Member postings for Howi

 

Andrew, a little leakage is inevitable, a little drop of light oil should deal with that.

The next thing to consider is timing, get this wrong and you are on a hiding to nothing.

Turn the engine over by hand, with the displacer piston furthest away from the heat source, the heat is being applied to the greatest volume of air which is going to increase the air pressure ( as the volume is fixed) and so push the piston towards the flywheel ( power push stroke) 

. keep turning the flywheel, the displacer piston should now go towards the hot end and push the (now) hot air to the cold end where it will loose heat rapidly, causing negative pressure at the power piston thereby sucking the piston back to the top of the cylinder, (second power stroke), the cycle then Repeating itself.

If this is not happening in the right sequence you may need to reverse the direction of flywheel rotation. Some Stirling's will work in both directions others will not.

General timeing is usually displacer piston 90 degree out of sync with the power piston.

I think you are very close to getting it running, 

Get some oil on all the bearing surfaces, and get the whole thing running via a drill or mill or whatever for 5 minutes at a time and everything will wear into place. Don't forget a striking needs heat, more heat means more power, use a blow torch. If this gets it going then it is only getting it run in that will allow it to run on a spirit burner.

Edited By Howi on 15/02/2016 12:42:58

Brian, you need to approach testing methodically,  looking at the plans you have shown shows the air inlet to the power piston is at the end furthest from the flywheel, my previous post needs the action of the piston reversing in that case. The opposite end of the power cylinder needs an opening the the atmosphere otherwise you are wasting power compressing air, this air needs to go somewhere.. Another thing you could try is, remove the power cylinder end cover ( one furthest from the flywheel, then spin the flywheel. It looks a fairly hefty flywheel so kinetic energy should keep it turning more than 6 times. You could also disconnect the power piston Conrad and the displacer Conrad and push and pull by hand how do they feel, rough/smooth?

Testing needs to be methodical and carefully worked out gradually adding more parts of the linkages until you have everything connected as it should be. The poke and hope method rarely works.

Usually the blindingly obvious suddenly smacks you across the face with a wet fish. The "Ah! Bisto" moment.

As you are getting 30 turns by spinning the flywheel, I would say friction is not your problem.

It is more likely to be an air leak or no connectivity for the air between the displacer and the piston.

If you remove the glass cylinder and the displacer, but leave the displacer rod in place, also disconnect the power piston from the flywheel, now blowing into the end where the glass cylinder goes, should push the power piston away from the flywheel, suck and it should go the other way.

If you cannot get this to happen then that is your problem. You need to find where the blockage is. Once you get this sorted you should find it runs. 

Check the plans and try and work out the air passages between the two cylinders and check you have done everything in this respect.

This is a successful kit from Beings, trying to redesign it without the knowledge and experience will only lead to dissapointment.

 

The 3mm hole is connected to the cylinder bore at the top of the cylinder and is shown as 2mm deep. The air in the system has to move freely between the power piston and the displacer piston with no leaks. A way to check if everything is OK is to disconnect the power piston and displacer from the flywheel, apply heat as normal and manually move the displacer piston backwards and forwards, you should see the power piston moving in relation to the displacer.

20 years, in our house, wine won't last longer than 20 days, I can smell unopened bottles from 20 paces.

That flywheel looks big for "Laura" - you say biggest you could find? Didn't one come in the kit? What is wrong with the one supplied? 

Stirling engines like Laura do not produce a lot of power.

I am sure there are plenty on here who use the cheap digital calipers without a great deal of problems, me included.

I might add that just because it says Mitutoyo does not mean it is, there are a lot of fakes out there, especially on eBay.

Bottom line - you get what you pay for.

The Magnet is 5mm in dia and 3 mm thick, hardley likely to cause imbalance.  

Edited By Howi on 13/01/2016 08:47:49

Make sure the torq screw holding the insert  is done up quite tight, if it is at all loose the tips will shatter on interrupted cuts. Tips designed for aluminium seem to work well on most materials, steel, brass etc

Plenty of choice on ebay

Brian the displacer needs to be a loose fit, make to size that is per plan. The displacer moves air from the hot end to the cold end. You need a a certain minimum volume of air in the engine for it to work. The driving piston is the one needed to be made to close tolerance I.e no air leakage.

In a Stirling engine the air contained within the system relies on the following variables :- volume, temperature and pressure. You have a fixed volume of air, the heat source increases the temp which increases the pressure to the driving piston, the displacer then moves the hot air to the cold end, temp of air now decreases causing drop in pressure which pulls the piston back in, sort of double acting piston.

I have not seen a shower like that, with those internals for a long time, I would suggest it is way past it's best.

It looks to have been mounted on top of the tiles, so no re tiling needed, electrics and water feeds are also external, so should be easy to replace with a modern unit. NO! An earth leakage fault is not a trivial fault.

For what a new shower would cost, it is not worth it - I think some people need a reality check before offering advice about repairs. While you may run the risk yourself, encouraging others to do the same is bordering on the criminal.

Sorry to be so forcefull about this, but what you or I may do in similar circumstances is one thing ( that is your and my risk), to encourage others who may not have the same skills or equipment, is another thing entirely.

BUY A NEW SHOWER!

Take the advice offered and just buy a new one, better safe than sorry, that stain does like ominous though. The elcb is there for a purpose - to stop you getting electrocuted - don't mess is good advice whether you (think) you know what you are doing or not.

Not much point really, as the igaging scales are cheap enough and designed for the job.

But, of course , if you want to have a go...............

I have adapted a cheap digital caliper from maplins, to give a readout from my lathe tailstock, just a case of chopping bits off rather than adapting electronically though.

Edited By Howi on 08/12/2015 17:27:21

Standards are falling - what can you do about it? - nothing!

There are more important things to worry about, like bombing the crap out of ISIS.

Come on chaps, where are your priorities 

Turbocad articles, I would second that

Been there, done that' just waiting for the tee shirt......

I made my dremel (proxon) holder in two parts to save all that sawing /filing, picked up some cheap diamond cutting discs at one of the shows, went through the glass easy least.

Good luck with the build, Jan Ridders plans very good.

Well done JasonB, beginners need to be encouraged, we can do without the negative comments.

The 10V/10H build may well be a simple build for many, others like me need all the help we can get.

Very brave of you Dave, keep the thread going, I for one will learn a great deal.

Howard

There ate thousands of these on eBay, mostly the same module, quite a lot do include a wiring diagram in the listing.

It is not rocket science, 

On mine, when power attached does a self test and comes up with a code on the display before resetting to all zeros.

It will work on any voltage from 5v, not sure of max but plenty high enough, I just used a 9 v wall wart - half an amp should be more than enough.

Hall effect sensors are polarity specific, the magnet to sensor will only work one way, if the sensor light does not come on, just turn the magnet round.

The magnets supplied are very strong super magnets, mine is attached to the mill spindle just by its magnetism, mill will go to 2500 rpm, has not come off yet and highly unlikely to.

With regards to non working units, just let eBay know if you can't contact seller ( I have had no problems with contacting Chinese sellers and Will usually just send you a new one - they do NOT want any negative feedback so you should not have a problem getting a replacement.

Agree with Peter and Neil, on mandrel handle, only just made mine, can't think why it took so long. I was actually bored, with nothing to do, well not quite true, just didn't feel like doing anything build wise, but felt I had to do something.