Llewellyn Loco Works #1

[Hydrostatic Dazza]

A little parcel arrives via the post. The workshop mob gather around for a gander.



I am working with Mike in NZ on some bike frame casting prototypes and I sent him some drawings and he printed off the masters for some investment castings.
Bingo, I have some Silicon Bronze steam chest covers. (and a few spares to go to another worthy home , wink)

[Hydrostatic Dazza]

While all this is going on I am checking the valve gear. Now please do not get me wrong, Brian's books is marvelous and a great source of inspiration and information, the big difficulty I have is the valve gear and layout. The book does not provide a valve gear/motion general arrangement drawing that is correctly or fully dimensioned. The Page 37 drawing is not fully dimensioned and the 88.0mm dimension from the front of the frame to the motion bracket mounting screws does not measure correctly. It seems closer to 92.00mm. Also there is a mismatch of fits and sizes due to rounding out of metric sizes from Imperial, not earth shattering but one needs to think these out. I reverse engineered the motion bracket location from the dimensions of parts and the motion bracket and bent up slide bar, (I am going to use a separate slide bar) but I cannot confidently confirm the layout as there are assumptions to be made so one can fill in the missing dimensions. There is also some errors to be seen in the page 37 drawing but of course, these things occur and can be sorted and thought out and we move on. So I come to what I think is the valve gear layout. However my CAD model shows some bad valve events. I confirmed this via the Docstrader program/model. If I get reasonable forward events I have impossible reverse. I have heard that others have had this trouble with their Eric locos, but is all this the builder's errors ? Is it my errors ? What is required is a fully dimensioned valve and motion drawing of the necessary pin locations etc in relation to the driver centre. Of great assistance would be a simpler version of this.

Of course we do not need as much detail, just the theoretical locations and lengths of the parts. So one can reference off to see where we have drifted with our dimensions on the parts or our mistakes. The tweaks can then be from that.
I am new to the the understanding the geometry of Walschaerts motion, so the books come out and I study and read and struggle with Don Ashton's writings and Martin Evans and others. I come to the conclusion that a redesign is required. The correct radius rod length to match the expansion link radius, anchor link alterations, allowing for the valve rod inclination with the return crank setting, moving the expansion link trunnions centre. Various other tweaks. I also altered the slide valve dimensions to assist with a better mid gear setting, the combination lever will always rock the valve but the ports stay covered, along with a few other things. I devoted many evening hours to this, realising that this is all good education regards my hobby time with full size heritage steam. I loaded up my version into the CAD model and the Dockstrader program. BINGO. It all fell into place. The events and cut offs were sweet. YAY!

OK. before I get cocky, I am yet to complete this loco and steam it and thus prove the Pudding is sweet or I have made a total mess !!!!!!!!!!!!!!!!!!!!!!!!!

I am just telling it as I find things with my little choo choo journey.
I also altered/reversed the lifting arm and reverser set up so the reverser is forward in the sector plate when the valve gear is forward. (It was like this in the Edwin design) Anyhow I will let you all know if I have made a mess of this when the time comes to set the valves etc. Now I know Brian Wilson frequents garden railway forums and understand he lives 2 hours drive from me but I have no contact for him. So if Brian is out there wants to contact me, to chastise me or other wise I welcome the call. 07 3353 3368. The book is terrific and it drives me , gives me direction. I will also add, I have no commercial interest or desire to make $ from the garden railway world. It is just one aspect of my model engineering hobby. Did any of that make sense ?

[Hydrostatic Dazza]

Prototype slide valve. Gunmetal.


Rubbish slitting saw, I have tried two and they are rubbish. I have a soft 3MT blank that is destined to be made into a nice slitting saw arbor, soon!



Rough out the exhaust pockets, made a spare, final pass was .05mm climb mill.



