Missing pages in plan??

[deadin]

Hello,
I'm a brand new "machinist" and just found this site. I think I'll like it here!
I am just starting to learn metal working after a lifelong desire to do so. (I'm 68yo.)
So far my experience is a successful wobbler and a disastrous "elbow" engine.

Anyway, on to my first question........
I downloaded a set of plans (from another site) that seem to be missing a page or two.
They are for a "Model Horizontal Single Compressed Air Engine" by Chuck Fellows. It seemed to be a likely project for a novice. However there are no drawings, specs, or instruction concerning the valve timing mechanism and eccentric, other than a note saying that the gears should be a 2:1 ratio. There also is nothing about the flywheels included, but I think I can fake them. ;D (I'm also having trouble figuring out how to machine the crank from a solid billet of steel, but I'm not ready to give up on it, yet.)

 

[Brian Rupnow]

Here is my version of the build of Chucks Horizontal.
http://www.homemodelenginemachinist.com/index.php?topic=5234.0
If you read through this it will help a lot, and it will also take you to a set of complete mechanical detail drawings in the download section

 

[b.lindsey]

Welcome to the forum deadin !

Bill

 

[Maryak]

deadin,

Welcome to our forum.

Best Regards
Bob

 

[rake60]

Welcome to HMEM deadin.

Rick

 

[deadin]

Thanks for the welcome!!

Now, on to more questions.....
I've downloaded Brian's plans(Great plans BTW ;D) and see that I need to turn a couple of 3 1/2" flywheels.
My first problem is I have a Grizzly Mini-Lathe and only 3" chucks. (3 and 4 jaw). I figured I would just get a larger chuck but then realized I don't have enough cross slide feed to handle anything bigger than 3".
If I center bore them for an arbor and don't get it perfect, I have no way to true up the outer circumference.

Any secrets or tips???

Dean

 

[b.lindsey]

Dean, You should be able to reverse the jaws in the chuck and hold something larger than the chuck diapeter itself. Looking at the Grizzly site the spec for the nimi lathe is 7" over the bed so you should have plenty of room to work with. The spec for cross slide travel is 2 3/4" so theorhetically you should be able to handle something near 5 1/2" in diameter along the cross slide axis.

Regards,

Bill

 

[b.lindsey]

Dean, You should be able to reverse the jaws in the chuck and hold something larger than the chuck diapeter itself. Looking at the Grizzly site the spec for the nimi lathe is 7" over the bed so you should have plenty of room to work with. The spec for cross slide travel is 2 3/4" so theorhetically you should be able to handle something near 5 1/2" in diameter along the cross slide axis.

Regards,

Bill

Uh, make that "mini" instead of "nimi"

 

[deadin]

Bill,
You’re right about the chuck jaws being able to handle a little more than the chuck diameter. I checked mine out and I will be able to get the 3 1/2” dia. into them. I won’t have the full thread support on the jaws, but it should work.
However, the “advertised” 2 ¾” cross slide movement is a bit of a misnomer. It is 2 3/4” , but that is only for a facing cut, as about the last inch of feed is past the axis of the headstock. With a 3 1/2” dia. work piece chucked up I can just about get an 1 3/4's allowing the tool holder to clear the outer rim. This doesn’t leave any room for the tool to project from the holder.
One possible solution I can think of would be to chuck the work up and then face the inner cuts, leaving the outer rim. I would also drill the center at this time. If I don’t get everything quite true and need to clean up the outer diameter I would then reverse the work and chuck it up by expanding the jaws into the cut I just made or put it on an arbor. Then by mounting a boring bar in the tool holder and running the lathe in reverse, I should be able to true up the outside.
This may not work at all, but I’m trying….. ;D ;D

Dean

 

[Tin Falcon]

Then by mounting a boring bar in the tool holder and running the lathe in reverse, I should be able to true up the outside.
This may not work at all, but I’m trying….. Grin Grin

Dean: first of all welcome.
Learning machining includes learning creative ways to hold the work and tooling to get more from the machine at hand. In your case the mini lathe. Just use good judgment and be safe. If a creative setup does not feel right or safe it probably isn't. Out of the box the minis have a lot to be desired. there are lots of accessorizes and mods to improve them. IMHO one of the best accessories for any lathe is a quick change tool post. also another option to get more travel from the cross slide is a mod found here http://warhammer.mcc.virginia.edu/ty/7x10/xslidemod.html
Tin

 

[deadin]

also another option to get more travel from the cross slide is a mod found here http://warhammer.mcc.virginia.edu/ty/7x10/xslidemod.html

I may try that in the future when I feel more competent to start cutting on my own machine.

Dean