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pntrbl
04-22-2007, 11:42 PM
I feel just a bit foolish putting up a picture of these bolts I made. Compared to the work I see here........ well it doesn't compare in any way to the work I see here! LOL! But for a new guy who's only had a lathe for about a month these 6 stupid bolts represent the fruits of a weekend long ordeal. I made a few mistakes. Would you believe I started with 6 ft of stock and have hardly a foot left? OK. I made a buncha mistakes!

But I'm learning.

http://i115.photobucket.com/albums/n300/pntrbl/bolts.jpg

1st experience with 4140. That led to grinding HSS bits for the 1st time because my trusty flat top carbides weren't having anything thing to do with small cuts. I eventually scalloped the top of that HSS so deep for top rake it looked like a hook! Got a cute little curly-Q at .003 tho.:)

Threading was the biggest issue again. I did the 1st 4 with my Phase II toolpost and was getting so much "buck and rub" I don't even know how I got away with it. After switching up to the "overly large for the machine" KDK toolpost that got a lot better. Chased 'em with a die tho. It just gets too risky in there deep and I was wrecking all over the place already!

Accuracy wise I'll claim plus or minus .020 and that was probably the most important lesson. I need to get a cheap a$$ DRO on the bed of this thing. That would be sooo much easier.

So now that the cheap a$$ DRO has hit the top of the list does anybody have pics of their install they could share? Are there any of the Chinese 12" calipers I should avoid? A trip to HF isn't far away.

Thanx for any further education.

SP

lenord
04-23-2007, 12:22 AM
PNTRBL,

Dude, I've used a lathe for a few years. I can make all kinds of things on it. However, I still have not learned threading. You are doing very WELL !

FWIW
Lenord

Fred_M
04-23-2007, 12:41 AM
As a relative nubie, good job!
I know how it is chewing up stock trying to make something.
So, when I head out to the shop, I tell my wife that I'm going to make some little pieces of meatle out of big ones. :D
Keep up the good work. - Fred.

pntrbl
04-23-2007, 12:53 AM
I dunno Lenord. Look at this one!

http://i115.photobucket.com/albums/n300/pntrbl/crooked.jpg

Still don't know what happened on that one. I didn't take it outa the chuck ....

SP

flyboy771
04-23-2007, 01:00 AM
I'd still say that looks pretty good for a first try. The very first time I tried cutting threads on a lathe was a real mess. I distinctly remember thinking, "this looks awful. why do people do this?!?!"

I've learned a few tricks since then though, and it's worked out. Just remember while threading (someone correct this if it's wrong, but it's straight out of my reference book)

For even threads, use any line on the dial.
For odd threads, any numbered line.
For half threads, any odd numbered line.
For 1/4 and 1/8 threads, return to original line.

Mike Burdick
04-23-2007, 01:03 AM
pntrbl,

Those bolts are very nice. Don't feel bad about making mistakes either as small long slender parts are very difficult to machine. First off, there's not much to hold in the chuck and second, they tend to bend under the forces needed for machining. Matter of fact, everything is against you!

So… good job and thanks for showing us the pictures!

J Tiers
04-23-2007, 01:14 AM
For a flappy part like that, just turn the threaded area, thread, finish turn the unthreaded portion, part, and then do the next piece. Head forming a secondary operation.

That minimizes the amount of overhang of thin part, and allows good threading.

Tin Falcon
04-23-2007, 01:54 AM
SP:
No need to feel ashamed. None of us here were born with Journeyman papers in one hand and a mic in the other. I was fortunate enough to be taught by profesionals on good quality good condition american made machines. Not to put down older or import machines. My South bend is 70 years old and my other lathe and mill are small imports. But the older and imports tend to have more personality to learn and work with. And the imports tend to have marginal manuals. I give the guys here that are self taught a lot of credit. As for scrapping parts look at the shop as a lab. they are not mistakes but learning projects.
Sounds like your priorities are in order
1) Work safe
2) Have fun
3) learn somthing new

It is not fun if you or your machines get damaged

Single point threading is a basic skill to often avoided by the newbie good work.
Tin
PS for a thin part like that you may want to center drill and support the end with a live center.

pntrbl
04-23-2007, 02:47 AM
The bolts are 2 1/8" long so I started by cutting six 2 1/4" blanks. After learning how to halfway grind a decent HSS bit I got those turned down and realized I shouldn't have taken them out of the chuck! That old Skinner 3 jaw I got is out .010 at the chuck face. No way I was gonna get them back in right.