For the valve rod I followed the words and music, 1/16" (1.585mm) stainless rod and run a new 10BA die over it. However this raises the thread diameter to 1.68mm which is close to the correct size for 10BA. The material is moved and pushed up into the die to become 1.68mm. This now will not pass down the 1/16" hole in the gland nut or the steam chest. One can fiddle the thread, knock the crests off, but that will make a sloppy fit as it screws into the valve. Slop/lost motion gives one late valve events. I ponder a solution. A valve nut with the pinch screw is my solution. It worked a treat and is very secure. It also allows the valve to lift and condensate can escape just like the bigger models.



I have stainless screws for the pinch screw when the time comes to fit up on the loco.





That is to date where I am on this journey. The parts box is filling up.



So you will not hear much from me for a while as I go back to the civil engineering part of the POR ( Potters Orchid Railway )

Cheers

[pandsrowe]

Wow!! I'm quite exhausted from reading this thread.
You really must be congratulated on the effort that you have put into this project, not least the actual photographing and recording of each stage. That alone is worthy of a 16mm Oscar (is there such a thing?).
There was me quite proud of my humble attempt of minor modifications to my Ragleth, which I was going to record on here but I don't think I'll bother now
I'm certainly looking forward to any future threads on this build.

[DLRdan]

Its rare to see that level of dedication in the larger scales let alone 16mm, I look forward to further writings. I am also going to steal that jig for cutting bolts to the same length, simple yet brilliant.

[Hydrostatic Dazza]

Wow!! I'm quite exhausted from reading this thread.
You really must be congratulated on the effort that you have put into this project, not least the actual photographing and recording of each stage. That alone is worthy of a 16mm Oscar (is there such a thing?).
There was me quite proud of my humble attempt of minor modifications to my Ragleth, which I was going to record on here but I don't think I'll bother now
I'm certainly looking forward to any future threads on this build.

Hi, I just dumped 8 months of work in one day, sorry about that, the updates will be a lot more spread out, more like one a week. I use a little Cannon IXUS camera for the pics, I have a system from my daily work where I send pics of their frame's progress
With my 32mm loco build I just save things into a folder and when motivated I load it to my flickr site.
https://www.flickr.com/photos/llewellyn ... 7760739050

For me it is important that one shares stuff, via magazines, internet, in person. I try to be a student of the world and listen to ABC Radio National (is that like BBC4 ?) all day.
In the bespoke frame building world knowledge the builders were very guarded, but that is a backward thinking attitude. This has changed via forums etc. The same with the heritage railway scene in Queensland. There was a us and them mentality. Some of us have devoted time to change that culture. It is changing but there are some crustys that will hold a grunge or beat on the drum of tribalism till they are pushing up the daisies. They are just miserable and failing sods that will take any of their valuable knowledge to the grave.
Please post your "minor modifications to my Ragleth" It all has value. Heck I have not yet completed a choo choo yet!!!!!!!!!!!!!!!!!!!!!!!!! We are all on a different point on our time line.

[Hydrostatic Dazza]

Its rare to see that level of dedication in the larger scales let alone 16mm, I look forward to further writings. I am also going to steal that jig for cutting bolts to the same length, simple yet brilliant.

From a previous ME magzine article, to me making my version, sharing the pics, then you or others making one. COOL! Then these are shared, and onwards. Almost as good as shout at the bar .........................

[Hydrostatic Dazza]

Its rare to see that level of dedication in the larger scales let alone 16mm, I look forward to further writings. I am also going to steal that jig for cutting bolts to the same length, simple yet brilliant.

From a previous ME magzine article, to me making my version, sharing the pics, then you or others making one. COOL! Then these are shared, and onwards. Almost as good as a shout at the pub .........................

[ge_rik]

Hi Darrell
I'm finding this thread fascinating. I'm not into metalwork myself and am not really a live steam enthusiast, but your detailed report has made me really interested in the progress of your loco.

Just a quick question - as you are starting literally from scratch, did you consider incorporating a flywheel device (similar to Slomo) at some point in the design? I'm assuming it would be easier to design and fit one from the ground up rather than having to retro-fit.

