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CNC Building Page | CNC Building Page | ||
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| + | Building a CNC Machine - The Parts | ||
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| + | So the big question is what do I need to build a CNC...? Looking at the web, its clear that there are just as many ways of building a CNC, as there are people interrested in this, so what I basically did was to look for what parts that were available for me, and build from those. | ||
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| + | Quickly I discovered that getting parts from Denmark were vertually impossible, because there simply is no market for used CNC parts here..., so I turned to Ebay, and found a huge selection of usable CNC parts, just waiting for me. | ||
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| + | To be able to dimention the CNC frame, I need to seek out the vital parts that need to go on the frame, this beeing: | ||
| + | |||
| + | - Lead Screws (XYZ) | ||
| + | - Linear Bearings (XYZ) | ||
| + | - Milling head with ER16 Collet. | ||
| + | |||
| + | Leadscrew / Ballscrews | ||
| + | |||
| + | So I started looking at leadscrews/Ballscrews, and came across this great offer. A set of 3 spindles including thrust bearings at both ends, only a spacer and a nut missing, but Ill manage (-: | ||
| + | |||
| + | These lead screws will set the physical limits of the milling machine. | ||
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| + | 1.jpg (6254 bytes)2.jpg (7454 bytes)3.jpg (8602 bytes)4.jpg (12021 bytes)5.jpg (13204 bytes)6.jpg (8799 bytes)7.jpg (10102 bytes)8.jpg (8694 bytes)9.jpg (10569 bytes)10.jpg (11131 bytes)11.jpg (10786 bytes)12.jpg (8513 bytes)13.jpg (7627 bytes)14.jpg (9437 bytes)15.jpg (8174 bytes)16.jpg (10144 bytes) | ||
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| + | (Used lead screws from Malaysia, purchased on eBay - No Problems) | ||
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| + | You might have notised that the pitch on these screws quite high (20mm pr. rotation) which by some persons will be considered very steep, and I agree and thinks it will be torture for the motors to try to drive these screws, resulting in loss of steps, and therefore unusable results. Therefore I investigated the possiblity of a reduction between the stepper motor and the spindle, and I managed to find a way to do a 4:1 reduction with tooth belts. In addition to reducing my motor to spindle ratio, I also eliminated another common problem in DIY CNC world, which is resonance. As the motors work, they make a horrible loud noise when beeing run directly on the spindles, so many use some kind of rubber bridge on the axis to isolate the motors harsh movents from the spindles just slightly. | ||
| + | |||
| + | The motors that followed the kit were 305 oz/in motors with a step degree of 1.8, which give a perfect 200 degrees pr. rotation. If I were to run the motors directly on the spindles, it would give me a resolution of 20mm/200 steps = 0,1 mm pr step (1:1 microstepping mode.). So when I build the 4:1 reduction, Ill have 0.025 mm resolution which will be more than enough for me at this first CNC build. If I find that I need more reolution, the kit from hobbycnc is able to run in the following microstepping modes: 1/1, 1/2, 1/4, 1/8, and 1/16. So in theory, my resolution could be 0,0015625 mm pr Step - But this is way beond the precision of this CNC anyway. And when you increase the stepping division, you are giving up power of the motor. | ||
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| + | Linear bearings | ||
| + | |||
| + | The Linear bearings were also found on Ebay, and was found after the leadscres were recieved, because if all the leadscrew length is to be used, its important to find the correct linear bearing. This is naturally because you need to have 2 bearing blocks spaced on each bearing rail. The further apart, the more stable the construction will be. | ||
| + | |||
| + | img_7744.jpg (150226 bytes) 2 at the top, these are the linear bearings for the Z-axis. | ||
| + | img_7746.jpg (138708 bytes)img_7740.jpg (164881 bytes) The long bearings at the bottom are the X-Axis bearings. | ||
| + | Im only missing the Y-axis bearing, I found one that are 21" 5/8, in length which is just perfect... However the Danish Post service has much to be desired.. Still not arrived after 15 Days in Denmark... | ||
| + | |||
| + | Ordered it the 29 Jan 2008, and today its 05 Mar 2008... And they are still not here... But I have the tracking number, so I know they are not lost.... I guess... | ||
| + | |||
| + | Belt reduction | ||
| + | |||
