# mini-lathe - getting it right...maybe



## zeeprogrammer

For all the poor souls that have followed my locomotive thread...I present a project that I hope will allow me to complete said thread.

Time to fix/modify/adjust/tweak/but probably just learn how to properly use...my mini-lathe.

The issue I'm hunting is true-ness (okay...and skill). Tailstock, chuck-run-out, anything that is a hindrance (other than my personal skill) in making 'good' parts.

First step is to break it down and clean it up.

Aha! Immediately we see that zeepster doesn't know the difference between 'tight enough' and 'enough to throttle the life out of it'.







Here we see the pan. Evidence includes bent washers and dents where the feet of the lathe sat.

Could this cause twist in the lathe bed? Could this cause bend in the lathe bed?

Why of course it could.

We now have two audiences...audience one is thinking to themselves, 'dolt' and audience two is thinking 'hm...maybe I have the same problem'. (I discount the audience saying 'huh?'. I used to be in the audience.)

I encourage audience one to help me as I go along. Their experience and knowledge is invaluable. I encourage audience two to follow along. My hope is that they will learn from audience one...cause they ain't going to get it from me.

But alas..this will take some time. I have much to do that will take me away...but I hope to make progress when I can.

Thank you. Thank you very much.

........................................

This post comes with no guarantee or warranty. Said thread may stop suddenly and without warning (as one or two of my previous threads have done). Be prepared for nonsense, stupid questions, dumb attempts, but a good heart. Reply at your own risk.

And before anyone says it...yes...I'm feeling good. Got visitors and we share a similar interest. ;D


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## Deanofid

zeeprogrammer  said:
			
		

> And before anyone says it...yes...I'm feeling good. Got visitors and we share a similar interest. ;D




Vodka?


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## Maryak

zeeprogrammer  said:
			
		

> The issue I'm hunting is true-ness (okay...and skill).



Carl,

I have always found you to be true. :bow: Hunt 1 over. :

Better take a cut lunch and a 0.38" hunt 2 could take a little longer. 

Seriously, Yep, you overdid it but then again your a pretty big man from what I can gather so don't sweat it.

Without buying an Engineers Level I thoroughly recommend "Roleys Dad's" method easy to find and download from the net.

Before you do that put you centres in the head and tail stock and bring them to almost touching and see what's what with the lathe unbolted.

Let's know how you get on.

Best Regards
Bob


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## steamer

Ahh yes , Bob speaks wisdom here

I know Rollie....he knows what he's talking about....

Can't help you with the common interest...though I think I might want to ;D.....shaken or stirred?

Dave


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## zeeprogrammer

Yep Dean. Your prize is in the shout box. ;D

Thanks Bob. I remember seeing the "Roley's Dad" method elsewhere in the forum. 

Using dead centers in the headstock and tailstock is what told me that things were off. That's the first thing I'll look at when I get the lathe back together. But that's just a start. That is, it tells me if things are aligned 'at that point'. I have no idea what I'll find as the tailstock is cranked.



			
				steamer  said:
			
		

> Can't help you with the common interest...though I think I might want to ;D.....shaken or stirred?



Ah..that question came up before. The answer is 'poured'.

Thanks Dave.


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## black85vette

Zee; of all the things I did to my 7x10 I think getting the tail stock aligned gained the most improvement.  I also took the compound off and replaced it with a solid block. Helped to make things more rigid and I set it so that most of my tools were on center without shims. Made tool changes quicker.

It is now over at my son's house so I don't use it anymore but it did good work. It was an issue of size (yes it matters) for me. I wanted to build larger parts and engines than the little guy could handle.

I'm sure this thread will become a good reference for others using similar lathes.


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## zeeprogrammer

black85vette  said:
			
		

> I'm sure this thread will become a good reference for others using similar lathes.



Uh...what's your batting average when it comes to these kinds of predictions?

..........................................

Well I cleaned up the lathe a bit. One thing I noticed was paint under the left foot of the lathe. I don't know if it matters, but it needs to go.






Then I thought I'd do a 'simple' measurement. Now when you see this pic, you need to wait for the text that comes after the pic...






There are a number of issues with this shot. For one thing, depending on whether you are moving towards or away from the headstock makes a big difference. The play in the ram allows it to twist and you will get a much different reading.

For another, I have no idea how flat the top of the V is on the lathe. I suspect it's the flanks of the V that have to be flat...not the top.

In addition, this can, at best, measure only one axis.

What I'm trying to understand is what happens as I move the ram. If the drill bit it's holding isn't true and concentric to the part in the chuck I'm trying to drill - as I move the ram...then it seems to me I can't drill and ream a decent a hole.

In other words, if the ram is at an angle to the headstock, then as the ram changes, the error at the tip of the bit must increase.

Short holes are one thing, but the loco's cylinder's are relatively long.

I'd be interested (as always) in what anyone has to say about this. How do I make sure the tailstock, when it's holding a drill bit or reamer, is true to the headstock?

Ta (which means thanks in some countries and good-bye in others).


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## Philjoe5

> For one thing, depending on whether you are moving towards or away from the headstock makes a *big *  difference.



Zee,
What do you mean by big? We want numbers. 


Cheers,
Phil


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## zeeprogrammer

Philjoe5  said:
			
		

> What do you mean by big? We want numbers.



You some kind of engineer Phil? :big:

Kind of difficult to say because the indicator makes some pretty good jumps when I change direction. But I'd say somewhere between 0.01 and .02. At least.

I expect a big difference when changing direction on the ram. I remember (I think it was Bogs) the warning about twist in the ram when I was playing around with putting a DRO on the tailstock.

I imagine, but could be wrong, that reversing direction is less of a problem. If I drill into the part and then reverse, I'd expect the hole to help keep things the way they were...much like a center drill bit. But I'm speaking with a lot less experience than others here.


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## Kermit

I've attached a pic showing a way to mount the base that will allow you to correct a small amount of 'twist', by torque applied to the foot mount bolts.

I've used this method to correct a small twist in my X2 mill that had the left front corner reading .002" high when the other three corners of the table were dead on in the vertical z axis.

