Hi,
I'm considering buying a miling machine and am trying to decide between
two Warcos. First up is the VMC which is a turret mill, this has a
speed range of 160 to 2500 odd and a table travel of around 14" x 6".
The other contender is the GH Mill Drill which is a very similar price
but has a speed range of 75 to 1600 odd and a table travel of a
healthier 23" x 8".
I intend the usage to be model engineering of course, currently scale
aeroplane IC engines, but I don't want to rule out a loco or
agricultural beast later on. I don't know how to weigh up the
advantages of speed range vs table travel etc, can anyone offer any
advice on which of these is the better machine to buy ? The larger
table travel appeals for something like drilling loco frames can anyone
say how useful it actually would be under those circumstances ? Or
doean't it really matter ?
I was considering a very nice Tom Senior M1 a dealer had in stock but
it's gone and also the idea of an M2 taper in the spindle didn't really
appeal so that's basically out of play atm.
All opinions gratefully received,
Go for the table travel. You don't need high speeds for home shop use
because speed of production isn't an issue. In fact if you run milling
cutters and drill bits nice and slow you rarely burn one out and as most
one-off milling ops have a considerably greater set up time than machining
time it doesn't really affect the total time for the job. My Bridgeport
clone has a top speed of 1800rpm but I can count the number of times I've
had it at over 600 on the fingers of one hand.
If you ever need to flycut the face of a large item you'll appreciate having
as much table travel as possible whereas you'll rarely miss speeds over 1500
rpm. A very low slowest speed is handy too. Something around 80 to 100 rpm
for big boring bars, reamers etc.
--
Dave Baker - Puma Race Engines
Boo wrote in message ...
A moveable knee machine is much more versatile and rigid than a round column
mill drill. Yes you will need enough table travel for the type of job you
envisage but not at the expense of resorting to a mill drill which will
limit your vertical movement to that of the quill without risking losing
registration with the job.
Just my 2p
Bob - VMC with head raising block user
Boo
Hi, I have used an RF25 (round column) mill drill for the past 4 years
and it has been a useful but very frustrating machine. Anything that
requires a change from short tooling (end mill, etc) to longer tools
(large drills, large face mill) means the head has to be raised and
alignment is lost. For this reason alone I will be changing it for a
VMC as soon as funds allow; even though I will lose some table travel.
I currently have a MT3 taper but will replace with an R8 because I
don't like bashing the drawbar with a lead hammer every time I want to
release it.
You don't indicate which of the GH machines you are thinking of if it
is the GH Universal (square column) then both that and the VMC (knee
type) will not suffer the same issue. If you are considering the Major
GH that has the round column then I would strongly advise against it,
particularly as you mention a range of sizes and possible uses later
on.
I haven't used all of the available speed range on mine and the machine
stays below 600rpm most of the time. However, if you are going to
machine a lot of Aluminium with small diameter cutters then faster is
better. The other issue I would look at is the fact that the VMC comes
with a (free?) power feed - you won't believe how boring it is winding
the table backwards and forwards time after time. A very useful
addition in my book.
I also haven't used anything near all of the available table movement I
have and unless you are going to build some very large engines I
suspect that 95% of what you have identified will be well within the
range of a VMC. Using it as a jig borer for frames is a good idea
(especially if you fit a DRO) but you only need one set of frames per
engine and the additional cost of laser cut frames is fairly reasonable
these days.
My use is fairly similar to that you have outlined and my current
priorities would be square column/knee type machine, R8 Spindle taper
and power feed to table. With regard to the speed range I believe both
the belt drive (VMC) and the GH types each leave a little to be
desired. Although the geared head is easier to change speed they are
usually a little more limited in the number of speeds available and in
my experience (my friends actually) they can get a little noisey when
they have had fair use. For those reasons I believe that a belt drive
(smooth, quiet) and a VFD to give a stepless speed range is the answer
albeit at greater total cost. I must admit though that the VMC lowest
speed is a bit high for fly cutting etc and will be one of the first
things I address when (if) I can get one.
The other cost I would budget for is for a reasonable DRO system. This
makes life so much easier and would be particularly useful if you are
going to do much jig boring with it. I currently have one of the cheap
chinese scales on each of the axis of mine and would not be without
them. Co-ordinate drilling is a doddle.