| + | This is how I obtained the 4:1 belt reduction. I located an Amarican dealer of alu. tooth belt pulleys and belts. Im impressed about the quality - but they didnt come cheap either!!! but unfortunately were my only option. - The shipping were the most expensive! | ||
| + | |||
| + | |||
| + | img_7741.jpg (159530 bytes) Pulleys ordered directly to fit the axis of the motors. | ||
| + | |||
| + | img_7742.jpg (87183 bytes) Pulleys for the lead screw, I need to make a cylinder piece to make the 12mm hole fit the leadscrew 10mm end. | ||
| + | |||
| + | img_7743.jpg (104962 bytes) The Belts.. Ordered some spares.. | ||
| + | |||
| + | Milling Head. | ||
| + | |||
| + | As for the milling head, I ordered everything for this from an existing product: the Taig milling machines has an exceptional good milling head, and you can get it with ER16 collet, which is a standard. So finding milling bits (Pro or hobby) will not be a problem. | ||
| + | |||
| + | Peatol Machine | ||
| + | 19 Knightlow Rd. | ||
| + | Harborne | ||
| + | Birmingham B17 8PS | ||
| + | England | ||
| + | 011-441-21-429-1015 | ||
| + | "www.peatol.com" -> They dont have email, so you will have to grab your phone... | ||
| + | |||
| + | And these are the parts I recieved: | ||
| + | |||
| + | img_7753.jpg (24037 bytes) 2 x ER16 standard collets in 2 different sizes, perfect to start up with. | ||
| + | |||
| + | img_7755.jpg (23716 bytes)img_7754.jpg (31955 bytes)img_7756.jpg (25023 bytes)img_7759.jpg (26422 bytes)img_7760.jpg (25233 bytes) The milling head with pulley, dovetail mounting plate and motor mounting plate. | ||
| + | |||
| + | img_7757.jpg (31067 bytes)img_7758.jpg (26557 bytes) The motor inclusive the pulley and drive belt. | ||
| + | |||
| + | The motor os 220 VAC. 0.18 KW. 1390 RPM. | ||
| + | |||
| + | The above items makes it so much easier to build the CNC, as it is off the shelve items, and spares can be purchased. And the mounting system is easy and the ER16 headstock is commonly available, so there will be no problem finding different tools for this collet system. | ||
| + | |||
| + | If in need to do so, the headstock can be removed from the dovetail mounting post, and placed horisontally, and the ER16 collet removed and replaced with a chuck off the shelve, and you have a Taig lathe... | ||
| + | |||
| + | If the result of the CNC turns out good, Ill add the 4´th axis to the CNC, which will be a second horisontal headstock controlled by a gear reduced stepper motor. this way its possible to make parts that were vertually impossible on the 3 axis machine. | ||
CNC Building Page
Building a CNC Machine - The Parts
So the big question is what do I need to build a CNC...? Looking at the web, its clear that there are just as many ways of building a CNC, as there are people interrested in this, so what I basically did was to look for what parts that were available for me, and build from those.
Quickly I discovered that getting parts from Denmark were vertually impossible, because there simply is no market for used CNC parts here..., so I turned to Ebay, and found a huge selection of usable CNC parts, just waiting for me.
To be able to dimention the CNC frame, I need to seek out the vital parts that need to go on the frame, this beeing:
- Lead Screws (XYZ) - Linear Bearings (XYZ) - Milling head with ER16 Collet.
Leadscrew / Ballscrews
So I started looking at leadscrews/Ballscrews, and came across this great offer. A set of 3 spindles including thrust bearings at both ends, only a spacer and a nut missing, but Ill manage (-:
These lead screws will set the physical limits of the milling machine.
1.jpg (6254 bytes)2.jpg (7454 bytes)3.jpg (8602 bytes)4.jpg (12021 bytes)5.jpg (13204 bytes)6.jpg (8799 bytes)7.jpg (10102 bytes)8.jpg (8694 bytes)9.jpg (10569 bytes)10.jpg (11131 bytes)11.jpg (10786 bytes)12.jpg (8513 bytes)13.jpg (7627 bytes)14.jpg (9437 bytes)15.jpg (8174 bytes)16.jpg (10144 bytes)
(Used lead screws from Malaysia, purchased on eBay - No Problems)
You might have notised that the pitch on these screws quite high (20mm pr. rotation) which by some persons will be considered very steep, and I agree and thinks it will be torture for the motors to try to drive these screws, resulting in loss of steps, and therefore unusable results. Therefore I investigated the possiblity of a reduction between the stepper motor and the spindle, and I managed to find a way to do a 4:1 reduction with tooth belts. In addition to reducing my motor to spindle ratio, I also eliminated another common problem in DIY CNC world, which is resonance. As the motors work, they make a horrible loud noise when beeing run directly on the spindles, so many use some kind of rubber bridge on the axis to isolate the motors harsh movents from the spindles just slightly.