Just tightened down the corresponding bolt and the x-y table leveled out in the z axis perfectly. I don't think this will correct much more than .005 or so inches without causing too much stress on the casting.


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## Troutsqueezer

Hi Zee, 

If you chucked up (no, not that kind of chucked up) a piece of metal that was nicely faced and coated the end with Dykem, then moved the tailstock up with the ram withdrawn completely, then put a live or dead center in the ram, it seems like you could lightly touch the center to the workpiece, give the chuck a hand spin to lightly etch what might be a small circle (depending on far off the tailstock is). Then, you could extend the ram, move the tailstock back a bit and touch the workpiece again and scribe a second small circle. If they overlapped perfectly, the ram is parallel, if not the ram is not parallel or the ways are not straight. 

I dunno, anything to be gained from that? 

It's getting late and brain starting to hurt...


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## Blogwitch

Zee,

As long as you have the ram lock ON, then you shouldn't get any deviation, as the ram is prevented from turning.

You are correct in assuming that the top face is not the place to be checking, either of the angled side faces are the ones that are ground to make the precision bedway.

Put a DTI in your main chuck, and clock around say the shank of a milling cutter or a largish piece of silver steel mounted into the tailstock chuck. Be careful how much side pressure you put on the main chuck as that could affect the reading, I would be tempted to turn the spindle from the gears end after the gear train has been disconnected, to make it easier to turn. You will need an 18" silicon rubber neck to be able to see the clock face in all positions, so a mirror can come in handy.

This will check if your tailstock is concentric with the main chuck, and don't worry about runout on the main chuck, as that will remain a constant throughout it's rotation.


I hope you can understand what I am getting at.


Bogs


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## zeeprogrammer

Thanks kermit. Your drawing looks similar to my setup - I think. My lathe is sitting on a bench I made. The top of the bench has two sheets of 5/8 plywood (screwed together and screwed to the bench) and 1/4 hardboard on top of that. The lathe was bolted down. Given the first pic in the thread, I wouldn't be surprised that I twisted the lathe - but it sounds like I can also control it.

How did you measure Z? (Cut it out guys ;D ).

Thanks Trout. Sounds like that would work. It would mean facing off a bit of metal and keeping it in the chuck to take the readings. Otherwise I think the scribing pressure will change as the chuck is rotated. Oh yeah, the other thing required is to put the carriage et.al. back together. ;D

Thanks Bogs. Yep...I understand. When you say 'largish piece', do you mean long? Or something less prone to having been bent? I have some 3/8". Also 1/2" stainless I got out of a printer last night.

Both methods far superior to what I was trying to do.


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## TroyO

I bolted mine to a block of granite countertop I got from a home recycling center. The theory being that the surface is flat and that the granite really doesn't want to twist and so would pull the lathe in to alignment. It of course is based on the presumption that the feet are properly co-planar with the bed from the factory.

Not sure if what I did is "right" or not, and I have a different lathe (HF 8x14) that is somewhat beefier than the 7X series, but if anything the theory of it is even more applicable to the Mini Lathe assuming that the granite would have an easier time pulling any warp out of a smaller lathe frame.

To do it, I got a likely sized scrap of the granite material (I got 2 for $5 if I recall correctly) and drilled 1/2 inch holes in it using a carbide drill for glass. I used plumbers putty to make a "well" and filled it with water and ran the drill pretty slow. It ended up boiling the water at the bottom of the hole, LOL.. but it cut fine. I learned to back out more often after that one.

Finally, I epoxied in some 1/2 all thread to the holes then bolted the lathe down (After cleaning it's feets.)

"It seemed like a good idea at the time"... anyone have input on the idea? I also wonder what a cheap surface plate might have cost to do it too... 2" granite seems even better than 1".

The granite is not attached to the bench... counting on the 360 pounds of Lathe and 30 or so pounds of granite to hold it down.


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## Blogwitch

Zee, 

Your 3/8" or 1/2" will be fine.

But really before you look at the tailstock, you need to get the spindle running true to the bed first, as everything else revolves around that being correct. No pun intended.

Make a very fine cut along say 2" of your 1/2" bar, until the outside is completely cleaned up. Then take a mic reading along the bar and check for parallelism. Any sign of taper and the headstock will need to be shimmed up to get the spindle running perfectly parallel to the bed.

The last four pics and text of this post.

http://madmodder.net/index.php?topic=627.msg5193#msg5193


Bogs


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## zeeprogrammer

Thanks TroyO. I like the idea of granite. There's a place not far from here that I can check. I always like a reason to take a drive from work during lunch.

Would a quartz counter top do the same?

Bogs...thanks for the link. I have no means at hand for modifying the chuck but shimming the headstock is something I'll have to look into. Right now the carriage and so on are broken down for cleaning.

In the meantime, using a dead center, I tried this...






The DTI showed about .001 with the ram not extended. It showed about .0013 with the ram fully extended. Ram was always locked.

Any reason a dead center wouldn't work?

That seems pretty darn good to me. Maybe too good. So I'll be repeating the test a few times.

Meant to say...the lathe is just sitting on the bench. Not mounted. Hoping any twist or warp caused by having it too tight to the bench will relax.


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## zeeprogrammer

This was a mod I did about a year ago.
It's the apron. There's two sheets of thin plastic.
The inner plastic is cut and used as a spacer.
The circle you see over the smaller gear is grease.

I'm glad I did the mod. It's really kept the swarf out of the gears.
Highly recommended.


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## Blogwitch

Zee,

That one I was working on in the link was a real dog, most probably one of the first few from some unknown backstreet maker hacked out of the solid with flint tools and chopsticks.

Modern versions, like yours, have really come on in leaps and bounds, and I doubt you will find much wrong, except just general adjustments of gibs etc.

I was just pointing the way IF you came across a tapered cut, and the priority and order it should be checked out.

That runout seems acceptable, but to check it isn't being caused by an off-centre centre and you could see even better results, mark the high spot on the centre with a felt pen, then move the centre into a different position in the tailstock. If it still shows up in the same position on the centre, then it shows the centre is out, but if not, then it is the tailstock alignment.

Whenever doing checks like you are, it pays to always do it in at least half a dozen locations, and note things down. You usually see a pattern emerging, and then you can take the proper corrective action.

