Member postings for Ron Laden

The Class 22 is awaiting a track test (next track day in two weeks) so thought I had better catch up and make the last few small parts for the Muncaster.

I made the valve this morning which seems to have turned out ok, Jasons drawing calls for bronze but not having any stock at the moment I went with free cutting brass in the hope it will be ok.

The rod slot is 2.6 mm wide x 4.0 mm deep and the nearest cutter I have is a 2.0 mm HSS 2 flute uncoated, the top end speed of the mill is 2500 rpm and I was a bit concerned how it would cope running at less than half speed. However it was fine and turned out ok, I started with a couple of 0.25mm cuts then increased to 0.5 mm and it cut just fine as did the two side cuts of 0.3 mm to achieve the 2.6 mm.

Valve and eccentric rods, the exhaust and a couple of oil cups will see the parts list complete.

Yesterday my cordless 18 volt drill/driver went pop or at least the pcb did, knowing I would have no chance of getting a new board off I went and bought myself a new drill.

This morning I stripped down the old drill to see if anything was worth saving in the maybe come in useful box. The thing that did draw my attention was the gearbox parts (picture below) I immediately thought differential.

Now I dont know yet if I can make anything of the parts I need to put pen to paper but it would be good if I can, I do like the idea of having a differential on the engine. I know its not essential and a single wheel drive works well enough but a differential would be good to have.

Nice work Jason as usual.

I notice that the tool is climb milling its way around the part is that something that is a normal approach with CNC or is it for a better finish less tool loading etc..?

Ron

One day,s work should see it wired I said well tomorrow is day 4 and still quite a bit to do. I,m not the brightest spark when it comes to electrics (excuse the pun) but a lot of what you guys think is simple has me deep in thought trying to fathom it out. Anyway what I,ve wired so far seems OK, I am now wirng the sound plus the lights which I am connecting into a double pole direction switch. The idea being when the direction is switched the headlights and rear lights are switched to match the direction or at least that's the plan.

Morning Jason,

I watched the video again I really do like the long stroke especially when running slowly, nice sounding engine also.

I see from the Thompstone text that the engine is just 1/16" shy of being under square by 2 to 1. Is that about as long a stroke you see on stationary engines or can they be longer.

Ron

If you want to go with cast iron M-machine will cut you 3 inches of 150mm x 150mm at £21.60 per inch so £64.80 plus £10.20 carriage covers up to 30kgs.

Hi Jason, don't want to butt in other to say the cylinder looks every bit a casting, you certainly have it down to an art producing would be castings from bar stock. I wondered could the rings on the larger full size engines be there for stiffness/rigidity maintaining size and shape on a part like a cylinder which heats and cools, maybe not just a thought.

Ron

Not just ships but aircraft also, if you get up close to a USAF Boeing B52 bomber (there is one on display at Duxford) the body skin is wrinkled vertically along the full length of the aircraft. Quite normal apparently, the body skin is thin alloy to keep the weight down on such a large aircraft. The wrinkles come about from the stresses and strains of flight and is said to cause no problems in flight performance or the service longevity, the B52 has been around for donkeys years and they are still in service so the wrinkling is not detrimental.

Edited By Ron Laden on 13/04/2021 16:06:35

I just set my tools (turning and parting) to centre height by eye against the turned point of my home made scriber set in the chuck. Is it absolutely spot on to a fraction of a thou, probably not but its as close as makes any difference as I dont have any issues in both turning or parting.

I am biased in that I am a big fan of Loctite 638, I have put some parts together with it in the past where I thought the joint was a bit risky to rely on a Loctite connection, but the 638 has always come up trumps.

I,m sure a brazed joint would be more belt and braces but I wouldnt be at all surprised if a 638 joint would work also, the surface pitting in the tube should certainly provide a good key and if the mating face of the flange is well abraded I think it stands a good chance of success, my thoughts anyway.

The one thing I have found with 638 is that it in ideal conditions it can grab very quickly so alignment of the parts needs to be in quick time otherwise it will be a case for the blowlamp to free the misaligned parts.

Ron

Warco sell a rear tool post which fits their 250 lathe, I know it has a tennon for the T slot but don't any sizes. Hemingway Tools also do a kit but how much work is involved again I don't know, sorry.

I guess I use aluminium quite a bit and for most cuts I use the 2 flute uncoated HSS cutters from ARC,s premium range. Good pricing and good quality they work really well.

I agree with Howard, if I was looking for a lathe and £1500 was my budget I would seriously consider the Chester Craftsman (18 inch gap bed) that Matts friend is selling at around that price. Only had around 10 hours use and £1000 less than new price, I would certainly want to be taking a look at least.

Its a fake for certain, I have one but mine cost £32 and assuming its from the same manufacturer (which it may not be of course) then its great value for money. It is a very good copy of the Mitutoyo but there are some slight differences which you would hardly notice unless you were doing a comparison against the genuine product..

Mine is very good especially considering the price, its super smooth well made and accurate in that it matches my genuine Mityutoyo spot on. My elderly Mitutoyo is starting to lose its display so took a gamble on one of the copies and I am not disappointed, whether there are a number of copies though with some not so good I dont know.

Thanks Bazyle

The dead man,s connection is a good idea, thanks for that.

Talking of too long a control lead I embarrassed myself not long after I joined the club. A club member let me take his class 37 for a run and that had a control lead which was way too long at about 6 feet or more, he did mention it to me so I coiled all the excess cable up and hung it on the trolley handbrake lever. I was half way around the track when I stopped for a red light and didnt notice the lead had uncoiled, when I set off again the trolley ran over the lead cutting it clean in half. He was ok about it but I could tell he was none too pleased..

Thanks Jeff

Yes hopefully it wont be too long before the club track is open again and I must admit I am now looking forward to the test run. It will be tinged with a bit of nervousness though, thinking are my motor calculations correct, is the gearing good, how will the belt drive perform etc etc. I am fairly confident it should be ok but like they say one should never count their chickens.

Ron

That will do for now, side valances have been added and there is still some small details to add but they can wait until after the track test. I have electrics on order and decided to go with a plug in hand control which I will make up myself.

I now have the AUW which is as near as matters 61kgs so a bit of a lump but it breaks down for handling and assy into the chassis 26kgs, the body 7 kgs and the pair of 12 volt batteries 14kgs each. Hopefully traction should be good, I cant see why not as there is a battery sitting immediately above each of the two bogies, well thats the plan at least.

Pressure Turning..? something new to me but I watched a Joe Pieczynski video where he covers the method to produce thin discs to a given size.

I have some 150mm x 3mm alu discs to make and it looks ideal but it does raise some issues re safety, he states on more than one occasion that it can be dangerous.

He emphasises the need for a rigid machine so I wouldnt want to attempt it on a small mini lathe but I think my Warco 918 has reasonable rigidity and wonder if its worth a try. He used a sizeable lump which he called a back plate in the 3 jaw and a slightly smaller one in the tool post on a live centre with the thinner disc sandwhiched between the two, relying on the pressure applied from the tailstock for grip and drive.

Just wondered if anyone uses this method and their thoughts good or bad.

.

Jason, would it be considered as a long stroke engine it seems to have a fair length of stroke and the cylinder looks a decent length to, just wondered.

Ron

Lovely Jason and I agree much nicer at tickover something very satisfying about it.

Ron