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Author Topic: MACHINING & BUILDING a STUART D10  (Read 59813 times)

ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #50 on: January 07, 2015, 06:14:29 am »

MAKING A SPLIT TAPER COLLET FOR FLYWHEEL.
 
Chuck the flywheel casting in the lathe using the outside jaws and machine the dia as near as possible to the chuck jaws,
turn the casting around so that the boss side is away from the chuck face and machine to meet the other cut, bore thro' 3/8" dia.
Leave the F/Wheel in the chuck and offset the top slide 2.5 deg , with a small boring bar machine the taper but don't allow the 3/8" hole be enlarged at the front as the screwed end has to pass thro'.
Once completed the casting can be removed from the chuck
 
To make the taper sleeve chuck up a piece of mild steel no less than 5/8" dia x 1.5" long and with the top slide still at the same setting machine a parallel 3/8" dia x 1/2" long, screw 3/8" X 26 t.p.i. or any other that you have dies for.
Once threaded bore thro 9/32" dia and make a small under cut with a parting tool 1/2" from the end.
At this under cut start to machine the taper checking for fit as you go making sure that the F/Wheel edge comes up to the start of the thread, the under cut allows the F/Wheel to be pulled onto the taper
 
With the tapered collet still in the chuck put the F/Wheel on to the taper and lock up with a 3/8" x 26" t.p.i. nut, it can then be machined to size and the end faced.
At this stage the F/Wheel can be removed and the taper sleeve parted off from the M/Steel barPut the nut on to the parted off collet and hold it in a vice allowing 4- slots to be cut with a hacksaw, make sure that it's a new blade which prevents wandering, finish with a polish.
 
F/Wheel can now be mounted on a piece of 9/32" dia rod which is center bored each end, mount the job in the chuck ,held at the other end with a revolving center and now with very light cuts it can be finally machined true and polished.
 
We now have the 3- components of the taper collet, and lastly fitted to the 9/32" dia main shaft which runs very true.
 
As can be seen the F/Wheel will foul the ground if not mounted on the boxbed which will be replaced later.
 
George.
 
 
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #51 on: January 07, 2015, 11:14:07 am »

George...I would be grateful as time progresses if you could explain more about your proposed taper locking bush for the flywheel to crank on your D10

I do understand and have used keyed Fenner Taper-Lok bushes for over 40 years in industry ...however in scale size are we not again getting back down to M2 or M3 HPGS?

My build has a 50mm diameter webbed flywheel on each end of the 4.0mm diameter paddle shaft, each wheel has two M3 tapping's on either side of the hub [four in total]

The area of concern is that the contact point on the M3 HPGS to the shaft is so small that I share the issue you note

Another complication is if the engine were reversed at speed, I would also be contending with the rotational mass of both 120 diameter paddle wheels ... Derek

Derek
I have waited until I had the Taper sleeve made so that you could see what I have made,
I don't think that you have enough shaft protruding to make sleeves for both brass wheels.
I have always found it a problem of the Grub screws tearing the shaft when you go into reverse even with a generous flat milled on the shaft and your problem is compounded by the small dia of your shaft, at 4mm its .001" larger than 5/32 Dia.

May I suggest that if you have 2- grubs to each boss could you drill thro' the shaft 90deg from the grubs and insert a taper pin ?
I presume that when you finally get the plant into a ship you will remove the 2-  fly wheels and fit paddles, will this mean extending the shafts to take the paddles by making couplings to widen the drive shaft.
If so at that time you could fit taper pins to the couplings.

