Gents,
Kryn's post a few weeks ago had me thinking about whether it was practical to do a 3-phase + VSD conversion on an X2 mill.
After some thought, and scavenging parts/materials, as a proof-of-concept I've substantially completed some upgrades/modifications to my X2 mill, including gas strut replacement for the torsion spring head support, 3 phase motor plus VFD to replace the DC motor drive, and column base strengthening/stiffening to reduce flexing of the column under cutting loads.
I used a flange mounted 550W 3 phase motor with a Danfoss VFD drive set to 100Hz max speed, and the new control box has Forward, Reverse and Stop buttons and a speed control pot. The motor is connected using the low speed (1400 RPM) connections.
With the 3 groove poly-vee belt drive, the maximum spindle speed with the belt on the low speed pulleys is 1300 RPM, and on the high speed pulleys is 2900 RPM.
To support the massively increased weight of the mill head, with the offset motor, I installed a 250N gas strut, which happens to have 10mm more travel than the mill head on the column, so I have full travel available now. The original torsion spring setup restricted the vertical travel by more than 30mm, and intruded into the work envelope of the mill.
After testing, I have planned to replace the 250N strut with a 200N strut, for more controlled support and vertical feed.
With the increase in the power and weight of the mill head, I decided that the stiffness of the column would need substantial improvement. This would be useful even with the original motor as the column base mounting is very marginal for strength and stiffness. Some internet research gave me ideas, and as can be seen in the attached pictures the parts I made were somewhat over designed. As a consequence, the column has become very rigid with very little movement even with the weight increase on the head, and it is now much easier to take substantial cuts while retaining a good surface finish.
DSCN8993.jpgDSCN8981.jpgDSCN8980.jpgDSCN8982.jpgDSCN8984.jpgDSCN8983.jpgDSCN8985.jpgDSCN8987.jpgDSCN8988.jpgDSCN8989.jpgDSCN8990.jpgDSCN8991.jpgDSCN8992.jpgDSCN8979.jpg
Things still to be done:
1. Cleanup of drive mounting plate.
2. Work out best mounting position and method for the control box.
3. Wiring/cable cleanup and mounting.
4. Install 200N gas strut
5. Construct belt drive cover/guard
6. Design/construct a spindle lock mechanism (spring loaded with lock in for hands free use?)
7. Drawbar pushdown mechanism to save spindle bearings from shock loads
Anyway, I'm very happy with the results so far - plenty of torque, motor much quieter, much more rigidity.
Andrew.
Attached Images
Read the full thread at metalworkforums.com...
Kryn's post a few weeks ago had me thinking about whether it was practical to do a 3-phase + VSD conversion on an X2 mill.
After some thought, and scavenging parts/materials, as a proof-of-concept I've substantially completed some upgrades/modifications to my X2 mill, including gas strut replacement for the torsion spring head support, 3 phase motor plus VFD to replace the DC motor drive, and column base strengthening/stiffening to reduce flexing of the column under cutting loads.
I used a flange mounted 550W 3 phase motor with a Danfoss VFD drive set to 100Hz max speed, and the new control box has Forward, Reverse and Stop buttons and a speed control pot. The motor is connected using the low speed (1400 RPM) connections.
With the 3 groove poly-vee belt drive, the maximum spindle speed with the belt on the low speed pulleys is 1300 RPM, and on the high speed pulleys is 2900 RPM.
To support the massively increased weight of the mill head, with the offset motor, I installed a 250N gas strut, which happens to have 10mm more travel than the mill head on the column, so I have full travel available now. The original torsion spring setup restricted the vertical travel by more than 30mm, and intruded into the work envelope of the mill.
After testing, I have planned to replace the 250N strut with a 200N strut, for more controlled support and vertical feed.
With the increase in the power and weight of the mill head, I decided that the stiffness of the column would need substantial improvement. This would be useful even with the original motor as the column base mounting is very marginal for strength and stiffness. Some internet research gave me ideas, and as can be seen in the attached pictures the parts I made were somewhat over designed. As a consequence, the column has become very rigid with very little movement even with the weight increase on the head, and it is now much easier to take substantial cuts while retaining a good surface finish.
DSCN8993.jpgDSCN8981.jpgDSCN8980.jpgDSCN8982.jpgDSCN8984.jpgDSCN8983.jpgDSCN8985.jpgDSCN8987.jpgDSCN8988.jpgDSCN8989.jpgDSCN8990.jpgDSCN8991.jpgDSCN8992.jpgDSCN8979.jpg
Things still to be done:
1. Cleanup of drive mounting plate.
2. Work out best mounting position and method for the control box.
3. Wiring/cable cleanup and mounting.
4. Install 200N gas strut
5. Construct belt drive cover/guard
6. Design/construct a spindle lock mechanism (spring loaded with lock in for hands free use?)
7. Drawbar pushdown mechanism to save spindle bearings from shock loads
Anyway, I'm very happy with the results so far - plenty of torque, motor much quieter, much more rigidity.
Andrew.
Attached Images
DSCN8993.jpg (172.2 KB)
Read the full thread at metalworkforums.com...
X2 Mill Mods/Upgrade
0 commentaires:
Enregistrer un commentaire