Wow has it been a year?

Wow! has it been a year?
Yes, yes it has.  I haven't posted in a long time, and I have no good excuse as to why, other than i am very lazy.  I did find work as an "engineer" for a year.  sadly it had no engineering work, and was not the place i wanted to be.  So I want to get back into my personal projects.  First and foremost is moving my shop from one garage to my garage (oh joy).  Which means i have to get my garage cleaned out, and i mean really clean, and not "clean enough, just pile that up there".

I have bought some new machines, and just finished a deal for some really nice ones that i will share at the end of the month.

I am in the process of cleaning out the garage now, and will post some pictures of the progress and what i apln to do with it.  what fun!

this is not a good thing

The rebuild of Jasmine has started!  I did some basic inspection and found that Jasmine has turcite on her table, and that it need replaced before she can make chips.  This requires me to get some turcite cut to shape, install it, and grind/scrape it.  Of course I am not doing all of this.  I am hoping that American plastics in Columbus cam make the strips.  I am looking for a rebuilder to do the scraping.

So in general that sucks.

But in for a penny, in for a grand.  So since the table is off, I am ordering new plumbing for the one shot lube system.  The one shot lube supplies all the moving parts of the mill with lubrication, and it’s a big deal when it breaks.  2 lines in the system were corroded and that is probably why the turcite was chewed.  In the mean time I have only 30 or so other things to do like build a table for the Rockwell, plumb some air lines, buy a compressor, finish the design for the rpc, build the rpc, finish the flood coolant for the saw, put some lights up, find a compressor, run electric to all machines, and maybe even get a job.  I feel like I still don’t know any answers but I am at least starting to ask the right questions.

What does an engineer do, really?

If I had a nickel for every time I was asked this, I could buy a double stack at Wendy’s.  I could describe what engineers do, but that would be boring, and this blog is boring enough.  So I thought “hey let’s use an example”.  Examples are great. just about any time I have a problem, I look into a book for an example that’s close, and already thought out, and use it.  So here’s the problem we have.  I want to design a table for the Rockwell drill press.  Now I could just get some big honking steel beams, and slap it up, but steel ain't cheap, and it is heavy.  Once we have a problem to solve, we try to bound the problem with requirements.  I made the following requirements:

1)      Must be fastened together (no welder, and easier to fix/change bolted parts)

      2)      Must hold drill plus 500 lbs (1000 lbs total) with less than .025 deflection.

      3)      Max material length 12ft per piece

      4)      Max material weight 150 lbs per piece

      5)      Must have a hole pattern  same as the pattern on the bottom of the drill (so drill can bolt on)

      6)      Finish height of table = to other drill finish height (makes the entire space more usable)

      7)      Table top, and must be stable with a heavy load.

Find lowest cost/ best performance material.  Who’s excited?!??!?!

The first thing is to determine how long and wide to make the drill table.  The drill is about 50” tall, and the table is about 20x25.  The drill head sticks out an additional 8 inches, so when looking from the top, the drill takes up about 34 inches, call it 3 ft, and I’d like some room from the wall, so let’s say 40” depth of the table, for easy of manufacturer (and because I have the room) 40 wide.   The drilling surface is about 4 inches thick, so the table needs to be 25 inches tall to have the drilling surfaces of the 2 tables at the same height.  So the table will be 40x40x25.  Now the drill has a hole pattern on the bottom of the drilling surface that is 17x23 and uses ½-13 threads.  So to use the drill pattern to secure the drill to the table we will need supports that mate to those holes.  This means an extra support in the center of the table.  Well look how much we have done , and we don’t even know what it will be made of!

Onto material!  I settled on square tubing because it has superior strength, doesn’t have any crevices where swarf can build up,  and it looks nice :(and it wasn't in the requirements so that means i can choose what i want).  Now that we know what shape we want to use, we look to see which we will use.  So we know the load, and the span, and the material, and the shape, and we can calculate the deflection based on thiswhere E is the modulus of elasticity and I is the moment of inertia.

All that changes is the moment of inertia depending on the thickness, and size of the tubing.   Now we can chart the deflection of different materials versus their cost per inch, and find the best candidate.

Luckily I made one charting several steel tubes, and a few extruded aluminum tubes.