I'm sure you will get a range of opinions and in my experience only you
can decide which is the right machine for you. I am a great believer
that if you really want or like a particular machine then get it. You
will find much less fault with something you like. Too many times I
have heeded the advice of others to find myself picking holes in it and
every time something is not quite right thinking I should have bought
"what I wanted". If it feels right to you, you will probibly enjoy
using it and the more you use it the better you will get.
Anyway, hope this helps you to sort out what is important to you. The
most important thing is to get a machine and start enjoying it. Don't
forget though as I suspect we have all learned with the lathe, leave
plenty of funds for that essential tooling.
Best regards
Keith
Fully endorse comment re maintaining alignment. Know this to my cost.
Long table is good. You can mount the vice and align it at one end,
this leaves enough room for a rotary table etc at the other end. Saves
all the hassle of re-alignment.
You just break them! The small diameter end mills and slot drills used in
model engineering need high speed - in fact most machines don't go fast enough
on spindle speed, including lathes and drills. Try putting a No. 80 drill into
steel at anything below about 8,000 RPM and see how long it lasts.
Dave Baker wrote:
snip
Hi Brian, My VMC is a genuine Myford that I bought new around 1986. The
raising block was bought via small ads in one of the ME mags in the mid 90s
I had contemplated a home brew one but did not have the welding capability
or a lathe big enough to swing it comfortably.
The block I bought was turned from solid bar.
Well worth having though as it adds nearly 100mm extra daylight under the
quill
If some photos and overall dimensions of the raising piece would be useful,
please let me know but give me a couple of days to reply as I'm going into
hospital tomorrow for a day or so.
Regards
Bob
I know it is a few extra quid but I'd suggest the GH Universal. It has a far
better table travel than the VMC (the main reason I didn't buy the otherwise
excellent machine) and it has a dovetailed column which get's around the
loss of head position if you need to raise or lower the head mid job. I
looked at all of the machines and ended up with the super-major (basically
the same as the GH Universal) which is the same in essence as the much
discussed RF45. It is, IMHO, an excellent, robust and accurate machine. If
the budget will stretch, I'd go for it. Of course if you can find a good
used Myford VME within the budget, I'd go for that instead!
Regards
Mark
Thanks to all who answered, I wasn't totally plain in my post so I'll
try to clear up any confusion here :
The machines I am considering are the Warco VMC and GH Universal, both
of these have square columns with dovetails. From the pictures the VMC
looks like a lot of machine for the money, and there is a kit from
Hemingway that gives a bottom speed around the 50 rpm mark (I presume
this fits the Warco machines as it was probably designed around the
Myford, does anyone know whether this is true ?)
..snip..
Interesting point. Others here have differed over the importance of a
longer table travel, I just want to know that I won't regret not
getting a bigger one later on. The loco frames issue is a long way off
(even assuming I ever build one) but I don't really want to be faffing
around making do with bodges if it's possible to buy one big enough in
the first place. Both machines are plenty big enough for my current needs.
I'm not clear what are the advanteges of the knee over the travelling
head of the GHU, can you enlighten me on this ? The GHU has a spindle
to table distance of 17 inches odd whereas the VMC only has 13.5", also
the spindle stroke on the GHU is 5" vs 3.5" for the VMC so on the
grounds of clearance the GHU seems to win out, or am I misreading things ?
...snip...
True, but I still need advice regarding the kind of capacity I need -
I've next to no milling experience at all and I was slightly put out to
find that it seems to be entirely impossible to mill a flat on an 8.5"
bit of bar on my Boxford lathe. I don't want to buy a mill and find
I've a similar problem in 3 months time :-).
Very true and a good point. Actually atm I'm still open to ideas and
would consider buying second-hand as others have suggested to get a good
selecton of tooling.
I see that Warco are exhibitors at the forthcoming Guidford MEE I may go
along and have a chat at the Warco stand. What's this gig usually like
does anyone know ?
Thanks,
Thanks for the reply Bob
Since I will certainly not be buying the mill before September I will contact
you when,
and if I buy it. I want to get a really close look at one, probably at the
Bristol SME
exhibition. You are lucky to have a genuine Myford they seem as common as hen's
teeth
these days and very expensive!