Just bear in mind, you are doing it the correct way. By the time you have finished, you will know your machine inside out, and if something does crop up in use, your experiences with it will make it easier to locate the problem.

Bogs


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## timB

Yeah! What Bogs said!

Zee,

Take this for what it's worth (newbie disclaimer).

When I made my fly cutter, I wanted it to run as true as I could possibly get it. I started checking alignment with a DTI similar to your setup at the top of this page. I used a collet instead of a chuck, more accurate maybe.

Reading at center height (where the tool cuts) and then 180° to the rear I got the tailstock aligned spot on. Reading at the top and bottom indicated the tailstock was .001 high, an insignificant amount. I slipped some rolling paper under the headstock anyhow, spot on.

I guess this could be called alignment on per piece basis. Anyhoooo, I setup my material between centers and followed a method described in "Text-book of Advanced Machine Work" by Robert H. Smith. I found a digitized copy on archive.org

In the end, I got parallelism within -.0005. If you do this on a suitable size piece you would end up with a test bar you could use anytime or on any lathe. Yes?

Comments from the experts always appreciated.

Several excerpts follow:


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## black85vette

Zee;

I took a measure similar to yours except without the dead center. Put my DTI inside the ram to measure it there. Eliminated one variable.


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## Artie

Im watching and coming along for the ride... all it took was a promise of "but a good heart" ..... Im a sucker for a good story....

Im using a much much larger older lathe.... accuracy is something I dont take for granted but are yet to have a problem with (I think). Im hoping to learn how to ensure that I dont in future.....

Keep the info flow happening....


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## zeeprogrammer

Thanks Bogs. And I got a favor to ask. If I remember right, you provided a link to me that showed a modification for the carriage gibs on the mini-lathe. Angled brass that slid against each other. I've looked and looked for that link but haven't found it. If it's at the tip of your finger I'd appreciate the link again. Not that I will necessarily do this, but I want to consider it.

Thanks Tim. I have no collets for the lathe. Thanks for reminding me of that. I need to go looking.

Thanks Rick. I thought about that too. I intend to do several different and same measurements to (as Bogs mentioned) get to know my equipment.

Thanks Artie. I hope you find it useful. It's going to be slow going I'm afraid.


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## zeeprogrammer

Well I did another measurement...this time with the DTI set to the inside of the ram. It only measures up to .0013 and I pegged it either direction. I don't know what's different but I wasn't happy.

[EDIT: To Bogs' point...I need to check out and/or true the chuck before I can really do anything with the tailstock. But no problem getting an idea of things as I go along.]

I put the apron back together. Some of you may recall the 'boo-boo' I had last year when I was drilling the holes for the plastic shield. The bit that cracked came off. No harm though...the shield and apron will work fine.

I did discover that I'd attached the wheel incorrectly last time. So the small gear was sticking out further...and that's the reason for the grease on the plastic.







One measurement in the evening doesn't sound like a lot (and it's not) but it's grab a minute here...grab a minute there...ah...got air that time.

Exciting isn't it?
Well of course it is.
Not worried if you're not excited. I'm the one that counts. :big:


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## zeeprogrammer

While I'm here and got another minute...

Now's a good time to consider additional modifications...

One of the mods I came across was to split the nut that sits under the cross slide. At the time I had no experience with a saw blade on the mill (remember the time I had it cutting backwards?). Now I feel more confident. Anyone else have experience with cutting the nut?

I also want consider attaching a caliper or two. (No electronics for me...I'm really burned out doing 'work related' stuff.).

Any suggestions for other improvements?

I know about a power feed for the carriage...but I don't think I need it. I enjoy the manual work.

I may return to fixing the clamp for the tailstock...but I think it just needs a shim.

A spindle stop would be good. And tools...I'd really like to make some die holders like Arnold did.

I'll tell you...getting the lathe cleaned up is really putting pressure on me to just put it together and get back to machining...

I think I'll join Jerry and get a refill.


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## Blogwitch

Zee,

The whole post is here

http://madmodder.net/index.php?topic=627.0

and the part you are after is this

http://madmodder.net/index.php?topic=627.msg3898#msg3898

It is very long winded as it is a warts and all post.

Bogs


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## zeeprogrammer

Thanks Bogs. Exactly what I was looking for.


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## zeeprogrammer

Hey all...I haven't posted since yesterday and I'm still at #2 in this topic. C'mon...get busy and make some more machine mods! ;D

I've been interested in that mod of Bogs (the gibs) for some time...but I think it's still going to be some time before I get to it. It looks like it requires a bit more 'skill' than I have right now. If you don't want to buy that excuse...then please accept the fact that my mill needs a lot of work to make such good pieces.

In any case...before I make such major mods...I need to understand my lathe better. So I'm going to clean it up, put it together, and see how much better I can make it as is.

I worked on the carriage a bit today. Here's a pic of it upside down. A couple of things I noticed...

The gibs (well not gibs, the thingies that ride along the bottom) were loose. Real loose. Maybe they were tighter while mounted on the lathe...but I'm thinking I didn't have them adjusted very well.

On a brighter note...I've seen web sites that talk about those thingies and how they can break pretty easily. But the pictures I've seen of them showed them much thinner than the ones I have. It looks like the manufacturer increased their size to minimize the breakage. Well we'll see.






I used my compressor to help clean out the swarf and kerosene. I forgot to cover the lathe, the wall, and myself. Spotted all over now.


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## cfellows

Zee, I made some tapered gibs for my mini-lathe and it wasn't that difficult. Here's a link to the thread:

http://www.homemodelenginemachinist.com/index.php?topic=9016.30

Starts on Reply # 14.

Chuck


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## rudydubya

Zee, maybe something else to consider with the tailstock...

I replaced that useless capscrew on the bottom of the tailstock with a capscrew on the top where you can actually get to it when trying to do an alignment.