George.
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derekwarner

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Re: MACHINING & BUILDING a STUART D10
« Reply #52 on: January 07, 2015, 10:12:55 pm »

Thankyou George for the explanation & photographs.......your design will certainly be food for thought down the track

You are correct with concern on the smaller diameters, my quandary is that the flywheels are also being used as the mechanical coupling between the engine crankshaft and the 200 mm long shaft extensions to the paddles

I have installed an ACTion P96 servo slow down to the ACS steam regulator & set this for a gentle ~~8 seconds for each direction for the 90 degree movement, so it should be literally impossible to impose a high velocity directional moment to the shafts

The next consideration maybe a micro switch mounted on the steam regulator servo that requires a ZERO position as a permissive to allow the engine reversing servo to operate

Derek
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Derek Warner

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AlexC

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Re: MACHINING & BUILDING a STUART D10
« Reply #53 on: January 07, 2015, 11:35:53 pm »

Thankyou George for the explanation & photographs.......your design will certainly be food for thought down the track

You are correct with concern on the smaller diameters, my quandary is that the flywheels are also being used as the mechanical coupling between the engine crankshaft and the 200 mm long shaft extensions to the paddles

I have installed an ACTion P96 servo slow down to the ACS steam regulator & set this for a gentle ~~8 seconds for each direction for the 90 degree movement, so it should be literally impossible to impose a high velocity directional moment to the shafts

The next consideration maybe a micro switch mounted on the steam regulator servo that requires a ZERO position as a permissive to allow the engine reversing servo to operate

Derek

Hi Derek,
 
I would suggest you reconsider your slow servo on the regulator... especially if you add a Zero point switch for reversing direction.
Set up like this it will take you at least 16 seconds to go from full ahead to full astern which, in an emergency situation, could land you in a collision condition... a heavyish model at full ahead or full astern can travel a long way in 16 seconds.
 
By all means add a zero point switch if you feel the need as it is not advisable to slam from full forward to full reverse with Stephenson gear... this would put considerable strain on the Stephenson linkage let alone the paddleshaft.
 
As long as you slow the engines down to a very low rpm (preferably stopped) before changing valve gear/rotation direction you should not have any problem in normal operation... in an emergency you need things to move a lot quicker... even if the risk is some minor mechanical damage...
 
Much better than a wreck situation. <:(
 
Just my 2 pence worth.
 
Keep happy.
 
Best regards.
 
Sandy. :-)) :}
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derekwarner

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Re: MACHINING & BUILDING a STUART D10
« Reply #54 on: January 08, 2015, 01:51:54 am »

Morning Sandy......how is the Haggis? {-)

Thanks for your comment, however I won't clog up Georges D10 build thread but will post comments/questions in my Saito engine thread when I have experimented a little

Derek
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Derek Warner

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AlexC

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Re: MACHINING & BUILDING a STUART D10
« Reply #55 on: January 08, 2015, 12:13:41 pm »

 
Hi Derek,
 
Understood.
 
My apologies to you George.
 
Best Regards.
 
Sandy. :-))
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Jerry C

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Re: MACHINING & BUILDING a STUART D10
« Reply #56 on: January 08, 2015, 01:54:42 pm »

When it's convenient George, will you give us a tutorial on taper pins. I am confused by the pic that shows what appear to me to be broken drill bits for pins in crank webs.
Jerry.

ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #57 on: January 08, 2015, 05:58:53 pm »

When it's convenient George, will you give us a tutorial on taper pins. I am confused by the pic that shows what appear to me to be broken drill bits for pins in crank webs.
Jerry.

Broken drill bits indeed !!!!!
Jerry wash your mouth out with Paraffin, no expletives allowed on this forum.
Jerry
What you see in the pic is a very poor quality and the taper pin shown is only 5/64" dia, which is reflecting the light..

Taper pins are bigger at one end , smaller at the other and the pins are ground steel, you need a taper reamer to fit them and the smaller the reamer the more costly they are.
Once fitted these taper pins stay in place but as long as they are not driven in you cam tap them back out before final fit.

You can also get Roll pins which are parallel and made of spring steel, they have a slot full length and are slightly over size so that you can drive them in and get them back out, not for crank webs as they need to be flushed off but as they are hardened steel they knock seven bells out of your file.

Here is a link for taper pins , explained much better than I can.

http://en.wikipedia.org/wiki/Taper_pin

You can also Google Roll pins and there are good explanations for them.

