March 21, 2019 at 21:53CNC machine from what was lying in the garage
I am assembling another portal-milling machine with a small working field for wood, plastic, and composites. About this story is given under the cut ...
I must say right away - not everyone had what I had in their garage. Due to some third-party mechanical projects, I have accumulated some rubbish, which could subsequently just rust, after which, it is only ferrous. To this type of rubbish I attributed polished guide shafts, a few scraps of duralumin sheets (although they do not rust, but take their place). I also had a stepper motor and driver.
Among other things, from the main it remains to understaff my existing set: ballscrews, carriages for guide shafts, motors, electronics and a spindle. In general, “a little”. And with all this, apart from all the little things in the form of metalworking and various hardware, I get a CNC machine.
Having estimated the price tag for the missing components, and realizing that I could handle such an amount without any special financial difficulties (especially if you didn’t buy everything all at once, but as it was being assembled), I still decided on such a rash step and started designing the future machine.
Based on the lengths of the guides and the size of the scraps of duralumin (fortunately they were about all the same size), I began by drawing the base.
Dimensions:
Scraps - length 700mm, height 70mm, thickness 6mm.
Guides (4 pieces) - diameter 25mm, length 740mm.
From these sizes and repelled during the construction of the entire structure. Accordingly, the length of the portal along the base turned out to be 600 mm (X coordinate).
Due to the fact that there are only 4 pieces of guides, and it was not planned to buy them, and the machine has three movement axes, I had to divide two guides into two smaller axes: Y and Z. I divided it so that the width of the working field along Y was 250 mm and Z - 80mm.
Since this is not my first project of a cnc machine, instead of the usual KOMPAS 3D, I used SolidWorks. It redrawn all the available and ordered standard parts (engines, couplings, slide carriages, bearings, ball screws, guide rails) that do not require additional processing. Then he began to add guides to the project, began to connect them with duralumin sheets, in which he made technological holes for mounting and installing engines, and reinforcing supports.
Speaking of the latter. In order to save money, support for guides could not be set, but since the thickness of the sheet is not enough, in my opinion, I thought that such supports would significantly strengthen the design.
The portal itself, it was decided to move, installing two ball screws at the edges, and not one in the center, although it is slightly more expensive, but do not worry about the weight of the portal.
After the foundation was ready, I proceeded to draw a portal. He painted the main beam, which will carry a portal and move it along the entire base. The beam turned out to be quite strong due to parallel plates bonded and pulled together by cylindrical axes. The main plane of attachment to the carriages mates with the plates forming the portal rack. They were reinforced with a 6mm thick sheet (I also had it in the garage). He painted everything else in the same way as the foundation.
Attaching the guide carriages and ball screws to the project with a nut along the Y axis, he threw a mechanism for moving the Z axis. It has already used T-shaped rail supports, and an end plate is attached to the guide carriages, which mates with the spindle.
I want to make a small digression and talk about my use of cylindrical guides. I know that some “specialists” in the comments will say that these guides will bend, the accuracy will be poor, the rigidity of the structure is also none and everything like that. To process the materials on which this machine is made and when using such a diameter of the guides, to such a length as mine, the deflection will be negligible, the rigidity is more than enough.
In the whole design I used ballscrews with a diameter of 16 mm with a pitch of 5 mm.
After outlining the power frame of the machine, I added several auxiliary elements to it, such as the corners on which the flexible cable channel and the supports attached to the base of the machine should lie.
The manufacture of parts for the machine began in the same sequence in which they drew. I processed parts from scraps and duralumin sheet on my last project - a CNC machine. I will say right away, if you count in the aggregate, it took no more than 8 hours to process all the flat parts. I spent more time on selecting the cutting mode and waiting for the few cutters I needed.
I mainly used a single-cutter with a diameter of 6 mm, and also for small holes with a two-feather with a diameter of 3 mm. Of course, broken cutters could not be without, but in the end it’s an experience, although not as cheap as we would like.