When you do that, tailstock alignment is a lot easier. Example of that mod <a href="http://www.homemodelenginemachinist.com/index.php?topic=8834.msg95996#msg95996">_*HERE.*_</a> I also added compressor man's adjusting system, helped even more, shown by him <a href="http://www.homemodelenginemachinist.com/index.php?topic=8834.msg98270#msg98270">_*HERE.*_</a>

With those mods, this is the way I now align my tailstock. First I find the centerline of the lathe by putting a test bar in the 4-jaw and centering it. My test bar is 0.500" in diameter, therefore I know the centerline of the lathe has to be 0.250" in from its outer surface. So I adjust the cross slide to force a reading of 0.250" on the dial indicator, giving me an indicator and cross slide set so that 0.000 on the indicator is at the centerline of the lathe. (I temporarily remove the tool holder and compound from the cross slide to make it easier to locate the indicator and its magnetic base.)  




I lock the tailstock and crank out the tailstock quill until it's almost fully extended, and lock it there. Then, without changing anything about the dial indicator, I carefully move the carriage down the ways toward the tailstock while pulling out on the top end of the indicator stem so the stem will clear the end of the quill, and stop the carriage so the indicator is now measuring the quill. My tailstock quill is 0.866" in diameter, so if the center of the tailstock quill is actually aligned with the lathe centerline, the outside of the quill should now indicate 0.433" along its entire length. If it doesn't, I adjust it until I'm satisfied with it.




Screwing in one of those added adjustment screws swivels the whole tailstock around and changes what was done with the other screw, so the alignment process is an iterative process (at least it is for me). I found that the best way to make progress is to work toward minimizing the _difference_ in readings from one end of the quill to the other first, without regard to the actual distance from the centerline. Then, when I'm satisfied that the quill is parallel with the centerline, I tweak both adjustment screws in or out in unison to get the quill axis aligned with the center of the lathe. I leave my test bar in the chuck during the alignment. If the dial indicator gets bumped accidentally during the process and my reference measurement is lost, I just crank the carriage back to the test bar, set it again, and continue.  

Aligning the tailstock this way assumes a lot, including that of the headstock being reasonably aligned with the centerline of the lathe. From what I've read, a good way to check headstock alignment on our hobby lathes is <a href="http://neme-s.org/Rollie's_Dad's_Method.pdf">_*Rollie's Dad's Method*_</a>. When I checked mine, it was off about a thou and a half over five inches, IIRC.

Regards,
Rudy


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## zeeprogrammer

Thanks for the link Chuck! I remember following that thread. A wealth of good information.

Why did you build a tool post for cutting tapers rather than using the compound? More rigid?

Thanks Rudy. Very helpful! I popped a bar out of a printer so that should be helpful.


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## cfellows

zeeprogrammer  said:
			
		

> Thanks for the link Chuck! I remember following that thread. A wealth of good information.
> 
> Why did you build a tool post for cutting tapers rather than using the compound? More rigid?



There were a number of reasons to replace the compound with one that fits on my "quick change toolpost". First, the supplied compound takes up a lot of real estate on the cross slide and I rarely use it. Second, I don't like having to crank the compound all the way out to loosen the screws so I can change the angle or remove it. And, third, my QC toolpost mounted on the cross slide is more rigid than than if it were mounted on the compound. I prefer to treat the compound as just another accessory for my QC toolpost rather than a main component of the lathe.

Chuck


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## black85vette

zeeprogrammer  said:
			
		

> Bogs...thanks for the link. I have no means at hand for modifying the chuck but shimming the headstock is something I'll have to look into. Right now the carriage and so on are broken down for cleaning.



Zee; I think your spindle has an MT3 taper doesn't it? If you want to check / square up the back of the chuck I have a 1/2" MT3 collet that you can borrow for this. Just let me know.  Might also come in handy for setting up the head. Eliminates the chuck entirely.


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## zeeprogrammer

Thanks Chuck. All good points. I'll have to think about how much I use the compound. That has so far been a source of many issues I've had.

Thanks Rick. Let me get further down the road...I may take you up on that.

-------------------------------

An update! An update!
Well not much of one.

I've been traveling, had visitors, and now that my garage is getting fixed up...all that stuff is in the basement.

But I did manage to put the carriage et.al. back together. It seems even better than before. I'm thinking it's because I've gotten to know the lathe more and gotten better at understanding torque requirements and play. In particular how to adjust the gibs. I highly recommend that people new to lathes take the time to take it apart and put it back together after a project or two. It makes a difference. At least for me.

Next step, when I can, is to see how the tail-stock lines up.

I have to admit I'm more anxious to build something rather than futzing with the equipment.


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## zeeprogrammer

I'd like to raise my lathe up using some aluminum blocks.

2x3x4 solid is on the order of $10
2x3x4 rectangular is on the order of $2.50
I'd need two.

The rectangular has 1/8" wall thickness. Would that be strong enough?

It may be time to strike up a relationship with some scrap yard or machine shop around here.


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## Twmaster

Zee...

Sorry for being a bit late to your party. Been out of town with now web access for the last 6 weeks. However late I'd like to offer a copuple my experiences with the 7x10 lathe I had.

1. Slitting the brass nut on the compound was a snap and worked well. The only caveat is you need to go back and squeeze it closed now and then. I used a very thin hobby saw to make the slit. IIRC it's something like 10 thou thick. Do be careful to not make too thick a cut and break the nut when you squeeze it. (Ask me how I know that one! ;-))

2. Lap your compound and cross slide. Loads of arm work but well worth the effort. Make sure your gibs are straight. 

3. If you have the time and inclination remove the silly set screw wetup on your carriage retainer plates and shim it to fit. I used strips of beverage can cut with scissors and perforated with a punch to make the shims. One of the best things I ever did.

4. Make sure the carriage rides flat on the ways. My carriage had a hump in the casting that would not allow the thing to sit flat on the ways. File the carriage, check again. File, che... layout juice is your friend. I finally got my carriage to less than .001" of movement up and down by the use of the shims and making sure the carriage was flat. 

Item last. The removal of the compound as done by Chuck and others will go a long way toward improving rigidity. Flex is the #1 downfall of these machine IMHO.


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## winklmj

zeeprogrammer  said:
			
		

> I'd like to raise my lathe up using some aluminum blocks.



Solid is overkill. I think 1/8" wall would be too thin. Here's how I did mine and I think it's 1/4" wall. Finding a local scrappy that lets you hunt around for stuff is a big bonus.


