Author Topic: Building a Redwing  (Read 12935 times)

Online Twizseven

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Re: Building a Redwing
« Reply #15 on: December 04, 2022, 08:13:56 PM »
I needed to ensure the jig plate was square to the bore so mounted casting with 12" PGMS bar in the bore onto the jig plate (jig plate mounted on piece of 12mm MDF to protect the table) and eventually got it all square.  Removed the casting and squared up the plate with large end mill.

Next exercise was to fit the adjustable angle plate to the table and get it square.  Ran Verdict gauge back and forth along 'Y' axis to get this correct.  Set the top of the angle plate horizontal and checked the top surface along 'Y' axis and found this not to be level.  Then spent at least an hour getting jig plate level and square.  In the end I needed a 6mm wide strip of paper along the rear edge of the jig pate parallel to the 'X' axis.  This took a number of attempts to get correct.



When happy with this set the angle to 25 degrees.



Used a 50mm six insert facemill to machine the main bearing faces.  Because of the 25 degree angle care is needed to ensure the casting does not hit the quill.  I had to remove the safety guard as this was in the way.  Took three passes to remove 15 thou.



In order to check the positions for the main bearing caps I first blued up the bearing surface and then fitted one of my large (but relatively small diameter) drill chucks with a cobalt stub drill.  I moved the requisite distance from the centre line (1.219") and very gently held the quill down so as to use the drill tip as a scriber and moved the 'X' axis so as to leave a scribed line.  Repeated this for the second bearing.



The holes were drilled 0.5" deep and then tapped 8-32 UNC.  The caps were then shuffled around to get the best looking fit.





Next step to face the sides of the bearings.


Offline steamer

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Re: Building a Redwing
« Reply #16 on: December 04, 2022, 08:47:07 PM »
Cutter organization "Kung fu" is on point   sweet deal.   I've always liked the redwing.....watching along!   Like the angle plate!
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Online Twizseven

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Re: Building a Redwing
« Reply #17 on: December 04, 2022, 09:01:26 PM »
Steamer,
The angle plate just needs a little bit of truing up.  To get the jig plate level I had to put a 6mm wide piece of paper along the long edge at the rear.  I have a couple of friends who both have Jones and Shipman 540 surface grinders. I may see if I can use one to true it up.

As far as the end mill organisation goes they are now all in 12 drawers of a Bisley filing cabinet. Hopefully I can now find what I want and not go out and buy/borrow something I thought I had not got. :)

Colin

Offline steamer

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Re: Building a Redwing
« Reply #18 on: December 04, 2022, 09:45:08 PM »
Yeah I have one of those too...I squint alot when I use it...cause I know I'll have to do something about it if I look too hard... :embarassed:
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Online Roger B

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Re: Building a Redwing
« Reply #19 on: December 05, 2022, 08:19:11 AM »
Looking good  :ThumbsUp:  :ThumbsUp:  :wine1:

That casting looks to need a few more interesting set ups  ::)
Best regards

Roger

Offline vtsteam

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Re: Building a Redwing
« Reply #20 on: December 05, 2022, 03:06:25 PM »
 :popcorn:  :ThumbsUp: :cheers:
Steve

Online Twizseven

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Re: Building a Redwing
« Reply #21 on: December 05, 2022, 09:32:22 PM »
Before putting the assembly back into the horizontal position I decided to do the main bearing oilers. Drilled into top of bearing caps going far enough that when bored out the drilled hole would be visible and then tapped 10-32 UNF for the oilers/greasers. Removed the rear cap and scribed a faint line on the bearing centre line to aid with location of fuel filler.



With this completed the assembly was rotated to the horizontal.



Picked the scribed line up with laser and moved 2.5 " back and 1" in to locate the filler. This did not quite locate in the casting correctly so amended position slightly. Drilled pilot and then ran 6.3mm drill through the casting into fresh air. Could not get the tap to start so milled a small 3/8" dia. counterbore to give level surface and then tapped hole 1/16" NPT.



