Member postings for Roy M

Have you considered using expanding polyurethane foam? Donkey's years ago the toolroom I worked in used this for storing broaches. Finished off with a few coats of PVA glue. Roy M.

I have a DRO removed from a Bridgeport Mill which needs re homing if anyone is interested? I am open to fair offers😊

Roy M.

Edited By Roy M on 03/01/2017 20:09:22

The hole size can be influenced by a few factors. Obviously if the reamer is worn undersize, it will be difficult to make it cut big. The hole size can alter depending upon the type of material being cut, and also the amount of material you leave on for reaming and the speed and feed rate. I have mentioned in a previous post that the type of coolant used will also affect the hole size, neat cutting fluid(rocol etc.) will tend to cut a looser fit and I have used this to get a nice push fit. Also remember that hardened dowels are normally ground over nominal size. These are just practical tips learned through donkey's years of tool-making. Roy M.

.

Just spent an enjoyable 20mins watching a British Pathe film on you tube. Called "Power(1930-1939) showing the making of all the engine components for Moris Motors. No wonder cars were so expensive! Well worth a watch. Roy M

Men Ifr. The photo shows two stages of grinding the bit. On the right shows the first stage, grind the bit similar to a screwdriver about 1.4mm thick. Second phase is to grind the drill point angle at about 140-150 degrees. Then grind minimum back clearance. Run at about 1500 rpm. It does require a bit of effort to get it to start cutting but it works well. I have made plenty of these, and used them to drill out broken taps, and, as the other photos show, drill through part off blades and even digital callipers etc. Roy M.

Neil, mine are just cheap imitations! I think the cutting geometry is very similar, but I make them off-hand.Roy M.

Paul J. If you look at my previous post, you will see that the design of the drill for HSS is based upon the screw drill. Carbide blanks are cheap on fleabay. Roy M

If you look up one of my early posts, you will see a simple and cheap method of drilling HSS. If you need more info, just get in touch. Roy M

Doug, if you can look at my previous posts, you will see a simple way of drilling through HSS. If you can't find the post, which included a sketch, then I could re submit it if you message me. I may even have a drill. Roy M.

Hydraulic and pneumatic fittings use thes sizes.

I'm surprised that no one has suggested making a drilling jig with turned register spigot, an drilled on the rotary table. The jig is then modified to suit the mating part and re used. You can then drill by hand to a high degree of accuracy. This system can be further improved by using slip bushes, and series drilling the holes. (Worked O.K. On aero-jigs!)

Roy M.

Depending upon your application, you can secure screws by drilling a hole about the same size as the core dia of the thread, start thread with a tap for one or two turns.Then "self tap" the screw to depth. This grips very tight. You may get improved results by a few trials. Roy M.

As long as we all stay sharp, and tough and un-yealding we will be O.K RoyM

In my opinion, hard brexit should be at least 65 Rockwell C.

Although it seems like a long time ago, I think that the original post was set up to eradicate tap breakage through drill size. I would like to suggest that unless you are taping a deep hole,( eg 2.5D) into a blind hole, then a spiral point tap should be your preferred tap, and not a spiral flute tap. Spiral flute taps need to have a smaller dia body by virtue of the fact that the swarf needs to pass backwards and out of the drilled hole, thus making the taps considerably weaker and more prone to breakage unless all the machining conditioners are near perfect. A spiral point tap pushes swarf away from the tap allowing the tap to be more robust, they are also more easily controlled when using as a hand tap enabling a square start without too much difficulty. Roy M.

Although breaking a tap is often a disaster, it should not sound the death knell for the workpiece. You can always drill out the broken tap.

Emgee, the cutting edges of the drill should be set vertically, so that any mis-alignment in the 'y' direction(which is adjustable) is minimised, this in turn assists the drill to cut size and true. Roy M

JasonB, I'm not sure that the flutes always go around the tool, especially on a two flute slot drill. If you would like to try clamping the cutter in a different position I'm confident you will see a difference. If you are working to less than .003 mm on a home mill, I guess it would be quite important. I suppose it just follows the same logic as positioning the drill correctly in the lathe tail stock chuck. Roy M.

John, from WNT home page, go to tool holders---rotating tools---- micro precision collets. Hope this helps. I used to deal with them until about 4 months ago. If you can get onto their site proper, there is masses of info on everything you need to know about machining, hope this helps. Roy.

Just a thought, for all those interested, the flat on the cutter shank is positioned so that it is not directly opposite a cutting flute. This effectively reduces the cutter run out.

Edited By Roy M on 07/10/2016 18:07:43