Silly newbie tricks

I propose a thread for those of use that are NOT machinists to share our screw-ups and successes so others can learn from them.

I'll kick it off with some lathe items that might be obvious to old timers.

Did you know that if you open the jaws of tstock 7x10 3 inch chuck, you can gouge the heck out of your cross-slide by moving it too far to the left? Not only will it take a chunk out of the cross slide, the chuck will keep turning!

When you change the gears for different threads, it makes a BIG difference if you put the B gear where the C gear belongs. In the case of a 40 tooth and 45 tooth, the difference was not enough to notice. The flashlight did notice.

Did you notice that the change gears are mounted on an arm that swivels? I didn't. It really cramps your style when you can only use 10 combinations of the gears.

The 16 or so threads listed on the harbor freight housing are not even a fraction of the threads you can cut. If you use one of the online programs to figure your cear combinations, make sure it includes all the gears you have. Some of the programs don't base their calculations on the same gears that you got with your lathe.

Does this thread have any appeal to others?


Daniel

lol damn gadget, learning the hard way are we? /ubbthreads/images/graemlins/grin.gif

Yea, I ALMOST had my chuck hit the cross-slide.
Scared me to death lol

Good thread though, there are alot of little things like this, that ppl just wont know, unless you tell them,,, or they learn the hard way. /ubbthreads/images/graemlins/wink.gif

Another trick... and why not to do it.


I have a 3 jaw self centering chuck. I threw a piece of 3/4 inch delrin into the chuck. The jaws were the set that grab the outside of a rod. It was not quite centered, but I was just playing, so it was not critical.

I faced it, getting a good 90 degree cut. Then I turned the piece down to 1/2 inch. Cool! Even though the piece was not centered, it was concentric when I was finished cutting it. I cut some threads to match a part that was sitting around.

So far so good.

Now here's why you should center the piece.

I took it out of the chuck and test fit it in the part. It was almost what I wanted. I put the rod back in the chuck and found it was almost impossible to get back into position. I had to keep rotating the piece in the chuck until the same imperfections lined up again. Even so, I could not get it close enough to it's previous position to be able to clean up the threads I had cut before.

I've since bought a cheap dial indicator and magnetic stand from ENCO (about $20) and use that to make sure it's straight every time.

If you don't have a dial indicator, you can use the toolpost as a visual guide. Just get teh work parallel with the edge of the toolpost and make sure it stays that way when the chuck is rotated.

Well, Other than the knurling wheel mixup, that' all I have so far.

Daniel

maybe you need this tool


(image from premium content of www.mini-lathe.com)

I purchased both standard sizes (55 and 60 degrees)

a dial indicator is in my wish list, also in the list a 4jaw INDEPENDENT chuck, because with my lathe came one 4jaw but self centering, which I found pretty useless.

Pablo

what I really need to figure out is a method of keeping all the tools in order in my bench, I keep looking for the allens, the brushes, the live center, all the cutting tools, keeping away the aluminium chips, is a real KILOMBO (mess) /ubbthreads/images/graemlins/smile.gif

Pablo

I found that gauge in the ENCO catalog. I'm not sur about all the uses, but I did see a reference to using it to ensure you have the correct angle when cutting threads.

Another silly newbie trick:

When you are trying to turn several sections to the same depth, you crank in the topslide, make a pass over one section, then back the tool out to pass over the
section you don't want to cut... then repeat. The trick is to move the tool out and then back in the same amount each time by using the index marks next to the crank. I was doing things like stoppping at 27, then backing it out, moving over and remembering to stop at 27 the next time too.

This is made a lot easier if you zero the index after geting the first cut to the right depth. The index is a friction fit, so you can rotate it by hand while holding the crank steady.

Daniel

Peu,

I have a wood shelf above my Atlas lathe and since I use Aloris QC tool holders, I cut a long strip of wood matching the dovetail that mates to the toolholder. I mounted short sections of this on the underside of the shelf and can "hang" my tool holders there in plain sight and within quick reach. I now spend most of my time at another lathe where there is no such shelf so I have reverted to a dedicated drawer in a rolling tool chest for the tool holders. I would think that those magnetic tool holder strips wold be useful above a lathe and want to get one when I remember to! I see it as a temporary spot for holding the tools in use at the time; drill bits, end mills, QC holders and the like.

