Member postings for Ian Richards 3

I've been a member on here for 6-7 years and a subscriber to the magazine for perhaps 10 years. I'm unable to access the 'for sale' adverts though and get a message about making a number of posts to see the seller's contact details. Any suggestions? I'm tempted by a second hand mill......

Ian.

Problem solved, and peace has returned!

First of all though, thanks very much for all the advice. I logged on last night wondering if anyone had replied at all, and was amazed by the number of detailed replies!

Anyway, the prize (if there was one) would go to wheeltapper. The pulley was loose. I can't believe that I didn't spot it sooner, or that it's such a simple explanation. I also can't understand why a loose grub screw on a keyed pulley would make such a racket.

I realised the cause when I tried to load up the motor on starting (to try and test the starting capacitor and centrifugal switch). Not only did the motor have plenty of torque, but my gloved hand on the pulley also stopped the racket!

Thanks again

Ian

Is anyone an expert on single phase induction motors (capacitor start and capacitor run)? Mine is fitted to a Chester lathe / mill, which is about 10 years old. The motor is 4 pole (1400RPM), 0.75 HP, frame size 80.

The motor has suddenly gone from running smoothly and almost silently to sounding very rough and making quite a lot of noise. I think it's still achieving normal speeds (unloaded), but I haven't dared run it for long enough to investigate the performance. So far I've checked:

- The centrifugal switch. Fairly confident this is OK. It's closed circuit at rest and goes open circuit when you spin the motor with a drill.

- The start capacitor, which was replaced about 3 years ago. When this failed, it struggled to start up.

- The run capacitor. I've replaced this since the problem started, but it hasn't had any effect.

- The bearings. There is no significant noise when you spin the motor with a drill, or when it's coasting down. It spins freely.

Running current (unloaded) is about 1.7A, which feels quite high. Is there anything else that I can investigate?

Thanks very much

Ian

Hi everyone

I know that this is re-opening a fairly old thread, but mine is finally running really well, on carburettor version 3!

I found that the engine ran fairly well on the gas carb (with a low pressure butane regulator), but 'ran out of steam' after a few minutes as (I think) the cylinder heated up. I think that the fundamental problem was that the air had to be sucked through two spring loaded valves.

Carb version 2 was Jan Ridders vapour carb. This also worked well for a few minutes, until the most volatile components had evaporated from the fuel. The mixture had to be richened after this, and I think that the pressure drop in the relatively long air hose I had limited the power available.

Carb version 3 is based on the 2 cylinder 4 stroke engine currently being serialised in the mag. It's much simplified (since no throttle is required) and has a 3mm orifice. Fuel is supplied via a needle valve, which controls the mixture well. With this carb, the engine will run until the fuel tank is dry.

The only other modification I've made is with the ignition. I'm using a modified mini contact breaker mounted below the crankshaft, and triggered by a 'cam' that's between the frame and the back flywheel. This means that you get a spark at every top dead centre, but it works really well. Power from a spare rechargeable drill battery (9.6V, but the 12V coil seems to work fine with it).

All I need now is something for it to drive! Any suggestions?

Ian

After about a year (and a lot of references to this thread), my Rina almost spluttered into life today!

I've 95% followed the design published in the magazine, with the clarifications and improvements published on here. I've deviated from the published design with the ignition system though - I've put a cam on the crankshaft (inside the 'back' flywheel), which drives the contact breaker from a mini and seems to work well with a test spark plug. This gives a wasted spark (at the end of the exhaust stroke), but I can't see a problem with this.

On butane (regulated down to 28 mbar), the engine fires fairly reliably, although the adjustment of the needle valve is very critical. It doesn't seem to generate much power though, and only runs for between 10 & 30 seconds before running out of steam....

My suspicion is that my valves aren't sealing as well as they should. When I turn the engine over by hand you get a certain amount of 'bounce' as the air is compressed', but if you do the compression stroke over about 5 seconds, it's apparent that all the pressure has leaked out. How does this match with anyone else's experiennce?

If you put a lit candle next to the exhaust port, you occasionally also get a puff of flame from the exhaust on the compression stroke when you turn the engine over at about 200 RPM.

Any advice as to whether this leakage is significant would be appreciated.

Thanks

Ian