Member postings for Brian John

Duly noted but I have already spent a few hours fidddling around with the aluminium plate and working out how it will fit. I have had a dry run and put it all together without drilling any holes and I don't think it looks too bad at all. The aluminium plate sets off the brass quite nicely.I will be glueing wooden lagging to the cylinder too ; that always looks good even though it serves no purpose. I have some small strips which are already varnished left over from a previous build.

To be honest, I think the supplied cast iron flywheel is too large for this small engine. The small brass flywheel I used in the video looks a more suitable size to my eyes.

You have a good point about using the wrong tool for cast iron. Can you post a photo of the tool you use when turning the flywheels ?

I am all astonished : it works !

https://www.youtube.com/watch?v=LD8_fxIZhxE

I made two more control valves using some 6mm bronze bushes fixed to a 4mm steel rod. You can see the old steel control valve beside a new one in the video. I used CHEMTOOLS 8609 retaining compound. It should stand a constant temperature of 150 degrees Celsius. How hot does the steam chest get ? At least I know that the steam chest/cylinder assembly is correct and I do not have to remake that. I can now have another go at making an all steel control valve in case the retaining compound fails.

http://www.chemtools.com.au/product/adhesives-threadlockers/retaining-compounds/general-purpose-2/

I still have to fit the larger cast iron flywheel by raising the engine mounting block by 5mm. I quite like the smaller brass flywheel though. Some screwed parts must be fixed in place with low strength Loctite as per the instructions. The engine runs very well first time ; it self starts as long as it is not on BDC.

NOTE : that 8609 retaining compound grabs in less than 5 seconds so be warned. Forget about the 10 minute fixture time as per the website !

Edited By JasonB on 24/08/2017 08:59:36

I made another control valve cover today but I still have the same problem. It could mean the bore for the control valve is not perpendicular to the end of the steam chest. That could be due to the quality of the drill press or the ineptitude of the operator....or both !

What to do next ? I think I will have to use the Teflon packing arrangement that PM Research use on their engines. That should allow for a bit of error. I can't quite remember how they did it but I will look closely at online photos.

You can see the parts 29, 4 , 30 and 18 in the exploded diagram below. They use this arrangement for the piston rod but I should be able to use something similar for my control valve.

http://www.jeff-z.com/livesteam/pm-3/pm-3.html

Edited By Brian John on 22/08/2017 14:38:33

I have decided to buy a new computer but nobody is doing any good deals on new laptops in Cairns at the moment so I will have to take what I can get. JB HIFI have two HP laptops. Both run Windows 10 : the 14'' costs $500 and has 4GB RAM, 1TB HDD and a 2.0 GHZ processor. The 15'' costs $600 and has 8GB RAM, 1TB HDD and a 2.5 GHZ processor. I spent an hour in the store today doing various things and the larger 15'' is definitely faster. I wanted a 14'' screen but I will have to go with the larger and faster computer.

Neither computer has a DVD reader/burner so I will have to buy an external device.

Edited By Brian John on 21/08/2017 10:20:31

Edited By Brian John on 21/08/2017 10:21:48

Jason : it was not screwed down when I took the photo hence that gap. I have measured all the holes and they are in the correct positions. The control valve is also the correct dimensions so I am not sure what the problem is. The front hole is being fully covered and the rear hole is being partially covered so something is wrong. I think I need to desolder the steam chest from the cylinder. The remelt temperature of the solder paste is about 340 degrees so it should not be too difficult. I do not know what sort of a mess I will be left with once the two pieces are pulled apart.

Lawrie : what is happening with your control valves and the steam holes ?

NOTE : I thought this engine build would be on par with the their Stirling engine kit !

I have removed the steam chest cover to observe the operation of the control valve as it moves back and forwards. When it is in the forward position should the steam hole on the right be open or closed ? And when it is in the rear position should the steam hole on the left be open or closed ?

I have measured the hole positions and the control valve but something is not quite right. I may have to desolder the steam chest and start again.

Edited By Brian John on 21/08/2017 08:07:25

Edited By Brian John on 21/08/2017 08:08:44

I have re-read the instructions concerning the control valve cover and watched that instructional video again : I had the cover on the wrong way ! The spigot goes inside the steam chest not outside as I had it positioned. Thinking I had solved the problem, I then tried it in the new position...just the same. I also tried the other steam chest and the other cover...just the same.

I am really not sure what is going on here now. There is nothing else to do but make a new control valve cover and see what happens. The engine is 98% complete but unless I can get this part to fit properly then it will not run.

Weary : thank you for that video. I may as well start with that ; it looks good. Yes, adjusting the eccentric will be a nuisance due to the hidden grub screw. I realised that yesterday when I was putting the engine together for the first time.

I just had a disconcerting thought : what if the problem is not the rear control valve spigot but the bore for the control valve is off centre by a few degrees ? I think the PM RESEARCH engines use a Teflon packing arrangement in this area. I have sold those engines so I cannot have a look at it now but that is something to consider if all else fails.

Edited By Brian John on 20/08/2017 00:59:27

I had intended to place that Al. plate under the small block of wood so that the existing holes would not be visible. I have plenty more Al. that I can cut to that size so a new plate could be made to fit on top of the small block and under the engine frame as suggested. At this point , I am not sure which would look better.

Bunnings have some Tasmanian Oak which is 25mm thick so I could also cut and varnish another block of timber. It would probably look better than the block of plywood supplied with the kit.

Lawrie : machining cast iron on my small machine is a real pain. I do not get a good finish so I have to spend a long time polishing it up using 120 to 1500 grit wet and dry. It is far easier to raise the engine a few mm. This is why I prefer brass flywheels ; I get a good finish with little polishing necessary.