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## cfellows

Twmaster  said:
			
		

> Zee...
> 
> Sorry for being a bit late to your party. Been out of town with now web access for the last 6 weeks. However late I'd like to offer a copuple my experiences with the 7x10 lathe I had.
> 
> 1. Slitting the brass nut on the compound was a snap and worked well. The only caveat is you need to go back and squeeze it closed now and then. I used a very thin hobby saw to make the slit. IIRC it's something like 10 thou thick. Do be careful to not make too thick a cut and break the nut when you squeeze it. (Ask me how I know that one! ;-))
> 
> ....stuff deleted



What's the deal with slitting the brass nut on the compound? Is that to reduce backlash?

Chuck


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## Twmaster

*What's the deal with slitting the brass nut on the compound? Is that to reduce backlash?*

Chuck, yes, backlash reduction.


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## zeeprogrammer

Twmaster  said:
			
		

> 1.I used a very thin hobby saw to make the slit. IIRC it's something like 10 thou thick.
> 
> 3. If you have the time and inclination remove the silly set screw wetup on your carriage retainer plates and shim it to fit. I used strips of beverage can cut with scissors and perforated with a punch to make the shims. One of the best things I ever did.



Thanks Mike (Twmaster). 10 thou eh? That's smaller than my 1/32 I have. I'll have to look around.

I don't understand #3. wetup? Where is the set screw? Thanks.

Thanks Mike (winklmj). I'm wanting to put the blocks between the lathe and the tray so I can get under and clean easier. On my way home I was wondering why not wood? The thing sits on wood anyway. Although...it would soak up oils and stuff...probably not a good idea. Under the tray would work...but that's not what I want.

Chuck...yeah...what Mike (Twmaster) said. Backlash. Although I'm wondering how the little setscrew that pushes down in the middle of it would work. I can't remember where I saw that mod. I think on mini-lathe.com or some link in it.

Thanks guys.


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## Twmaster

Come on Zee... get with the new lingo! 

What I was trying, and failing to say, is to remove the silly set screw *setup* from the carriage retainer gibs. Put shims in there. It took a bit of time to get right but worked great


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## zeeprogrammer

Twmaster  said:
			
		

> Come on Zee... get with the new lingo!
> 
> What I was trying, and failing to say, is to remove the silly set screw *setup* from the carriage retainer gibs. Put shims in there. It took a bit of time to get right but worked great



Gibs? Between the carriage and bed? The only gibs I have are on the cross-slide and compound. Pics!

It's not your failure...I just can't get the lingo.

know it jack?
feeling the scritch?
understandin' the toe?

Yeah. Me neither.


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## rudydubya

Zee, if I may, a few pictures may help with what Mike is saying. When you look at the bottom of your carriage, you'll see that it's held to the bottom of the ways, both near and far side, with retainers held on with three cap screws, with two adjustment setscrews between them. (Yes, I have a tiny assistant who crawls underneath my lathe to take pictures for me.) The set screws are supposed to be adjusted to provide just enough clearance between the retainers and the bottom side of the carriage to allow the carriage to slide along the ways, yet keep the it tight enough so it won't rock back and forth. I never did get them adjusted right with that setup.







You can get rid of those adjustment setscrews and duplicate their function with shims of the appropriate thickness, say from brass and/or aluminum, and put them between the retainer plates and the underbody of the carriage.






I used a feeler gauge to get an initial idea of the thickness I needed. Wound up using some soda can aluminum and brass shim stock I got from the hobby shop. If you look closely you can see the shims between the bottom retainer plates and the bottom of the carriage.











It did take me a little while to get an acceptable fit, but it was one of the better mods I made to my lathe.

Hope this helps.
Rudy


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## zeeprogrammer

Ah thanks Rudy. That made it clear for me. (And thanks again Mike N).

I did take a look last night and wondered if it might be them. (Have to admit I was looking for one, not two, and that was one reason I was confused.)

In any case, I noticed the plates aren't square to the carriage. Even though the carriage seems to be running smooth with no slop...I worry about wear. It can't be riding right. I can see how the shims would be a benefit.

Thanks again.


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## Twmaster

That's what I was trying to say. Thanks Rudy. Proof that a photo is worth a bucket of words.

I had to fit, try again and refit a few times to get it right. And as Rudy said worth the effort as it's a good mod you almost never had to ever fool with again. Go one better... Make a new pair of plates out of brass so they slide better.


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## zeeprogrammer

Twmaster  said:
			
		

> Go one better... Make a new pair of plates out of brass so they slide better.



Ah yes. That means taking the mill apart, cleaning it up, and doing some adjusting to it as well. It needs it bad and I'm very optimistic that I'll end up with a much better working machine.

Now if I could just get to it...

All the garage is in the basement while the garage is walled, painted, and cabinets and shelves put up. It'll be a while...but the upside is the stuff on the other side of the basement will have a place to go and I can set up some small woodworking stuff to make display bases, small boxes, and frames.

Even better...a place to set up a train set. Woo woo.


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## Twmaster

Excuses excuses.....


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## zeeprogrammer

I have my shop back...mostly.

I cleaned up and adjusted the mini-lathe. The increased rigidity is noticeable.

I also replaced the blade on my horizontal bandsaw. I must have done better this time...no hip-hop action and it cut through a bar of aluminum without trouble...twice. Said bits of aluminum used to raise the mini-lathe...






Next step is to clean and adjust the mini-mill.

I also need to choose my next project. I'm thinking a marine engine of some sort. I'm also looking for a boiler. Suggestions are welcome. Work has not decreased much (no complaints), so progress will be slow.

Some of you may be wondering about the little loco. Not to worry. It's sitting right here. ;D

I mentioned it elsewhere on the forum...I plan to be at Cabin Fever. I hope to meet some of you there.

BTW Pat...in addition to 'most often taped out of his shop' I can probably win in the categories of...

most kits bought of the same engine until he got one running
best use of shop oil
best legs in a tu-tu

Happy Holidays everyone.


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## zeeprogrammer

Thanks Pat. I just wanted a bit more room under the mill to make it easier to clean.

Started cleaning up the mill...stripped it down and found this...






