Lathe Question

[Murlin]

I'm looking at mills right now and from different machining forums I've
read, many people knock the round columns versus the rectangle columns.

Why is that? It seem all the ones with round columns would be a lot more
rigid and would have a lot less "flex".

Anyone have any input on this?

Rigidity has lots of key factors including twist. Because you are pushing from the side on a milling operation, it is easy to spin the headstock. Therefore loosing the machines zero on precision apps. A round ram is ok if all you do is drill because there is no side pressure.

Once you put an end mill in it is a whole new ballgame

The square ram design is far superior. However if all you do is cut with very small tools, then it may not be much of a factor. It really depends on how you use it.

If you are doing allot machining on steel, those little mills will wear out really fast.. Especially the nut and screw. But they do offer a cheep solution for light duty work.
As long as you do not have to be real precision.




regards,

Murlin

[HiggsBoson]

Murlin
It sounds as if you have spent more than a few hours machininig.
It's all good avice.
How many home users are going to push their machine as hard as an experienced machinist/engineer ?
Wear of the machine is always a factor in precision work but isn't this where experience comes in ?
An experienced machinist will get consistently better results from a substandard machine than a begginer.
Aaron
Before you buy your machine if you can feel a lot of movement in beds, shake them side to side, forward back, rotate left right and use all your strength and use sharp sudden movements, and do the same for the spindle. If you can feel a lot of movement precision work will be a pain in the arse.

I'd have to go with Murlin on the column, Round columns are fine until you get a bit of wear and after that it can be like a game of chess trying to get a accurate finished product.

[Murlin]

Murlin
It sounds as if you have spent more than a few hours machininig.
It's all good avice.
How many home users are going to push their machine as hard as an experienced machinist/engineer ?
Wear of the machine is always a factor in precision work but isn't this where experience comes in ?
An experienced machinist will get consistently better results from a substandard machine than a begginer.
Aaron
Before you buy your machine if you can feel a lot of movement in beds, shake them side to side, forward back, rotate left right and use all your strength and use sharp sudden movements, and do the same for the spindle. If you can feel a lot of movement precision work will be a pain in the arse.

I'd have to go with Murlin on the column, Round columns are fine until you get a bit of wear and after that it can be like a game of chess trying to get a accurate finished product.

Over 30 years....40 if ya count all the high school and home garage stuff when I was a kid...

I presently own my own machine shop and have done so for the past for the past 22 years....





regards,

Murlin

[Richie_asg1]

I think I share the same background as Stealth - being a CNC machinist.

As these tubes are quite stumpy with thin wall - you are going to run into a couple of problems machining them. -

1.Most lathes are 3 Jaw, and you will need to use reverse jaws to hold the outside, so you can bore throuh the inside.
2 .You will get distortion at the chuck end - because you need to clamp it hard enough to keep it there. When you machine it - true round - and release it, you will get a lobed tube which measures the right size - but is actually a funny shape.
3. - You will first need to push it into the chuck with a plate on the centre, then machine a steady band.
4. - You must use a running centre - so you can machine it safely without it jumping out at you.
5. - using a 2' boring bar - this will need to be at least 50mm dia - or you will get nasty chatter - and will take a long time.


The best machine I think to do this job would be a large hollow-spindle CNC - which has replaceable jaws.
Skim the jaws and hold the tube in the middle, then rough and finish turn it.
You could do 10 in an hour.

This way you may get about 0.020" run out at the centre, but the ends would be better - depending on who'se doing it

When we've done this type of thing before, we've made a pot fixture that basically clamps it in compression - then we're free to machine internal profiles without distortion, but fixtures cost, so it's a batch thing.

I still think farming this one out would be a good idea - due to size.

[Aaron]

9x19 lathe

Thanks for all the feedback everyone - very much appreciated!

This is the lathe I'm getting for sure:
G4000 9" x 19" Bench Lathe

I was going to get the Harbor Freight one but they're out for a few months
and I'm learning more and more than their customer support and tech support
is pretty much non-existent. I called their tech support to ask questions
about one of their mills, the guy took about 15 minutes to open the manual
and look it up - they really have no idea about anything they carry. They
have no on staff experts that have experience with their machining
equipment.

The prices are good but the equivelant lathe at Grizzly from reading all the
forums, etc.. is they are actually better built and more solid and customer
support is superior.

You can see everything this lathe comes with, including a 7.25" 4 jaw chuck.
On Amazon, there are 2 bad reviews, but on all the forums, groups, etc...,
they speak highly of it. Seems like a great deal for $975 + only $94 for
shipping.

[Aaron]

comments on these mills?

The mill I was going to get is this:

- Harbor Freight Tools - Quality Tools at the Lowest Prices

Grizzly's equivelant is this:

G3358 Mill / Drill

But if the round column has that much issue, I need to get a square one.

My friend has this smaller mill:

- Harbor Freight Tools - Quality Tools at the Lowest Prices
He says it has a lot of flex and is a piece of junk and not much more than
a glorified drill press.

This is Grizzly's equivelant:

G8689 Mini Milling Machine

So I'm thinking of not going with these smaller mills.

What do you all think of these?



