Monitor Steam Engine

[mklotz]

Couple of questions on the die holder...

Is the tommy bar short enough to not hit the lathe bed?  Should the die snag, you don't want the bar driven into the bed or acting as a stop to make something break.  Are there (at least) two tommy bar holes?

Are the screws located so as to correspond with the (presumed) dimples in the die edge?  Will they close the (presumed split) die when tightened?  Is there a screw positioned so as to force the die open if that is required?

If you do decide to knurl it, how are you going to hold it now that it's removed from its parent stock?  Did you think about that?

"I caught a lot of flak from several of you (especially Marv) in starting my first engine with a casting."

Considered professional advice and tutoring described as flak, heh?  I guess it's time to start volume four of the list.  :-)

[zeeprogrammer]

Thanks Don and Bill.

Marv...a couple of answers...

Is the tommy bar short enough to not hit the lathe bed?  Are there (at least) two tommy bar holes?
Are the screws located so as to correspond with the (presumed) dimples in the die edge?  Will they close the (presumed split) die when tightened?  Is there a screw positioned so as to force the die open if that is required?
If you do decide to knurl it, how are you going to hold it now that it's removed from its parent stock?  Did you think about that?
I guess it's time to start volume four of the list.  :-)

The tommy bar is the same one that came with my purchased die holder. It won't be any longer since the inner diameter is the same as the original holder.
I rarely have used the tommy bar. Your question seems to imply threading under power. I generally don't do that either...although I've experimented.

Just the one tommy bar hole. I made this holder the same as the purchased one. Chris suggested more. It can always be done if needed.

The holding screws are set to the dimples in the die. That's a big reason I used the rotary table so I could get 180 degrees to the other side.
The die itself has a screw to adjust the split. I didn't know that people could use the holding screws to do that. I wouldn't have thought so. The dimples are at an angle to the split and I doubt using them applies a decent force. This die has only two dimples. I see that my smaller dies generally have three.

Yes I did think about how to hold the part if I decide to knurl it.  It would be by the larger diameter. If I knurl, it won't be up to the larger diameter, nor the very other end. If necessary I can hold a live center against the end with the tailstock.

Only three volumes? That works out to less than one volume per year of knowing you. But surely those volumes are not zee-dedicated. 
If they are...please will them to me. 

[mklotz]

Even if you're not threading under power, you need the ability to rotate the holder through 360 degrees using the tommy bars.  This implies that the bars must clear the lathe bed.  It also implies that you need at least two bars since the situation will arise where one bar is pointing down and it's awkward to continue the rotation using that bar.  Would Chris and I give you bad advice?  (Don't answer that.)

On many die holders one of the screws has a 60 degree point.  You locate the die in the holder such that this screw enters the split in the die.  Thus it can open the die when screwed down.  Typically, when the die is so oriented the dimples will align with the other holder screws that can be used to close the die.  Adjusting the die with the external holder screws is easier than having to remove it from the holder to access the integral screw.  In fact, I remove the integral screw from most of my dies for just that reason.

Since your die has an integral adjusting screw, the paragraph above is moot but it does apply to other dies that don't have such an arrangement.

Any knurling operation puts a huge drag torque on the workpiece.  If you do knurl it pay a lot of attention to how well it's held in the chuck lest it slip and mangle your beautiful holder.

[zeeprogrammer]

I'm not sure I follow your 1st point. When I have used the tommy bar and it begins to interfere with the bed, or if I can't get to the bar, I just rotate the chuck along with the die holder.

I do the same when tapping (which happens more often). There I almost always use a tommy bar.

Thanks for the info on die holders. My purchased one must be pretty simple. I will look into that more.

To your last point...if I knurl I'll probably use a live center in the tailstock to hold the part.
But I just looked at my knurler. Too small. I won't buy or make one just for this.

And yes...both you and Chris would give me bad advice.  You certainly have in the past. 
Particularly in choice of beverage.

Never bad advice with machining though which is much appreciated.
All else is suspect. 

[mklotz]

Anyone who drinks stinking hoppies can't possibly get bad advice regarding choice of beverage.  When you're at the nadir, the only direction is up.

[zeeprogrammer]

When you're at the nadir, the only direction is up.

Good to know where the zenith is but difficult to fight gravity getting there.
Particularly after the aforementioned beverages. 

[zeeprogrammer]

Once again I'm dealing with limited 'z' on the mill...

I decided it's time to drill/tap the holes on the ends of the cylinders...

No way could I mount the cylinder on the rotary table using the chuck. Just no room.
The following will raise all kinds of questions about concentric and accuracy...but I couldn't figure another way.
I decided to make a plug that fits into the rotary table and cylinder...



A tad looser than I wanted. But there's enough slop in the holes of the covers and I don't think anyone can/will see any inaccuracy.
I decided not to worry about it.

