Information On The Smithy 1240 CNC Bed Mill?

[Willyb]

Hi Guys

I have been looking for a suitable CNC Mill and have some questions on the Smithy 1240 CNC Bed Mill.

(1) The Y Axis Ball Screw and Dovetail Ways do not have any Swarf protection? From looking at the Brochure Picture of the 1240, it's kind of hard to tell if the the Ball Screw might have a telecopic cover? The Dovetail Ways certianly do not have any protection. Does anyone know if the Y Axis Ball Screw is protected?

(2) The Smithy Brochure takes about a "High Speed Geared Belt" arrangement to control the Spindle speeds.

Quote: "Maximum power at low speeds, whisper quiet at even the highest RPM's. Single range variable speed drive takes you from 50 to 4,500 RPM's without stopping to change belts or gears"

This sounds like they are using a variable speed pulley/belt setup? The picture in the brochure is kind of misleading as it shows two levers on the left hand side of the Gear Box like it was still manually shifted? How is the Spindle speed set? With a crank like on the older Bridgeports?

I would be interested in hearing from anyone who has a Smithy 1240 CNC Mill and what they think of them? Thank you for your help.

Regards
Willyb

[Trebleplink]

I just took delivery of a Smithy 1240, "cnc ready" for $4400 delivered to my home shop floor. It has nice linear slides on the Z axis, ground ballscrews, and is truly cnc ready - the NEMA 34 motor mounts are designed into the machine, not retrofitted. It does not have way covers on the Y axis - this needs to be added. It has four gearbox speeds, 120 vac motor, large table - the shipping weight was 1600 lbs. The Y ballscrew does have a telescoping cover. Mounts for limit switches and adjustable activator cams are designed in. The X Y way bearing surfaces appear to be very smooth.

I looked at Tormach and IH, and this looked like the way to go if you're willing to add your own motors & controller. I'm going to use 1200 oz in steppers, Geckos, & Mach3. Haven't decided if I need to add an inverter speed control.

Originally Posted by Willyb Hi Guys I have been looking for a suitable CNC Mill and have some questions on the Smithy 1240 CNC Bed Mill. (1) The Y Axis Ball Screw and Dovetail Ways do not have any Swarf protection? From looking at the Brochure Picture of the 1240, it's kind of hard to tell if the the Ball Screw might have a telecopic cover? The Dovetail Ways certianly do not have any protection. Does anyone know if the Y Axis Ball Screw is protected? (2) The Smithy Brochure takes about a "High Speed Geared Belt" arrangement to control the Spindle speeds. Quote: "Maximum power at low speeds, whisper quiet at even the highest RPM's. Single range variable speed drive takes you from 50 to 4,500 RPM's without stopping to change belts or gears" This sounds like they are using a variable speed pulley/belt setup? The picture in the brochure is kind of misleading as it shows two levers on the left hand side of the Gear Box like it was still manually shifted? How is the Spindle speed set? With a crank like on the older Bridgeports? I would be interested in hearing from anyone who has a Smithy 1240 CNC Mill and what they think of them? Thank you for your help. Regards Willyb

[Trebleplink]

Here are the pics of the 1240 cnc-ready - 1600 lbs shipping weight:
Ballscrews: .750 dia on z axis, .950 dia in x ...


Overall - how does one check the gearbox oil level?

http://www.scott-inc.com/1240/1240.jpg

Showing z linear rails with grease fittings:

http://www.scott-inc.com/1240/linear-z.jpg

Showing lube grooves in x ways - looks like a ball valve of some kind for pressure oiling?.

http://www.scott-inc.com/1240/oiler.jpg

Built-in motor mounts:

http://www.scott-inc.com/1240/xdrive.jpg

http://www.scott-inc.com/1240/ydrive.jpg

And limit switch bracketts on all axis:

http://www.scott-inc.com/1240/zlimit.jpg

[Willyb]

Hi Trebleplink

Nice Pictures and great looking Mill. I have a couple of questions if you don't mined.

(1) What is the Hole for in the front of the Z Axis Stepper Motor Bracket? I see that there is a threaded hole in the top of the Spindle Housing Block that looks like it would line up with the hole in the Z Axis Stepper Bracket?

(2) What is the square metal cover for that is sitting on the left side of the Mill Base?

(3) It’s to bad Smithy didn’t take a little time and install some proper Swarf protection Covers. I sure wouldn’t rely on that Telescoping Spring Cover to keep the small stuff off of the Y Axis Ball Screw.

