72" x2" Knife blade Belt sander machine build

**Andrew Leigh** · 11-10-2016, 09:46

Thanks. Complete design change on the way.

**apocza** · 11-10-2016, 14:54

Originally Posted by Gert Odendaal

I will be looking around here in Witbank for these type of belts. I already ask around in hardware shops like Cash Build, Jack`s Paints Builders Warehouse and no one could sell me any of these types of belts. Which hardeware stores do you refer to in Port Elizabeth ? Maybe there is a branch here in Witbank as well?

Gert, the place we use is Measure Cut, they do not have a website but you can find their details here: https://goo.gl/maps/tDettZToEKB2

I have also found 2x72 belts at a local hardware shop called Strand Hardware - places like Builders Warehouse and Pennypinchers do not stock large belts. I have also ordered the small 1x30 belts from https://www.livecopper.co.za/ - they were the garden variety Alu Oxide belts. They wear quickly and I end up using a belt per bevel on the little grinder but I can't complain, much faster than the filing jig. Dirty cheap too, something like R3 a belt.

**apocza** · 11-10-2016, 15:03

Also to add, I am not sure if someone has authoritatively stated it but for steel you generally want the blue belt which is zirconium. The most common grit is the brown Alu Oxide which is fine for wood, black which is what most of your waterproof papers come in is silicone carbide. Here is a concise reference on the subject: http://www.customsandingbelts.com/graininfo.shtml

Also check out Uncle Sorrel's guide to belts, them Yankees get a lot nicer belts than what we have been able to track down locally, layered and impregnated belts etc:

**Erebus** · 11-10-2016, 15:07

Just on the belt colours apocza, the klingspor 34 to 80 come in both blue and brown for the aluminium oxide.

I think blue is their steel specific belt as it doesn't work nearly as nice as the brown ones on wood.

Sent from my SM-G900F

**Gert Odendaal** · 11-10-2016, 16:12

Thank you gentleman, this indeed is a lot of info to take notice of. I will be learning as I am using the machine, but it is really good to get info from members who already knows all the important aspects.

It seems I will probably reaching to fast speeds with the 220 mm diameter teflon drive wheel..the two pulley wheels on the other side of the teflon wheel is eighty millimeters in diameter...so I would not really need a fast running motor for the this sanding machine after all????

But that is a bridge I will cross when getting there, currently I am busy working on kitchen cupboards for my wife...

**Andrew Leigh** · 11-10-2016, 17:01

Gert

Wheel Diameter in mm x (22/7) x motor rpm = belt speed in mm per minute

mm per minute /25.4 / 12 = belt speed in feet per minute

So a 4 pole motor (1 420rpm)
220 x (22/7) x 1420 = 918 828 mm per min
918 828 / 25.4 / 12 = 3 221 feet per minute

When used with a VSD at 75Hz then you will be at
220 x (22/7) x 2 200 = 1 521 142 mm per min
918 828 / 25.4 / 12 = 4 990 feet per minute

So a 4 pole machine would be fine for the application and you can always dial the speed down,

**Gert Odendaal** · 12-10-2016, 14:53

Thank you Andrew for this technical detail. it is much appreciated. I will be looking for a motor shortly.

**Andrew Leigh** · 15-10-2016, 23:06

Ok the new design, have omitted a lot of the details due to clutter. So on Monday the cutting template in the bottom right will be sent in for cutting.

**Gert Odendaal** · 16-10-2016, 08:04

Andrew, would you consider to make available your plans to members on the forum who want to duplicate your belt sander..?

Here is a link to some good items about knife making:
http://www.homemadetools.net/forum/homemade-tools/

**Gert Odendaal** · 20-10-2016, 20:58

I had some time on my hands today and yesterday. I managed to melt more aluminium and cast another pipe full of aluminium..this will be my knobs for all the locking bolts...
Here are examples I will duplicate in the aluminium..the profiling will be done on the lathe and milling machine ...