SAG 180
Titanium
- Joined
- Sep 17, 2007
- Location
- Cairns, Qld, Australia
I thought rather than hijack the thread on flame hardening 1045, I'd start another on building belt grinders and fitting a backing plate to the belt.
I'm limited a bit in what's available locally, the counter jumpers at one of the bigger steel merchants have never heard of 4130 etc., and think I'm playing with them somehow. They have something they call "wear plate" so I'll have to see if they have a spec on it.
It's my first belt linisher/grinder unit, there are signs of black steel dust deposits in places on the backing plate after a few hours use. I ground the left over piece of backing plate that was hardened and cracked in the middle. I used a zirconium belt and was surprised at how easily it ground and how little it got hot for the rate of material removal.
The backing plate is a bit hard on the belt join and whatever you are grinding so I'm thinking of getting some of that thick graphite sheet to attach to it. The machine originally started out a 12" disc sander but had the belt parts added later and it will already be modified soon to put the spindle shaft on top of the brackets and cut off the top of the column tube to give the contact wheel more clearance when the belt is swung round to horizontal.
There is a bar fitted now behind the top idler to help guard against belt breakages and I have to alter the pulley ratios to slow it down as right now the surface speed of the belt is 109 KPH and the disc periphery is 160 KPH (100 MPH).
Basic layout showing the 8 inch rubber contact wheel at the bottom and the 12" steel disc. The parts
are actually 30 year old hand me downs from a friend cleaning his shop out.They are parts from two
different machines that just happed to fit together without modification. The Idler wheel is his own
casting and design, the long shafted knob is the locking knob and the knob to the rear right is the belt
tracking knob. Only the belt grinder arm and all the steelwork are of my construction.
Detail of the carbon steel adjustable backing plate arrangement.
Front grinding rest and bracket with adjustable angle and clearance.
Sag: 1060 backing plane for a belt grinder is not going to last. Not enough carbon to have decent wear resistance. What I have used is A2. I drilled and countersunk a screw hole into each corner for flat head screws. I fully harden the A2 in AIR and leave it fully hard. I screw it over the cast iron platen. When it wears,I can turn it over.
D2 would be even better,more wear resistant,but the A2 has stood up pretty well.
I'm limited a bit in what's available locally, the counter jumpers at one of the bigger steel merchants have never heard of 4130 etc., and think I'm playing with them somehow. They have something they call "wear plate" so I'll have to see if they have a spec on it.
It's my first belt linisher/grinder unit, there are signs of black steel dust deposits in places on the backing plate after a few hours use. I ground the left over piece of backing plate that was hardened and cracked in the middle. I used a zirconium belt and was surprised at how easily it ground and how little it got hot for the rate of material removal.
The backing plate is a bit hard on the belt join and whatever you are grinding so I'm thinking of getting some of that thick graphite sheet to attach to it. The machine originally started out a 12" disc sander but had the belt parts added later and it will already be modified soon to put the spindle shaft on top of the brackets and cut off the top of the column tube to give the contact wheel more clearance when the belt is swung round to horizontal.
There is a bar fitted now behind the top idler to help guard against belt breakages and I have to alter the pulley ratios to slow it down as right now the surface speed of the belt is 109 KPH and the disc periphery is 160 KPH (100 MPH).
Basic layout showing the 8 inch rubber contact wheel at the bottom and the 12" steel disc. The parts
are actually 30 year old hand me downs from a friend cleaning his shop out.They are parts from two
different machines that just happed to fit together without modification. The Idler wheel is his own
casting and design, the long shafted knob is the locking knob and the knob to the rear right is the belt
tracking knob. Only the belt grinder arm and all the steelwork are of my construction.
Detail of the carbon steel adjustable backing plate arrangement.
Front grinding rest and bracket with adjustable angle and clearance.
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