Friends ’rotated the guides and tails of the ball screws to me, too, there were some jambs there. These are all trifles, this happens when a person drank hard all his life, and then abruptly quit.
The machine was assembled as a designer, it seems that at one time I did not play enough of them and now make up for it with the assembly and construction of machines. It is nice when all the parts fit together and there is almost no need to modify and adjust them. However, it still had to be finalized. There was a difficulty in pairing engines and ballscrews.
Having ordered an additional three engines similar to the one I already had, as well as 4 couplings for connecting the motor shafts and ballscrews. When everything ordered came, it turned out that the diameter of the output shafts of the engines was 6.2 mm, and the couplings that arrived had 8 and 12 mm holes, which is necessary, since the output shaft I had in my engine had 8 mm. As a result, I ordered three new couplings with a diameter of 6 and 12 mm, after which I simply drilled a hole up to 6.2 mm.
It remains unclear why the motor shaft is 0.2 mm larger and what kind of standards they generally have, or it all depends on the particular manufacturer, which rod was available as such for the shaft and decided to use?
Be careful when ordering.
The mechanical part is almost ready, now you can move on to the electrical one. Engines connected to the drivers. Two engines of the X axis, connected in parallel to one DM542 driver, others connected to cheaper drivers (without a name) based on TB6600. I connected all three drivers to the DDCSV2.1 controller on 4 axes, only the fourth axis, namely the rotary one, cannot be assigned as duplicating any of the main three. Together with the controller, an MPG remote control came for the manual control of coordinates - a cool thing. I think in the future I will not like it and will continue to please me.
At the moment, I made a surface mount and did not stretch the normal wires, and the details have not all been bought yet. Actually connected to check the performance of the mechanics. The other day I just ordered a 1.5 kW air cooling spindle. and frequency converter with collets.
In the future, I will install the spindle, and I will breed wires; I will make and mount a box for electronics.
In the final part I will show and tell what kind of beast I got this way, we will talk about its pros and cons and draw conclusions.
Thanks for reading and enjoy reading!
Project 1
Project 2
I must say right away - not everyone had what I had in their garage. Due to some third-party mechanical projects, I have accumulated some rubbish, which could subsequently just rust, after which, it is only ferrous. To this type of rubbish I attributed polished guide shafts, a few scraps of duralumin sheets (although they do not rust, but take their place). I also had a stepper motor and driver.
Among other things, from the main it remains to understaff my existing set: ballscrews, carriages for guide shafts, motors, electronics and a spindle. In general, “a little”. And with all this, apart from all the little things in the form of metalworking and various hardware, I get a CNC machine.
Having estimated the price tag for the missing components, and realizing that I could handle such an amount without any special financial difficulties (especially if you didn’t buy everything all at once, but as it was being assembled), I still decided on such a rash step and started designing the future machine.
Based on the lengths of the guides and the size of the scraps of duralumin (fortunately they were about all the same size), I began by drawing the base.
Dimensions:
Scraps - length 700mm, height 70mm, thickness 6mm.
Guides (4 pieces) - diameter 25mm, length 740mm.
From these sizes and repelled during the construction of the entire structure. Accordingly, the length of the portal along the base turned out to be 600 mm (X coordinate).
Due to the fact that there are only 4 pieces of guides, and it was not planned to buy them, and the machine has three movement axes, I had to divide two guides into two smaller axes: Y and Z. I divided it so that the width of the working field along Y was 250 mm and Z - 80mm.
Since this is not my first project of a cnc machine, instead of the usual KOMPAS 3D, I used SolidWorks. It redrawn all the available and ordered standard parts (engines, couplings, slide carriages, bearings, ball screws, guide rails) that do not require additional processing. Then he began to add guides to the project, began to connect them with duralumin sheets, in which he made technological holes for mounting and installing engines, and reinforcing supports.
Speaking of the latter. In order to save money, support for guides could not be set, but since the thickness of the sheet is not enough, in my opinion, I thought that such supports would significantly strengthen the design.