George
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flashtwo

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Re: MACHINING & BUILDING a STUART D10
« Reply #58 on: January 08, 2015, 07:11:36 pm »

Hi,

Regarding the rate of change in direction of the D10. I've had no problems with my D10 doing 600RPM or more and immediately slamming into astern and then back to ahead as a standard manoeuvre and, since there is no steam regulator in my system, there is no means to shut off the steam; the launch displaces 35kg.

See YouTube:-  https://www.youtube.com/watch?v=2HV4s9MjfaQ

At 2:30 into the video, you can witness the need for an immediate astern manoeuvre as the rocks appeared ahead!

The steam launch has no flywheel and just relies on the 5 inch (125mm) prop acting as one.

I hope this helps in the decision making process.

Ian
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #59 on: January 08, 2015, 07:32:00 pm »

Hi,

Regarding the rate of change in direction of the D10. I've had no problems with my D10 doing 600RPM or more and immediately slamming into astern and then back to ahead as a standard manoeuvre and, since there is no steam regulator in my system, there is no means to shut off the steam; the launch displaces 35kg.

See YouTube:-  https://www.youtube.com/watch?v=2HV4s9MjfaQ

At 2:30 into the video, you can witness the need for an immediate astern manoeuvre as the rocks appeared ahead!

The steam launch has no flywheel and just relies on the 5 inch (125mm) prop acting as one.

I hope this helps in the decision making process.

Ian

Ian,
Stick a F/Wheel on your engine and see what happens.
I have experience of the F/Wheel chewing the main shaft on a 10 V never mind a D10 .
On both occasions I had to drill and tap 6 ba thro' the boss and the shaft to fit a H.T. Socket head cap screw.

All my engines including my flashsteamer has taper lock collets fitted which has cured the problem.

Possibly slamming into reverse without cutting off the steam has caused you to replace your Stevenson gear.

George.
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flashtwo

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Re: MACHINING & BUILDING a STUART D10
« Reply #60 on: January 08, 2015, 08:11:33 pm »

Blimey George you've got a good memory re the Stephenson gear - that was nearly three years ago!

When you suggest fitting a flywheel, are you suggesting it would improve the performance?

I also fitted a 6BA steel screw through the boss and shaft (it may have been your suggestion) having had experience of the grub screw on flats chewing up.

As I have said, I haven't the luxury of any valve between the boiler and the D10 - its just a straight through arrangement with no throttling losses.

Ian
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #61 on: January 08, 2015, 09:02:19 pm »

Blimey George you've got a good memory re the Stephenson gear - that was nearly three years ago!

When you suggest fitting a flywheel, are you suggesting it would improve the performance?

I also fitted a 6BA steel screw through the boss and shaft (it may have been your suggestion) having had experience of the grub screw on flats chewing up.

As I have said, I haven't the luxury of any valve between the boiler and the D10 - its just a straight through arrangement with no throttling losses.

Ian

Ian,
No it will not improve the performance by virtue of your 5" dia prop but if you had steam throttle control it will save a great deal of ware on the Stevenson gear if you could shut off the steam, reverse the gear and  apply steam to drive the engine.

I have a D10 in a 42" x 32 lb Steam tug CERVIA and doing as you were slamming it into reverse I knackered a servo and replaced it with a steel geared one that I now use only in dire emergency to stop the boat.
Other than that it's steam off, reverse and away I go, steam off and then forward.

George

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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #62 on: January 09, 2015, 11:45:20 am »

Making Con rods
 
Normally when machining the casting for the Con rods you could grip the rod in the 3-jaw with the machining stub but these castings are very poor , looks as tho' there has been some movement while casting so the stub had to be machined in order to get the casting running reasonably true.
 
I filed the outside of the big end in a rotary motion and gripped it in the 4- jaw and trued it up with my trusty surface pointer, this allowed the outside edges to run true.
Did the same with the flat side of the casting and trued it up which it was now running reasonably true and the stub could then be machined until all of the rough parts were gone.
At this point the end of the casting can be machined square.
 
