Restoration of a Lowne atmospheric engine.

[Alyn Foundry]

Restoration of a Lowne atmospheric engine.

A few weeks ago a member of my FB group was in contact about an R.L.E. engine that he’d recently acquired. After several messages I decided that it was enough typing and I called him instead. Needless to say I was able to help him get the engine running. A few moments later he sent me a link to eBay about the engine in question. Luckily for me the listing wasn’t placed anywhere near where you’d expect it to be like under engines or not live steam so there was minimal interest. I put one bid against it at £2.00 above the last, quite early into the auction and then watched and waited until the last hour before closing. I was expecting the bids to skyrocket, it being such a rare engine, but no one was biting. I had put a maximum bid amount that I was comfortable with and watched the closing stages with great interest. In the last minute the amount went up from the tens to the hundreds but suddenly stopped, I had won the auction. I was over the moon.

The engine is a late 1880’s RM Lowne patent atmospheric engine. A flame gulper in today’s parlance. This model was built by the company that RM Lowne founded and shouldn’t be confused with the engines, built under license by messers Hardy and Padmore Ltd of Worcester.

The engine arrived this morning in very good shape and over the coming weeks I’ll be posting the restoration progress.

   Graham.

[Dave Otto]

Looks like an interesting project!

Dave

[Alyn Foundry]

Thanks Dave.

I was aware that the Lowne was incomplete from the photos that the seller posted. However, from my point of view the missing pushrod and flame port flap were of minor importance.

My son and I have been looking at the piston and bore assembly this afternoon. We discovered that the Brass ring carried a pair of thin Steel seals, one of which had snapped. This is the actual main seal against the vacuum and is held in place by a pair of tension springs. The piston is almost a slack fit in the majority of the cylinder.

   Graham.

PS. The last photo is courtesy of a good friend who owns a beautifully restored twin cylinder version.

[Admiral_dk]

Congratulations on wining the Auction 

Looking forward to see more 

Per

[Alyn Foundry]

Thank you Per.   

Members may recall a recent topic about soft soldering Piano wire? I suggested to Allen that a good old “ Copper “ was the answer. Well I needed mine today. In the picture of the repaired seal you can see my “ one pounder “ this made short work of the job.

The Blue Steel ring had broken and had jammed the piston. Another problem was that one of the Brass wire tabs was missing and also needed replacement. The wire measured 1.2 mm diameter and is readily available on eBay, however I only needed 1/4” not 5 Meters. I ended up beating out a sliver of Brass sheet into a short wire.  The Blue Steel ring was tinned and re anchored to the collar.

I’m now ready to move onto the next stage and hope that the cracked ring won’t spoil the vacuum too much.

   Graham.

[RayW]

What a great find Graham. Watching progress with interest.

[Alyn Foundry]

Thanks Ray.    I’m really looking forward to to finishing the restoration.

The next item on the list was the shutter and cross arm. Again the rod diameter is 1/8” and drops into a slot on the pushrod side and slips into a clearance hole on the far side. I’m guessing it was done like this to aid periodic cleaning of the shutter and port face. Two Brass washers locate the arm in the slotted support bracket. The end of the arm carries a crank and hole that picks up the pin on the pushrod. A very crudely made arm made from 1/4”-1/8” flat bar is soldered at one end to the cross arm and carries the pivoted port shutter at the other. The flap is made from thick Brass sheet but I opted to turn down a piece of Brass and form the flap and spigot in one. This was then lapped on an oilstone before being fitted to the arm. From a mechanical point of view I assumed that this item was also able to pivot, or perhaps a better description, float within the arm.   My assumption being based upon the fact that a fixed flap would only touch at the top due to it moving through an arc. My friends engine was so heavily painted which he didn’t want to disturb left me with no option but to contact Nick Rowland of RMC fame who also has one of these motors for an answer. A short video was received from Nick via the FB group chat which showed it did indeed float about the pivot.

The two pictures are pretty much self explanatory.

   Graham.

[Alyn Foundry]

As a footnote the engine is really quite small. The flame port flap measures 1” or 25 mm in diameter.

I’ve just learned from Nick that the piston is sealed, not by the two Blue Steel rings but the whole assembly is a kind of Stuffing gland that pushes against some packing between it and a slightly larger opening in the front end of the cylinder. The gland is secured by a couple of small tension springs.  I have just ordered some 1 mm section, high temperature “ O “ rings because luckily the piston diameter is dead on 37 mm and the opening is 39 mm. The stroke is enormous…. A whopping 3,250 thousandths of an inch. 

