[Ricardoco]

Hi all, I have been reading this forum for a little over two years and now have decided to take the plunge and buy a mill and convert to CNC i have £1000 +/- a bit, what i would like to do, is draw on peoples experience to help me decide on the specs of this new machine. EG Physicle Type, Taper Type, Spindle Type,etc, and most importantly why. The full monty in fact, so that i can have a theoretical spec in my head when i part with my cash, I would like to mill various materials both metalic and non-metalic, (I restore motorcycles as a bit of a clue to its possible uses). If you have a particular make and model of machine in mind that would will be fine, however just possible specs that you think will be usefull would also be great but please again say why, i will be running MACH3 if that has any bearing on the subject. I think this is the place to post this hopefully, if not im sorry.

I look forward to reading your replies. Rick

[Dualkit]

In this bad economy for manufacturing there are hoards of full sized PC based CNC Mills for sale for as low as $1000 USD. I personally sold a 3 CNC axis model 10 x 54" for $1300 6 months ago, that held tolerances fine, and was less than 20 years old. Unless you are just looking for a project, there is no reason to build your own these days, with all the cheap used equipment out there.

[Ricardoco]

I was thinking an upright Mill, for space reasons. Something like the "SPG 2217-11" found on google.

[Ricardoco]

"In this bad economy for manufacturing there are hoards of full sized PC based CNC Mills for sale for as low as $1000 USD. I personally sold a 3 CNC axis model 10 x 54" for $1300 6 months ago, that held tolerances fine, and was less than 20 years old. Unless you are just looking for a project, there is no reason to build your own these days, with all the cheap used equipment out there. ":

You are quite right, I should have stated I have 1 requirement, A maximum height of 6' 6" this cuts out most of the larger industrial models - Also with so many machines out there, I would like an idea of what spec of machine to buy. Basicly I would like a theoretical but realistic spec to look for, as for the conversion, I was hoping that a better working knowlege of this theoretical machine would be gained by the DIY conversion.
I have all the steppers and drivers,PC etc, it seems a shame to just leave them sitting in the garage, Here in the UK we do have some sellers but no where near as many as you do in the states, and to be honest the prices havent changed here that much just the stock availability, I assume that in this unsure economical climate, sellers have just cut stock levels rather than prices. :confused

[Kipper]

Is the 6'6" a requirement to get through the door? My bench mill needs 8" when at it's full working height.

Have a look at the WM18 from Warco and others....nice size table......Also factor in the ballscrews plus reduction drive etc....oh and whether "you" can make the adaptors machine the table etc.

[Ricardoco]

Is the 6'6" a requirement to get through the door? My bench mill needs 8" when at it's full working height..

I Never even thought about the door, (legs it down to the shed weilding trusty tape).. no in fact the height requirement is the shed roof!!! i can tailor the bench to suit the mill.

Have a look at the WM18 from Warco and others....nice size table......Also factor in the ballscrews plus reduction drive etc....oh and whether "you" can make the adaptors machine the table etc.

The table size looks good and the Cross traverse of 220mm and Longitudinal traverse 565mm is more than most ive looked at.

Do you think the MT3 is the way to go though and why. What features do you think stand out from the others with this machine.

Im ok with the machining making adaptors and the such, and I have several Longer ballscrews and respective ballnuts than even the full Z travel would require, "Reduction drives??" Ok tell me more....

Ive now got 2 machines for consideration:-

WM18 from Warco
SP2217-11 From SPG Tools

The SPG offering is winning on price at the moment but as i said i need the knowlege of the forum members to make my decision.

[Kipper]

I think ISO 30 is the way to go...However the options are zero on a machine this size

The SPG machine has a limited envelope for machining! which makes me not consider it.

MT3 is a pain to use.....maybe an ER25 collet adaptor would alleviate the bashing out of the MT taper somewhat!

Bear in mind that a ballscrew/ballnut would need to be in a size range to fit under the table and also the saddle.....16mm maybe the limit?

Belt reduction on 5mm pitch is always an option to either increase resolution/torque.....unless you want 10M rapids?

Have a look at the GH Universal from Warco....a much stronger column.

[Ricardoco]

I think ISO 30 is the way to go...However the options are zero on a machine this size .

If Only!!

The SPG machine has a limited envelope for machining! which makes me not consider it.

Not sure what you mean comparing it to the Warco machine you suggested at an extra £300 odd quid.(it is a nice machine though)

MT3 is a pain to use.....maybe an ER25 collet adaptor would alleviate the bashing out of the MT taper somewhat!.