There went the first foot or so .....

Cut 6 more and tried threading after cutting the dia but it was just to wiggly. Not enough meat in the chuck. Over 1/3 of the stock is gone at this point and we haven't got one yet!

Then I got the idea of making them in pairs. Cut 3 blanks at 4 1/2" and worked both ends first. That's when I finally had some success.

There was still a double groove in there somewhere and I snapped the tip off the threading bit twice. Got a new shop rule now too. No talking allowed while threading is in progress! LOL! My Son-in-Law got me twice.

Great fun tho. Need more machines .....

SP

winchman
04-23-2007, 03:18 AM
"No way I was gonna get them back in right."

Just mark the part where it touches the center of the #1 jaw. It'll usually go back in with almost no runout from the error in the chuck.

Part of the problem with threading bolts is there's so much sticking out of the chuck. The flex from tool pressure ruins the finish and makes the threads fatter on the end. Using a live center to support the end would probably help a lot.

Instead of cutting blanks, just run the excess stock through the spindle. Turn down only the part to be threaded, do the threads, then turn down the shank. That'll reduce the waste if you mess up the threads, and reduce flex of the overhanging material if you don't use a center. Make an insert to keep it centered so it won't whip around on the other side of the headstock.

Roger

BadDog
04-23-2007, 03:22 AM
Looks a lot better than some of my early projects... heck... looks a lot better than some of my recent projects!!! :eek: ;)

Nice job, and you also got some experience with HSS. If you're like me, you'll find you rarely turn to the carbides after a bit fooling with hand ground HSS.

And threading gets easier, I hardly think twice about it now. Of course that means I screw them up regularly too. You gotta always think about what your doing BEFORE doing it, I sometimes get ahead of myself. It seems to progress like many other things that are complex and require some skill.

1) You start tense and screw up as often as not, time and time again you find out that you didn't understand a critical step, or there was some trick that would REALLY help (like compound at 29.5* threading) if you had known.

2) You start becoming more and more successful as you learn and internalize (rather than systematically regurgitate, mechanically going through the motions) the basic skills required to be successful in your area of interest and growing experience.

3) You find yourself making more and more "stupid" mistakes. Mistakes you KNOW how to prevent; you just overlooked it or missed the critical bit through inattention. I think it's mostly just an initial over confidence before it's really "earned" that causes it. This seems to be where I am currently stuck. Then again, maybe I'm being arrogant while still stuck on step 1...

4) Real skills develop and you CAN actually take care of the basics almost automatically while you concentrate on the important and unique aspects. Still not ignoring it or taking it for granted, just having truly internalized the basic and repetitive processes. Through that door lies the domain of the real machinists. Those who make everything look so easy and rarely scrap things. Not that they don't make mistakes, but rather that they have learned to minimize them, correct them, and if all else fails, how to HIDE them effectively. ;)

Mcgyver
04-23-2007, 07:04 AM
even the most complex model is just a bunch of individual parts, and getting a kick out of it is the main thing. doesn't matter how simple the part, pay attention to the basics, dimensional accuracy, relative positions of things, keeping things square etc and you'll learn work holding, setups, sequence of events etc and you'll be building skills where soon you will feel you can tackle anything

slowtwitch
04-23-2007, 07:05 AM
Very Nice work :D I'm just starting out myself, in this hobby and seeing stuff like this really motivates me.

thanks for posting :D

pete

pntrbl
04-23-2007, 07:58 AM
I was amazed at the number of steps it takes to switch from high speed freewheeling mode for clean up and polish of the finished dia, to the threading setup. Too many to list but I found myself a drill where I started at the back corner with the motor pulleys and worked my way around the lathe. One knob in the wrong place can spell disaster.

