Member postings for mick

If your using pickle to clean up brazing or silver soldering then lime scale descaler from Tesco takes some beating

This is a bit of a long shot, but does any one who has built, is building or knows someone who has built the Blackmore version of the BR2 rotary engine know of a foundry that has the necessary die casting moulds or wooden patterns to cast the top and bottom inlet ports. Or. Has any one had to pay the initial tooling costs in order for a foundry to cast these items and would like to recoup some of the expenditure by hiring out the tooling or patterns? If so I would be grateful for any information.

Regards.

Mick

Screwfix, Toolstation or Orbital fasteners, nothing much to choose between them for price

We used something similar when I was a lad as straps to hold small items while being drilled, much easier than mounting components in a drilling vice as the components are lying flat on the drill table. Toolmaker's clamps do the same job as well.

Solid dies are by their nature dead size, which makes them extremely useful for finishing and cresting a screw cut thread when you don't have a full form threading tip. They should really be reserved for sizing operations, as using them to cut a full thread will only blunt them making them useless for their intended use. A round split does give a very small amount of adjustment, which can be beneficial when cutting a thread in hard steel, as the first cut can be made with the die as open as it will go using the central screw, then finished off by loosening the central screw and tightening the side screws while sizing the thread using a standard full nut as a gauge.

Might need buying a couple of cutters with modern cutting geometry . Take out the bulk using a ripper cutter, then finish the sides with a carbide cutter, both from APT on-line budget range, not expensive and last for ages. Orders placed before 4pm are next day by standard mail.

Calibrators eh, back when god was a boy we called them formers and yes they were made of brass, mainly because the cooling trays were full of water.

If you are using the castings (original scale) then the crankcase is in one piece and I assume with all the internal features. If your making it from stock then there's no way you can machine the internal detail of the camshaft gallery without leaving the cutter radius in all the corners, you will also need long series cutters. I'm afraid you'll have to wait until the series reaches the stage when I tackle the assembly and the oil supply as its easier to show this with photographs. I do take the oil supply around the engine using external pipe work and the oil enters the engine from two ports on the sides at either end of crank case. The crankcase is held together by long series cap head screws, but you can't put these in until the oil ways and other features have been established. I used extra screws along the camshaft cover and the flange at the flywheel end for added strength. The two halves are finally secured using JB Weld, with all mating faces having a keying channel machined in them. Hope this helps.

Mick

Hi Francois. Your English is better than my French! The plans are from Hemingway kits, I've just multiplied each dimension by 1.5 to give the increased scale.

Hi. David. I'm building the BR2, but taking all the external detail from the original plans in the book, but constructing all the internal workings from the Hodston plans. The scale is different between the two, so the crankcase is to the American plans. My crankcase is Aluminium with cast iron cylinders and Ali. cooling muffs shrunk on. I've allowed a couple of thou between the two to achieve a close sliding fit, so it can be adjusted at a later stage, should the need arise. Mick

David is right about the three screwed spider being used to hold soft jaws apart. Multi legged spiders are used for supporting large diameter tubes while being turned, the more screws the less the chance of distorting the tube.

Hi. Jeff.

Sounds like a plausible explanation. When I spoke to Kirk at Hemingway kits he told me it was an intentional part of the original design, but I was a bit too far down the line to carry out remedial work. Perhaps a note on the drawings to alert builders not using, or without the build notes to the different in hole centres on different components, but there again we are only talking a sixty forth of an inch on the original scale, which shouldn't have too much detrimental effect in the greater scheme of things.

Regards.

Mick

I would say drilling a hole that small through 80mm of commercial mild steel and only running out by 0.020'' pretty good going, if you wanted a completely parallel small diameter hole through that thickness of material you should consider spark erosion. Which reminds me of the yarn an ex Rolls Royce machinist told me. Apparently in the early days spark erosion a Japanese engineering company sent Rolls a thick chunk of steel with a minute diameter hole, completely parallel, right through it as a demonstration of Japanese engineering prowess. The story goes that Rolls Royce sent it back tapped!

The mist has cleared, thanks to all. The Cnccookbook site is a useful resource Steve.

Hi. Neil, Hi. Dave.

I've had a quick play with this, but it doesn't seem to like rectangular pockets, as the graphics show two darts diametrically opposed, but its not beyond the bounds of possibility that I might be missing something here. Drilling a series of holes would be quite straight forward as there are no X or Y moves contained within the canned cycle, but the sub routine contains X, Y and Z moves all of which will enjoy both + & - values as the cycle progresses, so there needs to be some number crunching to reproduce the rectangle 18 times. As I said back in the day when I used this function regularly the angular value was proceeded with the letter address A, though for the life of me I can't remember the G number that was also called.

Mick

Now I'm of the old G code school of programing without access to any CAD/CAM. What I need to do is call a pocket sub routine 18 times at 20 degree intervals around a circular blank using Mach3 control. Back when the world was young I programmed Bridgeport series 1 where a sub routine could be rotated by including 'A' followed by the required angle. I've looked through the manual and all I can see is the coordinate rotation which isn't what I need, so is there a method of calling the sub routine incrementally at 20 degree intervals, or even better a short hand method of calling the sub routine 18 times at 20 degrees.

Thanks

Simply Bearings have no minimum order and a very extensive stock of name bearings both imperial and metric, their sales team are also very helpful even if you only want the one.

A slot drill makes an excellent boring tool, which can easily be off set and remain ridged.

I didn't remove the bearings, so the spacer is still in place. I got lucky with adjusting the bearings yesterday and was able to do a days machining, unfortunately the adjustment has settled down today is and producing some chatter, but on readjusting I was unable to repeat yesterday's success, so its back to the drawing board tomorrow, mind you I am machining a six and a half inch Aluminum billet which is bound to highlight and problem with the bearings

Thanks for the moral support Phil, I do lock the outer races before setting the pre-load, but seeing as there's rain forecast for tomorrow I'll give it another go, as by the law of averages I must get lucky one day. Thanks to one and all for your input, if there are any ex-Myford service engineers within easy driving distance of Hastings, East Sussex, I be interested!!