Author Topic: RLE Last & First  (Read 3352 times)

Offline Chipswitheverything

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Re: RLE Last & First
« Reply #15 on: November 30, 2023, 09:21:09 AM »
Nice work on the gears and cam, Jason, and customary super detailed photos.  Presumably you keep some sets, or part sets, of DP gear tooth cutters of various sizes as part of your tooling store?..   Dave

Offline Jasonb

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Re: RLE Last & First
« Reply #16 on: November 30, 2023, 01:21:32 PM »
« Last Edit: November 30, 2023, 01:25:47 PM by Jasonb »

Offline Alyn Foundry

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Re: RLE Last & First
« Reply #17 on: November 30, 2023, 06:09:40 PM »
Sadly weíre hampering Jasonís progress as our new foundry is having difficulties with the flywheel pattern. Virtually every foundry has their own box/flask system for plated patterns. Our plates donít fitÖ.

Needless to say Iím indebted to both Jason and Colin ( Twizseven ) for their help in upgrading and replacing the stolen patterns with some very nicely 3D printed versions.

 :cheers:  Graham.

Offline Jasonb

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Re: RLE Last & First
« Reply #18 on: November 30, 2023, 06:13:28 PM »
Is it worth going down the new flywheel pattern route and then either have them as unplated which they seem to get done or stick them onto new plates of the right size.

Could add some nice bosses to three of the spokes for a pully at the same time.

Offline Jasonb

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Re: RLE Last & First
« Reply #19 on: December 10, 2023, 08:11:46 PM »
The rocker arm pivot is supplied as a casting but if used for the reversed valve layout does not put the pivot very centrally in the rocker arm so I spent a while studying the casting and working out a cunning plan that would still allow the casting to be used but shift the pivot point nearer to the valve.

The first job was to just take enough off the casting to remove the draft angles on the two edges that will mount to the head and also set these at 90 degrees to each other so I had a datum to work with.





I also skimmed the draft off around the pivot so that I could get a decent grip of the casting to bring it to thickness.





The casting was offered up to the head and a line scribed to mark where the mating area stopped and a ball nosed cutter used to tidy up that area to the line



Then it was out with the Sharpies to refine the shape, I left as much material as possible on the face that was machined earlier which moved the pivot point further from the head so the green pen marks where the opposite edge needs the excess material removed and the red shows where the screws will go to mount it to the head.



Drilling and reaming 3mm for the pivot pin



Then rounding around the pin hole on the rotary table



Last bit of machining for now was the slot for the rocker arm.



Finally the bracket in place, I have removed a bit of material from the head so it matches the depth of the bracket. After test running it will be bonded on and filleted with JB Weld so that it looks like an integral part of the head casting. redges will also be eased to make it look like a casting. There is still work to be done where the push rod goes but more of that later



« Last Edit: December 10, 2023, 08:15:50 PM by Jasonb »

Offline Jasonb

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Re: RLE Last & First
« Reply #20 on: December 18, 2023, 07:03:43 PM »
Continuing with things up at the head end the valves were done in my usual way by putting a small ctr drill hole into some 303 stainless bar so the stock could be supported with the revolving ctr and a DCGT insert used as it can get in nice and close.



A 2mm dia insert was used to form a fillet where the stem meets the head and also to cut the 45deg seat.



While the valves were still part of the bar stock I used that as a handle to give them a quick lap with some 600grit silicon carbide powder and oil.



They were then saw off and held in a collet to face the head and then fitted from the back of the collet so the ctr drill hole on the stem could be turned away.



The rocker arm was cut to my new shape to allow for the inlet valve to be closest to the push rod, the curve allowing it to reach over that to the exhaust.



While I had the CNC going I also did the gocernor latch arm and the cam follower which also had two holes tapped for the latch.





All three parts went back into the manual mill to have the excess holding material milled away



The cam follower was drilled to take a spigot that will be formed on the end of the push rod



The latch arm was thinned down either side for looks more than anything



Lastly the under cut of the latch was machined using a flycutter with a suitably ground HSS bit



The reduced thickness could then be slotted and CSK for screws with enough length to the slot so it's position can be adjusted.


Offline Jasonb

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Re: RLE Last & First
« Reply #21 on: December 23, 2023, 04:36:38 PM »
I decided that I would like a square push rod on my engine rather than the round one shown on the original drawings so a length of 4mm keysteel was ordered. A spigot turned on one end so that the bronze cam follower could be Loctited to it and the other end was drilled and tapped to take a small threaded adjuster. Rather than fiddle about with a small part in the 4 jaw I just drilled a bit of aluminium to the across corners distance of the rod and after sawing a slot down the side used that as a split bush.



The engine was screwed to the machining plate once again and clocked in true before finding it's horizontal ctr line.



I slipped the cam gear and it's pivot into place and touched off on the side of the gear then zeroed the DRO. I could then set my other heights relative to that.



I could then mill off the excess from the cylinder mounting flange and the rocker pivot bracket followed by a 4x4 slot for the rod to run in.



A few M2 tapped holes for the retaining blocks completed the work that needed to be done in that setup.



The two retaining blocks were just suared up from some off cuts of brass, drilled for bolts and a small ctr drilled hole added for a drop of oil to be applied. I knocked the corners off after the photo with a small file so that they looked like cast blocks.






Offline Jasonb

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Re: RLE Last & First
« Reply #22 on: February 11, 2024, 04:21:45 PM »
Another thing I wanted to add to my RLE was a pulley on the non governor side. I will modify the spokes of the cast flywheel to allow one to be fitted but while waiting for those decided to make the pulley.