The other thing I found useful was to check my movement with the bit in the air before cutting. That became redundant after awhile but it don't hurt.

Something else I need is a way to write down a target number, or a thread stop number, or any number of numbers. Too much for the head sometimes. I have a cabinet above the lathe for tooling that needs some kind of wipable modern chalkboard on one of the doors. That'd help a lot.

Still screwed up a bunch of metal. $15 for the piece of stock so that's what? $2.50 a bolt.:eek: I prefer to think of it as tuition.

SP

jdunmyer
04-23-2007, 10:19 AM
RE: machining notes:

My lathe has a 3-tube flourescent light over it. I often stick notes or crude sketches to the reflector with either a magnet or a magnetic clip thingy. The light hangs down so it's just above my head level.

BobWarfield
04-23-2007, 12:46 PM
pntrbl, I like your bolts! Very custom.

Two hugely useful accessories for my shop:

1. I bought a stack of steno pads and an entire box of Sharpies to write on them with. There is now a pad near every machine and a Sharpie is always in reach. When I first started on the lathe I found things worked better for me if I wrote down the "before and afters"--measurements before and after taking a cut. Pretty soon I knew how much and when to trust the dials.

2. Shortly afterward, I bought a cheap electronic calculator with trig functions. Pretty soon I was keying in where I thought I was on the cut and subtracting what should have been cut on the dial turns. I just left the calculator on in this way. Very handy!

With those two aids I learned a lot about how my lathe performed, and pretty soon figured out how I could run turn a piece to diameter with a lot fewer measurements. I would take a skim cut, measure initial OD, run the dials until I thought I was less than 0.020" from final (that's my finish tolerance on my little lathe < 0.020"), take a final measurement to be sure, and then crank in exactly what was needed for finish. Accuracies went way up to where I could do 0.001" all day long because I'd learned what worked on my lathe. In other words, how much depth of cut it could reliably take and how accurate the dials were.

I think keeping shop notebooks is really handy, as you may have guessed.

Best,

BW

Fasttrack
04-23-2007, 03:32 PM
Nice job! Howd you make the bolt heads? Did you start with hex stock or... ?

The first time i threaded something on my little 3-in-1 it came out perfect. I was thrilled so i tried a second time and screwed it up. Tried a third time, also jacked it up... took me another four or five tries before i got it right again. I do wish i had a threading dial though...

Beginners luck, huh? :D

Lew Hartswick
04-23-2007, 07:26 PM
I've learned a few tricks since then though, and it's worked out. Just remember while threading (someone correct this if it's wrong, but it's straight out of my reference book)

For even threads, use any line on the dial.
For odd threads, any numbered line.
For half threads, any odd numbered line.
For 1/4 and 1/8 threads, return to original line.

I hate to see these kind of "rules" since lathes have all sorts of threading dials.
For example: the Clausing/Metosas at school have the dial marked 1 to 20
no marks between, for even threads any number, for odd threads , 1,3,5,etc
for half threads (something else I havent used that yet) :-)
...lew...

Dr. Nick
04-23-2007, 07:55 PM
Since you were learning, you should have pulled out the 4-jaw and practiced centering so you could use those first bits you cut. I only recently started using my 4-jaw alot and I'm turning to it more and more often as a first choice rather than for the odd job.

Oh..nice looking bolts too :)

Rob

J. R. Williams
04-23-2007, 09:53 PM
PNTRBL

The next time use a live center to support the end of the bolts when threading. The center makes life simpler. Revise the bolt head to include a "washer face" under the head.