   Graham.

[Zephyrin]

Lucky man, what an awesome bid you win !
atmospheric engines are fascinating, and I will watch the progress in the overhaul !

[Alyn Foundry]

More to come but I couldn’t wait to share the current situation.

<a href="https://www.youtube.com/watch?v=dGC7NqhCKgU" target="_blank">http://www.youtube.com/watch?v=dGC7NqhCKgU</a>

   Graham.

[Chipmaster]

That's running well Graham 

Andy

[Alyn Foundry]

Thanks Andy, it’s taken several hours of serious tinkering to get it dialled in.

Viewers will notice that the pushrod has a couple of 13 amp plug top terminals slid on to retain the springs. This was done because the only other engine available for any reference was a larger size. With this method I could adjust the stops to get the correct bias between the two springs for operation. I have to admit to a serious “ senior moment “ regarding the spring. Having ordered a stainless Steel spring of 300 mm in length from China I came to fit it and to my horror, it didn’t.
I had only forgotten to multiply the wire diameter by two! 

Luckily my workshop contains a massive selection of retained $#,t parts and a suitable 100 mm long spring was found. The remains of an old “ Proops pack “ of miscellaneous compression springs furnished the bias end.

Whilst the 37 mm O rings were still in transit I made a crude piston packing from some PTFE tape, twisted to form a thin rope. This enabled me to give the Lowne its first run in many decades.

A temporary gas line was rigged up to provide a pilot light for the main Bunsen Blue flame and the video above says it all.

Obviously there’s still quite a lot of work to do but to see it running properly for the first time gave me immense pleasure.

   Graham

[Admiral_dk]

Thanks for showing - helps the the Olde Two Bits upstairs ....   

Per

[Roger B]

Looks good to me     

How much power would this deliver, 10s of Watts?

[Alyn Foundry]

Hi Roger.

Probably a few Watts yes. So little is known about this particular engine whether they were used for work or just a toy. At this moment it’s pure conjecture.

Attached is a picture of another twin cylinder version that’s recently surfaced you can see a chain drive sprocket fitted to the crankshaft. The twins have a slightly larger bore diameter than the one I have.

   Graham.

[Alyn Foundry]

Due to a recently acquired viral infection things have been a little slow at the Alyn workshop. Luckily it hasn’t affected the operation of my trusty IPad. 

The second spring, this time the right size finally arrived along with the 37 mm Viton rings. Sadly the Chinese don’t work to BSS in the O ring department. They didn’t fit…. It seems they work on OD not ID as we do. So my O rings were 2 mm under size. Despite trying to stretch them a little the friction was too great so my Lowne is still running with the short length of twisted PTFE rope for the stuffing gland. I will post some video of the nearly completed restoration soon. I’m still waiting for vital information on the water tank top.

Whilst incapacitated I have been delving deeper into the Lowne history. It seems that the first patent may have been granted around 1859/61. I’m attaching some period advertising and a photo of the Hardy and Padmore vacuum engine that was built from the latter part of the 1890’s. Only 3 survive in preservation.

   Graham.

[Jasonb]

Imperial are sized by OD and metric by ID

I do prefer the look of that one to the horizontal

[Alyn Foundry]

The piston is bang on 37 mm Jason. So I ordered 37 x 1 mm to fit the bore of the gland @ 39 mm.

I agree with you that the older version is much nicer looking but unusually over complicated for what it does.

Edit…. Or are you referring to the Hardy and Padmore version?

   Graham.

[Alyn Foundry]

Have an “ ATMOSPHERIC “ Christmas.

<a href="https://www.youtube.com/watch?v=RUkslYmSE_0" target="_blank">http://www.youtube.com/watch?v=RUkslYmSE_0</a>

Now almost finished with just the cover for the water tank to go. Due to there being so few of these engines around I don’t know how the cover is made.

   Graham.

[Jo]

<a href="https://www.youtube.com/watch?v=RUkslYmSE_0" target="_blank">http://www.youtube.com/watch?v=RUkslYmSE_0</a>

[Alyn Foundry]

Thanks Jo….

One to many   

LOL

Have a great day. Graham.

[Jo]

Runs nicely Graham 

Good idea 

Jo

[Dave Otto]

Yes, you do have it ticking over nicely!

Dave
 

[Admiral_dk]

Runs and sounds really nice       

Per

[Kim]

Great running atmospheric engine, Graham!  Thanks for sharing the video with is! 