G0463 Mill / Drill




G0619 6" x 21" Mill / Drill
"Upgrade to this mill/drill and have all of the great features shown on G0463 and add a tilting head, a multifunction digital scale on the quill, a quick reversing tapping feature, push button speed control and digital speed display. With this machine you can quickly tap one hole or dozens of holes! Press the button, start the tap and when the thread is completed, push another button and the spindle quickly reverses, withdrawing the tap from the hole. And there won't be any question about proper spindle speed! Run the RPM up or down to best suit your tooling/material and be confident that you'll have fewer worn or broken tools."


Any drawback to a tilting head or is it very desirable?




G0704 Drill/Mill with Stand
The mill itself looks like one of those mini ones in the $450-500 range but is
just jacked up in price because of electronics. If this is small like those
and has a tendency to wear out quick, I won't even consider this one.



I'm thinking I'll wind up with one of these:
G0463 Mill / Drill
G0619 6" x 21" Mill / Drill


They have square columns, they're bigger than the mini's but
not so big that they're almost 700 pounds. Seems the 0463 is
popular because it is big enough but still small enough to be
considered a bench mill. If the tilting head is a real plus,

then I might go with the 0619.


Seems like Grizzly might get 2 orders from me for one of

the above two mills and the 9x19 lathe.

[HiggsBoson]

Aaron
The fine feed knob on the vertical will prove invaluable on the mill and some of the round column machines do seem to be a better machine for the price.
Murlin and myself speak from an engineering background where a machine is pushed to it's limit ie if the motor is about to stall or burn out back off a bit.
In a machine shop situation time is money so machines are worked very hard.
You will not be trying to produce 1000 products profitably and will have no need to push your machine as hard.
Some of the round column machines could well be a more versatile option and save you a few dollars.

[Aaron]

Sieg manufacturer

Just fyi for anyone shopping around like me:

Shanghai SIEG Industrial. Co

That is the one of the main manufacturers in China that makes the equipment
for harbor freight, grizzly, etc...

The difference from what I've read is the different companies have
different quality control standards, etc... HF having the lowest standards
according to many reviews.

[Aaron]

Lathe & Mill Update

Just wanted to post what I eventually got...

The Grizzly G4000 lathe - 9"x19":


Grizzly G0463 mill





Looks like a tight fit but it is plenty of room seeing that I'll only use one
machine at a time.

The shipping was very fast. Grizzly's phone customer service is incredible.
But I would avoid using their customer service email as hardly anyone ever
responds. Just phone them.

I had some issues with both the lathe and the mill but I won't mention what
they were because Grizzly made good on 100% of every concern that I
had - and they were quick to do so - very impressive!

I would definitely buy from them again. I had the mill for a little over a
month now and haven't even used it because I've been away and had
no time. I have used the lathe a few times and broke a handful of cutting tools
because I'm a beginner but it was definitely very fun and satisfying when
I did something right! lol

I made a mandrel to pin a round plate to that had to be turned on a larger
lathe anyway but was glad to be able to make it out of a round of steel.
That is about it other than just messing around getting a feel for the
machine.

I can see how this can be an addictive hobby. My hats off to anyone that
does this for a living because it is definitely harder than it looks.

The number one thing over the last 10 years that has kept me from making
the progress I wanted to with the energy projects is simply not having the
right tools to do the job and having to rely on others. Bubble gum and
scotch tape can only take me so far but I'm surprised what I was able to
get done without any machining tools.

With shipping, the lathe and mill
was about $2000 USD and I think that is actually really inexpensive for what
these machines can do - that doesn't include the tooling. Before I really
started looking into these machines, I was expecting to spend at least
$5000 for a lathe and mill like these and am very happy it was less than half
of that.

I have a handful of tooling for both - I would avoid harbor freight cheap
cutting blades, etc... and spend more for some real tools.

Anyway, I probably won't be making anything that looks like Jetijs' works
of art or any of the other mechanical engineers here anytime soon but
I'm very excited to have the tools and am looking forward to learning how
to use these machines little by little.

[everwiser]

Congrats Aaron! Looks good.

[Ted Ewert]

Nice setup Aaron.
I was in the same boat when I bought my lathe / mill. So I bought a book on basic machining and just went from there.
My mill isn't really big enough to do steel, although it will do some mild steel if you go slow enough. It works great on the soft metals and plastic though. The lathe is plenty strong enough for steel, or whatever else you want to turn.
Like you I have a lot of admiration for a good machinist. Producing accurate, clean pieces takes some practice. Like everything else, you get better the more you use it.
Here is a picture of my combo machine:



I would recommend getting a tool chest to keep all your bits, tools and small attachments in. It's much handier than having to run around and find things. Also, your lathe will throw a lot of oil out and away from the work piece. You may want to cover that wall behind it. Have fun.

Ted

[Aromaz]

Congratulations!

Just a warning, you bought a monster.

At 8pm you will reply to Darling "I will come to bed just now, got to do this . . ." and what feels like 10 minutes later you will hear her behind you with that voice "You did not come to sleep last night"

Just a few hours on both machine and you will be so happy with your results; and not know whay you never bought it ten years earlier.

Have fun and enjoy.

[everwiser]

I've only done some minor mill work in the past but I've had to create detail and assembly drawings for parts to be made. Be sure to think about where on your part(s) the tolerances (errors above and/or below the perfect dimension you want) can accumulate as the same two parts are rarely "the same", even on some CNC's. Also, approaching the part from the standpoint of "how would this have to be made one step at a time" will make you better at creating/dimensioning/simplifying your parts. Have fun!

[Savvypro]

Does anyone have any recommendation for those not in the US. I'm in the UK looking to get a good lathe and mill.