Building a Redwing

[Twizseven]

Graham. Thanks fir your thoughts. My mate is going to Purbright next week to order a casting and I was planning to go in with him. I would appreciate your foundry details in case we cannot get them done.   Do I need to polish or paint the pattern. Was planning to give very light sanding to remove the odd tiny bits of filament.
Colin

[Alyn Foundry]

Good morning Colin.
Being totally unfamiliar with this material in every way, how does it feel? Obviously a rough finish will be transferred to the sand. Back in the days of my cast Aluminium masters they were just brightly polished, no paint.

From your pictures the surface finish looks pretty good, perhaps a light going over with 1200 grit wet & dry?

   Graham.

[Twizseven]

Drilled centre hole to aid pulling from cope and drag boxes and put in pair of offset location guides.  Was in Walsall yesterday collecting equipment from closed down factory and happened to have the patterns with me so detoured to the foundry and hopefully will have a casting by end of next week.
Colin

[Twizseven]

Collected the casting couple of days ago.
Very pleased with how it came out.
Have included pictures of the inner faces if the patterns with locating dowels.

Colin

[Kim]

That's Excellent, Collin!
Hope it wasn't too expensive?  At least there was no shipping, since you provided the transportation both ways

Kim

[Jasonb]

That looks to have come out very well, almost no fettling required as the joint like is so fine.

[Twizseven]

Kim,
Define expensive.  Casting was £28 plus my fuel and time to collect.

Jason,
Yes the joint line is very smooth.  I wondered how I would align the two halves of the pattern to drill the location spigot holes, then had a brainwave.  I found that I could just fit a garden clothes peg on each of the six spokes.  It was a tight fit but held every thing perfectly in alignment to drill the two locating holes.

I have outdoor electrical cables to run and bricks to lay for next week or so depending on weather so may not get too much time, if any, in workshop.
Colin

[Admiral_dk]

That casting is as close to perfection as I can imagine a casting to be -> Great job Colin 

Per     

[Alyn Foundry]

That casting is as close to perfection as I can imagine a casting to be -> Great job Colin 

Per     

Indeed Per.
When I moved the majority of my patterns over to the Buckley foundry, Roger “ the pattern “ Hughes was insistent upon a meticulous surface finish. He said that “ to get a 100% casting you need a 110% pattern “

Having had a few flywheel castings done at the same foundry I’m certain Colin won’t have any problems with the finished pulley’s.

   Graham.

[Twizseven]

Finally can bring this thread back to life.  After a busy summer with major works in the garden, followed by eldest daughter wedding in Mid August, Week in France/Germany (in Caterham) mid Sept, Prague in mid Oct., first grand-daughter just after Christmas, I have only just managed to get back out into workshop.

I had done the flywheels and the Governor Bracket for it back in March, but the little castings for the Governor Arms and Latch Out bar had been staring at me all summer.  I was not looking forward to all the tiny fettling and awkward work holding.  I started on the Latch Out bar and gave this clean up with files and emery paper.  I cannot find a picture of how I clamped this to drill the holes.  The more I think about it, maybe I never took any because I was so ashamed of the somewhat precarious work holding methods I used.

Decided to make the Latch Out Bar and the Governor Arm pins first of all.  The plans just said steel and initially I tried piece of Silver Steel but the drive belt on the Cowells lathe could not cope so swapped to piece of BDMS.  One pin at 0.093" (3/32") and two at 0.123".  I needed a jig in order to cross-drill these so set up block of steel in Cowells Mill and drilled the two cross-pin holes first.  I had to use the nearest Metric size as did not have the correct Imperial drill. So 1.2mm instead of 3/64" and 0.8mm instead of 1/32".  These were the smallest holes I have had to drill and so took my time and success without any breakages.

Then drilled the holes for the pins to locate in at 90 degrees to cross-hole.  Removed block to blow out holes and then reset in position, fitted a pin and held in place with clamp and used DRO to locate the hole then drilled.  All went okay with the added bonus I found some 50 year old 1/32" split pins which went in the holes.




 

[Twizseven]

Then moved on to the Governor Arms.  These are quite awkward bits to hold, one colleague suggested soft soldering a block onto the weight portion in order to be able to clamp it in vice.  The casting was quite a bit thicker and needed to be thinned down quite a bit.  In the end I fitted it to my small jig plate.  It was placed on a sacrificial aluminum plate and up against two 6mm dia dowels located in the jig plate.  It was then clamped down firmly with a small piece of aluminium between the brass body and the clamp.  I ensured the arm was parallel to the jig base.  This was then mounted in the vice on the Cowell Mil and a long series slot mill used to thin the sides down.  There was some flex in the arm and a number of spring passes were taken until arm was parallel at 0.125".  This was then repeated for second arm.