I decided to center the table using my die holder. Took me a long time to remember how I'd done it before.
Both the die holder and rotary table are morse 2 taper.
Although the other end of the die holder doesn't fit anything I have...there's a bit of collar that's 3/4". That went into a collet.
I decided to bring the mill down to adjust the rotary and then clamp it down.



Since I couldn't hold the cylinder with a chuck...I decided to clamp it. This meant for every rotation I had to unclamp. No choice there so no decision. 
You can't see it in this shot, but like Chris I decided to run a line the length of the cylinder and used a marker on the table.
Had to be careful to keep them lined up as I rotated the table.
The markings will show me how to position the cylinder when I decide to do the other end.



I could not remove the mill's chuck with the cylinder in place so I decided to center drill and drill all the holes.
I decided tapping will come next.

That's enough decisions for now. 

[Jasonb]

Zee, you could have used co-ordinates to dril the holes and been able to clamp the cylinder to the mill table.

Regarding tommy bars I would remove them from teh die holder if you are threading under power unless you don't like your right thumb, also if its a double ended holder make sure the unused screws are not sticking out.

Making good progress

[Don1966]

Zee do you have collets for your mill. If you do cut a piece of drill rod to fit one of you collets an drill the other end to fit you drill bit using a set screw to secure the bit. That should give you enough hi eight.'

Don

[zeeprogrammer]

Zee, you could have used co-ordinates to dril the holes and been able to clamp the cylinder to the mill table.

Regarding tommy bars I would remove them from teh die holder if you are threading under power unless you don't like your right thumb, also if its a double ended holder make sure the unused screws are not sticking out.

Thanks Jason.

I had considered using coordinates...but without DROs and having to deal with what I consider severe backlash in the table, I felt more confident with the rotary.
This holder is single-ended but the other is dual. Good reminder about the screws.

Don...just saw your post. I do have collets. This has come up before. I need to give it serious thought.
I don't have the needed drill rod. Should add to my next order.
Hm. Some stainless steel bearing shaft would work wouldn't it? I have some spare of that. Large enough for a number of drills I commonly use.

[zeeprogrammer]

Uh oh. I think my lathe's tool post is about to fail.
A2Z
The handle one turns to lock the cutter seems to be breaking or bending and the threads in the tool post appear to be getting stripped.

I have a tendency to be ham-fisted and tighten things too much.

I'll have to check into replacement parts but I have a feeling it's all or nothing.

I wonder if it could be re-threaded and a larger handle used?

Any one with similar experience or suggestions?

[Don1966]

Hi Zee, yes that has happen to mine as well. It gets loose and you don't notice it and it messes up the threads. Just drill a hole close to it and tap it to fit the set screw or you could tap it larger and make a new handle.

Don

[zeeprogrammer]

Hi Zee, yes that has happen to mine as well. It gets loose and you don't notice it and it messes up the threads. Just drill a hole close to it and tap it to fit the set screw or you could tap it larger and make a new handle.

Thanks Don. I hadn't thought about a hole near it.

Say...is there any real reason for it to be threaded? Could it be used with a (there it is again) tommy bar?
I just saw that the threads are not 'starting' to strip. They ARE stripped. I can easily pull the handle out without rotating. Poo.

By the way...I asked earlier about using stainless steel bearing shaft instead of drill rod to make those drill bit holders for a collet. Thoughts?

[Don1966]

Hi Zee, yes that has happen to mine as well. It gets loose and you don't notice it and it messes up the threads. Just drill a hole close to it and tap it to fit the set screw or you could tap it larger and make a new handle.

Thanks Don. I hadn't thought about a hole near it.

Say...is there any real reason for it to be threaded? Could it be used with a (there it is again) tommy bar?
I just saw that the threads are not 'starting' to strip. They ARE stripped. I can easily pull the handle out without rotating. Poo.

By the way...I asked earlier about using stainless steel bearing shaft instead of drill rod to make those drill bit holders for a collet. Thoughts?

I would thread it, the tommy bar would work but not that well on this. I made another bar with bigger threads on mine. Yea stainless is fine, all you need is something to hold the bit.

Don

[crueby]

My A2Z post has not had any trouble with the top lever - still tight, no problem with threads. Must have gotten mine built the right day, not just after/before a vacation day.

For the bars on the die holder, I very often use one on the chuck, one on the die holder, and walk the one on the die holder from hole to hole, for larger threads that need more power. For small threads, I do like Zee mentions, hold the tommy bar in one hole on the die holder, and clamp/release the headstock with the other hand. I have never threaded under power - usually doing very short threads, no need. Guess a lot depends on the lathe, what you are used to doing.

I had the same trouble with rotab/chuck/drill/drill-chuck being too tall for the sherline mill column, finally got the taller column. Be nice if they just made the standard ones taller! At least I have a spare column to make a short bridge out of, or somethine....