Next up was the cylinder oiler. This needs a 3/8" recess milling in the top of the casting 3.250" from the rear of the casting. 3/8" endmill did this. Luckily my recent haul of carbide end-mills provided a long cutter which could be held in ER32 collet chuck and nestled into the recess and cut a flat on the cylinder top in the bottom of the water jacket.




This was followed by a long centre drill and then drilled 3/32" through to the bore. Amazingly I had a suitable long drill.



A 5.6mm drill then used to put 11/32" hole ready to be tapped 1/4-40 UNF. I found a long tap holder my father had made 20 plus years ago and carefully tapped hole with a bit of lubrication. Test fitted the drip oiler and all okay.



Now came to the bit I had been dreading, machining the gap between the main bearing boss and then reducing the mains down to 1" width. Before doing this I cleaned off the marking blue and lightly stoned the surface.  Put a couple of spots of Loctite on the surface, but the caps set in place before I had the screws located.  Tapped them free, cleaned them up, use a much tinier drop of Loctite and held the caps up until the screws were all started.  The Loctite would ensure the caps did not move whilst being machined.  Used a long 3/4" 4 flute end mill which meant I had to move .313" off the centre line to give the required 1.375".



I crept up to this very slowly taking around 15 thou of each side in turn. I used a set of Starrett sliding parallels to measure the gap and miked them whilst in place. Ended up at 1.3755".



Used same endmill do do the outside edges and in this case 2.065" on DRO gave me the 1" required width.



Fitted oilers and finished for the day.



Hopefully oilite bearings will turn up in next couple of days.

Online Kim

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Re: Building a Redwing
« Reply #22 on: December 06, 2022, 01:37:14 AM »
Wow, Colin! That's a lot of progress!   :popcorn: :popcorn:

Cute little oiler too!

Kim

Online Twizseven

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Re: Building a Redwing
« Reply #23 on: December 28, 2022, 06:31:17 PM »
Wanted to complete all machining of main casting before Christmas as we were to have family stopping over.

I set my angle plate up on table and checked face was at 90 degrees to X axis and the face was vertical.  It took a long time to work out how to fix the jig plate to the angle plate.  In the end I had a thick parallel resting on table bed and two small 1-2-3 blocks on top of this.  The edge of the jig plate rested on the two 1-2-3 blocks.  Was then able to use clamps on the top edge of the jig plate onto the angle plate.  Tapped down onto the 1-2-3 blocks and then could insert threaded rods in the gaps under the jig plate and through the slots in the angle plate.  I just had room to clamp the lower edge with standard table clamps.  It was solid.



Zeroed the DRO X-axis on the line between the jig plate and main casting and the Y-axis on the cylinder head face.  Moved to what should be the bearing centre on the split line.  Fitted laser centre and checked I was on the correct location.  Perfectly aligned.





Whilst laser was still fitted did a sanity check on 1.25” bar fitted in the bore. 



This was parallel to Y-axis.   Note in this picture the lower clamps can be seen.   As a further check I fitted the optical centre and this picked up the bearing joint line perfectly.  Now happy to start boring out the bearings.



Spot drilled the centre and then worked up from ¼” drill to 3/8”. 



At this point fitted long centre drill and spotted the middle of lower bearing.  I drilled the upper bore at one size and then drilled the lower bore at the size below until had both bores up to 19/32”.





Prior to this I had spent some time at my mates house where we did some trial bores on a piece of cast iron to see which was best boring head/bar combination and whether or not to ream to final size. On testing my 5/8” reamer it cut 4 thou oversize, so that went out of the window.  I have two boring/facing heads but had no boring bars small enough for either of them, an Arrand boring bar but the bar for this was bit too flexible.  I ended up using the ubiquitous 50mm boring head sold by all the usual suppliers.  I used the short carbide tipped bar for the upper bore.



