Question for Machinists!?

[lsippell]

T.C.

I built a CNC controlled router mainly for cutting wood, but have cut alum on it without any problem. Just slightly slower than wood.

I have a Smithy lathe/milling machine but didn't convert it, just built one from scratch. Steppers off eBay and a 'chopper' controller from Hobby CNC (http://www.hobbycnc.com/).

Mach3 is the operating software of choice. If I'd just take the time to adjust the backlash using Mach3, I could get the accuracy down to a thousand or so.
http://www.machsupport.com/artsoft/index/index.htm




There are a lot of designs for machines out there. I used what I had available.

Louis

[JWSanders]

Originally posted by lsippell
T.C.

I built a CNC controlled router mainly for cutting wood, but have cut alum on it without any problem. Just slightly slower than wood.

I have a Smithy lathe/milling machine but didn't convert it, just built one from scratch. Steppers off eBay and a 'chopper' controller from Hobby CNC (http://www.hobbycnc.com/).

Mach3 is the operating software of choice. If I'd just take the time to adjust the backlash using Mach3, I could get the accuracy down to a thousand or so.
http://www.machsupport.com/artsoft/index/index.htm

There are a lot of designs for machines out there. I used what I had available.

Louis

Thats a nice setup Louis. Great link for the CNC kits too!! You have to build it all from scratch, but the prices are amazing!! A 200oz/in 3 axis setup for $272.00!! Hell, that just moved it up in my priority list. Easily affordable. Never thought to look on Ebay for that kind of stuff, either. Looks like lots of decent prices on higher-res and higher torque motors, too. It's truly a place of wonder

That should run that Harbor Freight machine quite handily, I'd imagine. Would just have to build all the brackets to mount the steppers to the machine wheels. With that so (relatively) easily done, I'm running out of excuses to not get that mill....and build a plasma cutter table...and build a garage to put it all in.

[gerkenbruce]

Hey TC
I found something at work today you will like PM me your address so i can send it to you

XSivley
Bruce

[mro]

Hi lsippell

You gust changed my mind about people in Arkansas.
Way...cool
Bet with a diamond bit you could do a little art work w/glass?!
Something I've been thinking about but to many other things to do first.



mro

[LoserShoes]

No it wont bother the wheels. Reduces the friction on the blade as it passes though the work piece. Also helps the tooth cut smoothly. Therefore the motor works less hard. For aluminum you need as coarse a blade as you can find, something like a wood blade in a bandsaw. If you know the lenght of the blade, check out Enco etc.

In most habor freight tools a motor upgrade is a frequent occurance.

Steve

[Trikerneil]

Best lube for machining ally with high speed steel is paraffin (kerosene?).

[lsippell]

mro

I have not thought of cutting glass, but I have engraved a small piece of granit using diamond bits.

Louis

[LoserShoes]

WD40 is mostly kerosene. And comes in a handy dispenser.


Steve

[TopCatGr58]

Putting the checkbook to the "mill"stone!

Hey all,

Well, I got tired of trying to get my old "free" lathe to work. I contacted Harbor Freight, but they had already sold the 3 NEW in stock items of that 3 in 1 machine! But, they still had the FLOOR MODEL! It's missing the lathe 4" 3-jaw chuck, the Milling JT33 drill chuck, the dead centers, whatever the TieRods are? The tool post wrench and tool post is also missing.

What I have is are 2MT and 3MT dead centers, I have a 6" 4 jaw Lathe Chuck, but not sure if it will fit onto the new lathe shaft? The lathe is REVERSIBLE, there are 2 set screws holding/securing a small bolt hole flange onto the ~1-5/8" diameter shaft, my Lathe Chuck seems to have a 1-1/2" diameter mounting threaded opening? I also have a quick change tool post that I should be able to mount onto the cross slide and tool post base plate that IS there, complete with "T" channels!!

I'm not sure how the newer lathe chucks mount, since newer lathes are reversible, I'm thinking they bolt onto this small flange, whereas my old single direction lathe chuck screwed right handed onto the shaft!

But, I digress, I was able to get him to let me have it for $400.00, which was $75.00 less than the Clearance price for a complete new one? I have to go back Monday PM to pick it up, they have to get a engine hoist to lift it off of the display table and be able to load it into the back of my SUV! IT weighs about 350 lbs!