The base is not square with the shaft holder. See the gap? It's bigger at the point closer to you than farther away. (Yes the bolts are loose...I had noticed this before I loosened things up...then decided to take a picture.)

I don't know if it came this way or if I put it back together this way when I first got the mill and cleaned it.

I'm not sure how to make it square. Any thoughts?

They've changed photobucket! I don't like it. Took a while to figure out how to get the pic in this post. And I'm getting warnings about malicious URLs again. Grumble.


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## 90LX_Notch

Zee,

I would say that gap is meaningless. What counts is wheather or not the face of that casting (where the line for degree indicator is) is square to the ways. 

Bob


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## zeeprogrammer

Thanks Bob.

I agree, the gap in and of itself doesn't matter.

I just don't know how to get the shaft in line with the ways.


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## hobby

Could you elongate the farthest hole, and a small bit of the middle hole to pull things back square?

Then make a precise shim to fill in the gap to keep from vibrating forward.


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## zeeprogrammer

Thanks hobby.

I don't think there's a need to modify any of the holes. There's enough slop for the casting to move about...I can eyeball it enough to see it can be made square...I just don't trust the eyeball. (Over the years it has lied to me too often..."she looks great...wait...it's not a she".)


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## PhillyVa

Hi Zeepster,

The machined surfaces are the ones that need to be Plumb...Level...and Square, the rough casting pay no mind to.

Trgards

Philly

PS, Merry X-Mas to all. ;D


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## hobby

zeeprogrammer  said:
			
		

> I just don't know how to get the shaft in line with the ways.



One possible way, with the table on the mill base, fix up a dial indicator extended from the table, to bear up against the shaft, then run the table back and forth, as you tram in the shaft, that will at least get it close to parrallel with the ways.


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## Troutsqueezer

Hi Zee,

What did you do, paint your lathe blue? Maybe you mentioned that already and it didn't register with me. Well, it sure does look purty. 

If you make a marine engine, does that mean you're going to make the boat too?


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## zeeprogrammer

Thanks hobby. Is this what you mean? It looks like it'll work.






On a side note...when I first got my lathe and mill, I broke them down, cleaned them, and adjusted them. Now that I've built a couple of engines I've found it invaluable to do it again. Being more familiar with the machines, their capabilities, and 'something' about machining I am staggered by the improved stiffness (rigidity) and smoothness of operation. (Maybe it's the oil. ;D )

Hi Trout! I don't recall if I mentioned the lathe color before...but there's been pics. It came out of the box like that...Pro-Tech (Cummings I think)...but just like most of the other mini-lathes. Just a different color.

And yes...part of the reason for a marine engine is my dream to build a boat.

I'll probably wait until Cabin Fever to make a decision. This will be my second trip and I know a lot more than I did last year. I'm really looking forward to it.

Oops. I just noticed the ding in the table. Hee hee. There's two of them. They happened shortly after I got the mill. I'm sure no explanation is required for how they got there. :big: You can also see a few marks from having tightened things down a bit too hard.


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## zeeprogrammer

Bummage.

Some time ago I got a short bit of angle from Rick (black85vette) that he'd used to stiffen the column of his mini-mill.

So I slapped it into the horizontal bandsaw (with the new blade that had just cut two 1"x3" blocks of aluminum). Used cutting oil.

It started cutting...then about halfway through...no more cutting. Blade just spins along...but no cutting.

What'd I do wrong? Wrong speed? Should have been slower eh?
I went up a step in blade quality...but probably not enough.

Foo.


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## Troutsqueezer

Now, I'm only a Caveman Lawyer (feeble SNL reference) and a newbie machinist but I'm trying to think how, if indeed the shaft is not at 90 degrees (horizontal) to the table, that manifests itself to the accuracy of milling. The spindle/head would be in some degree of rotation to the table yes, but the table moves at X/Y in relation to the spindle. The spindle/head only moves up and down. 

Am I missing something? I'm sure I am but not putting it together yet.


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## zeeprogrammer

I've been struggling with that too. But better safe than sorry.

My thinking went this way the longest ;D ...

When I mount the vise, I square it by moving the table left/right with a DTI against one face of the vise. Cutting left/right should remain square.

But if I cut in/out...would it not be at something other than 90 degree to the vise?

I need to continue thinking about this...but it's time for supper and her food is better than any conversation I could have.


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## Foozer

A certain amount of Fly poop is allowed in the Pepper

Insect filth and/or insect-mold (MPM-V39) 	Average of 1% or more pieces by weight are infested and/or moldy (USFDA)

Under that and its OK. Would be nice if that shaft was perfect but i cant see what harm a slight out of whack condition would bring. Important tho that the vertical support be as close to 90 with the table and to that end the focus is fruitful. Line that casting up as best as it will, look up the torque values for those attach bolts and set that sucker in place. Shim as necessary to get the vertical in order.

Looking at a quick sketch, it seems that it'll cut proper anywhere on the arc, course nothing else has gone right today, missed the eclipse due to clouds. 

When you get that done come over and dig out my garage 

Robert


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## fcheslop

Hi Zee, did you say steam boat now I'm interested what size? what type of engine? but be very careful once you've built one your addicted for life :big: Iv recently started on a build of Basil Harley's Victoria but its going slowly
best wishes Frazer


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## zeeprogrammer

Robert! How are you? What are you working on these days?
And no...I won't come over and dig your garage out. I just moved my garage back out of my basement. I want nothing to do with garages.

Frazer...I don't know what size nor what kind of engine. At this point I have no idea how to size a boat to an engine. I'm hoping to learn some things at Cabin Fever.

Do you have a thread going on this? Give up a link please.

I found this...some nice detail work...note the shovel and refreshments.

http://modelsteam.myfreeforum.org/viewtopic.php?p=483978


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## hobby

zeeprogrammer  said:
			
		

> I've been struggling with that too. But better safe than sorry.
> 
> My thinking went this way the longest ;D ...
> 
> When I mount the vise, I square it by moving the table left/right with a DTI against one face of the vise. Cutting left/right should remain square.
> 
> But if I cut in/out...would it not be at something other than 90 degree to the vise?
> 
> I need to continue thinking about this...but it's time for supper and her food is better than any conversation I could have.




