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View Full Version : Newbie considering Taig, Sherline and Smithy Mills



Techniquest
07-07-2001, 10:39 PM
Hi,

I am completely new to machine work but am considering several different mills. The small "desktop" mills and larger stand alone units. Looking at the Sherline and Taig they have the fine specs that I would like to have and are CNC capable with several after market CNC upgrade kits from different suppliers. The Smithy BX-288 at http://www.campbelltools.com/smithy/smithybx288specs.html looks interesting, but I don't think that it has the specs of the smaller toy like (Looking.) desktop units, or do they? I don't see the specs that I want to see on their web page to compare with. The Smithy unit doesn't seem to be CNC upgradable.

I need some kind of direction on this. I want something to be able to prototype small parts several inches in diameter or length. The smaller Taig and Sherline mills allow high accuracy CNC manufacturing capabilities but man are they small which is a turn off considering their high price! Although, through all of my searchings for CNC mills on the net CNC mills are far from cheap making the desktop CNC mills seem inexpensive by comparision. The Smithy BX-288 is more like the size I want but I am afraid of it because this big 600 plus pound unit is so cheap, less than 1700 dollars. Why so low price? Is it a cheaply made sloppy mechanical mill, or are the small Sherline and Taig desktop mills just way overpriced?

Looking for recommendations for a good CNC or non-CNC mills. Is the Sherline better than the Taig? Is there a better CNC mill than either of these that is a bit larger? These two mills seem to be the highest quality CNC cable machines that I can find for under 7 thousand dollars. There seems to be quite a gap in price. The low priced CNC mills start out around 2200 dollars up to about 3,000 dollars. Then there isn't anything else to be found less than 8,000 to 16,000 dollars! And these aren't necessarily high priced.

I understand that these might be difficult questions to answer because I have not been specific enough regarding the applications that I might want to use a mill for. All I can say for now is that I want to work prototyping up some copper or aluminum heatsinks for computer CPU's and some other radio parts for switching RF power, possibly some stainless steel. Since these parts are fairly small maybe I shouldn't consider the larger mills. This said, I wouldn't want to be stuck with a smaller machine if I move on up to larger projects. Of course, I could cross that bridge when I get there.

Decisions, decisions....

URL to Smithy Mill (Non-CNC): http://www.campbelltools.com/smithy/smithybx288specs.html

URL to Sherline CNC: http://www.grifftek.com/turn_key.htm

URL to Taig CNC: http://www.taigtools.com/cmill.html

A much higher priced CNC machine, but cheap for its size: http://www.microkinetics.com/cncdmill.htm

URL for other mills: http://www.campbelltools.com/mills.html

CNC Conversion kits: http://www.microkinetics.com/convkit.htm



[This message has been edited by Techniquest (edited 07-08-2001).]

old sass
07-25-2001, 10:03 PM
I bought a Smithy XL 1220 six years ago, and really regret it. Finally got it working OK, but I was hoping to make stuff, not refit a brand new machine. I would sell this thing in a heartbeat and go with two larger size units, lathe and Mill/drill. The Prazi lathes are beautiful, but pricey. Quality is remembered long after the price is forgotten. Good luck!

martin_vanmeter
07-26-2001, 01:59 PM
A couple of sites to look at:
http://www.cnckits.com/
http://www.desktopcnc.com/index.htm

Your starting point for the search is to define for yourself the size of machine you will need. Taig and Sherline are model maker size machines, small and compact, the Taig made of steel, the Sherline of aluminum. The next size is the MaxNC machines and them the retrofitted Rong Fu RF-31 mill/drills. By the time you get to the RF-31 machines at 650 pounds, you have a "large" mill, taking up as much space as a 3/4 size Bridgeport turret mill clone.

Just by searching Google.com for - cnc desktop milling machine - you will get pages of site hits. So use the web and gather info before plunging into a rather sizable expenditure.

MetalMaster
08-07-2001, 10:00 PM
I,m 100% in agreement with old sass. I bought a Smithy CB1220XL about 4 years ago, and spent more time working on the machine than machining projects. The first one they sent had tapered ways, so that when you moved the carriage toward the tailstock, it would get tighter and tighter, until it finally just locked up about 60% of the way down the ways. The replacement that they sent for the first machine wasn't much better. While things could be machined with relative accuracy on the lathe portion of the machine, you could just forget about getting anything done on the mill. The mill would consistently cut at an angle, as if the millhead was a limp noodle. No hole could be drilled or bored on it without major setup work to compensate for the misaligned millhead. Also, when trying to use a milling cutter 1/2 inch or larger, you could not get the millhead to lock on the column, so you would be cutting along, and suddenly the millhead would start drifting, or just violently break free, sending pieces of milling cutter and ruined work flying all over the shop. I finally just gave up on the mill portion of the machine, and bought a Palmgren milling attachment for the lathe part of the Smithy. I finally got so disgusted with the whole mess, that the machine just sat collecting dust for the last year that I owned it. I finally sold the whole mess for $800, accessories and all. I had only gotten to (attempt) to use it one year. I was working on a Gingery Atkinson Cycle engine at the time, which can be seen at http://www.lindsaybks.com/dgjp/arch/cycle/index3.html and actually finished 90% of the engine within 8 months once I got some good machinery. All parts made on the Smithy machine except for one had to be remade due to tolerance and alignment problems. The machines that I finally got that would actually get some good, meaningful work done were a Birmingham 13 x 40 gear head lathe, and a Jet JMD-18PFN mill/drill. These have been excellent machines.
Good luck in your machine search. I hope that this information will be of value to you.

[This message has been edited by MetalMaster (edited 08-07-2001).]

Thrud
08-08-2001, 02:54 AM
I own a Emco Maximat7 (7"x18") lathe/mill that I purchased at an estate auction. It has a standard 1-1/2"x8 nose so getting new chucks is very easy. Getting a chuck for the smaller machines can be expensive (like Myford) It is very high quality and precise. It is not perfect, however. It does not have a feed gearbox, but I intend to build one for it (see "Projects in Metal"). The half-nuts, cross slide, and compound backlash nuts were cast alloy. The "Emco Guys" wanted $500 (Canadian) for a cast set of half nuts - so I made real ones from bronze & Stainless Steel.

It is a little smaller than I would like it to be. This results in many accessories being made to make it more useful. You will have the same problem with Prazi, Sherline or any smaller lathe/mill. Having a small lathe sucks when you want to make a steam engine that grabs your snappy, but you cannot swing a 12" flywheel on your 7" lathe. The mini mills are a pain for the same reasons. But if you are doing small stuff they kick butt.

If you really want a CNC machine you could buy a reconditioned Bridgeport and get a Ball screw /CNC conversion kit from ah-ha.com (612-641-1797). These guys can help you CNC nearly anything. Get the ball screws - you will not regret it (zero backlash).

There is no free lunch - used machines are cheaper but usually need refurbing. New machines - well - you get wait you pay for. Bargains do come along eventually - I looked for a small lathe for years before I got mine - it was worth the wait. Now I want Big Iron!

Good luck
Dave Smith