Rik
PS - I'm with you completely re using the web to share information, ideas and experience. In my own small way, I have been trying to do this with my blog for the past ten years
PPS - Like you, I have BBC R4 on almost continuously during the day. A lot of the time it's just murmuring in the background but when something interesting comes on my attention switches to it. I find talk radio is great as a background when doing something practical. I also have it on via headphones when playing trains in the garden.

[Hydrostatic Dazza]

Hi Darrell
I'm finding this thread fascinating. I'm not into metalwork myself and am not really a live steam enthusiast, but your detailed report has made me really interested in the progress of your loco.

Just a quick question - as you are starting literally from scratch, did you consider incorporating a flywheel device (similar to Slomo) at some point in the design? I'm assuming it would be easier to design and fit one from the ground up rather than having to retro-fit.

Rik
PS - I'm with you completely re using the web to share information, ideas and experience. In my own small way, I have been trying to do this with my blog for the past ten years
PPS - Like you, I have BBC R4 on almost continuously during the day. A lot of the time it's just murmuring in the background but when something interesting comes on my attention switches to it. I find talk radio is great as a background when doing something practical. I also have it on via headphones when playing trains in the garden.

Hi Rik, at this time I have not given any thought to a Slomo type flywheel, this is only due to my ignorance and thus only just recently gaining any hint that they exist. My wheels are on and quartered so if I have to retro fit I am reluctant to break the axle/wheel bond. Also there is a pump eccentric and then the pump itself and an ash pan for it to fit around. I have no drawings or any thing similar and or actually seen one. However I am convinced. From age 12 I likes see models move at walking speed. We used to try and time how long we could take to get to one end of my HO layout to the other end. Looking at the videos of steamers with them fitted, has me no doubt, every streamer should have them fitted. So it looks like I will be getting a tender mounted one. As I have not settled on the tank/body work yet, it looks like my little loco is going to have a tender. Looks like I will be buying a Slomo some time soon from a fellow Aussie.

[Hydrostatic Dazza]

Hi Darrell
I'm finding this thread fascinating. I'm not into metalwork myself and am not really a live steam enthusiast, but your detailed report has made me really interested in the progress of your loco.

Just a quick question - as you are starting literally from scratch, did you consider incorporating a flywheel device (similar to Slomo) at some point in the design? I'm assuming it would be easier to design and fit one from the ground up rather than having to retro-fit.

Rik
PS - I'm with you completely re using the web to share information, ideas and experience. In my own small way, I have been trying to do this with my blog for the past ten years
PPS - Like you, I have BBC R4 on almost continuously during the day. A lot of the time it's just murmuring in the background but when something interesting comes on my attention switches to it. I find talk radio is great as a background when doing something practical. I also have it on via headphones when playing trains in the garden.

also Rik, if my loco works out as a good runner and looks reasonable, I can throw the drawings your way, even if you do not have the 3D program, I have each individual part printed off on A4 and can convert them to PDF for any one. Simple but it does make for a box full of drawings. (I am not a fan of multiple parts on one sheet, I like taking one sheet to the Red Room and scribbling all over it and when the part is completed, updating the master 3D part and 3D assembly and the 2D sheet ) But first I must prove the design modifications and prove the build. This may take a year or two more.

[Hydrostatic Dazza]

Due to constant rain interrupting the civil engineering contractors at the POR the energies were turned to the Red Room and to knock over a project that has been on the bench for a while. ER25 Collet chuck mated with a machined register on a D3 backing plate for the Myford. First time I have ever done some thing like this, the result was as good as hoped. Next will be a better slitting saw for the mill/drill, I have two commercial ones but they are rubbish and wobble all over the place. I have a blank 3MT arbor and a 3 to 4 MT sleeve so it will machined in the Myford. Keen to get back to completing the cylinders soon.