Hi Zee,

I think, it would not matter if it is out of alignment as far as (x, y ) table movements, are concerned,
but if you look at it in a worst case analysis, by picturing it way out to the side, the x,y and z, movements are not affected, Bridgeport mills allow the horizontal pivot of the head, to reach farther on the table for milling and drilling.

But if you should want to tilt it at an angle on it's pivot, then the cut produced will be out of alignment.
The pivot needs to be in line with the x, axis, to cut true to table movements.


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## zeeprogrammer

I think I got it. It's the usual problem I have in understanding what is moving in relationship to what.

So long as the two table axes are square...the left/right and in/out cuts will be square to each other. The position of the spindle itself in relationship to the table doesn't change the relationship of left/right to in/out.

By the way...I've avoided the use of x/y/z. I still don't have a handle on that.

Oh well let's try...

Mill:
[EDIT: oops...]
x = in/out travel (+ towards you)
y = left/right travel (+ to the right of you)
x = left/right travel (+ to the right of you)
y = in/out travel (+ away from you)
z = up/down (spindle) travel (+ to the heavens)

Lathe:
[EDIT: oops again]
x = in/out travel (diameter) (+ towards you, increasing diameter with cutter between you and material)
x = in/out trvel (diameter) (+ away from you)
y = I dunno (and therefore, + I dunno)
z = left/right travel (spindle) travel (+ uh +...uh...I dunno)

Enlightenment would be appreciated.

Anyone who says "What? You been at this two years and you still don't know?" I will hunt down, take by the collar, stick my face in theirs, and say "Yep."...

with fetid breathe.


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## Troutsqueezer

Hey Zee,

X direction is to your left and right. Right is +X and left is -X. 

Y then is toward (-Y) you and away (+Y) from you. 

I do like that boat (link), a lot. That's a level I'll never get to, no doubt.


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## zeeprogrammer

Rats. You're right. I got the mill x/y mixed up. I knew that when I was writing it...even when I reread it. Funny how things stick.

However, the +/- of Y is a surprise. I was working off memory from when I designed robot controllers. I finally found a couple of links though...

http://www.efunda.com/processes/machining/images/mill/millCNCaxes1.gif

This next one was confusing...

http://www.efunda.com/processes/machining/images/mill/spd_rotary_table_2.gif

They have the cranks labeled correctly but the xyz symbol doesn't seem right.

In any case, I will edit my post. Thanks Dennis.


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## winklmj

Troutsqueezer  said:
			
		

> Now, I'm only a Caveman Lawyer (feeble SNL reference) and a newbie machinist but I'm trying to think how, if indeed the shaft is not at 90 degrees (horizontal) to the table, that manifests itself to the accuracy of milling.



I don't think it matters. The X/Y table is what needs to be square with each other. The fore/aft and left/right tilt of the Z axis column in relation to the table will matter. So will any similar tilt in how the head is attached to the column. That said, getting it as close as you can with the DI won't hurt anything.


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## shred

On the bandsaw, presumably the teeth are gone from the blade? In that case I'm guessing you stuck the angle it in the bandsaw vise with a flat down, which leads to cutting a very thin section on the upright leg, which strips teeth off the bandsaw blade..


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## arnoldb

Carl, good to hear you finally found your tools 

I agree with Robert after having had a look; the only time the horizontal alignment of that mounting will come into play is when you pivot the mill head away from vertical, and that will only have a tiny influence; but worth remembering if/when you do it one day. I've rarely seen someone posting photos where they use a mill like yours with the head pivoted though. 

As to your band saw blade, like Shred said; it will do that if you have a low tooth-count blade on thin metal - or if the cutting downforce is too big. You want at least three to five teeth from the blade in contact in the saw slot at the same time - and the less the teeth you have in contact, the lighter the saw's downforce must be; usually thats adjustable by tensioning up a spring on the side or on the pivot base. For thin materials I just "cheat" by lightly counteracting the downforce by pulling upwards with a finger on the handle while the saw is cutting. It also makes for more square cuts in the vertical plane; you might find your saw cuts thick stock pretty squarely, but with thin stock it wants to deflect off vertical if the downforce is too high.

Regards, Arnold


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## fcheslop

Hi Zee, that's the one sorry no build thread at the moment .The gentleman who owned that boat kindly send me a copy of the build articles and the plans came from My Hobby Store .They also sell a vac formed hull but its very thin and i like to build from scratch wasn't shure about posting a model boat on this site?.If you should want any info about her just shout
best wishes Frazer


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## mklotz

Troutsqueezer  said:
			
		

> X direction is to your left and right. Right is +X and left is -X.
> 
> Y then is toward (-Y) you and away (+Y) from you.



With +X to the right and +Y away that makes the +Z axis of a right-handed coordinate system point upwards (Z is vector cross product of X and Y) which is a bit counterintuitive. Making +Y point toward you makes +Z point downward which is the way the quill moves when putting on a cut.


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## zeeprogrammer

Thanks winkmlj.

Thanks shred and Arnold. I think you're right about the number of teeth being too few on the material. (It was a 14 tpi blade.) I'd forgotten about that. I had tried mounting the angle down flat...but that didn't work. It didn't occur to me to use some spare bar to hold it in. I ended up mounting it like an upside down 'V'. Maybe not the thing to do. Given the problem of sawing thin stuff, it wouldn't have mattered anyway.

Thanks Frazer. I may very get back to you on that boat.

We discuss and show our display stands don't we? ;D I for one have no problem seeing a boat build...particularly if there's an engine build along with it.

Thanks Marv. Now I'm confused again. I don't mean to beat this to death...but here goes...

Right Hand Rule
I thought I was taught to use the index to point in +X...but I see references to use the thumb to point in +X. It doesn't matter though so long as you go in the order of thumb-index-middle or index-middle-thumb or even middle-thumb-index.

So when facing the mill...

+X to the right
+Y into the mill
+Z going up to the spindle

When facing the lathe...

+X into the lathe
+Y down
+Z going towards to the spindle (just like the mill)

Which means I got my earlier post about +X and the lathe wrong.