JRW

awake
04-23-2007, 10:56 PM
I need to get a cheap a$$ DRO on the bed of this thing. That would be sooo much easier

Hmmm. What would the DRO do for you in making these? Are you thinking about the DRO helping you to know when it is time to back out? The only time I've needed that much precision in measuring the length of a thread was when I was threading internally up to a shoulder. Since I couldn't see it, I had to have a way to know exactly how far the carriage had moved. Of course there are other times when it is handy to be able to move the carriage a very precise distance -- for example, facing off a part to get it to the exact overall length. Face off, measure the length, and then determine exactly how much more to face off.

Here's what I use any time that I need to measure the movement of the carriage within .001" of precision:

http://home.earthlink.net/~a_wake/DI-Holder1.jpg

http://home.earthlink.net/~a_wake/DI-Holder2.jpg

http://home.earthlink.net/~a_wake/DI-Holder3.jpg

This is a holder for a dial indicator that I can clamp anywhere along the ways of my lathe with a quick turn of the handle. The handle is keyed to a cam that locks against the underside of the ways, drawing the aluminum V securely down onto the ways. I can move it and clamp it in a half a second -- so much quicker and easier than my first-generation DI holder, which used two pieces of aluminum with a SHCS to pull them together to clamp to the ways. But even that q&d DI holder served me well for quite a while.

I made the one shown above out of a piece of scrap aluminum, a short piece of drill rod for the cam and shaft, and some CRS for the handle. You can also see where I put in a "button" of delrin, mostly because I cut my V too big and needed something to hold the whole thing out a bit for stability when it is not clamped down. The only really challenging bit was turning the cam, since I did it as one piece -- I started with 5/8 drill rod, offset it in the 4-jaw, center drilled in the offset position. I pulled the drill rod out, carefully maintaining the alignment, so that I could hold the end with a center. Then I machined down the shaft section to .375. This gave me a .375 round shaft extending from the jaws to the center, but inside the jaws an offset section of .625 diameter. (In retrospect, this was too much difference -- would have been better to have had a smaller offset, and made the cam only .500".) I cut it off, leaving about 3/8" of the .625 diameter to be the cam. I milled a keyway in the shaft and made a double-ball handle (yes, that would also count as a more challenging part, except that I made a radius cutting tool holder :) ) to fit the shaft. Note that one could make the cam much simpler in two parts, and either press or silver-solder or even just loctite them together. And the handle does not need to be double ball, though it is nice to look at and to use.

The DI on this only has 1" of travel. That may not sound like much, and once in a while I wouldn't mind a bit more -- a 2" travel indicator would really be the cat's meow. Since my lathe is 30" between centers, even if I used a 12" caliper I'd still need a way to move and clamp it to different positions along the ways. But I don't think I'd want any more than 2" -- as it is now, I can "park" the holder at the headstock end of the ways, and it does not interfere with the carriage. And it has been very little effort to work around the 1" limitation, now that it is so easy to move and reclamp it. If I need to move the carriage exactly, say, 1.5", I set up by moving over .5", then move the DI over to rezero it. Then I return the carriage and start cutting. The dial doesn't move for the first .5", but I don't care -- all I care about is stopping it when it gets to 1" on the dial, which will be 1.5" altogether.

I didn't mean to hijack this thread, but I noticed that no one had responded to your comment/question about a DRO. To get back to the original topic, well done on making the parts. It was not very long ago that I proudly posted a picture of a single 1/2-20 bolt and matching nut as my first solo project. And in regards to some of the problems you experienced in threading these, in addition to the advice to support the end in a center, I would also add not to try to take too deep a cut with each pass. I've found that doing so can cause enough deflection (or even slippage of the bit) to give me double-threading issues.

CCWKen
04-24-2007, 01:11 AM
Nice job Bill! To go along with "Awake's" indicator, I just mounted a scale on my lathe a month or two ago. I use it for duplicating parts. It comes in mighty handy when you want the length of parts and the transitions the same on all parts. By the way Awake, I like the cam release. Sharp idea.