  

So based on cost and deflection, it looks like the 3x3 11 .120 wall steel is a winner.  And that is in a nutshell what engineers do.  Sure I could have just made it out of ¼ wall 3x3 or fancy 80/20 aluminum, and if I was charging 250 an hour, I would have, but engineers figure out how to make something as quickly and cheaply as possible, and if you have no cash or are making a trillion of something, then having an engineer to find out the best for the least is a necessity.
I look at it as the designer makes the requirements (frames the box) and the engineer makes the part you need fit in the requirements box.  sure lines are blurred sometimes, today i was the designer and engineer,. but i have to wear a lot of hats.

Now to figure the cost of hardware…

Moving Jasmine

Well I bought Jasmine about ½ a year ago.  I finally got up to moving her.  She is a Yamazen 5BVK CNC knee mill.  She was named Jasmine by my wife who for the life of her could not remember Yamazen.   I kinda like having a Jasmine in the shop.  Sounds way sexier that it should.  Onto the move.

good and cheap, what more can you ask for?

Once again I went to sunbelt rentals and had Shaun hook me up with a tiltbed trailer.  If anyone is ever thinking of moving anything, I highly recommend the tiltbed trailer.  It  makes that much of a difference.  I then swung by Ace hardware and bought the “blue bitch”, which is a large engine hoist with shitty caster wheels.  I brought my rollers, and my bag o tools, including a ryobi 18volt cordless set.    This is another must have thing when moving equipment.  You never know when you will need to cut a wedge or drill a hole/hack something off.

I removed the servos and bits and pieces from the mill.  I left the lube and mister attached, I didn’t want to create an environmental disaster on the way home.  First thing was to remove the variable speed head.  Three bolts attach the head to the fixed ram.

can you find the nut?

  The first is located behind the front panel,second is on the right side access panel.The third is in a blind spot with access through the fixed ram, what fun. 

tghe blue bitch doing her thing

Once the bolts were removed it the blue bitch was hooked up and as the queen of hearts would say...

Next was the fixed ram, the bolts were easier to find, but dam hard to loosen, thank you channel lock for making the “nut buster”.

IT made short work of the stuck allen head bolts.  If you don’t mind marred surfaces , and at the time I didn’t, they are fantastic.  So next was the fixed ram, which balanced well also, and was pretty easy to take off.

After that the based was rolled on using the old eqyptian method of rollers, prybars and muscle.  Once it was on the tilt bed, it was smooth sailing with a come-along.  Unload was done in the middle of the night, so no pictures, sufice it to say it was a long night.

what a putz

So a while ago I bought a cnc knee mill.  I haven’t even moved it out of the guys garage yet (I am doing that Saturday… I swear… promise with pictures for the bloggerz).  I had a small little bench top mill with tooling for $1200+shipping  new before I knew what the hell I was doing.  It was a bad choice money wise, but a good machine to learn on.  I had it for about a year, and made some good and bad parts on it (I also added a 3 axis DRO, Gas piston, lapped the ways, and generally kept it in decent shape).  I sold the bench top to make room, and have been looking for a small manual knee for a about a month now.  I have looked at some nice machines, and some absolute dogs.  The one today was a head shaker.  It was a Millrite MVI, with a nodding knuckle.  But it had been sitting for at least a year outside, was crammed full of grease (pet peeve of mine), and a dinged up table and rusty spindle..  the x and y lead screws hd tons of play.  The old fellow that owned it wanted $1500 originally, which I thought was supposed to be funny, then $500.  I replied that he could get $150 for it in  scrap, and I’d offer $250.  I think he was upset, because he replied he would give it to his grandson.  I personally have no problem with this.  What I do have a problem with is people not understanding that the value of something is really determined by the buyer, not the seller.  The owner has three prices he can choose from, mine (250) scrap (150) and free.  Oh well, that’s the way some people are, they’d rather lose money then think they’re giving someone a deal.  A goofy amchinist guy i know set up the meeting.  He knew i was looking for a mill, but seemed to take the old guys side, even adding "good luck finding a mill for $500".  wtf bud, youre supposed to be the wingman here!  Still looking for that nice mill, I’d like to spend about 750 or so.  Everyone says you’ll never find one for that, but then posts how they did… so I think I’ll be hitting the auctions for a while, and sticking to my axioms.  And looking for a TREE or Index...

