By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Mark Smith 3

Here is a list of all the postings Mark Smith 3 has made in our forums. Click on a thread name to jump to the thread.

<< First < Prev 1 2 3 4 5 6 7 Next > Last >>
Thread: Hot air and stirling engines
25/04/2011 00:23:53
Andy Ross has kindly allowed the down load of his wonderful book, Making Stirling Engines. It is available here http://StirlingBuilder.com. Thankyou Andy, it is fascinating reading.
Mark
Thread: Here we go again
26/02/2011 19:04:13
Hi all, yes I'm ok. My house is a mess but we are alive. My workshop is currently flooded with liquifaction and we have no power; may not have it for a week or more. My projects are on hold indefinately. My house has canted over a 1/4 bubble on the level. It has a concrete floor so they may be able to level it again, failing that it will be demolished. But that is small potatoes compared to the plight of many others.
Thanks for your concern
Mark
Thread: Steam engines
29/01/2011 01:10:34
I have read with interest the comments so far and some have merit, as many people have thought about this principle for a long time.
 
I have thought for some time about the idea of combining the hotair engine (open cycle) and a boiler, probably a flash generator.
 
The main idea behind the hotair engine is to get as much heat across the steel wall of the displacer cylinder as possible to expand the compressed air.
 
Steam has a large quantity of heat latent in it so it seems to me that if a quantity of air is compressed in a cylinder and steam is admitted via a valve, that latent heat will disipate in the air causing it to expand.
 
So instead of using the expansive properties of steam we use its latent heat to expand the air, much in the way an IC engine works; but remember, the IC engine only uses a fraction of the heat available from combustion to expand the air, the rest is dumped into the exhaust and cooling system. It could, if it works, be an economical way to use fuel.
 
If I am talking a lot of hotair, I'm sure someone will set me straight.
Mark
 
Thread: Stirling engines
29/11/2010 04:12:46
Thankyou Ray that was very informative, it just confirms the leak, friction and timing are the critical things. Interesting that stirling Silver II has that much potential power.
 
Good luck with the brazing, but also Ian's advice about running in is valuable. One of my engines refused to start and seemed to have too much compression, like yours; but after persisting it started and is one of the most reliable engines I have built
Mark

Edited By Mark Smith 3 on 29/11/2010 04:13:35

Edited By Mark Smith 3 on 29/11/2010 04:21:31

Thread: Hot air and stirling engines
28/11/2010 17:55:35
I am about to start a new project and have acquired some sg cast iron billets. Does anyone know what properties sg iron has against grey iron or white iron? Does it have the same self lubricating qualities for instance, and would it be suitable for piston rings?
 
Cast iron I have been using to date has been discarded window sash weights which is very brittle and sometimes I discover a void after a lot of turning.
 
Mark

Edited By Mark Smith 3 on 28/11/2010 17:58:09

Thread: Stirling engines
28/11/2010 17:46:21
Yes, like Ian I would be interested to know how you got on. If you have built it as the plans show you will have done a terrific amount of work for it all to come for nothing. Bye the bye, some engines will run at high speed with no flywheel at all, though they lack torque.
Mark
Thread: Stuck chuck
09/11/2010 04:14:16
I have several chucks and they all have screws to allow dismantling, some on the front and some on the back. If the soaking doesn't work I would look for these. Also, many woodturners use all manner of oils and varnishes they apply when the lathe is spinning much of this could have found its way into the chuck. Oils like linseed go quite hard when dry.
Mark

Edited By Mark Smith 3 on 09/11/2010 04:18:28

08/11/2010 09:38:54
Terry, thanks to you I have repaired the lathe drive. The manual showed a dog clutch that slides between the lathe drive and the mill drive. After some sweating and swearing I dismantled it and put it  in my old lathe where a few turns with emery cloth cleaned and improved the clearance, now it works perfectly. The gear is not damaged as I first thought.
Apparently a four jaw chuck and adapter plate is available for this machine.
 
Jim, I think you have no choice but dismantle the chuck and clean it.
Mark
06/11/2010 18:12:50
Thanks Terry that is brilliant. My Lathe must be a Grizzly as it is exactly the same. A manual is exactly what I want. Isn't the web a wonderful thing.
Mark
05/11/2010 17:40:34
Thanks, Ian and Terry. Yes, Ian, it is a screw cutting lathe, now I need to find some suitable steel to make an adapter plate. This should be interesting with my modest engineering skills, but I should learn a thing or two along the way.
 
