Member postings for colin hawes

How long does a job take?. Twice as long as a careful estimate. Colin

Absolute machine accuracy is unnecessary for hobby work: about the only things that matter are relative tightness between components and any old worn machine or micrometer can achieve that with care. Tolerances are usually only of interest for interchangeability of spare parts. Colin

Quite often there is stress in the bar which tends to close the slit when the cut is deep and pinch the saw. this is much less likely on cast iron than on steel. If it is possible to clamp the end being cut off this may help. Colin

Some people have the misfortune to be unimpressed with the huge manufacturing and intellectual skills displayed by the hobby machinists and if it gives them pleasure to be derogatory about them I am glad that my pleasure and theirs are complementary. Colin

I would use steel to slide against cast iron. Colin

For most jobs on a hobby lathe HSS Is more than adequate, cheaper than insert tools, and you will need them anyway for making various shapes. I normally only use tipped tools on tough steels or cast iron to speed things up a bit. As Duncan says tool grinding is quite easy after a little practice and it's a skill that will serve you in well in the future. I also make boring bars from silver steel and they work very well at the proper speed. Colin

I recently had to liberate some steel bar from an old lorry half- shaft I would not risk my bandsaw blade on that but the angle grinder made short work of it with a 1mm disk. Colin

There is a picture of one I made in my album under Colin's tool designs.

I am thinking about some sort of lifting device to handle a dividing head for my mill as I am not so young as I thought. I have a 7" centre height Drummond as well but I have fixed a shelf behind it for it's heavy chucks and can roll them onto a board placed on the bed at the right height to line up with the spindle thread. Colin

My tool advice for a small lathe using HSS tools is to keep them very sharp and have much more top and front rake than recommended by text books. Tools nearly always take a cut if wound back to the starting point so simply do your measurement after that. Let it cut in both directions. The return cut will often improve the finish as it is a very small cut and the cutting point is trailing. It is also better to approach the cut with tools' cutting edge either square to the work or at a negative angle. Colin

I look after a Freerider mobility scooter which does use one of its pair of 12v series batteries to provide 12v for its pcb and lights. Colin

A taper along the bar's length would make resonance less likely. Colin

Doesn't a hand reamer size the hole on it's parallel section? Colin

It is true that any hard edged tool such as a high speed lathe tool bit can be scraped very firmly along each flute of a reamer to raise a minute burr that will have the effect of sharpening it. This may not work on a badly worn reamer as it can only be expected to increase the diameter a maximum of 0.002" ​at the cutting edge.​ I used this method occasionally during my toolmaking years to make a reamer cut oversize. Colin

Shapers were in general use before low cost carbide tips were available. During my tool room years I used one a lot for getting black tool steel slabs flat and square as a preliminary process to machining press tool dies. This was done with HSS toolbits in a holder and these could easily be sharpened. I have an Elliott 10m shaper and it is very useful for preparing work for the minimill quickly as it is usually set up with it's own homemade vice and can be used instantly. I used it to machine down some old leaf spring steel, which I couldn't anneal satisfactorily, that would almost certainly damage any milling cutter. Colin

You will need to do milling and a shaper is desirable but not essential in a machine shop. The only way you can prefer a shaper is if your patience and the lathe allow the milling. However , the mill needs to be robust to do work at the speed of the shaper. I'm lucky, I have both. Colin

The tool needs to be rigidly supported too, ie not rocking. Colin

L.H.Sparey's "The amateur's lathe" got me started and hooked 60 years ago and I still think it is excellent. Colin

Many years ago I read an article about an electric car called the IRIS (It Runs In Silence) I think this car was made about 1900 ish , I can't remember exactly, but it seems that the battery set was on a railed platform ,was rented and could be quickly exchanged for a recharged one at the renter's "filling station". Colin

I wonder how the authorities will tax electricity used in cars when we buy far less petrol ! Colin