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## Maryak

mklotz  said:
			
		

> Z is vector cross product of X and Y which is a bit counter intuitive. Making +Y point toward you makes +Z point downward



IMHO this is one of the stumbling blocks to understanding 3D Cad. I'm still stumbling along at lesson 58 of 195. :

Best Regards
Bob


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## mklotz

Obviously, you can define the coordinate system any way you wish. However, you'll eliminate one more potential entanglemnent (ie, source of error) if you stick with a right-handed system since that's the standard in all of mathematics.

It seems more natural to me if the +Z axis on the mill points down (the working direction of the tool), hence my choice of X and Y above.

Similarly on the lathe. As on the mill, the chuck spins CCW, so the spin vector points out of the chuck. Pick +X and +Y to preserve this relationship. I would be inclined to make +X away from the operator (ie, the way you put cut on) and +Y up.

For Zee et al...

The right hand rule. Using your right hand, orient the extended index finger along +X. Extend the middle finger perpendicular to the index and align it along +Y. Now, the extended thumb, perpendicular to the XY plane, will point in the +Z direction of a right-handed coordinate system.

In mathematical terms, +Z is the vector cross product of +X into +Y.


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## arnoldb

:big: - I like being able to make up my own coordinate system - I stayed quiet so far about that...
Like Marv, for the mill, I prefer +Z going downwards. And +Y moving away from me. But I prefer +X incrementing from right to left...
This leaves positive in-feed on all handles on all axes of my mill in a clockwise direction :


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## zeeprogrammer

Not being narcissistic here...for me it's all about 'z'. :big:

I guess I got used to coordinate systems where '+z' is always up.
And while there has been some change over the years with respect to that...I still like to think it is...or can be. ;D

As Marv said, 'you can define the coordinate system any way you wish'. I'm still using the right-handed rule...I'm just placing 'z' where it feels right and that puts 'y' going the 'other way'. I admit though it doesn't feel right with the lathe.

On a side note...when I worked with computer graphics, it was also weird that 'y' went from top to down. 'x' went intuitively left to right. 'z' was depth so it made sense it went into the screen. For a right-handed system, the meant 'y' had to go from top to down.


----------



## Troutsqueezer

All depends on your perspective I guess. In chip design, wrt CAD, fabs (foundaries) and assembly houses, +Z is up and +Y is away from you. Everything's relative. But then, in chip/package design they still mix microns and mils interchangeably on the same design. Talk about confusing.


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## Deanofid

If I keep reading this thread I'll end up standing on my head to run my mill, and running the lathe from the tailstock end. Ignorance *was* bliss.


----------



## zeeprogrammer

Dean!

See...that's the only complaint I could have of this forum.
The mods are very good at protecting the forum from...
scammers,
trouble-makers,
ne'er do wells,
off topic discussions,
thread hijackers...

but here I am (we are) :big:

along with...well...I'll leave the list to you all...but I'll give some initials...

abcdefghijklmnopqrstuvwxyz

and just to be all-inclusive...

123456789
pi
sigma
delta
beta
alpha
one of my favorites...upsilon
that funny sign for the person who doesn't know who/what it/he/she is

okay...time to put the jelly jar away
I'm on vacation


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## Maryak

zeeprogrammer  said:
			
		

> one of my favorites...upsilon
> that funny sign for the person who doesn't know who/what it/he/she is



When Epsilon and Upsilon = 25 it can be said to be the sum of something slender. ;D How Greek is that ???

Best Regards
Bob


----------



## zeeprogrammer

Maryak  said:
			
		

> When Epsilon and Upsilon = 25 it can be said to be the sum of something slender. ;D How Greek is that ???



Epsilon: 5th letter of the Greek alphabet. Our 'E'. Value = 5.
Upsilon: 20th letter of the Greek alphabet. Our 'Y'. Value = 400.

I have no idea how the values are arrived at. Nor do I know what you mean by the 'sum of something slender'...tell me more.

I was wrong about my favorite...back in school...and still sometimes at work...I use...

Tau: time constant
Lambda : wavelength
Sigma : summation
Beta: gain
Omega: resistance
Delta: difference
Theta: angle
Pi : duh

I wish you all a

Mu-Epsilon-Rho-Rho-Upsilon
Gamma-Theta-Rho-Iota-Sigma-Tau-Mu-Alpha-Sigma

and a 

Theta-Alpha-Pi-Pi-Upsilon
Nu-Epsilon-w
Upsilon-Epsilon-Alpha-Rho

which is a complete trashing of the Greek alphabet and I apologize for that.
Be glad I'm not trying to write in English.

fröliche Weihnachten


----------



## ttrikalin

Frohe Weihnachten Zee. 
&#922;&#945;&#955;&#940; &#935;&#961;&#953;&#963;&#964;&#959;&#973;&#947;&#949;&#957;&#957;&#945;.

(Since you got to Greek)

Take care

tom in ma


----------



## Maryak

zeeprogrammer  said:
			
		

> I have no idea how the values are arrived at. Nor do I know what you mean by the 'sum of something slender'...tell me more.



Bob's convoluted mind arrived at the following, at least dubious and probably erroneous output: 

Epsilon is the symbol for "The sum of."

5+20 = 25

Upsilon means, (according to my Oxford Dictionary), slender. 

I'd never even heard of it and thought you had made a spelling mistake for Epsilon :.

As I said, total Greek or maybe even Double Dutch.

Best Regards
Bob


----------



## arnoldb

zeeprogrammer  said:
			
		

> along with...well...I'll leave the list to you all...but I'll give some initials...
> 
> abcdefghijklmnopqrstuvwxyz
> 
> and just to be all-inclusive...
> 
> 123456789
> pi
> sigma
> delta
> beta
> alpha
> one of my favorites...upsilon
> that funny sign for the person who doesn't know who/what it/he/she is
> 
> okay...time to put the jelly jar away
> I'm on vacation



You skipped 0 and &#8734;  

Put away your jelly jar while on vacation ? - unthinkable...

And a *Merry Christmas* to you all too !

Kind regards, Arnold


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## Deanofid

What? 
No, no... Please don't explain further. 
I'm going back to the Weebles and Playskool forum where I can actually interact with the members.


Merry Christmas, everyone. I love you guys.  ;D


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