PMR 7 Twin Cylinder Steam Engine

[zeeprogrammer]

Carl, I don't now what you intend to use for piston rings but I find rolled up graphite yarn soaked in oil works great

Thanks!

The kit came with teflon rings and I'll stick with that.

If it makes any difference, the engine will only be run on air.

[b.lindsey]

Two parts closer to a runner Zee. The pistons look good from what I can see in the pictures.

Bill

[zeeprogrammer]

Two parts closer to a runner Zee. The pistons look good from what I can see in the pictures.

Thanks bill. The pistons themselves seem to be near spot on (perhaps a thou under) and fit easily into the cylinder.
With the teflon rings though, they don't go in. It may be that I didn't cut the ring slots deep enough but there may be something I don't know about fitting such a piston into the cylinder.

I've never made pistons with rings before.

[zeeprogrammer]

Remember that 3D printed spindle stop I made?
Remember the little 'idiot' sign I made to remind myself to remove the spindle stop before turning on the machine?
Remember you might have said to yourselves, "yeah, I'm sure THAT will help"?

A clever idea for use only by a clever person.

I'm printing another spindle stop.

 

[b.lindsey]

And maybe a bigger sign? 

Bill

[zeeprogrammer]

And maybe a bigger sign? 

Thank you for your support. 

Worked on one of the crossheads.

1st pic shows an end being squared off.
2nd pic shows the hole for holding the connecting rod. (There's a piece of rod on the other side of the vise to keep pressure on the vise the same.)
3rd pic shows milling out the area for the connecting rod.
4th pic shows the part being cut off using a slitting saw.
5th pic shows the crosshead almost done.

I haven't put in the drilled/tapped hole for the piston rod yet. I believe the cylinder is a tad off center so will wait and see if I can mark where the hole should be.

Speaking of the slitting saw. It reminded me of the first time I'd used one.
The part was successful cut but an eagle-eyed member noticed something odd about the setup.
The slitting saw was installed upside down.
I'd essentially rubbed the part to completion. 

[mklotz]

Remember that 3D printed spindle stop I made?
Remember the little 'idiot' sign I made to remind myself to remove the spindle stop before turning on the machine?
Remember you might have said to yourselves, "yeah, I'm sure THAT will help"?

A clever idea for use only by a clever person.

I'm printing another spindle stop.

Maybe you could use a Sharpie to write "remove spindle stop" on the inner surface of your safety glasses' lens?

Brings to mind a sig I saw on another forum...

A few learn by reading. Some learn by observation. The rest have to pee on the electric fence for themselves.

[crueby]

Remember that 3D printed spindle stop I made?
Remember the little 'idiot' sign I made to remind myself to remove the spindle stop before turning on the machine?
Remember you might have said to yourselves, "yeah, I'm sure THAT will help"?

A clever idea for use only by a clever person.

I'm printing another spindle stop.

Maybe you could use a Sharpie to write "remove spindle stop" on the inner surface of your safety glasses' lens?

Brings to mind a sig I saw on another forum...

A few learn by reading. Some learn by observation. The rest have to pee on the electric fence for themselves.

 

[zeeprogrammer]

Remember that 3D printed spindle stop I made?
Remember the little 'idiot' sign I made to remind myself to remove the spindle stop before turning on the machine?
Remember you might have said to yourselves, "yeah, I'm sure THAT will help"?

A clever idea for use only by a clever person.

I'm printing another spindle stop.

Maybe you could use a Sharpie to write "remove spindle stop" on the inner surface of your safety glasses' lens?

Brings to mind a sig I saw on another forum...

A few learn by reading. Some learn by observation. The rest have to pee on the electric fence for themselves.

As in 'doing'. To learn by experience or not?

In my case...I just forgot to turn off the fence.

[Jasonb]

Tie some Tutu elastic to your spindle stop and fix the other end to the ceiling that way it will have to be held in place and will automatically release

[fumopuc]

Remember that 3D printed spindle stop I made?
Remember the little 'idiot' sign I made to remind myself to remove the spindle stop before turning on the machine?
Remember you might have said to yourselves, "yeah, I'm sure THAT will help"?

A clever idea for use only by a clever person.

I'm printing another spindle stop.

Maybe you could use a Sharpie to write "remove spindle stop" on the inner surface of your safety glasses' lens?

Brings to mind a sig I saw on another forum...

A few learn by reading. Some learn by observation. The rest have to pee on the electric fence for themselves.

Hi Marv, as always, great humor.

[zeeprogrammer]

Tie some Tutu elastic to your spindle stop and fix the other end to the ceiling that way it will have to be held in place and will automatically release

  Then I'm back to a 3rd hand with #3 holding the spindle stop in place. 

[zeeprogrammer]

Well that was close...

I'd not used/installed the 4-jaw yet and it was time...

Both chucks have a back plate that inserts into a ring lock on the spindle.
I took the 3-jaw off and started installing the 4-jaw.
I did a little rotation and it seemed the 4-jaw chuck rotated.
What? This can't be a screw on.
Twisted a bit more and it popped off.
Got my hand a little but not much.
A very good thing I'd built that wood holder!!!

So then I discover that 4 bolts are missing that are used to hold the chuck to the backing plate.
No idea why they hadn't mounted the chuck to the plate.
The 3-jaw was already secured to its plate.
I suppose because the 3-jaw came installed on the lathe.

But here's my question...in looking at the backing plate...4 bolts...

Does that mean I might find a collet chuck that fits that?
If so, how is this spec'd so I can find a collet chuck that fits?

Or, is this what is meant when people talk about making a backing plate...to fit the plate in the picture and to fit a collet chuck?
And even then...what consideration is there in choosing the collet chuck?

This also tells me I have two different backing plates. One with 3 holes (for the 3-jaw) and one with 4 (for the 4-jaw).
Is there something I need to know about this? (Seems the plate in my old mini worked for both chucks).

Do I have the terms correct? I'm calling that thing on the spindle a backing plate.

Thanks.

[Jo]

Do I have the terms correct? I'm calling that thing on the spindle a backing plate.

Thanks.

Hi Zee, yes that is a back plate but please screw it to the back of your four jaw chuck rather than try using it for multiple jobs.

Back plates can be purchased already threaded to fit on the nose of your lathe then you turn the shoulder to fit what ever chuck you want to fit. Then you drill for the chuck fixings; making sure you drill the right number of holes, in the right place 

As you can guess there are a number of opportunities of "Zee_features" to be added to back plates 

Jo

[Jasonb]

Zee's spindle is not threaded. Its a flange and keyhole plate mount

Zee you need to buy or make a backplate with a plain bore and the 3 flange mounting studs and nuts at the back and then machine the front to fit the register in your coller chuck which will more than likely have 3 hole mounting.

As Jo says fit one chuck to one backplate and don't keep swapping them about.