I am sure all the group wish you luck for your hospital visit
Regards
Brian
Remember the Myford machines are just imported milling machines that
Myford re-worked. The quality of the imported machines has improved a
great deal since then. Personally I'd go for a good second hand
machine, but if you're not sure what your buying I can see the
advantage of a new machine.
One thing no-one has mentioned yet (in this thread) is rigidity. The
GH Universal may be a "larger" machine but it weighs 320kg against the
VMC at 415kg. This would certainly suggest to me that the VMC is a
more robust machine. FWIW I'd spend my money on a VMC -it's a propper
milling machine, not a mill-drill.
Regards
Kevin
Boo
Hi, interesting discussion you have started here. Although I have been
planning to buy a VMC for nearly a year I also have some concern that I
might not be buying what I need. However, my alternative would be a
secondhand "industrial" machine not the GH in any of its' guises.
Your concern seems to centre around the capacity of the two machines
and here I believe is a basic difference between the design criteria of
the two machines you are considering. In my opinion the VMC is as Kevin
says "a proper milling machine" with a design priority of rigidity and
shear mass of cast iron which significantly aids vibration damping. A
vital attribute when you are milling with anything like a reasonable
cut. On the other hand, the mill-drills (round or square column) are I
believe designed to give the largest capacity and widest capability in
a given space, a vital attribute if you are limited for room and
envisage a wide range of uses. I know from my aerospace career that you
can make very light structures extremely rigid so my main interest is
really the vibration damping ability of increased mass.
My decision to go with the VMC was based on the fact that you will face
the problems of lack of rigidity/damping with EVERY job you do large or
small, for me only the very occaisional job will be outside the machine
capacity. This was shown recently when I completed one of the John S
toolposts, milling 10 off 1/2sq slots with a mill-drill is a long and
boring process that shakes the machine constantly. Here I think you
have to decide which of the criteria is most important to you. I'm not
saying that the GH machines won't mill properly, of course they will
although you will need to take more care with speed/feed/depth of cut.
In my book, the advantages of better rigidity/damping are exhibited
every time you use a machine and far outweigh the benefit of larger
capacity
Whatever you decide I'm afraid you will always find that any machine
you buy is a bit too small to do something or other. We used to find
this when buying some very large and very expensive machines at work -
they were ultimately just a few inches too small.
I can't really comment on the different attributes of square column
against knee type, my very practical outlook says that all slides will
have some clearance and I would prefer to keep the length of the levers
(slide to base/column joint) as short as possible. So here in my book
the knee type wins hands down.
I've not been to Guildford MEE but by all accounts it is a good
weekend. I have visited the Warco stand and their showroom and the
oportunity to see and touch the machines you are considering side by
side before spending your money is well worth the trip (300miles for
me). You do however, owe it to yourself to visit a few machine tool
dealers and look at some of the smaller industrial machines in the same
price range. From my experience you will be surprised what you can get
for =A31500 but also (if you are like me) a bit intimidated by their
poor appearance and potential wear. The potential cost of a rebuild for
some of these machines even if possible is frightening. Don't forget
that in industrial terms a 1 1/2 ton Bridgeport is considered "very
flexible but a bit lightweight" so it always pays to "colour" advice by
which direction it is coming from.
I hope you get plenty of advice to aid your decision as I personally
find it a difficult one; but I must say as my experience of milling
with small machines increases my determination to get a rigid/heavy
machine grows stronger by the job. I have already accepted that any
machine I buy will be too small for something I need to do. Personally,
I do not have sufficient experience to identify a "good" secondhand
machine so I will have to go with the VMC and accept its' size
limitations. Every VMC owner I have spoken to (yes I accost all sorts
of people at shows etc) has said that it is a "real" milling machine
just smaller. Not sure this helps really but only you can decide if
being able to occaisionally do larger work more slowly is more
important than not wasting excessive time watching the machine take
light cuts on every job you do. Good luck.
Best regards
Keith
As I've said elsewhere I think that the VMC is an excellent machine but
unless you plan to use it on a specific type of job that fits within it's
range, you will probably find the table travel is a limitation. The problem
is that once you have a milling machine, like a lathe, you tend to find no
end of jobs you would like to do on it. The reduced table travel will limit
the jobs you can undertake and the scales you can work with.