The next task was to mark out for drilling.  This was a fun task.  It appeared that the casting was accurate enough that when laid on the surface table the arm was parallel to the surface table, so out with the Marking Ink and scribe lines all over to give the hole centre and the correct dimension of the arm in the other orientation, and also the locations for tensioner bolt and springs.  Repeated for second arm.  Arm then clamped down on 123 block with required hole location over a hole in the 123 block.  The 123 Block was too big for the Cowell Mill so migrated to the Bridgeport clone.  Used the laser centre finder to pick up hole centre (forgot about my optical centre).  Hole then drilled and reamed 0.125" (1/8").  Block rotated in vice, whilst still aligned on center position and hole drilled for end of spring (1/16").  Block rotated again and the location for the spring adjuster found and then drilled/reamed.  This again was slightly precarious and needed and adjustable parallel to support the end of the bob weight whilst drilled/reamed and slight counterbore. Repeated again for second arm.

[Twizseven]

The pivot end of the Governor Arm now needs to be filed to shape.  This is basically a case of filing, fitting to Governor Arm Bracket on the flywheel and testing the fit/operation.  Eventually ended up with both arms operating the Shift Collar.  Great I thought, so fitted to the crank and rotated. the flywheel.  The pivot ends foul on the Latch Out bar.  Then realised that the pivot ends needed to be radiused down to 0.125" (1/8").  It would have been easier possibly to make a filing button to help with this.  Instead I swung the arm suspended on a 1/8" diameter bar resting on a pair on 123 blocks, blued up the arm and used height gauge to scribe the radius on both sides of the arm.  Repeated for second arm and then spend happy hour or so filing to shape.  The picture shows the arm with scribed lines on the right and the fully filed item on the left.

Second picture shows one arm with its mating parts, third picture shows both arms and Latch out Bar.

Next task will be to broach the keyway in the Governor Arm Bracket, the flywheel is done so will leave bracket on flywheel whilst being broached.  These will be followed by Push Bar and it components and then the drive pulley.

Colin

PS Happy New Year to one and All

[Twizseven]

I really cannot believe how long it took to make these fiddly little bits, it was at least 6 hours.

The Push Rod Guide plate is a small casting, this was cleaned up with file and then the two sides milled down to clean them up.  Milled face down to 0.150″, Drilled two fixing holes whilst supported reasonably in  the vise, then took down to final 0.12″ thickness.

RedwingPushRodGuideRes

Started with the Push Rod bar,  seemed quite hard to drill, one hole 0.125″ (1/8″) for the pivot pin and the second hole for the fixing screw should have been 2.35mm for a 4-40 unc screw.  I did not have a 2.35 so opted for a 2.3.  Came to tap it and could not get more than 1 turn of the tap and could see the tap twisting.

Stopped and went to the pub.  Whilst talking to my mate we both realised it was a length of key-steel we had bought from a business that was closing down (we in fact brought all their stock).  Back home i put it in the kiln along with a couple of small castings and cooked it at 800 degrees Cent for a short while.  Next day it was certainly easier to tap.  Note to self – buy 2.65mm drill.

This was done on the small Cowells mill in the warmth of my office.  Followed this by drilling the two 2.1mm holes for the 3-48 unc screws holding the Push Rod Plate.

RedwingPushRodPlateHolesRes

The Push Rod Keeper was cut from a 1.75″ x 1″ piece of .250″ thick plate. Sawed it down a little smaller the into vice on Cowells Mill.  I had a 6mm Carbide end mill close by and used this to gradually whittle down to size.  Then drilled 2.9mm (should have been no.32 drill but I do not have any) and countersunk for fixing screw.  At the same time i drilled the hole for the pivot pin all the way through as I was not looking forward to holding the 0.1″ thick bracket whilst it was being drilled after I had milled down the opposite side.

RedwingPushRodKeeperDrilledRes

I had great fun trying to find suitable height material to act as a parallel so as to keep the material well held in vice but still able to mill down to 0.1″ thick.  Again very careful use of 6mm carbide end mill.

RedwingPushRodKeeperRearMachineRes

The Push Rod Keeper was fixed to the Push Rod Bar and clamped in the vise and 0.125″ (1/8″) reamer used to ensure holes were aligned with one another.

Because I was using a ball bearing race rather than a solid cam follower I had to deviate rom the plan for the Pivot pin.  This was a simple turning job.

The final bit is the Push Rod Plate and this needed to be 0.048″ thick.  Hunted high and low through stock to find suitable material and finally came across a flat grinding wheel cover which was 1.25mm.  Hacksawed a piece out and by time I had polished the paint off it came out at the requisite 0.048″.

This was a difficult thing to hold in the vise.  In the end used a set of Starret adjustable parallels with a piece of sacrificial brass on top of them.  Drilled the two holes at the end of each slot and then used a 3/32″ slot mill to clean out the slot and open to the required 0.110″.

The various parts shown below.

RedwingPushRodBarPartsRes

And assembled.

RedwingPushRodBarAssyRes

[Roger B]

That's some nice work on some more fiddly bits    Those small castings look quite fragile 

[Twizseven]

Roger,

 Thank you.  There was a bit (LOT) of head scratching to work out how to hold them.  I'm sure others would have done it differently and in a better manner, but they are done and none broken.

Colin