I’ve now cut all the pieces for my home made belt sander out of MR-MDF. I hate working with MDF, It seems no matter how much extraction I’ve got going the dust still seems to go everywhere. A problem not helped by the fact I did a lot of the cutting with a jigsaw and an SCMS which are impossible to collect dust from effectively (IMHO).
The shot below is of first cut, I only include this because it shows off the track saw attachment I made a while back. It’s proved to be surprisingly accurate and useful. I’ve decided that one day I have to save up for the real thing.
Next came marking out. I went for the straight edge and knife approach. I managed to arrange it so that all the parts fitted into a piece of MDF 1220×725. That doesn’t include any tables, stops or other attachments which I’ll be making separately once I’ve proved that the machine generally works – in other words the belt doesn’t keep flying off.
After a couple of hours turning the workshop green I had all the parts cut and ready for a dry fit. I decided to go for a simple glue and screw approach rather than a more complex rebated design. This should save time and if I find the case isn’t strong enough like this it will be easy enough to glue in some additional supports.
I’m not over the moon about my level of accuracy on a couple of the parts (unfortunately the larger ones) but the parts that I think really matter I ganged up and cut in one pass so I think I’ll get away with it. I found that I could plane the MR-MDF as long as the blade was good and sharp. I managed knock my LN block plane (just about the nicest tool I own) off the workmate. It hit the leg on it’s way to the (concrete) floor and has dented the corner – gutted.
The one thing that is concerning me is drilling the holes for the bearings. They have to be pretty much bang on perpendicular to the face of the MDF but I don’t have a pillar drill. I’m thinking I’ll probably make up a jig and route them.