From reading on this, and other forums is R8 no better? Ive read that others prefere it for the increased tooling available, and the cheaper price bracket for that tooling, but other than that nobody else says any more that i can find.

Bear in mind that a ballscrew/ballnut would need to be in a size range to fit under the table and also the saddle.....16mm maybe the limit?!.

Blimey, never thought of that,(5mins pass) Phewww. just checked mine and they are all 12mm im thinking maybe they would be ok???

Belt reduction on 5mm pitch is always an option to either increase resolution/torque.....unless you want 10M rapids.

Ahhhh reduction,, Well i will have to have a look at that point, because the increase resolution/torque would be desirable as you say.

Have a look at the GH Universal from Warco....a much stronger column.

I wish i had the funds for that machine but it falls just outside my budget.

by the way thank you for your input, it was just the kind of thing i posted for.

[Kipper]

I think R8 is a slight improvement over MT.

£300.....The extra travel in X is the difference between making one part at a time or two...and not being able to make it at all if the part is too big for the envelope......It's only money

[Ricardoco]

LOL..It's only money I cant argue with that, mind you the thought of waitng for another month looking at this new piece of kit, while i save for some tooling so i can use it, makes me cringe.. lol

1/ Ok R8 is a touch better than MT3.

2/ The bed travel is a big consideration..

Well that is settled unless anyone else has anything to say about it.

[RICHARD ZASTROW]

I hope your M3 tooling has a draw bar to hold the tools in the spindle. Morse taper tools tend to pull out of the spindle in some cases. Ex. milling, tapping with solid connection etc.

Dick Z

[Ricardoco]

I find myself leaning towards R8 tooling with a draw bar as i have read about the consequenses of no draw bar, however most of the machines I have looked at have MT3 tooling with the odd exception. Once I have a better idea of my theoretical machines specifications/requirements I'm going to send some mails to the sellers to see if R8 tooling is a possible option.

Firstly I have to get some more opinions of the forum members if they would be so kind



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

Rick

[M250cnc]

Rick

I am a toolmaker who had never used MT3 but thought i could live with it.

Wrong decision,removing/breaking the taper lock you need a massive whack on the draw bar to loosen. Net result i bored out the taper and converted to R8 i even already had a Bridgeport Mill

If you are not an engineer there is a big learning curve as well as a big money pit.

I suggest you list everything you need to buy to see how the costs stack up

Don't forget the cost of software and yet another learning curve.

It can be simpler to get the parts you want made by another member who has already gone through that learning process, the parts might seem expensive but you will only pay for a finished part NOT the learning process.

If you just want to learn then great but if you want something in a hurry let someone else take the strain.

Phil

[Kipper]

Rick

I am a toolmaker who had never used MT3 but thought i could live with it.

Wrong decision,removing/breaking the taper lock you need a massive whack on the draw bar to loosen. Net result i bored out the taper and converted to R8 i even already had a Bridgeport Mill

If you are not an engineer there is a big learning curve as well as a big money pit.

I suggest you list everything you need to buy to see how the costs stack up

Don't forget the cost of software and yet another learning curve.

It can be simpler to get the parts you want made by another member who has already gone through that learning process, the parts might seem expensive but you will only pay for a finished part NOT the learning process.

If you just want to learn then great but if you want something in a hurry let someone else take the strain.

Phil

A chap on another forum was going to use a rubber mallet for this particular task.....might have taken years to loosen......I would have liked to watch the effort.....Just for a few hours

[M250cnc]

A chap on another forum was going to use a rubber mallet for this particular task.....might have taken years to loosen......I would have liked to watch the effort.....Just for a few hours

Yeah but at least it would still be in tram.

Phil

[Ricardoco]

Rick

I am a toolmaker who had never used MT3 but thought i could live with it.

Wrong decision,removing/breaking the taper lock you need a massive whack on the draw bar to loosen. Net result i bored out the taper and converted to R8 i even already had a Bridgeport Mill

If you are not an engineer there is a big learning curve as well as a big money pit.

I suggest you list everything you need to buy to see how the costs stack up

Don't forget the cost of software and yet another learning curve.

It can be simpler to get the parts you want made by another member who has already gone through that learning process, the parts might seem expensive but you will only pay for a finished part NOT the learning process.

If you just want to learn then great but if you want something in a hurry let someone else take the strain.

Phil

Hi Phil.

Firstly thanks for your reply You have helped make a descision for me... R8 will be the format of what ever mill i buy.

--------------------------
First requirement of my theoretical mill is R8 tooling!!