The portal itself, it was decided to move, installing two ball screws at the edges, and not one in the center, although it is slightly more expensive, but do not worry about the weight of the portal.
After the foundation was ready, I proceeded to draw a portal. He painted the main beam, which will carry a portal and move it along the entire base. The beam turned out to be quite strong due to parallel plates bonded and pulled together by cylindrical axes. The main plane of attachment to the carriages mates with the plates forming the portal rack. They were reinforced with a 6mm thick sheet (I also had it in the garage). He painted everything else in the same way as the foundation.
Attaching the guide carriages and ball screws to the project with a nut along the Y axis, he threw a mechanism for moving the Z axis. It has already used T-shaped rail supports, and an end plate is attached to the guide carriages, which mates with the spindle.
I want to make a small digression and talk about my use of cylindrical guides. I know that some “specialists” in the comments will say that these guides will bend, the accuracy will be poor, the rigidity of the structure is also none and everything like that. To process the materials on which this machine is made and when using such a diameter of the guides, to such a length as mine, the deflection will be negligible, the rigidity is more than enough.
In the whole design I used ballscrews with a diameter of 16 mm with a pitch of 5 mm.
After outlining the power frame of the machine, I added several auxiliary elements to it, such as the corners on which the flexible cable channel and the supports attached to the base of the machine should lie.
The manufacture of parts for the machine began in the same sequence in which they drew. I processed parts from scraps and duralumin sheet on my last project - a CNC machine. I will say right away, if you count in the aggregate, it took no more than 8 hours to process all the flat parts. I spent more time on selecting the cutting mode and waiting for the few cutters I needed.
I mainly used a single-cutter with a diameter of 6 mm, and also for small holes with a two-feather with a diameter of 3 mm. Of course, broken cutters could not be without, but in the end it’s an experience, although not as cheap as we would like.
Friends ’rotated the guides and tails of the ball screws to me, too, there were some jambs there. These are all trifles, this happens when a person drank hard all his life, and then abruptly quit.
The machine was assembled as a designer, it seems that at one time I did not play enough of them and now make up for it with the assembly and construction of machines. It is nice when all the parts fit together and there is almost no need to modify and adjust them. However, it still had to be finalized. There was a difficulty in pairing engines and ballscrews.
Having ordered an additional three engines similar to the one I already had, as well as 4 couplings for connecting the motor shafts and ballscrews. When everything ordered came, it turned out that the diameter of the output shafts of the engines was 6.2 mm, and the couplings that arrived had 8 and 12 mm holes, which is necessary, since the output shaft I had in my engine had 8 mm. As a result, I ordered three new couplings with a diameter of 6 and 12 mm, after which I simply drilled a hole up to 6.2 mm.
It remains unclear why the motor shaft is 0.2 mm larger and what kind of standards they generally have, or it all depends on the particular manufacturer, which rod was available as such for the shaft and decided to use?
Be careful when ordering.
The mechanical part is almost ready, now you can move on to the electrical one. Engines connected to the drivers. Two engines of the X axis, connected in parallel to one DM542 driver, others connected to cheaper drivers (without a name) based on TB6600. I connected all three drivers to the DDCSV2.1 controller on 4 axes, only the fourth axis, namely the rotary one, cannot be assigned as duplicating any of the main three. Together with the controller, an MPG remote control came for the manual control of coordinates - a cool thing. I think in the future I will not like it and will continue to please me.
At the moment, I made a surface mount and did not stretch the normal wires, and the details have not all been bought yet. Actually connected to check the performance of the mechanics. The other day I just ordered a 1.5 kW air cooling spindle. and frequency converter with collets.
In the future, I will install the spindle, and I will breed wires; I will make and mount a box for electronics.
In the final part I will show and tell what kind of beast I got this way, we will talk about its pros and cons and draw conclusions.
Thanks for reading and enjoy reading!
Project 1
Project 2