(4) What size of Geckos are you planning to use with your 1200 oz. in. Stepper Motors?

Sure looks like they did a nice job designing and assembling that Mill. Lots of mass in it which should keep the vibrations down. You should have lots of fun with it.

Willy

[philbur]

The Smithy CNC web site - special offers page - identifies a "Nitrogen shock for millhead movement stability" so its probably the mounting points.

Trebleplink, have you costed the finished machine yet.

Regards
Phil

PS: Looks like a good mill - first projects - one shot oiler and way covers.

Originally Posted by Willyb Hi Trebleplink Nice Pictures and great looking Mill. I have a couple of questions if you don't mined. (1) What is the Hole for in the front of the Z Axis Stepper Motor Bracket? I see that there is a threaded hole in the top of the Spindle Housing Block that looks like it would line up with the hole in the Z Axis Stepper Bracket? Willy

[Trebleplink]

Those holes are indeed for the nitrogen shock, and the square cover is for the X axis motor. I think I paid ~ 175 for the the 1200 in oz steppers, rated at 6 amps - the Gecko 202 would appear to work fine with about 60 volts. I bought a 3 ghz Hp Celeron computer for $419. Total cost is estimated in the same range as the Tormach and IH - but I don't have to install the ballscrews or motor mounts, and in comparison to the Tormach, its a beefier machine. I enjoyed talking to Aaron, but I was a little concerned with getting the ballscrews installed precisely. When I talked to Tormach, I found I couldn't even relocate the control box without voiding the warranty. I was also a little nervous about how the non-metallic ways would react to swarf over time.

I'm an seasoned electronics guy but a machining apprentice. My main hitch is a stand / enclosure. There is a fairly large chip tray / coolant collector provided, but its not wide enough to prevent dripping off the ends of the 40 inch table when offset just a bit... It does seem that I would be shortsighted not to include provision for flood cooling and collection, and some kind of shield to prevent chips and coolant from splashing out ...

Are the oil ports (not the zirc) designed to just push an oilcan nozzle against or is there some fitting intended? Anybody know how to check the gearbox lube - is it pulling the motor off the top?

[Willyb]

Hello Trebleplink

Originally Posted by Trebleplink Those holes are indeed for the nitrogen shock, and the square cover is for the X axis motor.

I wouldn't think you would require the Nitrogen Shock when using 1200 oz. in. Stepper Motors. They should have no problem moving the Z Axis or for that matter any of the Axis.

Originally Posted by Trebleplink I think I paid ~ 175 for the 1200 in oz steppers, rated at 6 amps - the Gecko 202 would appear to work fine with about 60 volts.

1200 oz. in. Stepper Motors sounds lots big enough? What does Smithy recommend for Stepper Motors? Do they have a minimum recommendation?

Originally Posted by Trebleplink Total cost is estimated in the same range as the Tormach and IH - but I don't have to install the ball screws or motor mounts.

Yes, I hear you. The proper installation of Ball Screws and their mountings can be tricky to get lined up correctly.

Originally Posted by Trebleplink When I talked to Tormach, I found I couldn't even relocate the control box without voiding the warranty.

I heard this also and cannot see what the big deal is. I could see them not wanting you to disassemble the Mill it's self, but moving the Control Box to a different location is not all that hard. I feel if a person cannot lengthen a few wires and move an Electrical Box, they are going to have problems running a CNC Machine?

Originally Posted by Trebleplink I'm an seasoned electronics guy but a machining apprentice. My main hitch is a stand / enclosure. There is a fairly large chip tray / coolant collector provided, but its not wide enough to prevent dripping off the ends of the 40 inch table when offset just a bit... It does seem that I would be shortsighted not to include provision for flood cooling and collection, and some kind of shield to prevent chips and coolant from splashing out ...

The Stand I am planning to build is going to be similar to a Mini Mill setup with sliding doors on the front. I find it allot easier to keep the mess contained than having to clean the floor all the time. I am going to try and design my Cabinet with two large Drawers, one on each side of the Mill to collect the Swarf. For clean up, one would remove each Drawer to empty it. One thing I am still trying to figure out, is an easy way to have the Coolant drain back to the Tank but also allow easy removal of the Drawers with out having to disconnect any hoses?

Originally Posted by Trebleplink Are the oil ports (not the zirc) designed to just push an oilcan nozzle against or is there some fitting intended?