Projects, Projects, Projects

I think I have at least 8 irons in the fire, in various stages of incomplete running from “just a few more seconds”, to “I don’t even know where to begin”.

Yesterday I replaced the bearings on my radial arm drill.  It is a walker turner model 1600, and I have wanted one from the day 1. 

Replacing the bearings was a pretty easy task, I ordered 8 6230’s from Mcmaster Carr, and proceeded to beat them into place with a combination of wood blocks and a hammer. 

I also adjusted the locking mechanisms.  Now replacing the arm… that was not easy.  Luckily there were no pictures to show how I did it, it wasn’t safe, or pretty, or fun.  After the arm is in place, the bearings have to be adjusted to provide proper contact to the dovetail.  Each bearing is on a cam, and rotating the cam provided about an 1/8^th of linear motion for adjustment.  I did my best, but I think I will contact the folks at wwm to get a better procedure to do this.  I checked how much the arm flexes under load.  It was about .010” at full extension, and .003” at the minimum.  That may sound like a lot, but I can live with it, the drill only has a ½ hp motor, so I am limiting it to ½” holes.  Next to the WT is a drill for bigger holes currently acting like a desk and waiting on a table.   I wonder what it's deflection is…

Every shop needs at least one drill press.  It is the ubiquitous tool of the shop, capable of precision and just “burning a hole”.  It’s a poor man’s press, and a stable table for other work.  I have two now, the Walker turner, and a huge Rockwell 70-x.  The Rockwell needs a table still… but that’s a project for another day.

The 5 Machine Buying Axioms!

When I left my employer of 10 years, I thought I would work on some neat ideas I had.  I bought a0small 7x10 lathe and a small milling machine (model 3900 from little machine shop, a great little mill).  I quickly learned I couldn’t make some of the bigger parts I needed, and that I had a lot to learn.  I used a machine shop in Columbus, Ohio to provide me the bigger stuff, and even fixed some of the parts they made on my dinky machines.  I started reading online forums… a lot.  I joined practical machinist, homeshopmachinist, hobbymachinists, you name it, I had an account (and still frequent most of them).  I learned a few axioms about buying machines:

1)      You can make small parts on big machines, but you can't make big parts on small machines (to a point).    

This is a classic line for anyone that wants to start a hobby or business.  As soon as you buy that HF (harbor freight) 7x10 lathe, you’ll outgrow it.  Then that 9”Atlas you got at an auction… too tiny.  Then that 14” southbend… well you get the idea.  Now some large lathes won’t have the RPMs to turn small stuff, so Buyer Beware.

2)      Bridgeports are the Jordache Jeans of the machine world.

Everyone and their mom wants a Bridgeport.  Well they are very nice machines, but I always suggest looking at other less known names (Gorton, Tree, Millrite, US Burke, a host of Chinese and Taiwanese BP clones, and my fave Wells-Index).  Now all of these have their faults, (except Index, they’re perfect), but you can usually get them for much much less than a comparable BP.  However the spindle may also take something other than r-8 collets. Again buyer beware.

3)      Know in your head you will spend as much on the mill/lathe as you will in tooling for it.

This is a classic mistake, and one I made personally.  You will need for your mill before you start a very good vise, a very good dial indicator, a very good set of endmills, drills, a Jacobs chuck, collets, and some hold down tooling.  You will soon want on your mill DRO’s, power feed, a second vise, some angle plates, and coolant of some sort.  For your lathe you can get by with less, a set of boring bars, some indexable tooling, maybe some HHS bits and a few carbide tipped ones… but you will need at some point, collets, a steady rest, a follower rest, lathe dogs, a dead center, a live center, a 4 jaw chuck.  Look for the extras!

4)      It’s for sale for a reason.

And it behooves you to find out why.  It may be bad, it may not, this may be a “just me thing” but I have had more success with older owners than younger ones.  I personally love kicking the tires and fixing up stuff.  I wouldalso suggest not buying on internet auctions.  I think it’s best to kick the tires around on em, and maybe see an easy fix or a major problem before you buy it.

5)      It’s not the brush. It’s the painter.  

You can still do sloppy work on a deckel, and I’ve seen great work on a mill/drill.  It’s something to think about before sinking 20k on a mill.

Well that’s my insight for the day, and what I’ve learned so far when buying and looking at machines.