanding and drag the belt to one side, release the pressure and it re-centres.

Maybe I am not keeping abreast with modern engineering practice.

My belt sander pulleys are crowned, its the flat plate between the pulleys that gives you a flat sanding surface.

Hi Guys,

If you think that the pulley is flat, lay a straight edge across it !

Well, I put a straight edge on the roller pictured above - definitely flat although it does taper by about .3mm from one end to the other. The drive roller at the other end has though got what could be described as tapered ends so not quite crowned but almost!

John

As mentioned above, one can simply machine opposing shallow tapers - 2 degrees will do it - and blend using a file.

This tracks fine with 6" pulleys at 2850rpm, and the tracking adjustment is capable of putting the edge of the belt exactly on line with the edge of the platen (and keeping it there) if needed. Both of the wheels have a shallow 2 degree crown.

Hi Guys,

I used to think that line shaft pulleys were flat, until you stood one up on a flat surface and it leaned to one side or the other !

Well, I gotta let you and John Baron score on that one!

I took a close look at my Parkside with a straightedge and there is something - though 'cos the big roller feels like it's covered in some sort of springy plastic, it'd be very hard to measure.

Never mind, it was cheap, it holds its line and works well - I wouldn't now want to be without it.