They look like the ones that you use an Oil Can with.

Originally Posted by Trebleplink Anybody know how to check the gearbox lube - is it pulling the motor off the top?

My Square Column Mill has a small Plastic Window on the right side, near the rear of the Gear Box, approximately 5 iches down from the top. I don't think you should have to remove the Motor to check the Oil Level? Does the Manual not say anything about this? Maybe you should give Smithy a call and ask them how to check it?


Thanks for your help with my questions.

Regards
Willy

[Captain]

Hi Guys
( Thanks for the Picks It does does look nice )
Are you considering going to a 2hp motor on the Z Axis, and using a VFD
like the IH guys are doing?
I also spoke with Karry at Smithy last week about one of the new mills with the belt drive.
I am still waiting on a Quote.
As for the gas shock it is to keep the z axis from drifting down after the machine is powered off.

Keep posting

Richard

[1990notch]

Originally Posted by Willyb The Stand I am planning to build is going to be similar to a Mini Mill setup with sliding doors on the front. I find it allot easier to keep the mess contained than having to clean the floor all the time. I am going to try and design my Cabinet with two large Drawers, one on each side of the Mill to collect the Swarf. For clean up, one would remove each Drawer to empty it. One thing I am still trying to figure out, is an easy way to have the Coolant drain back to the Tank but also allow easy removal of the Drawers with out having to disconnect any hoses?Regards Willy

Willy,

The collection drawer seems like a great idea to me

What I would do is make the drawers with some kind of perforated metal at the bottom rear of each drawer. I would also maybe slope the bottom of each drawer leading to the perforated area to help the coolant runoff to the back. To collect the coolant to return to the pump, I would create a tray shaped like a square funnel under each drawer, somewhat larger than the perforated area of each drawer to collect any coolant that wants to drip from the edge of the drawer.

Regards,

Greg

[Willyb]

Originally Posted by Captain I also spoke with Karry at Smithy last week about one of the new mills with the belt drive. I am still waiting on a Quote.

I also asked for a Quote (4 weeks ago) on the CNC932 Basic and Barebones models and still havn't received a reply.

Which model are you waiting for the Quote on?
Can you let me know if you receive your quote? And I will keep you informed.

As for the gas shock it is to keep the z axis from drifting down after the machine is powered off.

I see what they are using the Nitrogen Shock for.



Willy

[Willyb]

Originally Posted by 1990notch Willy, The collection drawer sounds like a great idea. What I would do is make the drawers with some kind of perforated metal at the bottom rear of each drawer. I would also maybe slope the bottom of each drawer leading to the perforated area to help the coolant runoff to the back. To collect the coolant to return to the pump, I would create a tray shaped like a square funnel under each drawer, somewhat larger than the perforated area of each drawer to collect any coolant that wants to drip from the edge of the drawer. Regards, Greg

Hi 1990notch

That's a good idea to put perforations in the rear of the Drawers. You could build a U shaped channel under the rear of each Drawer to catch the Coolant. Position one end of the channel lower so that the Coolant would run over to one side of the Stand and drain into your Coolant Tank.
A friend of mine who works in a CNC Machine shop told me to try and do all you can to prevent as much Swarf from getting back to your Coolant Tank.
I was thinking of trying some of that Plastic Furnace Filter Material over the drains of the Drawers to help catch the Metal Chips. You could lay a chunk of it over the perforated holes of each Drawer. Haas use a similar material in the bottoms of their Swarf Collecting Tanks. It would be worth a try. If metal was still getting back to the Coolant Tank you could try installing a second collection Drawer between the outlet of the U Channel and the Coolant Tank. You could install a baffle system or possibly more Plastic Filter Material or both. With a Drawer setup, it would be easily removed for cleaning.


Willy

[Trebleplink]

Regarding a question in an earlier post, I have not decided about VFD - I'm guessing it will cost ~ $600 for an inverter drive and three phase motor. If I recall, the gearbox speeds are something like 240-600-1000-2800. I've heard that these mills can overheat gearbox oil at 2800, and the mill has no window to detect this. It appears that to check oil, you have to rotate the head ccw 90 degrees, the remove a coverplate (it has a visible gasket) .

As I think about the stand / enclosure design, I obviously need way covers - I'm thinking some kind of pleated / folded bellows -ish type. Anybody know a resonably priced source of kits or just the material?