Kim

[Zephyrin]

well restored engine, runs as a new one !
still with the teflon "ring" ?

[Alyn Foundry]

Thanks to you all for the comments. 

Zephyrin, yes just a simple thin rope made from twisted PTFE tape wound around the piston for three turns or so. The engine is lubricated with a light machine oil.

Just as a side note, many years ago I used to use the famous Three in one oil for bedding in my engines. I soon discovered that it was actually wearing out the piston rings and cylinder bores. I’m not sure if it contained a fine abrasive but it certainly accelerated the wear and the used engine oil would show with a charcoal Grey colour that sparkled in the light.

As previously stated the only finishing touch is the cooling tank cover. I can see traces of soft solder along all four sides of the top inner edges. You can see from the attached photos that there’s a rather ornate Copper opening. I would like to think that this can be rotated to provide a larger opening for filling but the only other single cylinder version’s top cover was also missing. The owner of the twin cylinder engine, with original top, doesn’t want to touch it for fear of damaging the paintwork which is quite understandable. The last picture is of another twin but has been user modified to provide the cylinder seals with water vapour.

   Graham.

[Alyn Foundry]

Now here’s a question for the “ technical “ folks….

With both the Lowne built and Hardy and Padmore built engines the piston is sealed at the entrance of the cylinder. Effectively the piston floats around inside the bore. Being horizontal the Lowne built engine has a small Steel plate that gently rub’s along the bottom of it. ( cylinder )

Is there a greater surface area presented for atmospheric pressure to do work with or merely just the the front face of the piston, as in most other types? I have been pondering this question since I got the engine. The reason I ask is because it seems to have a much greater power than expected.

   Graham.

[Jasonb]

Not sure but any vacuum on the side of the piston is not going to suck it back into the cylinder in the same way sucking on the end would and possible cancelled out by any vacuum on the opposite side of the piston.

[Zephyrin]

I would say that this large increase in surface of the piston is expected to augment heat exchange during the cycle, deeper cooling of the air inside leading to a deeper vacuum.

[Alyn Foundry]

It’s me again….

I have recently acquired another, slightly larger RM Lowne patent atmospheric engine, ripe for restoration. More to come over the next day or so. Here’s some extra period technical information from the 1870’s

   Graham.

[Jasonb]

So how many more do you need to make it a full set of six 

What size is this one?

[Alyn Foundry]

So how many more do you need to make it a full set of six 

What size is this one?

       
( a size 3 ) Four…. That copy of the range of engines has only recently surfaced. So I now own a size 2 and a size 3.  Currently there are only  a few known survivors of both sizes in existence. I’m a very lucky man.

The one man power engine sounds like an interesting project, more down your alley than mine! Three castings, five tops and M-Machine have 3” diameter 16 gauge Brass tubing to make the pistons.  Otherwise these engines were totally fabricated from sheet Copper and miscellaneous pieces of Steel and Brass.


     Graham

[Sanjay F]

No.6 must be a beast, 3 inch cylinders and 16" flywheel!!

[vtsteam]

I realize the question of what the loose piston might do is 3 years old, but since the thread is resurrected already, I agree with Jason and Zephyrin' comments, and also think that it's possible sliding friction is reduced, or at least that might have been a motivation. Sliding friction of a piston body keeps the piston exactly aligned with the bore in a conventional engine. That's not necessary in this engine, there's wiggle room. So presumably a reduction in friction occurs both by the reduction of cylinder contact surface area, and the usual sidewall pressures generated to keep the piston straight as it is driven by the connecting rod. It's also easier to build, considering the loose fits vs the usual alternative.

[Alyn Foundry]

This last few weeks I have mainly been  relearning the skills that the multiple strokes have taken away from me.  Driving the lathe and milling machine, grinder and pillar drill. My fine motor skills are still shit but they ARE improving very slowly.

My recent acquisition, a number 3 Lowne patent Atmospheric engine has been the subject of my relearning processes….


A couple of years ago I acquired a number 2 Lowne patent atmospheric engine on eBay. The engine was incomplete missing its pushrod and port face valve flap. These little engines are quite rare but as luck would have it an old friend of mine had a number 3 motor in his possession. After several phone conversations and even more photos and measurements I was able to fabricate the missing components and get the engine to work properly again.
During our conversations my friend told me about a gentleman that had also bought a number 3 twin cylinder engine in a near complete state. Subsequent conversations revealed that it too was missing both pushrods and one of the cylinder port face flap assemblies. With The photos he shared I was able to fabricate the missing gas pipe layout for the single.
As time goes by we are all affected by life changing events. A serious health issue occurred and as a consequence the near complete Lowne engine became available to me. A deal was struck and the engine was packed into a box ready for the courier.
The following day it arrived safely on my doorstep.