Staying abreast of entropy in a shop is never ending. /ubbthreads/images/graemlins/frown.gif I lost the battle some time ago........

[ QUOTE ]
McGizmo said:
Peu,

Staying abreast of entropy in a shop is never ending. /ubbthreads/images/graemlins/frown.gif I lost the battle some time ago........

[/ QUOTE ]
Magnetic holders RIIIIGHT, I have one of these in my kitchen for the knifes. Great Tip /ubbthreads/images/graemlins/bowdown.gif

There is always a scientific explanation for shop disorder:

The shop is part of the universe, so according to the big-bang theory (or the 2nd law of thermodynamics) entropy will increase with time, where entropy equals the amount of disorder in a system. With increasing disorder, there is inherently less energy that can be used to do useful work... /ubbthreads/images/graemlins/smile.gif

Pablo

I thought entropy was why a can full of beer seems to prefer being on its side /ubbthreads/images/graemlins/grin.gif . Wood blocks make great holders for round shank tools. They are easy to make/customize- just drill blind holes.

Larry

I finished my lathe mods

front view of the camlock tailstock


view of the camlock handle (made of a long 1/4" screw and a piece of aluminium)


Modification of the handles, so they are like the ones in the carriage and back of the tailstock. I changed these because the original ones kept unscrewing all the time.


and a BAD picture (due to backlight) of the lathe you can see in this picture that I machined a handle for the QCTP also, which uses the original screw as the core.


Now that I'm confortable with the lathe comes the hard part: make my 1st light /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/help.gif /ubbthreads/images/graemlins/smile.gif

Pablo

When first starting out, consider the type of work you are going to do and on your first order of raw materials (Delrin, aluminum etc) get enough diamater stock that you are going to be using.

Do not do what I did and get 0.5", 1" and 1.5" assuming I'd be able to use one of them to turn down for the work I was going to do.

You should try to get stock as close as possible to the diameter you really need. Why? I found out that taking 1/2" off the diameter (Turning) takes literally a good hour and cranking the lathe back and forth. You can reallistically on Aluminum take 0.010" - 0.020" off per pass. That means a 1/10 inch takes 5 - 10 passes. The resultant swills of chips can easily overflow your lathe too.

While this is great exercise for the arms, it is very time consuming.

I've heard that using tubing is extruded and not necessary round as pure round stock. Be careful there.

When boring, try to drill out as much material (in steps) before using a boring tool. I found out again the hard way. I would drill a pilot hole big enough for the boring tool and started boring away. Well, if you have never used a lathe before, you can at best take 10 thous to 20 thous off per pass. A 1/10 inch takes a good 5-10 passes. 2/10 takes twice as many.

A good drill set is manditory. Don't get the cheap sets. They don't drill straight and thus your drilled hole usually ends up larger than you expected. This will ruin your work if this is your final drill size before boring and you only have 10-20 thous as a finishing operation. you might end up drilling a larger diameter past what you wanted very easily with a non straight cheap drill.

Chucking up your work. on the 3 jaw chuck. I tighten the chuck up till it almost grips the work. I then rotate and slide the part in and out. This movement helps the part from getting stuck and cocked in some strange angle. I keep moving the part (sliding back and forth slightly) while slowly tightening the chuck. This usually gets most items centered very nicely. Even short items where the chuck grips very little of the work surface. When all else fails I use a dial indicator mounted to a magnetic base to center the work surface.

For the mini-lathe, I find that I chop off just enough material to make what. Working with small diameters and soft parts past a few inches gets rather iffy real fast. Don't fool yourself into chopping off enough work material to make 2,3 or four off the same part. The added length will usually end up biting you, unless your stock is small enough to fit through the center of the chuck.

Items that are longer than 5-6 inches can apply a lot of lateral force on the part when turning. The longer the part, the lighter the cuts one might want to consider.

Parts do get hot when making a lot of cuts. Check you work if you been doing a lot of cutting on it. If it gets real hot hit it with some freeze mist or use a compressed air can upside down. Common day freeze mist and compressed air are the same. One has a tube down to the bottom and the other doesn't. Turning either one upside down reverses the roll of the can. A freeze can upside down is just compressed air and a compressed air can upside down is freeze spray.

With that in mind. You don't need to buy separate freeze sprays and compressed air. I buy a 6 or 10 pack of compressed air and leave a can near the lathe, workbench and computer.

