puddleduck engine build

[ParCan]

Hi All

I have had a Myford ML7 for a while now.
It makes fantastic 3D Printer parts for me but I wanted something more of a challenge.

I have decided to try and build a puddleduck engine as my first lathe project (Sinse school).
Ambitious ? definately, Foolhardy ? probaly.....

After my 1st error (I cut the base plate 4mm to short) I think everythign else is prety close.

I'm waiting on some Slitting saws to try and cut my 2" square brass bar rather than Turn/Mill it all to swarf.
Is this a good idea ?
All I have to do this on is the myford. Tips welcome.

Cylinder caps, base and block plate, Packing Gland screws, eccentrics (nylon) are all made.


I'm also waiting on some 3/4" brass round bar to arrive to make the Crank webbs and Packing Glands etc.

Updates when they happen...

Alex.

[ozzie46]

 That was the first engine I built. If I can do it you can too.
   Good luck and post lots of pics.


   Ron

[ParCan]

OMFG a slitting saw on a lathe is scary !

I put it away rather quick !

used a hacksaw instead.....

[Brass_Machine]

Yeah it is!

Don't think I would try it...

[DaveH]

a slitting saw on a lathe is scary !

I put it away rather quick !

used a hacksaw instead.....

Hi Alex
Good idea, and you lived to tell us about it 

One does need to be careful with slitting saws they are very easily broken  Broken bits do fly 

Good start, look forward to the journey - with the pics of course

 
DaveH

[mzt]

OMFG a slitting saw on a lathe is scary !

I put it away rather quick !

used a hacksaw instead.....

Alex,

http://www.homemodelenginemachinist.com/index.php?topic=14631.0   

I'm waiting on some Slitting saws to try and cut my 2" square brass bar rather than Turn/Mill it all to swarf.

chain drilling before hacksawing may be an option. Second and third picture down.
http://www.homemodelenginemachinist.com/index.php?topic=15270.msg187276#msg187276

As for the Paddleduck ...them drawings are not on my to do list.

They are on the table.

So, I will follow this thread with interest.

but,

 

Marcello

[ParCan]

After a few days off sick, i got back in my workshop yesterday.

I now have a Block, Pistons and packing Glands to add to the other bits.


The pistons still bind slightly and need a tiny bit more lapping.

[ParCan]

Just been reading the Build log done by Tim
http://madmodder.net/index.php?topic=1525.200

I soooo need a mill. Would make life so much easier.

[boatmadman]

This was also my first proper engine build.

Doubting my ability to get success, I decided to build 2 hoping for 50% success rate. But, they both worked!

There is a build log on here somewhere.

Good work, keep it up.

Ian

[spuddevans]

Great start there Alex    You are doing really well without the use of a mill, Bog's designed it so that you can build it only on the lathe if a mill is not available.

That being said, having both machines (lathe and mill) is a real bonus and a real timesaver too. But you are showing us all that you can produce great results just by using what you have.

I'm looking forward to watching your progress,

Tim

[ParCan]

Got off work early and wondered down to the local engineering supplies for some of the blue marking out gunk.
They sold me a tin of "Stuarts micrometer engineers marking"

Have I got the right stuff ?

This seems rather reluctant to dry.
The stuff I used years ago I remember drying in a few mins......

And yes - I now have Blue Fingers !

[spuddevans]

I think that you have got some of the engineers blue, ink that never sets. What I use for marking out is just the biggest permanent black marker that I could lay my grubby hands on, works the best ever. I had 3 or 4 of them in my workshop laying around the place.

They may not be great for marking up large surfaces, but anything 6" square or less will "black" up just as quick and much easier. A lot easier to store too.


Tim

[ParCan]

2 Crossheads made today.

Oh boy was that a long and slow task, and 1 could end up in the scrap bin

I drilled the Piston rod hole 90 degrees out ( in the wrong side )
The part would be fine but the drill got pulled off line by the hole for the pin.

Repair attempted - we shall see.

Photo - ya gota be jokin - had enough for today and I still need to clear up.

[ParCan]

Got some more done today. (With Pictures)

Remade 1 packing gland.
Put the Cylinder caps on. They look good.
Made the Flywheel.
Assembled most of the top of the engine.
Put the Base plate on the Cylinder Block.

The slides still need lapping in a bit.
Pistons all move as they should without Binding on the glands.

I made the fly wheel over size then drilled and reamed the center hole.
To keep it concentric I have turned it to size on a bit of Rod turned to fit the hole.

It's still slightly wide. I will trim it to thickness another day.
Also I need to work out how I drill it.

Tomorrow I will tackle the Bearing Blocks.
Plan is to Drill and ream them all on 1 bar.
Drill the Mounting holes using the Milling Slide still on the Bar.
Part them off and turn them to thickness.

[ParCan]

I think that you have got some of the engineers blue, ink that never sets. What I use for marking out is just the biggest permanent black marker that I could lay my grubby hands on, works the best ever. I had 3 or 4 of them in my workshop laying around the place.

Hi Tim

Got a Big Balck sharpie today.
Works 100% Perfic.

Thanks for the tip.

Alex.

[grayone]

That blue stuff is for checking things like metal bearings and is not intended to dry - have made the same mistake

[mzt]

That blue stuff is for checking things like metal bearings and is not intended to dry - have made the same mistake

Engineers blue? Me too!

And when I got a big 500cc bottle of the proper one, the brushes usually got dipped too much or not enough.
When I upset that bottle on the table (drawings, trousers, chair..) I decided it was time for an homecrafted solution



No more brushes with too much or not enough ink, no more cleaning of them after use.
Still easy to upset, tho.

Marcello

[ParCan]

Cylinders assembled.
Still a bit sticky in places but nothing a bit of use will remove.
Pistons seal well

The washer is my tool for drilling the Cylinder caps and Packing glands.

1 10mm washer. Put in 3 jaw chuck.
With a Spirit level get 1 chuck jaw horisontal.
Scribe a mark on the washer with the lathe tool. Repeat 2 more times.
Mark a circle with dividers.

Drill 2.5 mm in 3 places

Crude but it worked for me.

Made the bearing blocks today.
Had to make em out of 3/4 square bar which is only 19mm. Close enough (I hope).

They were not hard to make.
Take bar. Mill to 15mm thick.
Put in a 4 jaw and center for the 5mm hole.
Drill 4.5 mm and ream to 5mm

Part off 2 at 10.5mm thick. Make a note of which way around they go.
Re drill / ream for the 2nd pair.
Part off the next 2 and repeat (I made 6)

Mill both sides to get to 10mm thick.

Drill the holes for the base plate and screw down as they came off the material.

Lapping was a breeze - took maybe 5 mins and the shaft spins freely.

Alex.

[ParCan]

Oh Bother !

I made the beraing Blocks upside down !
I can see there is no chance with getting away with that and whilst my bits are not the best - this is a learning thing for me, I'm not even going to attemt to turn em over.

I think what I'll do is once this one is complete and I have a Mill I'll make another one - and make it nice.
I am slowly but surely working out Cutting speeds. Things have been far to slow esp. on th eMilling side.
 
Alex.

[Brass_Machine]

...

I made the beraing Blocks upside down !
I can see there is no chance with getting away with that and whilst my bits are not the best - this is a learning thing for me, I'm not even going to attemt to turn em over.
...

I have done that! In fact, I did it on a team build for an engine. I didn't realize it until I sent out 10 of them to other people 

Still, you said you are learning right? Doing a pretty good job of building it.

Eric

[ParCan]

Hi All
Bit of an update. (sory no pics).
Yestarday I made the crank webs.
They are not easy, far from it.
I started 6,
1 parting off failure.
Got 5 completed.

Of the 5, 3 are perfic. 2 the Screw hole was off center.
All in all I think I have 4 usable, time will tell.

Assembled the crank and it turns quite freely in my origonal bearing blocks.
Maybe they will actually work so I Turned the Boss on those.

Today I made the pillars, the lengths are slightly wayward at the moment all to long.
I Bolted the crank and block together and the whole thing locked up solid.
A few washers and bits of shim and things are better on the crank but both Crossheads are very unhappy.
Lostened the Rods and made some improvements but they are still far from good enough.

Made the Con rods from 6.5mm (well a tad under) hex Brass, had real fun centering those to drill the holes.
I put a 6.5 mm drill in the Lathe chuck and raised the Milling vice until the jaws just touched.
Center drilled and then reamed to 4 mm.

Measuring 28.5 mm then became an issue.
I have a Metric Screw in the Cross feed.
14 1/4 turns /should/ give me 28.5 mm yes ?????
It was closer to 30 mm
I checked lash and that was fine. Barely any.
Tried again - measued it this time and 14 1/4 turns on my metric screw = 29.8 mm
Makes no sense whatsoever to me I have to say......

3rd attempt I got 2 Usable Con rods.

Went to make the Pins and destroyed all 3 points on a carbide insert.
Gave up for the day at that point......

There must be a trick with silver steel. I just have yet to find it.

Couple of Q's.

How do I line up the flywheel to drill the Screw hole?
How do I turn something accurately (such as the pillars) to length ?
What is the secret to turning silver Steel without chipping your carbide Inserts ?

I'll get some pictures for you tomorrow.

Alex.

[ParCan]

Silver Steel Q solved
Slow down and use Cutting oil

[mzt]

[1] How do I line up the flywheel to drill the Screw hole?
[2] How do I turn something accurately (such as the pillars) to length ?

1) Chuck in a pointed rod ot tool and place a ruler over the workpiece, bring them into contact and move the workpiece till the ruler is square to the tool.

2) I use a spindle backstop or a micrometer stop for the saddle, often together.

A word of caution about the item in the first picture: it must NOT be used when protruding from the back of the spindle more than a little: it would bend and hit You. That handy knurled wheel on the far end will increase the risk. Replacing that long threaded bar with a shorter one would be quick, easy and safer.





..and a word of caution about the second: running the carriage into the micrometer stop under power does no good to your lathe. Do not ask why...

Marcello

[ParCan]

Hi.

At long last some pictures ......

The engine turns but there are issues with the Con Rods and Cross Heads.
I may need to remake the Top Plate. the Con Rods i can dress dowm a little.

Started this am on the Spool valves.
I think the pictures tell their own story
It's been costly. 2 Totally destroyed Tips. 1 partially desrtoyed.
1 Broken M2.5 tap.
I started with 300 mm of 6mm rod, 50 or so mm left.
It's taken me all day to get 2 Spool Valves.

[spuddevans]

We all get days like that Alex, in my paddleduck build, in total I ended up making 4 spool valves (2 had far too much leakage in the bore of the valve)

I too had problems getting it to turn over smoothly, the best advice I can give you is to just take your time and work methodically through where it is sticking. On mine it was only slightly binding up, but it was binding up in quite a few places and so all that "slight binding up" added up

I ended up slimming the con-rods down using a bit of emery held on my surface plate, that along with fiddling with the crosshead bars after enlarging their mounting holes in the top plate, got me to the point where there was much less resistance. Then I left the fiddling until I had it ready to run on air and did any last fine-tuning while running it in.

Stick at it, it's coming together nicely. We're starting to see an engine appear 


Tim