Do you intend to add timber lagging to the cylinders at some point ? I have found that looks quite good. I use JB WELD to glue the timber strips in position. The strips are varnished first on both sides with three coats of matt clear.

Edited By Brian John on 19/08/2017 17:50:47

Yes, that makes sense but I am not sure how that could have happened. I made two of everything and the other one is no better. I need to work out what I did wrong before I try making another. (The other side is flat.) 

I have gone ahead and assembled the rest of the engine without that rear cover. There was a problem with the eccentric being too thick but I have machined that down and everything now runs smoothly.

Setting the timing : where should the control valve be with the piston is at TDC ?

Edited By Brian John on 19/08/2017 12:03:50

Edited By Brian John on 19/08/2017 12:11:08

I have found some 5mm thick aluminium plate which will fit under the small wooden block. There is a piece of it in the photos below already cut to the exact size from another job. I will fit that later and in the mean time I will use a smaller flywheel from the spare flywheel box.

I got the main piston moving smoothly in the cylinder ; that did not take too long. But the big problem is the control valve (21) and its rear cover. I have spent over an hour filing, fiddling and fettling but I cannot get the control valve to move once the rear cover is tightened. Just that last little bit (1/8 turn) to tighten the screws will jam it stuck. I am out of ideas for the moment. I may have to make another control valve although I am not confident that will solve anything. I have already widened the holes through which the screws pass from 2.2mm to 2.6mm.

Edited By Brian John on 19/08/2017 07:39:22

Edited By Brian John on 19/08/2017 07:40:06

Edited By Brian John on 19/08/2017 07:41:08

There will be a bit of fettling required tomorrow to get the piston to run smoothly in the cylinder for the full stroke. I think I know how to fix that. But the unexpected problem is that the flywheel cannot be fitted on the axle : the supplied small block of timber on which the engine frame sits is 18mm thick and this is not high enough to allow the flywheel to be fitted. It needs to be at least 20mm thick to give enough clearance for the flywheel. I don't have anything to hand at the moment so I will have a look in Bunnings scrap bin tomorrow.

Lawrie : how thick are your supplied small blocks of timber ?

DOH : I did not take enough off the flywheels when I machined them. Diameter should be 80mm but mine are 82mm. I was not thinking of clearance when I machined them.

Edited By Brian John on 18/08/2017 12:45:51

I finished the piston today and fitted it to the piston rod using two M3 X 5mm grub screws. I filed two flats in the piston rod as discussed above. I also put low strength Loctite down each screw hole before tightening everything up. I just realised that all the parts are made..... it is actually finished ! All I have to do now is assemble it and hope it works. If it doesn't then I will have a very interesting paperweight.

Edited By Brian John on 18/08/2017 08:06:17

Edited By Brian John on 18/08/2017 08:08:13

Many thanks for all the valuable advice. My old computer has a DVD-RW and that seemed to be standard 11 years ago. But now most of the sub $400 laptops do not have it ; I would have to buy an external DVD burner. I am still looking at ebay. I have not tried cash converters yet.

My old HP laptop computer (Windows 7) is giving a lot of problems so after 11 years it might be time to buy a new one. I saw some second hand laptops (Windows 10) in the pawn shop which do not look like they have had much use. Some still have the original owner's invoice and are only 6 months old. They do come with a 30 day warranty.

Would you buy a second hand laptop ? I have bought second hand desktop computers in the past and got good use out of them but a laptop is a different proposition.

What basic tests would you perform to see that things were working okay ?

Lawrie : I found that the 243 soft solder penetrated further in along the shaft than the solder paste as I could not remove the grub screws from that one. I ended up filing them flat.

I buy my displacement lubricators from Executive Model Design in the US. ( LUB-2 = 3/16-40 thread ) Postage to Australia is expensive from the US so I wait until I have a large order and buy about $400 worth of items. The postage is the same as if I buy just a few things.

**LINK**

The steam chest & cylinder assembly looks okay : I soaked it in citric acid and scrubbed the flux off with a wire brush. I polished the inside of the cylinder with some 2000 grit to make sure all the flux was removed. The only part I have left to make now is the piston. I will try to complete one engine by making that part tomorrow.

Lawrie : will you be connecting the two cylinders together with a steam pipe on your double engine ? I had a twin cylinder engine from PM Research once and the two cylinders were connected.

Edited By Brian John on 15/08/2017 14:19:23

The day started out bad and only got worse : my computer died this morning and I lost all my data and photos after using the system recovery discs. I knew I should not have tried soldering the steam chest to the cylinder today but decided to give it a go anyway using the solder paste.

I used some toothpicks to try and keep those steam holes open. I had made some stainless steel pins but I could not get them to sit correctly. The toothpicks quickly went up in flames so that was a useless idea. Other than completing the steam engine to see if it works, how can I tell that the solder has blocked the holes it should have blocked and not blocked the holes it should not have ?

Okay, thank you for that information. No, I have never seen that for sale anywhere. I should imagine it must be VERY expensive !

Perhaps not as expensive as I thought. Is this it ?

http://www.gemcuts.com.au/euro-tools-silver-solder-paste

Edited By Brian John on 13/08/2017 13:21:14

Henry : the solder paste I used was the silver solder paste. It is good stuff but quite expensive : $20 for a small syringe which is mostly filled with air ! I bought it from the marine and boating supply shop. I assume the boaty people like to keep it around for emergency repairs at sea. I will be using it again for the steam chest/cylinder assembly as I am not so confident about using soft solder and a plumbers iron to do the job.

Jason : okay, I will file two flats for the grub screws to bear against and see how I go.