NEXT!!! requirement ?????
---------------------------

My mechanical engineering background has not been a career apart from two years as a machine operator in an engineering company after leaving school, but I have family in the industry who I have spent much time with learning, and making the decision that rather than getting them to do the machining on the casting I made of that unobtainable rear set for that old 60s restoration job i would like to do it myself.

The software side of things shouldnt be a problem as my HND in software engineering may or may not be of some help but does indicate that i have the want to learn it. and rather than learning on some project that sits on the shelf i would learn on something i can use for the thing i love to do, Play with and restore motorcycles both old and new.

Do you have any other points for the benchtop milling machine that you think i may find usefull??

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

Rick

[M250cnc]

Hi Phil.
Do you have any other points for the benchtop milling machine that you think i may find usefull??
Rick

Patience mainly.

I suggest you go to some of the model engineering shows so you can see the machines for real. Or go to machine tool dealers to checkout your short-list.

You must go ballscrews, zero backlash if you want to cut harder materials as software compensation cannot overcome the consequences of the cutting tool when climb milling.

Phil

[Ricardoco]

Well patience I have..
having done a shed load more research both on this forum and others and not to mention trawling the net, here is where i am now.

Several long Lineaer Rails and bearings (Never could spell that word)

I have the ballscrews and ballnuts (12mm) in my garage from a large machine of the bed and gantry type certainly large enough for any mill i have space for in my shed.

I have Mach3 software (Licenced!!)

Also 4 nema34 steppers and drivers, Dual Parallel interfaces and PC with two Parallel Cards.

An old MPG and several small limit switches,plus 3 e-stop switches and two power supplies 0-48v and 0-24v.

A coolant pump and 4 nozels, several 12v phnumatic solonoid valves.

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

Just got to choose a machine now......
Im finding more models each time i look,
but her is the Short list So far:

Chester Century.......................£939.00

Axminster SIEG X2 Super Mill ......£1,029.50

Axminster SIEG X3 Mill Drill .........£892.99

Amadeal XJ25 Milling Machine.......£870.00

Warco WM16 Variable Speed Mill..£998.00

Arc Euro Trade Super X3L...........£1,121.00

SPG Tools SPG 2217-11 .............£930.00


I have sent some mails to see how many have an R8 tooling option.
That will narrow down the list a little more.

Ok Ive recieved some E-mails and it looks like I would have to convert most to R8 from MT3 Myself, I can do that to most of these mills by changing the spindle, which I suspect from the drawings I can do to most of them with the odd exception..

[handlewanker]

Hi Ricardo, retired fitter and turner be me, for my two cents worth, R8 is Ok if your strapped for dosh, but it's better to have something solid and more grippable like Int30 or INT40 in the head and and sets of ER40 collets, takes all sizes from 1mm continuous up to max 25mm diam cutters, or if you want to save some then ER32 which go up to 20mm.

The ER collets will hold the cutters under loads, but R8, which go up to 3/4" 0r 19mm, can suffer from "down pulling."

Both R8 and INT30/40 are non stick tapers so no probs with "bashing out".

R8's are more compact and a set in metric and imperial on Ebay via China will be most cost efective.

I've used R8 on my Bridgeport, but now have an Ajax mill with INT40, very solid, hence my preference, you can't beat a shell end mill on an InT40 taper.

BTW don't forget the cabinet round the mill otherwise you'll be milling with a dribble and wondering why you wear cutters out, also the coolant gets in everywhere.

Spindle speed is only as good as the bearings, and any compromise here does not cut the muster, same goes for ball screws, Acme doesn't even figure.

If you intend to "bore" out an existing MT3 taper, best of British, I take it you have lathe experience, the bore is most probably case hardened, and the core soft, also there probably won't be a draw bar hole, or enough material to drill one at least 10mm or 12mm diam.

For NC work the spindle will be your biggest factor, it will or it won't, no sense in milling with a 6mm carbide cutter at 800 rpm, your bearings will soon let you know when you try to overspeed them.

Like the man said, if you want to reinvent the wheel be a masochist, it never works out time wise and financially if you have to get the work subcontracted out for a rebuild, but a ready made off the shelf dedicated CNC (made in China) makes your day, you only live once and the kids will only spend it anyway.
My 2 cents worth.
Ian.

[fragger6662000]

i don't really know while people always bash morse, ok yes they can be difficult to remove but also allows you to interchange work from a lathe to a mill without rejigging. big bonus for me personally. also most new morse come with a thread so they don't pull out.