I've got some stand legs that I should be able to mount it onto, just will be fun getting it out of the back of the Xterra, will have to ask a couple of neighbors for some lifting help, since I don't have an engine hoist, and don't want to bother trying to rent one! Looking forward to being able to do some REAL machine work with this new toy!!!

3-IN-1 MULTIPURPOSE MACHINE




Micro Feed Handle for Precision Drilling & Milling
Built for the professional but priced for the hobbyist, this space-saving machine is ideal for boring, facing and turning. Built tough for non-stop everyday use and loaded with all the features you need.

Standard equipment includes a 4'', 3-jaw lathe chuck, JT33 taper drill chuck, two dead centers, tie rod, V-belts, tool post wrench, fork wrench, hex wrenches and wedge.

Heavy duty cast iron frame and bed for rigidity
Micro feed handle for precision milling and drilling
16mm tool post stud accepts most quick change tool posts
Mill/Drill head swivels 360°
6 spindle speeds—375 to 1600 RPM
120V, 3/4 HP single phase motor
Overall dimensions: 36-3/4'' x 35-1/4'' x 19-1/4''
Weight: 332 lbs.
Lathe Specifications:
Spindle speeds: 500, 900 & 1600 RPM
Swing over bed: 16-1/2''
Distance between centers: 15-3/4''
Spindle bore: 3/4''
Spindle taper: MT3
Longitudinal travel: 16-1/8''
Cross slide travel: 3-9/64''
Tailstock taper: MT2
Mill/Drill specifications:
Spindle speeds: 375, 500, 675, 900, 1180 & 1600 RPM
Spindle travel: 3.15''
Spindle taper: R8 with JT33 drill chuck taper
End mill capacity: 3/4''
Face mill capacity: 2-1/2''
Drilling capacity: 19/32''

ITEM 46199-1VGA
$729.99

$599.99 Online Sale Price!

[JWSanders]

That one is a bit different from the one at my local Harbor Fieght store. It looks like a newer model of the one that is there, and a lot nicer. More open on the sides and top, and it has a longer lathe base. Hmm, I wonder what else they're hiding from me!


Sounds like you got a great deal on it! Hope it gets you going!!

[TopCatGr58]

Pictures are Deceiveing!

Hey JW,

That picture is just what I got off of their web site, the one at the store IS older, has a round shaped Mill head support shaft, not square, cause the mill head can be unlocked and swivels 360 degree around the base!? But otherwise, is the same layout. I'm surprised at the amount of Swing over Bed length of 16", mine was barely over 6"!! Yeah, I hope it gets me into being able to crank out those S.O.F.A.'s, I've got several folks patiently waiting for me to get my act together and get them done!!!

With this, I should be able to get them done, and at a decent savings in $$ from my previous price, so perhaps more folks will be wanting them!?
T.C.

[TopCatGr58]

What it really looks like

Hey JW,

Here's a photo of one by Northern Tool, which is an exact copy of the one at Harbor Freight!


They are all China products made under contract I'm sure!
T.C.

[JWSanders]

Yep, that's the one. Had my eye on that for a long time now.

That new one from the site is nice too. I wonder when the local stores will have it.

[TopCatGr58]

Hey JW,

They won't be carrying them in the stores from now on, that's why it was clearanced from what I was told, that they will ONLY be offered as a Truckable item!?
T.C.

[Trikerneil]

My newish Chester 920 lathe is reversible and has a screw on chuck. There is a small plate screwed on which locks the backplate to the thread. If yours is the same DO NOT reverse it without the locking mechanism. You don't want a chuck rattling around your workshop. DAMHIK :-(

Have a look at your design and see if there is a way of reducing the number of cuts you have to take. These machines cannot remove much metal in one pass and winding the cross slide by hand repeatedly is a real PITA. It may be better to plunge in a trepanning tool to the rough depth, move across and repeat then face off to finish size.
Again I speak from experience.

As a rough guide to start you off, try 1,000 rpm per inch of diameter (for ally) so 4 inch would be 250 rpm tomachine the OD.
Steel is roughly 250 per inch diameter, assuming high speed steel tools.

Sorry If I am repeating previous advice but I'm typing this in a hotel room in Switzerland on a very sloooooow connection and it'll take me all night to reread the previous posts.