[Hydrostatic Dazza]

Rain all day Saturday so the civil engineering gang stayed in doors on the "POR". The Red Room saw action for most of the day.
Work on the cylinders progresses.
Mike Jack sent me these covers he cast in Silicon Bronze, they were off my drawings and these are the start of the education and processes of using many more castings from my drawings in the future.
I gave them a wee bit of attention with some 600 grit



Then a wee careful mill to get a clean face.



The lads, they look a bit rough and untrustworthy, but they have redeemed them selves from their past and they do good work. The air is bit blue with their language when things do not go quiet right but they figured out a little jiggy for the cover and chest drilling. (jiggy is a Dazza technical term)



The 7.20mm drill is align the steam chest to the cylinder and the frame mounting face. (I like using a datum) Even though I have DRO I carefully marked out the sanity lines, just be to be sure (I am glad I did)



The clamp on the jig is removed and the chest and cover removed but the clever bit is that the cylinder stays held in the vice and the location for the X= 0 and Y=0 stays undisturbed.
Done and happy. You may see that one hole for the 10BA studd to pass through is in a different location, that is give clearance for the inlet to the chest. A detail that is visible on close inspection not noted or dimensioned in the Steam Trains In Your Garden Book's drawings or text.



When the next adventure in the Red Room kicks off I will use the DRO to pick up the holes to be drilled 3.50mm deep and taped 10BA for the studs. Have I said recently how much I like DRO on the mill/drill ?

[Hydrostatic Dazza]

Chest stud hole drilled and taped 10BA, ports drilled. Have I mentioned lately how much I like DRO ?



Passage way drilling



nailed it to the bull's eye, tis was a happy chappy when I finished on Saturday evening

[Hydrostatic Dazza]

There has been a death in the family.
For 30 years this was my go to good vernier caliper. It was cared for and loved and used for many projects. Made by NSK in Japan.
Yesterday its mechanism went belly up.
It lived a good and useful life. It gave me great value.



Ebay, New Mitutoyo Dial 200mm for $75 inc inc postage. Beats $230 from the local supplier. Think of all the beer that $155 will buy

[tom_tom_go]

At least it was supplied with a suitable coffin.

[Hydrostatic Dazza]

New toy, took a bit to get all spinning true and dialed. Assemble and disassemble a few times but all clocked to .02 over 150mm spinning etc. At least till the high spots wear off in the chuck. Still not bad for under $500.









Mill the last two sides and the profile. Aimed for 26mm

[Hydrostatic Dazza]

Not a lot of action in the Red Room due to track laying at the Potters Orchid Railway, however rain is about, the weeds are zooming with growth, but this week with a day night second Test I will enjoy some evenings making some parts. I made a start on the cylinder drains, but first I needed a thinner blade to clean off the thread runout on BA threads to a shoulder, so I got 1/16 parting blade, a bit of grinding, rub over and I had it down to .85mm. PB and 6BA and all went well. I am modifying the drain design, I am not keen on the drains blowing directly downwards and blasting grot all over the undersides of the loco and motion , so I added a 1.00mm to the body and cross drilling so they exhaust to the side.

[Hydrostatic Dazza]

Making cylinder drains as per Brain Wilson's words and music but for the sideways exhaust.





Meanwhile the English batting wobbled, then the Aussie batting wobbled under lights with the new ball, but we have plenty on runs in the bag. Nathon Lyon continues to be the Aussie national folk hero. What a catch!

[Hydrostatic Dazza]

Whaoooo, the Aussie batting wobbled under lights with the new ball in Anderson's hand.
Calm, we will get the remaining wickets to today for the win. We have the Lyon!
All this was happening as I drilled the 1.20mm cross passages using the collet chuck for the first time. This was to hold the small drills with no measurable run out and with that I am very pleased. Of course, there are no drawings of the linkages to the cab so that I have to sort out soon. To fit the servos in etc.



I am pleased with the out come, I will give them a touch up with the files off to break the edges. The drains will now exhaust to the side so this will be handy to scare off grass hoppers and spiders etc.



As I was doing this, test cricket is on the radio and MAM was priming her Lady Ann frames.