Here's the scale:

http://img.photobucket.com/albums/0903/CCWKen/Tools/Craftsman%20Lathe/Accessories/DROScale-1.jpg


Here's one of the parts I was duplicating. These are 3/8" in diameter and about 3/4" long. The thread is 1/4-28.

http://img.photobucket.com/albums/0903/CCWKen/Projects/Model%20T/GenRebuild/2007_0108Generator0002.jpg

awake
04-24-2007, 03:23 PM
By the way Awake, I like the cam release. Sharp idea.

Thanks, but I should have pointed out that the whole thing is not my original idea. I saw something like it and said, "I want one!" I didn't have any plans, and didn't recall all the details of the one I saw, so I made this one up with seat-of-the-pants engineering. But the one thing I do recall from the original was that it used a cam lock.

Ken, what is the length of your bed? And am I right in thinking that the bracket on the end closest to the camera in the picture, as well as the bracket holding the display, are both adjustable? It looks like they just "pinch" on the flat ways. A very good solution to the mounting problem, and gives you all kinds of flexibility ... with that design, I take back some of my reservations about going with a caliper as a cheap DRO!

J Tiers
04-24-2007, 05:01 PM
For a fail-safe (sort-of) length, I much prefer a stop to a measurement.

of course, for half-nut disengagement, it would be better to have a "soft" limit, but for hand feed to depth, a hard stop is better.

You don't have to watch closely, you don't have the chance of going too far and digging in, it just seems better overall when you REALLY don't want to go too far.

I made my stop to take the micrometer head OR an indicator, and I have used the indicator maybe once, the micrometer stop I have used so much I don't even have a guess how much.

CCWKen
04-24-2007, 08:17 PM
I'd agree that a stop works better for one transition but I've got four on the above piece. I'd have to have one of those octopus looking things and reset it for each piece. With the DRO scale, I can zero it on the end and make my four cuts using a predetermined index hanging in front of me. I just watch the scale and when it gets close, I slow down until it hits the index. Anyway, this works for me. It's also great for setting the taper attachment up. With a dial indicator on the slide, I move the carriage 1.000" and check/adjust the attachment. Three moves is the most I've had to do and I'm ready to make dead-on tapers. Well, the first time it was four but that was because I forgot about the included taper most specs state. ;)

Awake, Yeah I remember seeing the concept but couldn't remember who posted it. It's still a good rendition. This lathe is the 12x36. I have the scale attached at the threading dial mounting hole and the display mount is clamped to the way. The end nearest the camera is free to move along the way. The two brass screws are used to adjust the height and keep from scratching the way. The specs say no more than .001" misalignment on the scale so make sure everything is right before tightening it down.

In the picture, just below the live center, there's a way clamp that I use for a return stop. It keeps me from running the carriage too far back and jamming into the DRO case. The DRO isn't hard to move for a range of work but I seldom have the need. The DRO is listed as a 12" but it will move and register a little over 13". Plenty of movement for most of my work. When I do have to move it, I just loosen the way clamp at the display and the whole scale can be shifted to another area.

There's other mounting methods, I'm sure. I just used what I had on hand and pieced it together. I can still use the thread dial by simply mounting it between the scale mount and the carriage.

Added Pic
Here's the DRO display mounted to the way clamp.
http://img.photobucket.com/albums/0903/CCWKen/Tools/Craftsman%20Lathe/Accessories/DROScale-3.jpg

awake
04-24-2007, 10:33 PM
Ken, very helpful clarification, thanks! You've done a great job. Did you use something actually made to be a DRO, or did you make this from a caliper? On my pitiful little mill-drill, I cut up a cheapo HF 6" caliper to serve as a DRO on the quill -- it does a pretty decent job. Were I to make a cheap DRO for the lathe (as the OP has talked about), or more likely for the x-axis of my mill-drill, I would think about cutting up a HF 12" caliper ...