Friday, November 26, 2010
These parts are too long to CNC drill the end holes, so I had to make a drilling guide first.
I used a 3mm milling cutter to pocket and profile the shape in the Delrin, then I used the pillar drill and put the aluminium part in the portable vice and held the Delrin guide onto the end of the part to do the drilling. I only used the guide to drill a small depth, then I drilled them through later.
Wednesday, November 3, 2010
I had a problem with this part. The sawn piece was a tight fit in the pocket in the wood sub-table, so it didn't glue well, so it came unstuck soon after the start of machining. You can see the bent path left in the metal, in the video. I remachined the wood and chiselled the side of the pocket bigger and everything else went well, but there is a bit of a gouge out of the top of the circular post feature. Maybe it won't matter too much? The surface finish doesn't seem any different ( the one on the left of the picture is the most recent part ), despite lowering the feedrate to 50 mm/min instead of 100 mm/min. The tool looked slightly worn after the ungluing accident. It doesn't look much more worn after all the machining, so I think that 200 mm/min is better than 300 mm/min. Hopefully the next one I make won't have any mistakes in it.
Tuesday, November 2, 2010
I made this part. No holes in the ends yet, though. The surface finish could be better. I am doing the finishing pass at a feedrate of 100. Maybe I should try 50?
Most of the time was spent doing the roughing, because I was only happy descending 1mm at a time with the 6mm tool. It took about 2 hours machining.
Monday, November 1, 2010
I am going to make this part out of aluminium alloy.