I still have 10 finger!!! YAY.

Note: long stock through the chuck and headstock is not safe either. /ubbthreads/images/graemlins/frown.gif Especially long THIN stock.

It will rapidly transform from a long thin rod or tube into a long L-shaped bar whipping a large swath out the end of the headstock and the area around it. Not good.

Thanks for the heads-up about thin stock poking out of the back of the headstock. I worried about bending it by accident, impaling myself on it and other things, but never occured to me that if it becomes imballanced at high speed it becomes a metal weed whacker!

That was a great contribution Wayne. Thanks for sharing.

I should point out that the commmercial freeze sprays are not identical to the compressed air in all ways. I use the compressed air cans like Wayne does, inverting them to quickly chill hot parts. Use caution when using it on electronics. The commercial freeze sprays are avialble in 'zero residue' varieties while there are no assurances in the compressed air cans.

Now for the stupid newbie trick portion of this message:

Metal that's being ground gets hot. I knew that. What I forgot is that metal being sanded on a belt sander can get very hot too. /ubbthreads/images/graemlins/frown.gif I was trimming down the back of an aluminium Dorcy Spyder reflector in preparation for doing a luxeon mod. A wooden jig held the reflector at a nice 90 degree angle.

After sanding a little I'd hit it with freeze spray and test it for proper focus. When the reflector was popped out of the jig I thought nothing of it. I reached out a snatched it off the ground and... promptly sent it flying as I snatched my hand back. I figure the temperature was just under the point where it would char wood.

So the lesson should be: grinding or sanding use gloves and glasses.

The other lesson, let parts fall an think before you grab them.

Daniel

a steady rest, a follower rest and a live center help with long pieces also

be sure to finish the piece without these, because they EAT a little of the rod in compensation for the work /ubbthreads/images/graemlins/smile.gif

Pablo

Here's another one that may be obvious to you machinist, but, is not intuitive to a newbie.

I've had my lathe now for what?? 6 mo's. I've gone through a lot of aluminum and delrin.

I am just finishing an intro Manchining class for work and I watched in astonishment as the instructor proceeded to take off 0.2" while turning soft steel. My turning, facing and boring that I've been doing have not taken more than 0.020" off at a time. The binocular camera adaptor I did the other day I had to bore out the inside to 1.3". The whole job took a good 3 hours of cranking. It would have been duck soup if I bored off 0.05 or 0.1" in a pass. That one tip alone will save me countless hours of "exercise" on my forearms.

Now I'm fickled... Should I continue to exercise more or be more lazy?

Wayne

What kind of lathe are you using Wayne?

Eric

Hey Wayne. Did the instuctor have to do anything different to take off that much, or was it just the use of sooft steel?

Daniel

Even though I have a QCTP, I still use the turret tool post occasionally. Since the retaining bolt that came with the QCTP is longer than the stock bolt (which is double-ended and harder to change), I machined a 3/4" long bushing out of 1" round aluminum stock to use the bolt that came with the QCTP. I can now quickly change between the toolposts for various operations - until I can afford more tool holders for the QCTP.

Interesting side note when it came to threading, the gear chart on my lathe was missing a 'B' column. So the gear combo for 20TPI was listed as 40t and 50t gears only. I'm glad I spent a lot of time @Mini-lathe.com while I was waiting for my lathe, or else I could still be trying to figure out how to make gears 'A' and 'D' make contact. /ubbthreads/images/graemlins/icon15.gif

Yesterday a friend of mine taught me a simpler way to thread:

instead of putting the cross slide at 60 degrees and using the dial indicator to see where you engage the leadscrew:

put the cutting tool square to the piece using the arrow tool shown in a previous post, move a few milimeters to the right of the piece, start the lathe with the leadscrew engaged, make the first light pass, without stopping pull away the cutting tool and then stop, then switch the lathe to reverse and start it again, move it all the way to the beggining and do the same increasing the depth of the cut a little.

You must not use the carriage handwheel, just back and fort using the forward & reverse, and the leadscrew must be engaged always.

Did I explained right?

Pablo

Wayne, I also take off VERY little with each pass.
Was the instructors lathe a small one like ours? Ive seen large lathes take alot off at once, but not small ones.

I bet if I try that, ill be snapping tools right and left. /ubbthreads/images/graemlins/icon15.gif