Author Topic: Vickers Inverted Engine  (Read 25225 times)

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Vickers Inverted Engine
« on: January 03, 2025, 08:08:04 PM »
One of the collectors on The Stuart Models FB page posted an image of his new addition a few months ago and I thought it would make a good model.



No idea if it is based on any specific full size engine or was ever offered as plans or castings but the cylinder and valve chest do have the look of Stevens Model Dockyard about them so it may have been built using one of their sets of cylinder castings. I've named it after the guy who now owns it.

As it was on the Stuart Group and there was some interest from others who may want to build it I thought I should at least include one Stuart casting. The proportions are not quite right to use both a 7" flywheel and their 2" x 1" cylinder as this engine has a larger cylinder so I drew it around the flywheel as that would probably be the harder part for people to make. First job was to put an image into Alibre and once scaled to suit the flywheel pull a few dimensions off it. This image also shows it stood against an early Stuat No10 for an idea of size, mine will be smaller. I've changed a couple of bits I did not like the look of but it is basically the same.



Over a couple of evenings the various parts were drawn up and assembled, had to spend quite  awhile playing with conrod length and cross head guide spacing to make sure the two did not clash but I'm quite happy with the way it looks. I will probably make my own flywheel but the image is with a Stuart one. All metric as is now my norm.



I made a start on the four panels for the base. The usual practice would be to bend up half round beading and fix around the openings. However 1mm radius beading is not available although not hard to make your own and it also has a tendancy to curl up when you want to to lay flat around a curve. Also the beading was set back only 0.5mm from the edge of the openings. After a bit of thought I came up with a cunning plan. Rather than use half round beading I thought I would try milling a 2mm wide x 1mm deep slot and simply solder some 2mm dia brass wire into the slot.

The four plates were sized on the manual mill and then over to the Cuts Nice Curves machine to do the slots and cut out the arched hole.



I use 4 or 5 tabs to retain the waste material rather than risk it coming loose and damaging the cutter or work, they are only 0.75mm high at the peaks so easily sawn through and tidied up with a file.



After straightening a length of the 2mm brass wire I filed one end to 45deg for the mitre joint, clamped that end into the slot and it was then easy to push the wire down into the slot with one hand as the other guided it around the arch and back down the other side. Marke and miter the end then just a straight length for the bottom.



A bit of flux and some soft solder fixed it all together then a quick cleanup of the small amount of excess solder and they are ready for the "key stones"




Offline crueby

  • Full Member
  • *****
  • Posts: 22697
  • Rochester NY
Re: Vickers Inverted Engine
« Reply #1 on: January 03, 2025, 08:37:23 PM »
Great proportions  on that model!  I really like how you put the wire in the slot around the openings  to form the moulding, neat trick!   :popcorn:

Offline pirmin

  • Full Member
  • ****
  • Posts: 203
Re: Vickers Inverted Engine
« Reply #2 on: January 03, 2025, 08:47:08 PM »
Beautiful job on those Window Portals ! Good Looking design !

Offline Michael S.

  • Full Member
  • ****
  • Posts: 1983
  • Germany, Magdeburg
Re: Vickers Inverted Engine
« Reply #3 on: January 03, 2025, 09:12:03 PM »
You have good ideas 💡!
An interesting engine.

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 5237
  • Boise, Idaho USA
    • Photo Bucket
Re: Vickers Inverted Engine
« Reply #4 on: January 04, 2025, 12:29:16 AM »
Lots of detail on that one and you are off to making a nice model of it!

Dave

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #5 on: January 04, 2025, 01:24:41 AM »
I only just figured the Cuts Nice Curves comment!  ;D

I always think about getting one, especially when I can see what amazing things can be done, but I'm not far enough along my current journey with a lathe and mill to be venturing into pastures new. I've seen a few articles on converting manual mills to CNC.

Anyway, forgetting all that, the project looks great, the engine looks tall and elegant and I'll be following along  :popcorn:
Best regards

Sanjay

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #6 on: January 04, 2025, 07:37:25 AM »
Thanks for the interest. It should make a nice model and a reasonable size at 350mm tall.

I know some have gone over almost exclusively to CNC but I just tend to treat it as another tool and if it is the best one for the job will use it so don't rush to get one. The smaller end panels could have been done on a rotary table and even the wider ones could have had the arch filed and the bead thinned to half thickness for the arch with the straight bits done in the groove.

There will be a few parts that make use of the CNC on this but all could be done in other ways depending on what you have to hand.

Someone on ME mentioned about using the CAd assembly to check for fits, so I made this quick video of what moves where.

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

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #7 on: January 06, 2025, 12:00:50 AM »
My problem is 30 years in software and looking at a screen all day; the workshop, working things out with paper and pencil and then machining provides an escape. I have a laptop in the workshop which is there to keep me updated on the forum, machining techniques on YouTube and ordering numerous taps 'n' dies!  ;D

Never say never though ......
Best regards

Sanjay

Offline Zephyrin

  • Full Member
  • ****
  • Posts: 889
  • near Paris, France
Re: Vickers Inverted Engine
« Reply #8 on: January 06, 2025, 04:30:22 PM »
clever trick for making these beadings !
The attention you put into rendering the decorative parts of these period engines is always astonishing!

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #9 on: January 06, 2025, 06:16:01 PM »
Thanks

I used up a few scraps of brass for the keystones, first milling to overall size then with a small vice set at 5degrees milled the two tapering sides. After that a rebate wa scut so they slipped over the brass panel, there position was marked on the panel and the bit of beading underneath cut away before soldering into place.



I know they say measure twice and cut once but I measured the 14mm square steel that I had bought for the corner posts 4 times and each was 10mm too short :-[ So I cut up some cast iron and milled it to 14mm square then faced to length ond drilled it lengthways in the 4-jaw.



I milled the lengthways 3mm slots for the panels to go into then tilted the vice 0.75deg to cut the tapering sides and lastly the bead around the top was reduced by 0.5mm all round so it protruded the same 1mm from the face that the base does.



I still need to knock off all the external corners so they look more like castings but a trial fit shows it all goes together OK.



I made a start on the bottom plate. After milling to overall size the holes to attach the corner posts were drilled and a slot cut all round for the panels to just drop into.


Offline crueby

  • Full Member
  • *****
  • Posts: 22697
  • Rochester NY
Re: Vickers Inverted Engine
« Reply #10 on: January 06, 2025, 06:22:14 PM »
Those walls are spectacular!

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #11 on: January 06, 2025, 07:01:31 PM »
The milling marks on columns make it look like they are made from stone - this ones guna be a stunner!
Best regards

Sanjay

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #12 on: January 11, 2025, 06:57:16 PM »
Turning the base plate over I used a 3-Flute aluminium specific cutter to rough out the profile then a 6mm ball nose cutter again intended for alumining to form the concave part of the moulded edge. After that I changed to a TCT rounding over router bit to produce the concave lower part and quirks. All cut very cleanly, this is without any burr removal, just a brush and wipe over.



After squaring up a piece of 3/8 aluminium I cut a similar slot and holes but threaded this time in the underside like I did for the base which will locate the tops of the panels and take long studs that pass through the columns and base to hold everything together. I also drilled and counterbored for some M4 cap heads which will hold the columns and bearing pedestals in place and finally stitch drilled out some of the waste material.



As I've not used the cNC much on the last couple of engines that I have completed I decided to use that to do the work from above which consisted of:
- A facing cut all over with a 25mm 2-insert cutter to reduce the 3/8" stock down to the 8.5mm thickness that I wanted
- multiple full depth contour cut to finish the large central cut out 4mm 3-flute ali cutter
- Adaptive to remove the material around the 4 column bases leaving 0.3mm for finishing with a 6mm 3-flut ali cutter
- Horizontal to finish the lowered areas with a 4-flute 6mm cutter with 1mm radius corner to leave a fillet around the column bases
- Adaptive to rough out the eccentric clearance slot with a 4mm 3-flut ali cutter
- Same cutter to finish contour that slot
- Same cutter again to do the 8mm dia x 2mm deep counter bores to positively locate the column ends.

Finish is better than it looks as the light has made the tool marks look like they are rough but you can't feel anything.



Then back to the manual mill armed with a flycutter and freehand ground HSS bit to do the flat Ovolo moulding around the top edge, not the best photo.



Then a cove cut to the underside with a wood router corebox bit.



I've made a start on the columns, just turning the bottom spigots and drilling and tapping the screw hole in the bottom.



The milled finish looks as it is in this photo without the light reflecting on the machining marks.

« Last Edit: January 11, 2025, 07:08:00 PM by Jasonb »

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #13 on: January 11, 2025, 07:38:54 PM »
Great progress.... the base edge profile looks like a picture frame.... amazing!  :ThumbsUp:
Best regards

Sanjay

Offline PaulR

  • Full Member
  • ****
  • Posts: 1221
  • Staffordshire, UK
Re: Vickers Inverted Engine
« Reply #14 on: January 11, 2025, 08:13:32 PM »
Great progress.... the base edge profile looks like a picture frame.... amazing!  :ThumbsUp:
Looks like a fireplace to me!