Terry, the grizzly model my lathe looks like isG4015Z
05/11/2010 04:58:42
You are right, the chuck is fixed to a permanent back plate with three socket screws. Would it be possible to make an adapter back plate with a spindle type thread to enable the fitting of standard Boxford 3 and 4 jaw chucks? I realise that the chucks will be a bit further from the head stock, but my old Barns lathe has a rather large overhang of the chuck as standard.
Mark

Edited By Mark Smith 3 on 05/11/2010 05:01:00

02/11/2010 18:06:03
Thanks Guys I hadn't considered that as I didn't know such beasts exist. Yes I will post a pick of the chuck. I have taken the mill off as I want to drive it from a separate motor; the dogs on the back of the bevel gear appear to be stripped as they are only nylon.
If it is the case as you suggest that the chuck is held on with screws there is little point in taking it off; I  will just use my old lathe for four jaw work.
Mark
02/11/2010 10:12:38
I have recently bought a chinese copy of a Grizzly late mill combo ( I can hear the howls already). I know the are not ideal but it will suffice for my modest engineering needs. My problem is the chuck refuses to unscrew. I have put timber in the jaws only to have it shatter. I am afraid to hit too hard in case I damage the chuck or the spindle. Any suggestions would be welcome as I want to fit a four jaw at some point.
Mark
Thread: Hot air and stirling engines
21/09/2010 20:06:12
What I did on one of my less successful engine that only just ran normally was drill holes around the top and bottom of a normal displacer and packed it with stainless wool. The engine ran just as well (or badly) as with a normal displacer. Your drop in torque was probably due to the increased dead space. The idea obviously works as that was the kind of displacer in the robinson design. Also David Urwick of Malta did some important work in this area.
Mark
29/08/2010 20:05:26
I never thought I would hear someone yearn for winter, Gordon. I can attest that Ians engine runs very well.
Mark
27/06/2010 20:11:47
There is probably not enough room for ball races, but the plain bearing are free running anyway.
Mark 
26/06/2010 22:16:46
They are plain bearings, Ian. Good to see you are back on line. Windows 95, wow, vintage!
Mark
25/06/2010 06:40:29
The little bit you see is a long allen screw that is supposed to block the end of the transfer tube. I don't think it was like that originally.  The transfer tube is screwed into the displacer via a brazed boss which is threaded internally. I suspect that is another source of leakage which teflon tape should cure. But the greatest leak seems to be between the flanges below the power piston. A gasket should cure that.
The displacer rod is large for such a small engine 3/16". Also the gap around the displacer and its cylinder is large, too. I estimate nearly 1/16"; too big according to Rizzo. But the engine does run with enough heat.
Mark
23/06/2010 06:23:49
Hi Ian,
I did get an email but there was no message, not sure what happened there.
I was going to take the boys to Mc Lean's Island to the steam society for a crank up with the vintage machinery club but the weather going to put a stop to that, shame, they have been asking when we go again to run their hot air engines for a crowd. Maybe the weather people will be wrong, we can only hope. 
A friend has the engine above and he has been trying to get it running better, but since he started he has only made it worse; I fear he is going to damage it before he hands it on to me to fix. The main problem that could see was it leaks air at the flanges - no gaskets just gasket goo. There is no friction and it might leak back past the piston which is not a big deal so long it is at a minimum.
I did get it to run when he first brought it around but it took 5 minutes of gas  flame before it started and was ant power. Also it has no cooling system and the heat transfered to the cold cylinder very quickly - maybe some wet undies might help here in the interim, what think ye? This engine should easily run with meths or a mamod tablet.
As for your computer, now I understand why I got no replies. Thought I was in the dog box maybe.
Mark
22/06/2010 06:47:45




Can anyone throw light on this old engine, it seems to have been made from a set of castings probably maybe fifty or more years ago.
Mark

Edited By Mark Smith 3 on 22/06/2010 06:49:11

<< First < Prev 1 2 3 4 5 6 7 Next > Last >>
Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Shopping Partners
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate