Building a Redwing

[Twizseven]

Late in 2020 or early 2021 I purchased a partial set of Redwing castings from the guy who used to import them into the UK and also build them.  He had made a start on the main casting having skimmed the base, faced the cylinder head end, and machined the main bearing platforms.  There were a couple of crankshafts, a used machined piston and a partially machined flywheel and partially machined carburettor.

At the time I had just finished a couple of Alyn Foundry engines and was working on a Stuart 10V.  Covid and my Dad passing (just short of his 100th) and various other issues then got in the way and I have finally decided I need to get back in the workshop and try and do something useful.  Although I have another 12 or so sets of castings on the waiting pile I decided to try and do the Redwing.

So this week I started to look at the main casting.  Checking it on the marking out table, having removed a few burrs/bruises from the base showed the bore to be parallel to the base and the big end platforms at the correct 25 degrees.  Checking the height of the bearing platforms I found that the main bearing centre would not be quite in the middle so I need to take a small skim of the platform to move it.

Started by mounting the casting upside down in the vice on previously machined area on top of water hopper.  Several layers of thick card either side of the casting, clamp on top of the cylinder and a machinist jack under the free end of the casting.  A bit of tapping and jiggling about and all was square.  At this point in time all I wished to machine was the recess in the base for the steel forming the underside of the fuel tank, two dowel holes for lining casting up on a jig plate, 2-56UNC tapped holes for screws to hold the fuel tank base, main fixing holes for the casting and associated counterbore, and the tapped hole for the dummy cylinder water drain tap.

I had to borrow a 3/8" two flute slot mill as for some unknown reason I did not have one.  Before starting machining I had done a drawing with all dimensions/moves calculated for the recess , main holes, tapped holes and dowels.  I had also marked direction of table handles so as not to cock up.  So pleased I have DRO on this mill. All went well, even the 2-56 tapping.  I did not have the requisite 1.85mm tap so stayed with 1.8mm and went very slowly, 1/2 turn forward then half turn back.

I had ordered some .8mm stainless for the fuel tank base and carefully cut and shaped it and drilled holes.  Next step is to modify a counterbore to use as reverse counterbore.

This will be a very steady and slow build.  It is good to get back into the workshop and actually make something.

Colin

[mikehinz]

I'll be watching your build closely as I've had a fantasy about purchasing the casting kit from PMR and attempting it.

Great start!  Keep up the good work!


Mike

[Alyn Foundry]

Great to read you’re “ back in the saddle “ so to speak Colin.

Are these the castings that JB used to market? If yes, he approached me many years ago to take on the franchise.

Did you get the gears and governor parts? If memory serves you had to get them directly from the States?

   Graham.

[Twizseven]

Graham,

Hope you and family are keeping well.

I would need to search my Ebay/Paypal invoices to find the note of the guys name, but certainly he was the guy that used to import them.

There are a lot of little brass castings but I have not related these to the plans as yet.  There were no gears, so I am either going to have to make my own, get them made or buy them if available (possible Forest Classics or Engineers Emporium).  Never made gears so could be interesting.  My mate Tom has lots of gear cutters as he is into clocks so he may possibly have the correct cutters.

Regards,
Colin

[Jasonb]

They look to be bog standard 24DP gear so should not be hard to cut or find, someone like HPC will have them, you may just need to reduce the thickness and adjust the bore. The presure angle is not critical so 20pa will do so long as both gears are the same.

Could even change to MOD1 gears which are cheaper to buy, change the 1.5" distance from crank to cam gear pivot to 37,5mm and use 25T & 50T
https://www.beltingonline.com/steel-c-366_367_375_517_386/?sort=20a&page=3

[Twizseven]

I mentioned earlier about the 0.8mm stainless steel sheet.  I was not sure how well this would cut and drill.  I was able to use the small guillotine and it cut very cleanly and then radiused the corner using radius cutter in the fly-press.  The middle recesses were files out.  Having had fun drilling stainless sheet with some work jobs in the pas I was a bit worried about drilling this material.  I had planned to put small pilot/dimple in and then use punch in fly-press, but did not have a small 2.3mm punch.  I laid the sheet in the recess in the base as a support and used a 1.5mm cobalt drill at around 2500rpm.  This went through easily.  Then used 2.3mm Dormer drill in Proxxon mill at high speed to increase the holes size .  Very happy with the result.





I had a piece of Tooling aluminum plate to use as a mounting jig for the engine.  This was drilled and tapped to match the holes in the engine casting and also had the two reamed dowel holes put in.  Because I cannot guarantee 100% that the locating dowels in the engine base are perfectly parallel to the cylinder bore I will mount the engine to the base, square it up using bar inserted into the cylinder bore and then machine the edges of the plate.



As I needed to remove the machine vice to machine the base casting and then machine the main casting I decided to machine the main bearing castings first. These had been partially machined and drilled when I purchased the castings.  For some reason the holes had not been drilled at the requisite diameters.  Mounted the first one in vice and located first hole using blank drill rod.  Zero'd the DRO and then moved to second hole.  This was correct distance away but fractionally offset.  Drilled out to correct dimension 13/64" and then rest to first hole and repeated.  Then used end-mill to counterbore the top.  Slight mistake here in that I misread  micrometer and took 25thou too much off.  Not a huge problem but need to make the rest all the same depth.  Skimmed top of cap for oiler location.  Repeated this for second cap.  Not the best of pictures.



Removed the vice from mill and mounted the base casting upside down on two pieces of thin card.  Clamped down and then squared it up.  Did not want to use Verdict gauge so I used laser centering device.  I could easily see as ran the laser down the edge of the casting.



I then went to do a double check with a Verdict gauge, which went well till I lifted the Verdict off the casting and power fed the table along the X axis.  I had forgotten to remove the laser centre and ended up with a two piece centre as it met the hold down clamps.  Doh!!!.  How else to do a double check?? Used a standard rotating edge finder and checked each end of casting. I stopped testing when both ends were within 1.5 thou of each other.  Used the edge finder to then center both Axis's. 



Used carbide insert tipped facemill and cleaned up the bottom face.



Drilled the four 13/64" holes for the feet, then turned the base over and reclamped in order to drill tap the mounting holes for main casting and also counterbore the holes just drilled in the feet.



I used the edge finder again in same manner to centre the base up again.  To ensure all was okay I put the 13/64" drill rod in the drill chuck, set the correct dimension in the DRO and picked the hole up perfectly. repeated for the other four holes.  This proved my method of squaring the casting up had worked satisfactorily.  Facmilled the surface to 2.313" height and then drilled the four holes 3.9mm and then tapped 10-24UNC.  Then used 5/8" end mill to counterbore the tops of the base casting mounting holes.



Assembled main casting to base casting to check all holes etc. aligned.



Nice 12" length of PGMS 1.25" dia has now arrived so can set up main casting on jig-plate, get jig plate fully square and move onto main bearing platforms.

Happy so far.

[Kim]

Unfortunately, I can't see your images.  Is it possible they are marked private?  Or taken from a place the rest of us can't see if we're not logged in to DropBox?

Kim

[Don1966]

I can see them and I am not logged into drop


Don

[crueby]

Couldn't see them yesterday, but today I can. Nice!

[Twizseven]

Thanks for reporting back Chris and Don.  For some reason I cannot use Dropbox as my source even though I can get the Image Address, so I have changed to use my Album on the Model Engineer/Model Engineers Workshop Forum.

Thx,
Colin

[Twizseven]

No work on engine today.  Helped mate to wire up Colchester Triumph 2000 lathe to his 3 phase supply and test it out.

Then finished sorting my milling cutters out.


Taken a few days,  Just have 'T' slot cutters, Dovetail cutters and slitting saw blades to sort now.

I have been intending to sort this lot out for several years.

Colin

[Kim]

You have a LOT of mill cutters there!

And I can see all of your pictures after your most recent update.  So whatever you did worked! 

Thanks, Colin,
Kim

[vtsteam]

Very nice looking base casting! 

[Twizseven]

Kim,

Yes there is quite a lot,  50 or 60 or so of the HSS ones were my fathers.  There are over 100 carbide cutters.  I went to buy some HSS cutters of a guy a couple of weeks ago and as I was leaving he said did I know anyone who would like some carbide cutters and carbide drills.  He had around 250 of them, lots of them new and all high spec manufacturers.  I had a quick word with my mate and I bought the lot for about 50 pence each.  I split them with my mate 50/50.  I think I got a good deal    I priced a couple of them up and depending on who they were bought from were anything from £75 to £200 EACH.  I have not started to sort out the drills yet.  Think I may need to order some more of the plastic holders I am using.

Colin

[Admiral_dk]

Great start to your build + what a Bonus to be offered all those nice Carbide Tools for that kind of money     

Per