Offline Michael S.

  • Full Member
  • ****
  • Posts: 1983
  • Germany, Magdeburg
Re: Vickers Inverted Engine
« Reply #15 on: January 11, 2025, 09:26:14 PM »
Excellent finishes!
It looks absolutely good.

Michael

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #16 on: January 18, 2025, 07:03:33 PM »
Thanks.

Next job working my way up the engine were the columns. As with other engines to save materials I opted to machine spigots at either end to locate the bases and capitals which were machined separately. I could then hold the 12mm diameter steel by the bottom spigot and with a boring head offset in the tailstock the taper and mouldings could be turned.



The bases and 2 part capitals were fairly straightforward with a mix of form tools and files to create the mouldings on the end of a bar before parting off and repeating the process. The squares were cut from the waste material out of the base end plate arches.



After glueing the bits together with epoxy and allowing a day to set the columns were all machined to one setting ensuring they all came out the same overall length.



An old aluminium casting was machined up to 7mm thick and to the overall sizes on the manual mill before transferring to the CNC. I used that to form the four raised bosses for the column nuts, to bore the large 39mm dia hole and also drill the other various 3, 4 and 5mm holes.



Then back to the manual mill to cut the coved detail to the underside of the edges



A 7mm hex was milled onto the end of a piece of 8mm dia round and then a form tool from a previous job was repurposed to form the acorn nuts which were then sawn off, faced and tapped M4.



Starting to look more like an engine.






Offline crueby

  • Full Member
  • *****
  • Posts: 22697
  • Rochester NY
Re: Vickers Inverted Engine
« Reply #17 on: January 18, 2025, 08:36:02 PM »
Beauty!   :popcorn:

Offline Michael S.

  • Full Member
  • ****
  • Posts: 1983
  • Germany, Magdeburg
Re: Vickers Inverted Engine
« Reply #18 on: January 18, 2025, 08:57:45 PM »
A temple for a steam engine! It looks perfect!

Michael

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #19 on: January 26, 2025, 06:30:41 PM »
I was in two minds whether to fabricate the cylinder from Brass and Bronze using silver solder to hold it together or to JB Weld fewer pieces of cast iron. In the end the cast iron option was the one I went for.

A piece of 50mm bar was roughed out externally, faced and then bored to 30mm diameter.



I then used a parting and grooving tool to set out the position and depth of the various diameters that would become the flanges and decorative beads.



Further cuts with this tool removed most of the waste material and also cut the 1mm x 1mm step either side of the beads.



I then made a form tool from silver steel to form the 2mm radius beads around the cylinder.



A round nose tool took care of the stepped fillets at each end to complete the turning.



With the cylinder held horizontally a flat was machined to locate the central port face and also two blocks that would form the steam passages to each end of the cylinder which you can see sitting in place.



The inner face of these blocks and that of the port plock were milled out to form the passages and some further work done on the port block to form the undercuts and the exhaust boss. These were all then bonded into the slot with JB Weld and given 48hrs to set.



The port face could then be skimmed flat, the ports milled with a 2mm dia cutter and the stud holes drilled and tapped.



Each end had it's pattern of holes drilled and tapped and a notch was milled to link the passages to the cylinder.



Offline scc

  • Full Member
  • ****
  • Posts: 1143
  • Lancashire, UK
Re: Vickers Inverted Engine
« Reply #20 on: January 26, 2025, 06:55:09 PM »
Lovely  :ThumbsUp: :popcorn:     Terry

Offline pirmin

  • Full Member
  • ****
  • Posts: 203
Re: Vickers Inverted Engine
« Reply #21 on: January 26, 2025, 07:19:05 PM »
Beautiful Cylinder jason ! I am sure you get this engine done before my Upper Casting is safed :facepalm:

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #22 on: January 26, 2025, 07:43:16 PM »
Looks like a cast cylinder, only better! I've never seen one of those round nose tools before, that certainly makes the finished look in my opinion  :ThumbsUp:
Best regards

Sanjay

Offline Chipswitheverything

  • Full Member
  • ****
  • Posts: 715
Re: Vickers Inverted Engine
« Reply #23 on: January 27, 2025, 09:23:52 AM »
Just caught up with your amazing fast-track build of this interesting engine:  the elaborate moulded base looks terrific, and features some ingenious practical solutions. And has a crispness of detailing that no small castings could approach, even with considerable fettling and re-working.  A very interesting build log, thanks.  Dave

Offline Michael S.

  • Full Member
  • ****
  • Posts: 1983
  • Germany, Magdeburg
Re: Vickers Inverted Engine
« Reply #24 on: January 27, 2025, 12:38:57 PM »
The cylinder looks absolutely good. A good example of how it can be put together from several parts. And I have never seen tools from Škoda! I only know cars or steam locomotives.

Michael

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #25 on: February 01, 2025, 06:40:02 PM »
Thanks for the comments from those following along.

With the cylinder complete the various bits that fit to it were next.

The lower cover is fairly straightforward turning, it is a bit thicker than your usual cylinder cover as there is an 8mm thick boss on the bottom which locates in the large hole in the entablature.





The top side just has the usual shallow spigot to locate the cylinder and was reamed 5mm for the piston rod



Some holes finish that part off, the two tapped holes in the thicker section are to take the crosshead rod guides



A quick modification of my beading tool by grinding one edge to 45degrees allowed it to be used to form the 4mm balls on the ends of the 5mm guide rods.



The top cover is rather busy with a lot of fine moulded detail to the "cast" part



The main turning was done on the lathe but rather than fiddle about with small form tools to turn the detail I used the rotary table to rotate the cover while I used various milling cutters to form the shapes including a 6mm dia bull m=nose cutter with 1mm convex corner and a 1.5mm radius corner rounding cutter.



The valve chest and it's cover are much the same as any other just being rectangular bits of cast iron with some holes drilled in them.



A couple of minutes each on the CNC had the elliptical boss and gland shaped on the end of the chest and a decorative recess in the cover.




Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #26 on: February 01, 2025, 10:49:09 PM »
Those ellipitical glands look perfect, both the valve chest and brass part - are they machined together?

I need to make a similar shaped exhaust flange for the engine I'm working on; pencil, paper, some round stock and a file unless theres a clever way of making ellipitical shapes using a rotary table??
.
Best regards

Sanjay

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #27 on: February 02, 2025, 07:25:16 AM »
Yes i did them together.

There are several options, rotary table, boring head, jig on the lathe. The later two require some filing of the small radius at each end

Though are the Centaur ones actually elliptical or a flattened diamond with rounded corners? In which case the rotary table can be used.

Post a photo of the mating surface in your thread and we can take it from there.

Offline gbritnell

  • Full Member
  • *****
  • Posts: 2636
Re: Vickers Inverted Engine
« Reply #28 on: February 02, 2025, 01:28:51 PM »
Beautiful work Jason! The cylinder looks like the one on my Mary beam engine. Elegant looking engine!
Talent unshared is talent wasted.

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #29 on: February 02, 2025, 09:49:59 PM »
Yes i did them together.

There are several options, rotary table, boring head, jig on the lathe. The later two require some filing of the small radius at each end

Though are the Centaur ones actually elliptical or a flattened diamond with rounded corners? In which case the rotary table can be used.

Post a photo of the mating surface in your thread and we can take it from there.

Yes, will do, thanks - once I have have overcome the current issues  :)
Best regards

Sanjay

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #30 on: February 09, 2025, 05:10:22 PM »
Onwards and downwards to the bearing pedestals.

I started by milling some 6082 Aluminium into rectangular blocks, tapped the bottom halves M4 and drilled the tops 4.0mm. These were then screwed to a scrap block on the CNC to cut the oval shape.

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

The pedestals have an arched shape on the side, I replicated this by JB Welding on some rectangles of 1mm aluminium to the bottom halves and some arched shaped pieces cut on the CNC to the tops. Once the JBW had set the pedestals were screwed together and drilled & reamed



The bronze bearings were basic turning and boring



The crankshaft has an offset on one side so I made the webs for the built up construction two different thicknesses which were drilled & reamed on the manual mill. I then used the holes with some top hat bushes to secure them to a scrap piece and let the CNC cut the dog bone profile.



The web with the offset had the waste cut away with a hacksaw and was then held on a mandrel to round the remaining metal to match the CNC'd shape



The pin and rod were 10mm PGMS and it was all stuck together with Loctite 648 and left overnight.



The unwanted piece of shaft was sawn out and the faces filed flush.



All seems to go round and round as it should.



I then decided to do the big end. Two pieces of bronze were milled to size along with a steel bottom keep plate and drilled for the fitted bolts. capheads and nuts were used to hold the bronzes together for drilling and reaming.



