Monitor Steam Engine

[b.lindsey]

What kind of toolbits are you using? HSS, cemented carbide, inserts?

Bill

[zeeprogrammer]

Thanks Bruce. The longer lengths of steel is an idea.  I hope to see your build soon.

Thanks crueby. Silly me. It did cross my mind to double check the cutter height. And then I forgot. I've still got a ways to go to reach 1" diameter so I have lots of experimentation I can do before I have to chop another piece of stock.

Should have some updates on mine tomorrow

Don't forget pics. Otherwise, you know who will jump you. 

You posted while I was writing Bill...

The boring bar is (cemented) carbide. Cheapie bought as a set from LMS.
The flycutter was HSS and I'm thinking not particularly sharp.
For facing and turning I've been using an insert and have had good luck. Or think I do.

[crueby]

Definitely sharpen the boring bar! Nice that you are not too close to final size on bore, good chance to experiment with hieghts, speeds, and feed rates.

The suggestion of clamping on other bars under thin stock in the vise is a good one. Did that a couple times, really helped. For supports underneath, a machinists style jack is handy, can rig one up out of big nut/bolt. For really long pieces I made a wood crossbar on threaded rod once. Does not have to look fancy, just has to work!

I'll be sure to include pics and text on my thread for those guys. Might mix up the order, or throw in "Number 3, the Larch" to see who is paying attention.... 

[zeeprogrammer]

I don't get it.

I checked the cutter height as well as the angle of cut.
Put a little oil on.

Came in for a cut. Nice cut.
Backed off and came out. (i.e. I didn't cut in reverse).
Stayed at same position.
Came in for a 2nd pass. Nice cut.
Backed off and came out (without cutting).
Stayed at same position.
Added some oil.
Came in for 3rd pass. Chatter and crappy cut.
3rd pass was supposed to be the same as the 1st two.
Tried a 4th and got the same as the 3rd.
Tried to keep the same speed for all cuts.

hm.

I've seen this before. Comes and goes and I can only hope I get a good cut for my final passes.
Not acceptable.

I have to get good at making cylinders or my dream of a loco will not be.

Just ranting a little. Not much. Just a little. 

Wish I could blame something. Lathe, cutter, Cletus. Something. 

crueby...you posted while I was typing. I have a couple of home-made jacks. But shouldn't the parallels have been sufficient. Ah...
I had mentioned how the parallels came loose after tightening. Putting the jacks under after tightening the vise might do it. Thanks.

[tvoght]

Looks like progress to me, Carl. I sympathize with your boring frustrations. My least favorite shop activity. Remember that old joke?

Q: Excuse me sir, how do you get to Carnegie Hall?
A: Practice, Practice, Practice.

--Tim

[PStechPaul]

I made a "boring" video about two years ago that shows some of the steps I took to make a 1.500" bore in a 2" diameter aluminum bar, 3.5" long. I drilled through up to my largest drill of 1/2", and then used various boring bars to open the hole to full size. I bored about 2.5" deep from one end and then finished the job from the other end, which may not be advised but it worked for me. It's not perfect, but it seems to fit the pistons I made for it (from acetal) well enough, and I did some work on it with a cylinder hone as well as abrasive cloth. This was really my first attempt at boring and I learned from the experience.
 
[youtube1]https://www.youtube.com/watch?v=VyKSS5CBhf8[/youtube1]
 
The finished cylinder (well, not quite completely) is shown here with one of the pistons:

 

 
And some pictures of the process that might also be in the video:

 

 

 

 

 

[90LX_Notch]

Carl-

I assume that you are boring straight through.  Two things to consider: the toolpost is oriented slightly off, creating no side clearance and the side of the side edge is rubbing.  Or, the boring bar is rotated along it's axis creating excessive back rake thus causing the side edge to rub.  Those bars are set with the front cutting edge parallel to the ways.

I hope this makes sense.  My wife just got home with pizza.  Gotta go!

-Bob

[zeeprogrammer]

Thanks Tim. I know...practice practice practice. That's gotten me 40 years of marriage so far. 

Thanks Paul. That seems to be the way I'm doing/trying it.

Thanks Bob. When you say "the toolpost is oriented slight off off"...what do you mean? That it should be or should not be?
I did rotate the toolpost slightly. Had to or the part came up and screamed against the shank. (Maybe my boring bar is just too short.)

I do wonder about the cutting edge being parallel to the ways. I've tried and tried. Seems like it doesn't take much to make a difference.
I will play some more with it. (I have to...or I'm sunk.)

Still...how does all this explain the 3rd pass when things went awry and I hadn't changed anything.
Seems like something changed...I just can't find it yet.

Pizza!!! You lucky dog. I have two more days to get mine.

[yogi]

Zee, some tips I could think of:

-Use the biggest boring bar possible, and keep the stick out of the holder as short as possible.
-In aluminum, I would suggest an HSS boring bar with a very sharp grind.
-Reduce surface speed and increase feed. While boring, as diameter increases, so does surface speed.

As for cutting oil, I would suggest WD40. But the cutting fluid is not critical, as long as it's not dry.

Hope that helps...
yogi

[zeeprogrammer]

Thanks yogi.
I'm using the biggest boring bar I have...but it's still small compared to the workpiece.
I don't have an HSS boring bar. (I'm hoping for a new lathe at which point I want to get better tooling.) Yes I know I could make one.  Marv can educate you about me.  I may surprise him when it comes time to make some keyways.

I'm having better luck tonight. The finish is looking good. The only change was a slight change in cutting tool angle. Maybe speed.
On the other hand...it could be what I said earlier...same setup etc. and sometimes it's nice and sometimes it's not.

But I've had two motor stalls and I don't know why yet.

On the up side...I'm having a blast.  And that's what counts in my book.

[Tennessee Whiskey]

Let it rip,  tater chip.  Just keep playing wit it until it's a couple of thou under and then find out where Stan gets the hone with the balls on it thingee 

Cletus

Dave said it was sure nice to see your camera working 

[joe d]

Zee

Been following along with your adventures...

One thing that strikes me from the last batch of pictures is the tool holder you have the boring bar in.

Can't quite tell from the angle of the picture, but does that tool holder have a groove along the bottom for the shank of the boring
bar to ride in?  If not, with only two off-center screws  holding it on a flat surface, it may well be moving around on you.

Cheers, Joe

[yogi]

I understand, we all have to get by with the tools we have. That makes it that much more of a challenge...   
I'm glad you're having fun. That's what it's all about...

[PStechPaul]

Zee

Been following along with your adventures...

One thing that strikes me from the last batch of pictures is the tool holder you have the boring bar in.

Can't quite tell from the angle of the picture, but does that tool holder have a groove along the bottom for the shank of the boring
bar to ride in?  If not, with only two off-center screws  holding it on a flat surface, it may well be moving around on you.

Cheers, Joe

Those pictures are probably mine. I agree that it's not the best way to hold a round shank boring bar, but it worked OK. My lathe is a little larger than Zee's - I have a 9x20.

[crueby]

I think zee is using an A2Z qctp, I have same one, had to modify it to keep it from twisting during cutoff or boring operations on my sherline. Zee, make a pen line at its base, when things change see if toolpost turned slightly. Drove me nuts till I figured out a fix for it.