The question of rigidity is, as Keith says, important. Having not used a VMC
I can't comment but I can say that I have never been conscious of any lack
of rigidity on my Super Major (in essence a GH Universal without the swivel
table but with power feeds) even when used near it's limits.
Having spent months agonizing over the decision myself, I can say that there
is no perfect solution (unless you have an unlimited budget - even then
you'd probably choose to buy several machines) but I think the key is to
find the machine that offers the most flexibility so that you do not unduly
limit your future options. In term of priorities for general use (and
sticking my neck out here!) I suggest:
1) Size/weight to suit available space, - It must fit, you must be able to
get it there and it must not fall through the floor!
2) Dovetailed column (for either head or table) - round columns loose their
alignment as soon as the head needs to be moved.
3) Table / Head / quill travel,
4) Rigidity - within reason this is not an serious problem, most machines
will do what is required of them assuming they're not in a production
environment (and they're not knackered).
5) Spindle speeds - again, not a major issue unless used in a production
environment, although not being able to run below say 150 rpm may be a
problem for boring / face cutting.
I guess that build quality fits into the sequence somewhere but my brain is
too addled to decide where!.
I'm sure that others will disagree with my priorities but you have to decide
which fit your requirements best - flexibility is the key!
Mark
Looking at these two on the web the GH Universal has a larger table
and greater height but a lower speed range.
The VMC has a higher speed range but smaller table even thought it is
heavier but not by a lot.
Having used Mill drills since they first came out I can say that the
biggest factor I found doing jobbing work was the depth to table
dimension, followed by the long axis travel.
Using a dividing head with a collet chuck only leaves you a very small
window to work in.
No way can you get something like a 5/8" drill on a VMC with DH on the
table.
Speeds are also an issue that's not easily compared as one is belt
drive [ VMC ] and the GH is gear driven.
It's not obvious from the web site if the GH is available in three
phase to retrofit an invertor plus the increased speed in a gear head
could cause noise.
It may be better to go with a speed increaser head for small cutters.
The VMC head is a throw back to the conventional mill drills and these
suffer from large differences in pulley diameters to get the reduction
needed with the disadvantage of low wrap around on the small low speed
pulley.
This is the speed that need to most torque and because of this design
fault it will slip the belt.
Over tightening will only partly cure this but also take the top
bearings out, don't ask
So basically both machines need to be addressed on speed issues.
My personal choice given these two would be the GH and address the
speed issue as needed
--
Regards,
John Stevenson
Nottingham, England.
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From what you say, it sounds as though some mills have a solution
to this problem but it's not used here. Why's that ? Cost ?
How do better machines handle it ?
-adrian
John Hi, couple of interesting points you make, enough to make me
review my own decision. A couple of questions if you have time to
clarify for me.
John Stevens> Having used Mill drills since they first came out I can say that the
I had recognised the relatively small depth but had thought that I
would just add a 6" or 7" riser block, is this not a good idea? Does it
introduce any further issues?
I fully agree with your comment and had decided to go 3phase and
inverter with a "poly-vee" set up. Would this be OK? I had considered
that the GH type would be more problematic (grear wear/noise) to
increase the speed although possibly no trouble to decrease. Am I being
too concerned about gear wear in this situation given that they claim
to be "close tolerance"; with my sort of use (3hours/day?) could I
expect a reasonable life at say 150% of the current top speed?
With these modifications to address speed issues on both machines and
also provide power feed/stand on the GH the price goes up to well over
=A32K with the VMC at just below =A32K. Prices at which I feel I should
be able to get a reasonable basic Bridgeport (if they still exist) even
from a dealer. I had thought of a Boxford VH30 (small table travel
again) or possibly a Marlow as they both seem to be available from
schools etc at the moment. Any thoughts?
Thanks again for your help, best regards
Keith
Only worry I can see there is whether you can get close to the table
with the riser block on or if that will stop you getting near for the
jobs where you need to clamp direct to the bed.
Sorry, can't honestly answer that as I have never hear a GH running.
Bear in mind that gear noise rises proportionally to speed and 150%
'could' be more than 1/2 as much again.
Only real way would be to listen to one under power and note the
increase from 3/4 speed to full and 'project' that up to 150%
What about the Chester 626 mill?
formatting link
--
Regards,
John Stevenson
Nottingham, England.
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