Then onto the same 10mm mandrel used for the cranks to turn down each side to leave the round bosses.



Lastly the keep plate was added and a 3mm rounding over bit used to profile the sides



« Last Edit: February 09, 2025, 06:26:18 PM by Jasonb »

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 5237
  • Boise, Idaho USA
    • Photo Bucket
Re: Vickers Inverted Engine
« Reply #31 on: February 09, 2025, 05:23:44 PM »
Coming alone nicely Jason, this one is going to be stunning when completed.

Dave

Offline Michael S.

  • Full Member
  • ****
  • Posts: 1983
  • Germany, Magdeburg
Re: Vickers Inverted Engine
« Reply #32 on: February 09, 2025, 05:38:30 PM »
The crankshaft and connecting rod bearings are very nice.

Michael

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #33 on: February 09, 2025, 10:23:57 PM »
Looks as near perfect as possible, the finish is superb on all the components
Best regards

Sanjay

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #34 on: February 15, 2025, 06:50:53 PM »
Thanks for the interest.

While down at the bottom end of the engine I decided to do the eccentric and strap next. For the strap two pieces of brass were milled leaving a bit of extra material on the one for the lower half. I then milled the flats before drilling and tapping for bolts. A non ferrous cutter with 3 flutes was used cutting a full 20mm height, may as well use all of the cutting surfaces you have paid for!



The two halves were then held together with some temporary cap heads to bore the hole for the eccentric and cut the 1mm x 1mm slot to accommodate the retaining rib of the eccentric The extra bit of material on the bottom half helps stop things being distorted by the 4-jaw but I did not overtighten to be sure.



A previously used arbor was altered to be a close fit in the strap which was then clamped in place with a couple of penny washers and a screw so that the outer profile could be completed on the rotary table. A bit of file work finished it off where I could not do the full arcs due to the screw heads being in the way





A narrow parting insert was used to turn the eccentric first getting the outer spigot a nice fit in the strap and then using the same handwheel setting to do the area behind the central rib. No measuring once I got close just using the starp as my gauge.



With the material held in a square collet block it was easy to offset and ream the hole for the crankshaft and then reposition the block to drill and tap for a grub screw directly inline with the highest part of the eccentric throw which helps when setting the initial timing as you can see the angle by where the allen key is pointing



The block also ensured the balancing hole was correctly orientated on the curre cutting machine which made quick work of it using a 3mm dia cutter



Last thing was to hold it on a piece of 10mm stock and turn the boss on each side using a tip with 0.8mm radius to leave a nice looking fillet.



In hindsight I would probably leave a bit more thickness between the counterbalance hole and the outer edge as it looks a bit thin in the flesh.




Offline crueby

  • Full Member
  • *****
  • Posts: 22697
  • Rochester NY
Re: Vickers Inverted Engine
« Reply #35 on: February 15, 2025, 06:53:50 PM »
Great job on the strap!   :popcorn: :popcorn:

Offline Michael S.

  • Full Member
  • ****
  • Posts: 1983
  • Germany, Magdeburg
Re: Vickers Inverted Engine
« Reply #36 on: February 15, 2025, 09:41:20 PM »
I am very impressed. Nice!

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #37 on: February 18, 2025, 06:44:37 PM »
Thanks.

With the eccentric and its strap done the next logical part was the valve. Nothing too exciting just the usual rectangular block with a slot for the nut and another at 90degrees for the valve rod and a bit of eight reduction around the sides.



Flip it up the other way and cut the cavity with a 2mm dia cutter



A scrap of 3mm thick brass was found and three sides of the nut machined and the central hole tapped before sawing it off and milling the final edge. I find it easier to do it that way than fiddle with a small piece of material.



The clevis for the valve eccentric rod had the end turned before drilling and tapping M2.5 then over to the spin indexer to square it up and drill the hole. After sawing off and rounding the end a 2.5mm cutter formed the slot.



No photos of the valve rod but it was just a piece of stainless steel threaded M2.5 at one end for the nut and a small 1.5mm dia x 1mm long spigot turned on the other. This spigot located in a hole drilled in the edge of the "eye" to hold it in place while the two were silver soldered together. A small guide bush in the entablature stops the rod being pushed sideways by the action of the eccentric rod.