On the top bore I went up in size very slowly and the last few thou had about 6 passes at each setting.  Had clean piece of paper under the hole so I could see the material being removed.  The Oilite bushes were nominally .625” but they were actually .6261.”  I managed to get to dead size and with a firm push from my thumb the bearing went in the hole.



Extremely happy, just needed to repeat on the lower bearing.
I changed to the longer bar for the lower bore, but did not fully push it fully home. I just had enough length for the tip to finish cutting and partially exit the bore and still leave about 1/8" clearance between the boring head and casting.  The auto stop on the down feed worked very well.
longer bar was a little more flexible and I was doing 6 to 8 passes for each size adjustment.  Eventually second bearing also pushed in.





With the bores done, moved onto the reamed hole for the timing gear.  This went okay.  When I came to the slot for the push rod, the boss on the casting did not appear to be quite where it should have been and the tapped screw holes would have been right on the edge of the casting.  I elected to put them in the centre of the casting which put them out of place by 110thou.  Looking at the length of the latch-out bar I do no think I will have a problem.  Lets hope this is not “famous last words”.



I also drilled and tapped for the spark plug.  This is exactly as per dimensions on drawings, but the boss on the casting is a tad high.
I then removed the casting from the jig plate and turned it over and remounted it, located and then drilled/tapped the 1/16” x 27 NPT hole for the fuel outlet union.  Removed from jig plate, did some fettling of the casting around the bearing , and then assembled the bits so far.

The engine castings, as said before, had been started and I had been given a fabricated crankshaft.  When fitted in the bearings and all done up, I could turn it but not very easily. 



Did I have a problem with my boring or was it the crank.  Only one way to find out, remove the crank and replace it with a ½” diameter length of straight bar. 



This turned nicely. I will have an attempt to see if crank will straighten, otherwise will have to make a new one.
« Last Edit: December 28, 2022, 06:43:32 PM by Twizseven »

Online Jo

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Re: Building a Redwing
« Reply #24 on: December 28, 2022, 08:58:44 PM »
Looking good  :)

Oilite buses always seem to be oversized before they are pressed home  :headscratch:.

Jo
Enjoyment is more important than achievement.

Offline crueby

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Re: Building a Redwing
« Reply #25 on: December 28, 2022, 09:12:24 PM »
Great sequence!

On the crank being a snug fit, is it possible that its a hair larger than the 1/2" straight bar you tested with? Do the bearings turn smoothly if the caps are not tightened down?

 :popcorn:

Online Twizseven

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Re: Building a Redwing
« Reply #26 on: December 28, 2022, 09:19:41 PM »
Thanks Jo and Chris.
The bush was a firm bush (and I mean firm) with my thumb.  So I think a dead fit rather than pressed and slightly compressed.

Chris,
It felt stiff before tightening the main caps down.  The bushes turn relatively easily on the crank before fitting the caps.  Wil check it again tomorrow.  Will put the crank in lathe tomorrow and see if it appears to be running out.

As regards the build sequence/photos I hope its not too much detail.  I have a few more photos but left them out.

Colin

Offline crueby

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Re: Building a Redwing
« Reply #27 on: December 28, 2022, 09:29:35 PM »
Might be worth checking the bearings by chucking the 1/2" straight bar on the lathe, slipping the bearing over it, and see if there is any runout in the bushing itself. I've had cases where the bearings I made were a touch crooked or off center from bore to outside, and required clocking them to find a smooth running position when installed.


Great sequence, nice amount of detail - its a complex setup, good to see the details.

Online Twizseven

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Re: Building a Redwing
« Reply #28 on: December 28, 2022, 09:55:05 PM »
Chris,
Will have a look at that tomorrow.  Thank you.
Colin

Online Kim

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Re: Building a Redwing
« Reply #29 on: December 29, 2022, 05:55:33 AM »
I'm with Chris - really enjoying the detail in your post!  Thanks for taking the time to document your work for us to follow along and learn from!  :popcorn:

Kim

 

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