Potty Lads and Dads Mill Engine

[NickG]

Lee if you only loosen 2 jaws it is going to clamp back in as near as damn it the same position. The point of turning the centre was to have one large enough such that the jaws are wide enough apart to act as drive dogs.

[sbwhart]

From a technical point of view doesn't making a center in your chuck and then moving it negate the benefit of turning the center in place?  From a practical point of view, keeping the center aligned with chuck in the same position it was turned, surely means it works out fine.

Sorry to be so picky, it just popped into my head as I was reading your excellent write up.  I am enjoying it very much.

Lee

Lee:- Yes and No the parts I'm turning are not that critical if things move a bit all that will hapen is that the part will be turned tapered slightly, and I'm turning a taper on one of them any way, and the other it won't make any diference if it is tapered. That's why its important to try and understand the function of a feature, that way you get it right when it needs to be and you can slaken up where it doesn't.

Stew

[sbwhart]

A few more parts done,

First up the bearing brasses:- drill the clamping holes in some 1/4" brass square bar



Then bolt them too the con rod mark the centre line and drill and ream through 6mm dia



Then make the end plat sorry no pics for that bit.

Then make the little end gudgion pin



The the slide bars to get the M4 tap square I light held the tap in the chuck jaws just enough to keep them square but not enough to stop it turning in the chuck then with the wrench clamped on the parallel bit of the tap start the tap nice and square, and remove the job from the vice to finish it off.



Thes are the bits



And how they assemble



Stew

[b.lindsey]

Very nice Stew...still following along and enjoying your thread on this build.

Bill

[NickG]

Yeah looks good, like it. 

[sbwhart]

Thanks for the support Lads  :thumbup:


I ordered a chunk of 1/4"* 3" ally plate from ebay, for the bed plate I first carfully marked out the position for the cylinder assembly i had to drill and tap 2 more m3 hole into the cylinder base to fix it I intended to screw to go right through the bed plate through the cylinder base into the cylinder but my M3 countersunk cap screws were too short for this hence the extra holes.

Drilled and countersink the bed plate.



Then made the crodd head slide bars from some 1/4" squ mild steel bar, I put the drill vice stop to good use to get them all drilled the same with the stop set and the vice clamped to the table it it just a matter of setting up on the first then driiling it then dito for the rest having first made shure they were all the same length.



Then the spacers were made I just truned a length up enough to make three centrree drilled then drilled through 2.5 than carfully parted them all off to the same length. No pics

Then it was the turn for the supporting pillars it important that these are made to match the assembly so a took my time and measured the centre height of the piston and did a bit of a calculation to get their heght (29.4mm). I made them from some brass hex bar i had in my stash, first I parted four off 31mm long faced and tapped one end M3 and did the same to the other end but M2.5. These pillars need to be all the same exact length, so I fitted my back stop into my lathe head stock.

This is the beast its just a No 3 morse taper with an M8 hole one end for the stops, and a M10 in the other for a draw bar.



And it in the lathe



And with the chuck mounted.



It was just a mater then of setting the sadle facing off at the same setting, to make them all the same allowing .5 for final finished, put on the final .5 flip them round and face off job done.

I then turned a parallel to just leav a short length of hex.



I then carfully marked the position to driil the holes for the pillars in the bed plate ensuring there was enogh room to tkae up the travel of the cross head etc, and then drill and chamfered the bed plate to take m3 countersunk cap screws to hold them

To ensure the valve rod support lined up with the rod a turned a point on a bit of 3mm silver steel mounted it in the valve chest and gave the support a light biff to mark the position for the hole.




Time for a few hows it looking shots.





Not bad just the crank eccentric and the fly wheel to make.

Stew

[Bearcar1]

You are indeed making good progress Stew. These mill type horizontal engines get my heart pumping. 


BC1
Jim

[arnoldb]

You're really cracking along on this one Stew! Good work 

Kind regards, Arnold

[zeeprogrammer]

Nice post!
Reminds me of some tooling I need to make sometime.

[b.lindsey]

Its really starting to look like and engine now Stew. Very nice too!!!

Bill

[sbwhart]

Cheers Chaps

The Boss was has been away all day visiting an old school friend, so I was in pigs heaven, all day in the shop.

First bit the crank shaft, turn up and thread the end and cut off



Next bits the crank webs, made from 1/2"*1/4" mild steel bar cut off a couple of bits allowing a bit for cleaning up, then mark out



Then drill both 8mm



Then stick a bit of 8mm bar through both bits and then drill 6mm hole this way the hole centres will be exactly the same for both bits.



Then turn up a 8mm mandrell



Mount both bits to the mandrel tighten up tight abd skim down the ends to form a nice rad



Turn the mandrell down to 6mm mount the bits back onto it and turn the other end down.

Give both parts a tidy up and a polish



Then with high strength loctite assemble the crank shaft and cronk pin.



Just to make sure drill and pin the webs in place.



For the pins use nails cut off just a little longer than required and rivet in place and clean up, and cut out the middle bit of the crank shaft.



Next bit the eccentric to avoid the use of a milling machine this is fabricated in two part plus the eccentric sheath.

Luckily I had a bit of brass tube that was near to dam it the corect size all I had to do was part a ring off, and drill and tap M3 for the shaft.



The eccentric first part was a top hat outer part.



Then the inner part this as the off set for the throw.

Turn up dia for assembly to the top hat bit



Try the fit



Flip it round in the chuck face to thickness and put in a small centre.

Then mark out the throw.



Set it up with a wobble bar



Drill and ream



Turn up the boss



And stick the bits together with high strength loctite



And a try for fit of todays bits.



Stew

[NickG]

She is looking great Stew, shows what can be done without a mill!

[sbwhart]

Thanks Nick

I'm getting to that stage when your arse start to twich with self doubt:- will she run or won't she.

Stew

[b.lindsey]

She'll run Stew...I have no doubts

Bill

[Bearcar1]

I'll second that, it will run, and quite well I am sure. I've certainly enjoyed the ride so far Stew, thanks for that.


BC1
Jim