I had designed and scaled the engine to suit the generic Stuart 7" casting but decided to make my own as it keeps me out of mischief for a bit longer than just machining another cast flywheel would. As with several other engines, I started with some 203mm OD x 25mm thick wall steel tube leaving the diameter and width a bit oversize. The profile of the inner edge was done with a series of co-ordinate cuts using a 0.8mm tip radius insert in a boring bar - 22 cuts from each side. You can see the contours of these cuts best just below the boring bar.



With a piece of round bar in the toolpost to act as a tool rest a woodworking HSS scraper was used to take the tops off the contours and blend them into a smooth profile.



The 10mm bar for the spokes had a suitable concave curve cut on the end to sit closely against the profile of the rim.



Then after ctr drilling both ends the boring head was used to offset a small rotating ctr and the spokes were tapered.



The two halves of the hub were profiled in a similar way to the rim, a spigot on one locates the other and a 6mm hole allows them to be bolted together.





I then drilled 6 holes with a 6mm drill followed by plunging with a 10mm 3-flute cutter to form pockets for the other end of the spokes to locate into.



Quite a nice push fit into the holes and no spokes falling out which will mean no jigs needed for the next steps



The spokes were then machined to final length and a couple of chamfers were added as the bottoms of the pockets actually meet. I then redid the chamfers in the correct positions which should have been at the sides not top and bottom.



The rim joints were fluxed and silver soldered



Then when cooled the hub joints were done.



After a clean up it was back onto the 4-jaw to bring the slightly distorted rim to final size, skim the face of the hub and bore to fit the 10mm crankshaft



Lastly keyways were cut and a gib head key filed up from gauge plate.



Then it was time to play.

https://youtube.com/shorts/OoAvHGTUnUM?si=zeuWVTpmjVnR4a2G

« Last Edit: February 18, 2025, 06:48:44 PM by Jasonb »

Offline crueby

  • Full Member
  • *****
  • Posts: 22697
  • Rochester NY
Re: Vickers Inverted Engine
« Reply #38 on: February 18, 2025, 06:53:50 PM »
Love how you made the flywheel! The split hub is very clever too!

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #39 on: February 22, 2025, 06:47:18 PM »




Thanks, The split hub was really the only way it would go together even then I had to "spring" it all together but at least that way there are no holes through to the face of the flywheel.

With the round and round bits done it was time to get on with the bits that go up and down.

Starting with the piston this was faced and tapped M4 with a 3mm deep x 4mm dia counterbore and after turning to 0.5mm over diameter I cut the piston ring slot to the final inner diameter and width.



After cutting it off from the stock on the bandsaw I held it in my soft jaws to face to width and bore a counterbore for a lock nut.



It was then screwed onto the piston rod and the nut fitted - no need for scale looking nuts here, off the shelf plated or stainless will do. A few light cuts had it down to final size, I don't know what that is but it just "fits" the lapped cylinder bore with the right feel but probably less than  0.025mm smaller diameter.



The conrod started out as an offcut of 8mm structural Hot Rolled steel flat, milled and drilled/reamed as required with a bit of extra length on the little end for chucking.



The turning was then done in the lathe, the end thirds being tapered 1.5degrees and then all blended with files and Emery. The chucking material was then cut off, the end rounded over and a bronze bearing Loctited into place.



The cross head had all the important holes reamed while it was an easy to hold rectangle and I also milled out the pocket for the conrod at the same time.



With some packing to prevent the pocket from getting deformed it was held in the 4-jaw to turn the top spigot where the piston rod fits.



Then a couple of scalloped cuts to make it look nice.



There is still some external profiling to do on the cross head but it was far enough along for me to see if the engine would run. Just knocked up the wrist pin and retaining nut then fixed the piston rod to the crosshead with a taper pin and gave it a whiff of air at 5psi. One quick adjustment of the eyeballed eccentric position and it was off :pinkelephant:  :cartwheel:


https://youtube.com/shorts/HpOObuCh440?si=Lp8hJcYsgCm-ubGH

Just needs the piston gland, oilers and a bunch of studs making then it will be ready for paint and a wooden base.
« Last Edit: February 22, 2025, 06:51:39 PM by Jasonb »

Offline EricB

  • Full Member
  • ****
  • Posts: 308
Re: Vickers Inverted Engine
« Reply #40 on: February 22, 2025, 07:16:17 PM »
Such beautiful workmanship! :ThumbsUp:

Eric

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #41 on: February 22, 2025, 09:09:13 PM »
Looks awesome, and the motion is so smooth - fantastic workmanship as stated previously!
Best regards

Sanjay

Offline pgp001

  • Full Member
  • ****
  • Posts: 843
  • West Yorkshire - UK
Re: Vickers Inverted Engine
« Reply #42 on: February 23, 2025, 10:16:25 PM »
Jason

Just curious as to what angle of advance you ended up with between the crank and eccentric ?