The motors that followed the kit were 305 oz/in motors with a step degree of 1.8, which give a perfect 200 degrees pr. rotation. If I were to run the motors directly on the spindles, it would give me a resolution of 20mm/200 steps = 0,1 mm pr step (1:1 microstepping mode.). So when I build the 4:1 reduction, Ill have 0.025 mm resolution which will be more than enough for me at this first CNC build. If I find that I need more reolution, the kit from hobbycnc is able to run in the following microstepping modes: 1/1, 1/2, 1/4, 1/8, and 1/16. So in theory, my resolution could be 0,0015625 mm pr Step - But this is way beond the precision of this CNC anyway. And when you increase the stepping division, you are giving up power of the motor.
Linear bearings
The Linear bearings were also found on Ebay, and was found after the leadscres were recieved, because if all the leadscrew length is to be used, its important to find the correct linear bearing. This is naturally because you need to have 2 bearing blocks spaced on each bearing rail. The further apart, the more stable the construction will be.
img_7744.jpg (150226 bytes) 2 at the top, these are the linear bearings for the Z-axis. img_7746.jpg (138708 bytes)img_7740.jpg (164881 bytes) The long bearings at the bottom are the X-Axis bearings. Im only missing the Y-axis bearing, I found one that are 21" 5/8, in length which is just perfect... However the Danish Post service has much to be desired.. Still not arrived after 15 Days in Denmark...
Ordered it the 29 Jan 2008, and today its 05 Mar 2008... And they are still not here... But I have the tracking number, so I know they are not lost.... I guess...
Belt reduction
This is how I obtained the 4:1 belt reduction. I located an Amarican dealer of alu. tooth belt pulleys and belts. Im impressed about the quality - but they didnt come cheap either!!! but unfortunately were my only option. - The shipping were the most expensive!
img_7741.jpg (159530 bytes) Pulleys ordered directly to fit the axis of the motors.
img_7742.jpg (87183 bytes) Pulleys for the lead screw, I need to make a cylinder piece to make the 12mm hole fit the leadscrew 10mm end.
img_7743.jpg (104962 bytes) The Belts.. Ordered some spares..
Milling Head.
As for the milling head, I ordered everything for this from an existing product: the Taig milling machines has an exceptional good milling head, and you can get it with ER16 collet, which is a standard. So finding milling bits (Pro or hobby) will not be a problem.
Peatol Machine 19 Knightlow Rd. Harborne Birmingham B17 8PS England 011-441-21-429-1015 "www.peatol.com" -> They dont have email, so you will have to grab your phone...
And these are the parts I recieved:
img_7753.jpg (24037 bytes) 2 x ER16 standard collets in 2 different sizes, perfect to start up with.
img_7755.jpg (23716 bytes)img_7754.jpg (31955 bytes)img_7756.jpg (25023 bytes)img_7759.jpg (26422 bytes)img_7760.jpg (25233 bytes) The milling head with pulley, dovetail mounting plate and motor mounting plate.
img_7757.jpg (31067 bytes)img_7758.jpg (26557 bytes) The motor inclusive the pulley and drive belt.
The motor os 220 VAC. 0.18 KW. 1390 RPM.
The above items makes it so much easier to build the CNC, as it is off the shelve items, and spares can be purchased. And the mounting system is easy and the ER16 headstock is commonly available, so there will be no problem finding different tools for this collet system.
If in need to do so, the headstock can be removed from the dovetail mounting post, and placed horisontally, and the ER16 collet removed and replaced with a chuck off the shelve, and you have a Taig lathe...
If the result of the CNC turns out good, Ill add the 4´th axis to the CNC, which will be a second horisontal headstock controlled by a gear reduced stepper motor. this way its possible to make parts that were vertually impossible on the 3 axis machine.