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Thanks for the quick responses, chaps. I realise that the two tapers are very close relations, but I was assuming that I could make an adaptor like a sewing thimble (does anyone still use them?) with a wall thickness of maybe 1 - 2 mm - it will push the chuck a little closer to the table, but...

I have owned a chinese pillar drill for many years, its accurate and works well for what it cost. The chuck has decided to lose all its gear teeth (a bit like its owner) and I need to replace it. Heres the snag: the end of the drill spindle has a male JT33 taper, but replacement chucks with...

I have found that making split or shell bearings from solid bronze bar is a very expensive process, as almost all of the metal ends up as swarf. Instead, I buy suitable oversize Oilite sintered bronze bushes, split them lengthwise and solder the halves together before machining. Separating the...

Golly chaps, I'm learning a ton of stuff here! In answer to one of the points raised, the bluish flame at the exhaust ports I don't think is necessarily an indication of poor timing (although the timing may well be off). Its more that the ports are very short, directly visible from the outside...

Thanks again for all the suggestions and advice. I have tried shooting a squirt of juice into the carb, but it seems to make it worse rather than better. The plugs look ok as well, dry and clean. The engine does run, just not on its own. The best results I have had are from cranking it at...

Some progress to report. I stripped the blower down and discovered that the fuel seems to have swollen the tufnol vanes enough to make them bind a bit, and that the leaf springs needed some slight changes to the form to allow them to sit amost flat when the blade is fully in. Back together...

Yes, thats the engine that mine is based on - I used to work at the company that made them waaaay back in the sixties. To run the engine without the 'charger would require a new manifold of some sort for the carb, as the charger sits between the carb and the inlet ports. Also, I'm not sure if...

First off, many thanks to all for the suggestions and ideas. I was a bit concerned that the carb was too small, but I reasoned that it should be ok to get it going even if restricted the revs. The information from Petertha is absolutely priceless in this regard, so thanks again - it also looks...

The title sums up my problem, but this is not your average engine :) Its a 2 cylinder 2 stroke, running on petrol, with horizontally-opposed pistons and the spark plugs in the centre of each cylinder. It uses a small vane-type supercharger to scavenge the cylinders, and the inlet piston lags...

Hmmm. When you say 'these are dials for a clock I am making' its a bit like describing an atom bomb as a 'bit of a firework'. I am truly amazed, not only at your workmanship but also the superb design and flow of every single piece. Gives us all something to aspire to, though I suspect I may...

Have to say that my prototype looks very amateurish compared with your fantastic work. What material did you make the case from? I'm finding that the hardest part is making a professional looking dial, stretching my capabilities quite a bit. And fitting the hands is a challenge with my size...

I know its not engines, but I was wondering if anyone else on here had experimented with making their own watches? I don't mean necessarily all of the gears etc, just making their own unique wristwatch from off the shelf movements. I recently had a go at a prototype, and was encouraged enough...

Thanks for that, Cynthia. Unfortunately, even the last 60 years spent in all aspects of mechanical engineering has not yet persuaded me to invest in a massive furnace and a set of drop-hammers - oh, and of course, a building to put them in. I suspect that it might be overkill for the single...

Many thanks, I'll see if I can dig up a copy. I am currently deciding whether to go down the 'machine solid bar between centres', or the 'fabricate with lots of bars which are then mostly sawn off ' approaches. Plenty of other bits to work on which I decide. Thanks again Martin

I like it! My crank is a little more difficult because each cylinder has 2 opposed pistons, and one lags the other by around 15 degrees, so none of the crankpins are in line with any of the others - picture here of the first one maybe shows this a bit. In spite of this, loctiting all the webs...

Hi Parksy, I'm new to this model engine game, so learning as I go. The crank has four separate throws with webs in between each one, and I solved the alignment problem by making a flat on each of the webs and using that as the reference point for drilling and assembly. The problem I have is...

Hi Niels, Unfortunately the design of the engine makes the crankshaft a little difficult. There are two cylinders with two pistons in each, firing in the middle of the cylinder. In each cylinder, one piston operates the exhaust ports and the other the inlets, with a small supercharger to...

Thanks chaps. I suspect that I knew deep down that the CI was not really going to work, I guess it could if it was massive enough but I don't have space in the crankcase for that. Looks like machining it from a solid bar is the best option, fabricating is not really rigid enough and alignment...

Hi all. I have been working on a new engine and am having trouble getting a strong and true crankshaft - the engine is a horizontally opposed 2 stroke, with two 'clapping hands' pistons per cylinder, which makes it difficult to make a non-wobbly fabricated crank. The bores are 30mm with each...

Hi Niels, Running the blower with a motor would be a good idea as that would let me vary the speed and therefore pressure easily - I have seen some model engines where the blower runs at 4 times crank speed, but even with a relatively low engine speed of maybe 4000 revs the blower is going to...