I have quite a few 5kg cast weights from a multi-gym and although it is not the best cast iron in the world I thought it would do for this job. I piece was cut from one of the weights with my Femi bandsaw and then held in the 4-jaw to get it to the basic shape, here the inside has been turned with a 3degree "draft" to the edge and an insert with 0.8mm radius was used to leave a fillet between the inner edge and what will be the mounting lugs for that cast look.



I then held it the other way round in the 3-jaw and machined off the remaining corners before transfering to the Cuts Nice Curves (CNC) machine to shape the mounting lugs and drill their holes.



I probably should have gone 1mm lower with the profile cut as the "step" that can be seen is the fillet left from using the 0.8mm radius cutter.



It was not a problem as I had intended to go over the inner "cast" surface with the Dremel to texture it a bit so did the remaining fillet at the same time.



I wonder what is hiding in the other bits of that weight :thinking:



<a href="https://www.youtube.com/watch?v=YghxCw-0vu8" target="_blank">http://www.youtube.com/watch?v=YghxCw-0vu8</a>


Offline Jasonb

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Re: RLE Last & First
« Reply #23 on: February 22, 2024, 10:42:39 AM »
The two flywheels arrived at the beginning of the week, they did look a bit rough and had a fair amount of thin flash so the first thing I did was to take a small cross pein hammer and carefully chip the flash off. This shows the one on the right after chipping and the left as delivered.



I then fettled the flywheel, I like to do this before any machining a sit saves marking the finish turned rim if you intend to leave that bright. It was mostly done with files and then a quick tickle with the Dremel equipped with a grinding bit, again one on the right has been fettled. There is a little more to do between the spokes where they meet the hub.



Where possible I like to hold flywheels by the inside face of the rim and get that to run true as it is not  a surface that is going to be machined, this is another reason to clean them up first. With the 3-jaw's jaws reversed it fitted easily and was just tapped on the side until it ran with minimal wobble.


My machining sequence was:

Rim OD, Rim Side both these done with CCGT inserts using the holders that make use of the two "spare" corners.

I then changed to a boring bar with 0.8mm corner radius CCGT insert and flattened off the side of the inner rim, this ended up 1.75mm below the side face of the rim.

The hub was then faced, spot drilled, drilled 6mm with a stub length drill, opened out to 9mm and then a boring bar used to take it out to final 10mm dia using the crankshaft material as a plug gauge to get the fit right which is tighter than a nominal 10mm reamer gives.

Lastly change to a brazed tip tool with 1.5mm nose radius, set the topslide to a few degrees and clean up the OD of the hub. Knock off all corners with Lathe file.



To do the other side I changed to the 4-jaw and got the flywheel OD running true before machining Rim side, recessed side, hub face, hub OD.



With two done it was time for a trial fit


Offline Jasonb

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Re: RLE Last & First
« Reply #24 on: February 23, 2024, 06:37:08 PM »
I needed a way to mount the belt pulley described a couple of posts previously so clamped the non governor side flywheel to the mill table and located it's centre and ensured two opposite spokes were along the Y axis. The DRO made quick work of spotting, drilling and tapping the three holes at 120deg spacing and then I went round again with a 3-flute milling cutter to form a counterbore.



Some short lengths of 10mm steel were drilled M3 clearance and then bonded into the counterbores with JBWeld and left to set for 48hrs.



Once set the flywheel went back into the 4-jaw on the lathe to have the three bosses machined to length and also a small step turned that would locate the ID of the pulley.



and with the Pulley in place.



J

PS If you buy one of those Alyn Foundry stickers that can be seen bottom right of the last photo they give you a set of castings free. Stickers are not cheap though:LittleDevil:

Offline kuhncw

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Re: RLE Last & First
« Reply #25 on: February 24, 2024, 12:15:54 AM »
Nice work, Jason.  I attach pulleys to flywheel spokes also, but my spacers are loose.  Thanks for the hint to hold them in place with JB Weld. 

Chuck

Offline Jasonb

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Re: RLE Last & First
« Reply #26 on: April 09, 2024, 07:17:58 PM »
I was not that keen on the look of the governor weights as shown on the drawing which replicate the old Gramaphone governor weights that Graham used on his original nore the bent metal bracket that swing on. So I drew something up along the lines of what I did on the 1/5th scale vertical IHC Famous many moons ago.

The bracket was fabricated from two pieces, first a flat plate that will fit around the crankshaft and attach to the inner face of the flywheel hub with screws.



To keep the clevises at each end lined up they were machined from one piece that then had the central section machined away after silver soldering.





I neglected to take a photo of the actual weights but they were turned from 8mm rod having a taper at each end which was blended into a parallel central section and then flat tongues milled at the extremities for  the springs and adjusters. 4mm rod was soldered to these and at the other end of the rods were the blocks with the pivot holes and fingers that locate in the spool, first photo shows these pivot/fingers being machined



Add a couple of pivot pins and these are the main governor parts



The adjusters were turned from 4mm rod down to 2mm and threaded before milling the head flat, cross drilling for the spring and rounding over once they had been cut from the parent bar. The spring draw provided a couple of suitable springs that were cut to length and the ends bent into loops with two pairs of long nosed pliers.








Offline Alyn Foundry

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Re: RLE Last & First
« Reply #27 on: April 10, 2024, 11:54:07 AM »
Many thanks for the update on your R.L.E. engine Jason.   :ThumbsUp:

Nice to take a Ď virtual Ď trip to the workshop, something I fear will not happen here for several months to come.

 :cheers:  Graham.

Offline Jasonb

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Re: RLE Last & First
« Reply #28 on: April 10, 2024, 12:22:08 PM »
Hope it won't be too long for you.

Should have "Gassie" ready to show you in the next week or two.  ;) That should speed up your recovery and make up for not being able to get into the shop.

 

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