I could then grip the stub back in the 3- jaw to machine the Con rod to size.
After machining the big end dia to size the top slide is off set at 1/2 deg and with very fine cuts about .005 the rod was machined to a taper with a round nosed tool and finally the top side squared off.
 
Finally the big end casting can be marked off for cutting thro'. the shaft center line after marking off the 1-11/16" center
this can be done with a slitting saw but as I don't have one the Junior hacksaw with a new blade will be used.
 
Next job is to bore and face for the main shaft.
 
George.
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #63 on: January 10, 2015, 11:58:37 am »


Having changed to a new Mac this is a test pic to see if I can post direct from the new Mac as previously I had to size my pics , mail it to a lap top and then post to the forum, so it seems as tho' I have been successful
George.



Con rod now bolted and ready to bore
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #64 on: January 11, 2015, 04:39:25 pm »

Hopefully I have cracked posting pics on the MAC direct to the forum so I can continue with the Con rods.

No 1.
Before removing the Rod from the chuck I center drilled the eye of the casting for future work.

No2.
As the ends of the bearing block have been faced of leaving it at 5/8", enough to saw off and still have plenty of material to machine the ends to 1/4" thick giving a bolted dimension of 1/2" it's now time to saw in half.

No 3
Bearing blocks cut in half ready for machining.

No 4
Using the 4-jaw the bottom end is roughly set up to run true, the heavy packing pulls the job straight on the 4 - sides  and then machined to 1/4" thk.

No 5.
The top half as the bottom with the rod inside the 4- jaw and face to 1/4" thk.

No6.
The 2- halves are bolted together ready to be bored and reamed 9/32" dia for the main shaft.

George.
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xrad

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Re: MACHINING & BUILDING a STUART D10
« Reply #65 on: January 11, 2015, 08:48:57 pm »

Nice job!   for those new to machining, Note that the big end split (pic No3) is 'below' the punch so that the 'little end' - 'big end' distance can be maintained....a very important measurement.
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #66 on: January 13, 2015, 08:55:31 pm »


Pics No1& 2,

The big end bush was flattened by rubbing it on a flat file until both sides were smooth, a flat packer was set under the big end and  I ran a D.T.I . over a flat side and when level the pop marked center was drilled with a center drill, a 5/32" dia pilot hole was bored thro' and then a .270 drill passed thro' for fina; reaming to 9/32" dia.

No 3 4.

The conrod is mounted on a short piece of 9/32" dia rod, cut a strip of paper to give about 2- turns around the shaft, tighten up the 2- halves of the big end which now allows a fine cut to bring the block to size.
The finished size of the block has to be .312" and as it measured .372" .030" has to be machined from both sides this can be done with a sharp nosed tool. turn it around in the 3- jaw and take .030" from the other side

No5.

With a round nosed tool both side of the block can be machined down each side by another .030" to give a final size of 1/4".

No6.

The Conrod can be turned around and the small end mounted in the 3-jaw.
Having previously marked of and center punched the connecting pin hole it ran very true just as mounted.
Drill thro' and tap 5 B.A. and then drill and ream 5/32" dia by 5/16" deep for the connecting pin.

No 7.

Now can be seen the reason for center drilling the conrod small end as previously described, this allows the rod to be mounted vertical in the machine vice and the drill center
 found.
After locking the table loosen the vice and turn the rod round 90 deg and the end will now be central for milling the slot to clear the cross head when made.
Use a 1/4" dia slot drill and with .020" cuts millout the yoke.

This can also be done by drilling a hole verticaly in the flat behind the pin center, cut down with a hack saw and then file to shape with a round file., this was how I did it before having the luxuary of the mill.

No.s 8&9

Rods now completed and fitted to the crank shaft, they are quite tight but will run in when the standards and the cross slides are fitted.

George.


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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #67 on: January 17, 2015, 06:04:30 pm »

Continuing with the build the next thing was to drill the Standards feet which was an easy proceedure,

Pic No1 .

the Standards were gripped in the machine vice and all holes drill to suit 7 b.a .clearance.

No 2.

The holes in the base plate were marked off from the feet, drilled and tapped 7ba., the assembly is held by a cast in bar on the underside of the Boxbed, another reason for using this at the start of the build although it will not be used in the end.

No 3.

The first Conrod is fitted after bolting down the standard and all is well, turns over freely with no binding.

No 4 and 5.

Second Conrod fitted and horror of horrors, for the eagle eyed there is a gap in the bottom of the feet which is caused by the big end journal on this Conrod being out of line .
As shaft webs come up to T.D.C. it pushes the standard over to the left, correspondingly when at B.D.C. it pushes the standard over to the right.

After some thought I changed the Conrods over to see if the 9/32"  Big end hole  had been drilled and reamed out of line but no it did the same thing when turned over.
So nowt else for it but to make a new shaft, but here was the rub, 9/32" dia round bar in the past had been like finding Hens teeth but after a search on the web I found this supplier that I didn't know of (  http://www.glrkennions.co.uk/ )
Phoned them on Friday morning at 10-30 am and the items arrived much to my surprise on Saturday mornings post with a full Cat enclosed, now that's what I call service.

Next job a more carefully made new shaft.

George.
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xrad

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Re: MACHINING & BUILDING a STUART D10
« Reply #68 on: January 18, 2015, 02:24:59 am »

Looks great!  Can't wait to see the cylinders and steam chests! Too bad about the crank! I had to replace a big end journal pin in a Stuart triple. I was able to cut out the old pin, then drill out new pin holes in the webs ,   re-centered the whole unit square, cross  pinned and silver soldered. Worked out fine.  but this was a one piece cast crank.   Any way to save the good parts of the crank?
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #69 on: January 18, 2015, 08:35:29 pm »

Looks great!  Can't wait to see the cylinders and steam chests! Too bad about the crank! I had to replace a big end journal pin in a Stuart triple. I was able to cut out the old pin, then drill out new pin holes in the webs ,   re-centered the whole unit square, cross  pinned and silver soldered. Worked out fine.  but this was a one piece cast crank.   Any way to save the good parts of the crank?

xrad,

The mistake that I made was not to drill the crank webs in pairs, I used to make them without the use of a mill but this is the first time that I have tried to be clever and bored the holes individually using the graduations on the tables.
What I shall now do is bore them in pairs by drilling the 9/32" dia hole and then wind the table forward by .375 to drill the 1/4" hole for the big end journal, before drilling the 1/4" hole I will put a piece of 9/32" dia rod in the first hole before drilling the 1/4" hole to keep every thing in line.

Unfortunatelly I can't save the shaft as the offending crank webs are out of line and I don't like to S/Solder cranks as I find it dificult to clean the job after soldering.

I have never attempted to machine a crankshaft from the solid as I think that the Chinees lathe that I have would complain at cutting the offset material supplied with the D10 casting kit so I stick to my method of fabrication, it's not a big job doing it this way.

Thanks for your comments and interest

George.
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Re: MACHINING & BUILDING a STUART D10
« Reply #70 on: January 19, 2015, 08:43:56 pm »

exactly right. in pairs with the crank pin(or other pin) as the alignment tool. Or all four at once. But it's Ok if one crank-rod pin pair centers are a few thou off the other (as long as the piston does not slam on a cylinder cap AND the pins are all square). Have to clamp the webs both vertically and horizontally so they don't wiggle.


Built up cranks are nice too. I built one for a Tiny power 2V10M ( a real nice kit). came out fine.
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #71 on: January 20, 2015, 10:08:58 pm »

MAKING A NEW CRANK SHAFT.


xrad ,
That was how I built all of my crank shafts before purchasing a mill and never had any trouble, so that was my reward for trying to be too clever.

In making the new shaft I cut the 4- pieces of steel for the webs and using some square tool steel as slips set them up in the vice.
Clamped them in pairs and center drilled the hole for the 9/32" main shaft, drilled and reamed and on the same position below the drill inserted a small piece of 9/32" dia rod.
Wound the  table forward .375", drilled and reamed a 1/4" dia hole thro' both crank webs while still clamped in the same position which ensured the journals to be parallel

The big end journals are 9/32" dia with the ends turned down to 1/4" dia and shouldered at 5/16" wide which is the dimension inside of the webs,
Glued and pressed them together and slipped them on to the 9/32" dia shaft before they set to ensure that they remained parallel and left overnight to cure.

When cured they can now be glued in position on the main shaft and set at 90deg before curing, after curing for 24 hrs they can be taper pinned and and the center piece of the main shaft at the webs can be cut out, cleaned up and assebled  in the engine.
which should cure the problem.

George. 
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Re: MACHINING & BUILDING a STUART D10
« Reply #72 on: January 21, 2015, 02:04:27 pm »

Nice. Looking good.  Should be a square as needed this time.
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #73 on: January 29, 2015, 08:59:01 pm »

NEW CRANK SHAFT

New crank shaft made and fitted, I made sure this time that the webs were taper pinned on the main shft end and the big end , that's 2- pins per web , 8 in total.
I mounted the whole assembly in the lathe and gave it about 10 mins running in with lashings of oil and it now turns over by hand with no sticking points, must say that I am pleased with it now.

I next started on the cylinders by setting the cylinder in the machine vice and held a square to the valve face to ensure that I drilled and tapped verticaly the exhaust ports.
The steam passages have to be drilled at 20 deg and as I don't have a tilting vice a piece of C.L.S. had an angle of 20 deg cut into it as seen in the pic.
A 3/16" dia by 3/32" deep pocket was cut with a slot drill, the casting is then held by hand and drilled 3/32" dia to meet the top steam inlet, turn it around and repeat for the bottom inlet, being very careful not to break into the exhaust port.

Steam chests were next, the square cast hole was cleaned up with a file and the width measured, the equivalent material was taken from both sides to bring it to the drawing dimension.
They were then mounted in the 4- jaw and trued with the surface pointer, the valve rod boss can then be machined true and equal amounts machined from both ends to bring it to size.
Bore right thro' 1/8" for the valve rod , drill and tap the end 1/4 x 32  t.p.i for the stuffing glands, before removing drill thro ' into the far end 3/32" x 1/4" deep, this takes the top end of the valve rod as a guide.
The casting can now be turned around and the domed end machined and then the same amount was turned from the casting to bring it to size.

The castings can now be set up in the milling vice and equall amounts machined from both side to bring them to size.

Next job will be to drill the steam chest mounting holes and attach them to the cylinders.
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ooyah/2

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Re: MACHINING & BUILDING a STUART D10
« Reply #74 on: January 31, 2015, 10:48:07 am »

The bolt fixing holes are needing to be drilled, so having previously described how I machined them now the holes were required.
This was a simple job done by mounting the covers in the circular jig that I made to machine them and with them mounted in the rotary table the holes were set out at 1.125" p.c.d and then spaced out at 72deg .

They were then clamped to the standard and using the drilled holes, drill thro' to complete.

The same was done with the bottom covers but a hole was drilled and tapped then held down to drill and tap the holes  7 B.A. ensuring that all was square to the cylinder end that takes the steam chest.

The top cover was assembled on the cylinder and standard and it was here that I hit trouble.

I have read on several forums that Stuart castings were not as good as they used to be, I have never encountered any trouble but this time the drilled holes at 1.125" p.c.d. were breaking thro' the edge of the castings.
I have been very lucky in that although the holes are breaking thro' on 3- holes I still am able to get a thread long enough to catch the bolt.

So anybody in the future deciding to have a go at building a D10, before drilling the holes in the covers make sure there is enough meat on the casting, if not redice the p.c.d.
to 1.063" p.c.d. or even 1" p.c.d.

Any suggestions on how to over come this problem would be appreciated.
Some may say that I should have checked the p.c.d. before drilling the covers but it's not a thing that I would consider as the drawing and Stuart castings have been around for a long time, hopefully the new Company will make the castings a bit better.
I can't send the cylinder castings back to Stuart as I didn't buy them there, if I had bought from Stuart they would replace them without hesitation.

George.
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