I’m sure you folks can see the rather strange circular object perched precariously atop the cooling tank? This turned out to be a cylinder lubrication system fitted by a previous owner.  I’m not sure if I’ve mentioned the fact that the pistons are not a machined fit to the cylinders?  They are sealed using a crude spring loaded stuffing gland on each side. These would have used thin Leather rings,lubricated by Sperm Whale oil. The cooling tank had also been modified by sealing it up and fitting extra pipe outlets for even greater cooling capacity. This aside underneath the oil box cover I discovered nearly all the parts associated with the missing pushrod assemblies. The time had come to start upon the restoration process. The pushrods were the first to be attempted. When I tried using the one I had made for the single cylinder engine I quickly learned that I had not used the right thread. In fact several different dies were tried to no avail. The breakthrough came when I found one of the screws used to attach the gas tap to the framing fitted snugly on the locking nuts. It was Jason Ballamy that did the detective work from a photo I placed on the MEM forum. It turned out to be a gauge 10 Thury thread. The Thury system was used primarily for instrument makers of the later Victorian period and actually became the basis of the BA system still in use today. The closest equivalent ended up being a ‘ rounded off ‘ 4 BA. Having finished the first pushrod it was time to see if we could get the first signs of life out of the engine. I spent several hours adjusting the position of the arm to set the timing. It just wasn’t having anything. Only after asking Alan what the hell was I doing wrong did the answer come, ‘ it’s not you Dad it’s what someone else has done ‘ I hadn’t noticed that there were additional pivots and arms fitted to the rocking lever.  For some reason, still to be understood, the owner had added a pin that ended up putting the timing out by 180 degrees! They had even butchered the wooden plinth to accommodate the change. The modification had been well executed requiring some serious heat to break down the hard soldered joints. It took but a few moments to reset the timing and the flame applied to see her running for the first time in many, many years.
Over the next couple of weeks I started making the rest of the missing components. The surviving flap had been stood idle for so long that the Asbestos washer had welded itself to the port face. Upon close examination it was  very nicely made with a thin Copper foil backing. I decided to just remove it and make a plain Brass flap instead.
At this point the remaining missing pieces were made using the original parts as patterns. The only difference was that the RHS flap was handed in the opposite direction. A couple of flat section Neodymium magnets were used to keep each pushrod pivot in contact with the piston lever arm because the owner had cut the ends off for his/her modification. At this moment I’m not sure of which direction I should take to repair the damage. It only needs around a 1/4” of an inch of metal with a small cross drilled hole for a retaining wire and washer.

Now the engine was running on both cylinders we turned our attention to the rather ghastly looking, pissed up oil box. We initially tried to straighten it out but it was fabricated from some very thin Brass sheet and immediately distorted. Out came the small gas torch and within a few minutes the whole top collapsed in on itself. Underneath we discovered that there was a Brass pipe that was placed to ensure that the tank was filled to a certain level, the overflow situated at the front face of the engine.  We had no choice but to rebuild the top back to its original form. Before this we removed the two short pipes that had been installed for the extra cooling and soldered a couple of Copper patches over the holes.

Now finally finished my work is done.  The next step is, do I leave it like this or fully redo the paintwork?  Decisions, decisions….

<a href="https://www.youtube.com/watch?v=Zuu4n4oD0og" target="_blank">http://www.youtube.com/watch?v=Zuu4n4oD0og</a>

<a href="https://www.youtube.com/watch?v=E5hjyPixo6Q" target="_blank">http://www.youtube.com/watch?v=E5hjyPixo6Q</a>

<a href="https://www.youtube.com/watch?v=tEtTVwNS9Hw" target="_blank">http://www.youtube.com/watch?v=tEtTVwNS9Hw</a>

Also attached are some photos of the Lowne before it arrived in N Wales.

   Graham.

[Admiral_dk]

Nice steady beat to it after restauration 

Per     

[Jasonb]

I think I would leave it as is rather than a new paint job. The one exception would be to get rid of the melted Mamod plastic funnel

[Sanjay F]

Very nice and the rhythm is great - I think it looks superb as is, its an old engine, shiny new paintwork may not look right?