Phil P

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #43 on: February 24, 2025, 07:27:11 AM »
I've played with it a bit more since that initial video and tweaked the eccentric a bit, I have a piece of soft aluminium wire under the grub screw so it can be twisted on the shaft without having to remove the strap each time. Looking at it this morning I would say it is about 5 degrees which is quite low considering I usually start with approx 25- 30deg and it is running really slow and smooth.

However this may have something to do with the eccentric though more likely I feel these things are not as critical as a lot of experts would have you think particularly for engines that will run for display. The reason for this is when drawing it up I used an existing eccentric and strap from the James Coombes but forgot to alter it to suit the ports on this engine. The JC one had 4.3mm offset, the ports required 2.3mm! So a bit of trimming of the valve's lap got it to work without the valve hitting the ends of the chest.

I was expecting to have to make a new eccentric but I'll be leaving it as is as it is a nice runner and self starts in most crank positions provided it is just past TDC/BDC

I have also run engines where the valve rod has come loose and lost a lot of movement but does not have much effect so I just don't stress over these things much and also don't use the usual way of setting the valve by watching when it uncovers the port. I just set it for equal movement each side of ctr and then set an angle on the eccentric and give it some air.

Offline pgp001

  • Full Member
  • ****
  • Posts: 843
  • West Yorkshire - UK
Re: Vickers Inverted Engine
« Reply #44 on: February 24, 2025, 09:58:14 AM »
Jason

When you say 5°, I assume you mean 95° between crank and high point of eccentric ?
I agree there seems to be a lot of waffle about having this angle set very precicely which is why I asked. I find if I set it just a tad over 90° like yours it seems to work just fine on compressed air, maybe if running on steam it might be more critical if you are looking for maximum efficency.

Nice job so far on this one by the way, it is a well proportioned good looking engine. Once painted and the cap screws replaced with studs etc, it will be a bobby dazzler.

Phil P

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #45 on: February 24, 2025, 10:11:55 AM »
Yes 90+5 as opposed to 90+30 that you often see.

I'll stick the compressor on it again later at both settings and see what we get.

I must get round to making something with a slip eccentric, over 60 engines made and I've not done one yet. In the last couple of weeks I have drawn up a 1/2 scale of a A J Weed engine which is what the P M Research #6C is said to be based on and that could probably be fitted with one. Also drawn a Stuart MTB1B to be known as the MTB 1M but it would not suit that.

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #46 on: February 24, 2025, 06:35:21 PM »
Running it on exactly the same pressure of 5-6psi and flow regulator settings having less lead allows the engine to carry over dead center at slower speed.

When I increased the angle to 90+20 it was stalling at TDC whereas with 90+5 it would run smoothly at around 35rpm.

Opening the flow regulator a bit more so it was running at around 60rpm there was no noticeable difference so I suspect the greater momentum in the flywheel was carrying it over ctr.

It may be able to run the lower angle due to the excess movement that the eccentric is giving which would see the valve opening a bit earlier than it would with a shorter throw to the eccentric.

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #47 on: February 27, 2025, 07:13:04 PM »
With the engine proven to be a runner the last remaining items could be done.

The ends of the cross head were reduced down in height and a couple of top hat bushes machined so I could screw it down to a bit of aluminium and shape the outsidewhich was done on the CNC. An adaptive pass to remove the majority of the waste leaving 0.3mm to be taken off with three contour cuts, all done at the full 12mm height.

<a href="https://www.youtube.com/watch?v=LmZZe4jkzxI" target="_blank">http://www.youtube.com/watch?v=LmZZe4jkzxI</a>

The 1mm spigots around the guide bar holes were then completed on the rotary table and a couple of buttons knocked up to shape the area around the underside of the wrist pin by file.



I'll probably bead blast this and the eccentric strap for a nice even satin finish.



Some 8mm brass was used for the oil pots, turning a spigot and threading to start with, then into the spin indexer to machine the hex. Back into the lathe to cut the waist with a rounded tool and blend into the diameter of the cup with a file. Once sawn off they were screwed into a threaded arbor and a 5mm ball nosed cutter use dto hollow out the inside.



I also made just over thirty assorted studs but not worth taking a photo of them or the couple of stubby lengths of pipe for inlet and exhaust. Time to strip and paint it now.


Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #48 on: February 27, 2025, 09:42:56 PM »
I watched all 4:15 minutes of the video - it's quite mesmerisng watching the part being formed and the finish is great. Definitely better than watching the T.V   ;D
Best regards

Sanjay

Offline Jasonb

  • Full Member
  • *****
  • Posts: 11116
  • Surrey, UK
Re: Vickers Inverted Engine
« Reply #49 on: May 02, 2025, 07:57:32 PM »
Sorry but the paint on this one seemed to take a long time to dry, or was it getting distracted by the next engine? but fear not the pics and video are finally here. It's not quite the colour I had hoped for being more cream than beige but I'm not going to repaint it now.







I went with a bead blasted finish on the bronze bits as not being a fan of too much bling quite like the satin finish that it gives.







Seems to run quite nicely with a bit of a "Chuff"

<a href="https://www.youtube.com/watch?v=SG2lHXjgl-M" target="_blank">http://www.youtube.com/watch?v=SG2lHXjgl-M</a>

Online Sanjay F

  • Full Member
  • ****
  • Posts: 1980
Re: Vickers Inverted Engine
« Reply #50 on: May 02, 2025, 08:21:01 PM »
Fantastic as usual! I actually don't mind the colour, but the sound and motion is what appeals to me most  :D :ThumbsUp:
Best regards

Sanjay

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 9441
  • Portland, Oregon, USA
Re: Vickers Inverted Engine
« Reply #51 on: May 02, 2025, 10:01:59 PM »
Very nice, Jason!  The engine is quite appealing!  :ThumbsUp: :popcorn: :popcorn:

And I love the nice, slow, smooth motion. And yes, it has a very nice chuff to it too!
Another engine, well done!
Kim

Offline crueby

  • Full Member
  • *****
  • Posts: 22697
  • Rochester NY
Re: Vickers Inverted Engine
« Reply #52 on: May 02, 2025, 10:19:45 PM »
Looks, runs, and sounds fantastic! Well done!

Offline Vixen

  • Full Member
  • *****
  • Posts: 3633
  • Hampshire UK
Re: Vickers Inverted Engine
« Reply #53 on: May 02, 2025, 10:40:30 PM »
Jason,

What a nice looking engine . Love the slow motion, so smooth.  :ThumbsUp: :ThumbsUp:



In the back of my mind, it reminds me of something else............ :noidea:

Ah!............That's it. Plate it with gold and they could use it as this years Le Mans Trophy.



Cheers

Mike
« Last Edit: May 03, 2025, 05:08:48 PM by Vixen »
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline RReid

  • Full Member
  • ****
  • Posts: 2108
  • Oregon
Re: Vickers Inverted Engine
« Reply #54 on: May 03, 2025, 02:35:54 AM »
That really is a truly fine runner, Jason. Outstanding fit and finish as well. Lovely! :ThumbsUp: :ThumbsUp:
Regards,
Ron

Offline Chipswitheverything

  • Full Member
  • ****
  • Posts: 715
Re: Vickers Inverted Engine
« Reply #55 on: May 03, 2025, 09:18:50 AM »
Lovely looking engine, the light paint finish seems to give it a surprisingly modern look, somewhat abstract in its simple geometry, I think it's quite striking. And helped by the treatment of the bronze work. Runs superbly! Dave

Offline ShopShoe

  • Full Member
  • ****
  • Posts: 506
  • Central Iowa, Central USA
Re: Vickers Inverted Engine
« Reply #56 on: May 03, 2025, 01:38:22 PM »
I can't say moe than what has already been said.

I think this one looks good and runs well. And I have to add that I like the sound as well.

I think the color becomes more beautiful as you look at it. A good break from bling, black, green, or red.

Thank You for posting the build and the completed engine.

ShopShoe

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 5237
  • Boise, Idaho USA
    • Photo Bucket
Re: Vickers Inverted Engine
« Reply #57 on: May 03, 2025, 05:08:39 PM »
Nicely done Jason!

Dave

Offline Michael S.

  • Full Member
  • ****
  • Posts: 1983
  • Germany, Magdeburg
Re: Vickers Inverted Engine
« Reply #58 on: May 03, 2025, 07:01:45 PM »
Another absolutely beautiful engine. And the paint is just right.
(Do you already have a room just for model engines, full of shelves? That adds up to quite a lot.)

Michael

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 1147
Re: Vickers Inverted Engine
« Reply #59 on: May 03, 2025, 07:02:51 PM »
Splendid  :ThumbsUp:

Andy

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal