Author Topic: Elmer's #33 Mill Engine - MZT  (Read 17010 times)

Offline Don1966

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Re: Elmer's #33 Mill Engine - MZT
« Reply #15 on: September 21, 2012, 07:34:39 PM »
Gee..... You been a very busy fellow Marcello. Looking great.

Don

Offline sbwhart

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Re: Elmer's #33 Mill Engine - MZT
« Reply #16 on: September 21, 2012, 07:45:42 PM »
Looking good Marcello  :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp:

Stew
A little bit of clearance never got in the way

Offline zeeprogrammer

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Re: Elmer's #33 Mill Engine - MZT
« Reply #17 on: September 22, 2012, 01:19:21 PM »
Very nice Marcello.

I like that round-over bit you made. Timely post for me.

I've never seen a pic of someone sawing on their machine vise so that was interesting too. I noted the duct tape for protection.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline mzt

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Re: Elmer's #33 Mill Engine - MZT
« Reply #18 on: September 24, 2012, 10:41:38 AM »
Carl,

Round-over bit: mine works no better than for roughing a curved shape, someday I will try to make a 'finishing' one. Possibly on a grinder.

Machine hacksawing: I'm never sure whether that practice does any good to my machines, put probably they're not facing harder jobs than the ones they're made for.
Sure, I'm placing a board of wood on the lathe bed when hacksawing a piece held in the spindle.

Marcello

This is a fitting job,
not a production job that can be measured in.

Offline mzt

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Re: Elmer's #33 Mill Engine - MZT
« Reply #19 on: September 24, 2012, 10:42:17 AM »
Top Base

Having the already bevelled top base sanded and polished I realized a rather huge slot was missing...




The good point being I finally have an occasion to use that 12mm MT2 T-slotter.
The piece of scrap on the between the wp. and the fixed jaw of the vice was put there so I could also fit an angle plate
into the setup, the wp. being bolted to the angle plate itself from the back.
I suppose Simon is now in credit of a ruined workpiece with me: thank You for sharing that problem with the eccentric strap.


 
Bearings

Started with making the short one, pres fitting a brass bearing I had drilled 5.8mm into the alu. body.




 Then, I made the tall one (decided to make the body in two parts, don?t ask...)
Now, I have to solve the problem of drilling the second bearing in line with the first. Time to experiment a bit.

Chucked in the lathe a short (maybe 50-60mm) piece of 6mm steel rod, reduced one end to 5.8mm and drilled it through 3mm dia,
hoping for the best.    The drill wandered, You bet.
Not being interested into another try, I reversed the rod in the lathe, chucked a 4mm end mill into the TS and plunged the
wp. ~10mm deep to gain some kind of guide for a 4mm bit. 

Something like this:










 
Now being put into use, the tall bearing being supported by a jack screw.



 

drilled to 9.9mm, then bushed,




and line reamed to 6mm dia.




Most of the parts, so far.



Marcello
This is a fitting job,
not a production job that can be measured in.

Offline b.lindsey

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Re: Elmer's #33 Mill Engine - MZT
« Reply #20 on: September 24, 2012, 11:49:37 AM »
The engine is looking great Marcello!  Nice finish on all the parts too. 

Bill

Offline mzt

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Re: Elmer's #33 Mill Engine - MZT
« Reply #21 on: September 27, 2012, 11:19:52 AM »

Crosshead


The c.i. blank. I knew I would have found some use for it, someday. That material cuts like butter, btw.
 




A blur photo of the finished crosshead, pin and pin blank.





Now in place
 




Pity, I noticed now, I forgot about the ?key? at the bottom.




Either there?s still material enough to cut it on the upper face, or some exercise into putting metal back where
it should be will be in order, tonight.


Marcello
This is a fitting job,
not a production job that can be measured in.

Offline zeeprogrammer

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Re: Elmer's #33 Mill Engine - MZT
« Reply #22 on: September 27, 2012, 11:34:51 AM »
Pity, I noticed now,

A familiar experience.

I hope it works out.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline mzt

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Re: Elmer's #33 Mill Engine - MZT
« Reply #23 on: September 27, 2012, 11:51:42 AM »
I have ideas a round key press fitted (a drop of glue won't hurt) into the bottom of the crosshead would do. .
Rather let the press aside and use the vice, tho.

Marcello
This is a fitting job,
not a production job that can be measured in.

Offline b.lindsey

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Re: Elmer's #33 Mill Engine - MZT
« Reply #24 on: September 27, 2012, 12:24:49 PM »
Marcello, even though the crosshead will be held straight by the con rod and crank rod, the key protects against any side movement. A round "key" would accomplish this without having to remake the part, but I am thinking a square key, as per the original design even if added on to the bottom would provide a much larger contact area and protect against wear over time. The round key will only touch the crosshead guide at two points. Just a thought.

Bill
« Last Edit: September 27, 2012, 12:43:37 PM by b.lindsey »

Offline mzt

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Re: Elmer's #33 Mill Engine - MZT
« Reply #25 on: September 27, 2012, 12:38:58 PM »
Bill,

the point is good.

Thank You
Marcello
This is a fitting job,
not a production job that can be measured in.

Offline NickG

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Re: Elmer's #33 Mill Engine - MZT
« Reply #26 on: September 27, 2012, 11:36:26 PM »
Looking great, it's a nice design that one - well executed  :ThumbsUp:

Offline mzt

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Re: Elmer's #33 Mill Engine - MZT
« Reply #27 on: October 05, 2012, 04:41:53 PM »
Crosshead (again)

I could reverse the crosshead on the guide (the hole for the piston rod was in line with the rod itself, but non at the center of the c.h.)  and mill a key for it to slide into the guide.
Not exactly to size as per drawings (1/32) but very very close (a little less than 1/96...)
That could do, providing I will leave very little clearance between the lower and upper guides.
 I will know for sure in a little while.

Should it not, I see making an entirely new one would not be much work, pity for the scrapped piece.
But I would surely find a use or two for a small sized C-clamp in time.

Marcello
This is a fitting job,
not a production job that can be measured in.

Offline mzt

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Re: Elmer's #33 Mill Engine - MZT
« Reply #28 on: October 08, 2012, 09:37:28 AM »
Crank

That ?blank? from the scrap steel box, already turned to size, drilled and tapped M3 for the crank screw and bored somewhere above
(but close to) 5.9mm for later press fitting the crankshaft.

I also turned an alu. collar to a close fit with the crankshaft bore and drilled it for an M4 screw with no play.




Put the RT in the vice, then the faceplate on the RT, centred the RT with the spindle, then added a scrap plate I could drill
and tap in the needed positions to the faceplate.
A few layers of paper to keep the workpiece a little above the surface, then I milled the crank at coordinates.






Connecting Rod

Or part of it. Here is shown while tapping, together with the filing button I used to bring it to shape.




Here it is, together with the piston already fitted with a new shaft. Facing the bottom of the piston in the lathe while
held with a 3mm shaft was not a good idea.




So much for ?taking the risk? not to switch to a larger collet to hold it properly.



Eccentric

Yet another occasion for my eccentrics jig.






Eccentric strap

I?m definitely into building up engine parts, today.  The bearing came from a thick brass washer, here I?m cross drilling the
arm 1.5mm dia. using an improvised jack for support.



 
In place, after filing two flats for the valve rod.





 
Steam Chest

An occasion to put the recently made faceplate (and angle plate) into use, finally!

After turning, facing and drilling the inboard end of the steam chest , I drilled the faceplate for a 2mm locating pin
 



to aid keeping things aligned when cutting the second end.



 

Flywheel

Decided it could do with a few holes: I centred a 6mm shaft held vertical in the vice with the mill spindle, added a scrap alu. disk
(a VCR head) to protect the vice itself, then the flywheel and drilled the six 8mm holes at coordinates.




Marcello
This is a fitting job,
not a production job that can be measured in.

Offline zeeprogrammer

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Re: Elmer's #33 Mill Engine - MZT
« Reply #29 on: October 08, 2012, 11:27:14 AM »
Looks like you're really moving along.
It's coming together very nicely!
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.