fleinbach
06-03-2005, 07:53 AM
I purchased my first ShopBot in August of 2003 it was a PRT96. When ShopBot announced the alpha in the spring of 2004 I had already been considering a larger table so I thought that would be a good time to change. I had considered a 12 foot table but due to space constraints I settled for and purchased a PRTALPHA120 in May of 2004.
Well here it is, one year later and I decided I really did need the 12 foot table even though it fits in my space just barely. The main issue with the larger table has to do with the location of my breaker box. Now that I have extended the table to 12 feet I can no longer reach my electric panel when any breaker trips. I need to crawl across the table now to reset it.
Changing the rails was not that difficult. The total time to make the change so far was about six hours spread over the last two weeks. Finding the time to work on it was the hardest part. Keep in mind there is still more to do later but the rail change itself is complete and the X-car is running the full-length of the new 14' rails.
Changing the rails involves a few more things than just the rails themselves. My E-chain containing all my wires from the X-car had to be relocated to reach the additional 2' since there was not enough slack in many of the wires the easiest solution was to move the main control box 2 feet along the end of my table. I had luckily installed my control box on the outside end of the table making this change feasible. Had I mounted it under the table where it is suggested to be mounted I could not have done this as the reset and start button would be out of reach.
The last part of the equation to consider was that the vacuum hose had to be relocated. Due to the many obstructions and limitations this forced me to make another modification I had been contemplating for some time. That being to relocate my spindle motor. Relocating the spindle motor was done for two reasons. One was to change the routing of the vacuum hose up through the X-car rather than on the outside of the Y-car rail. This decreased the need to extend the vacuum hose less than 1 foot rather than 2. But the main reason I had been contemplating relocating the spindle was to eliminate some of the error that occurs when the cutting forces twist the Y-car pulling the cut line off course. This has been discussed in other threads. While moving the spindle closer to the Y-car motor will reduce the error some, it will not reduce the error as much as adding a second Y-car motor. But it is definitely a less costly fix. There is one more modification that I will be making to reduce this error more but I won't go into that at this time.
The first thing pictured here was to extend my C-channels the additional 2 feet needed. To do this has simply welded an additional 2 foot piece of C-channel pictured here.
305
The most time consuming part of changing the rails was re-drilling all the holes. It just so happens that the 12 and 14 foot rails are mounted using the same number of bolts so naturally the holes did not line up.
Here is a picture after the change. As you see at this point I do not yet have any of the table parts constructed. Aside from extending the table I will also be mounting my indexer in this location. Hopefully I will find time in the next couple of weeks to complete the rest.
306
Well here it is, one year later and I decided I really did need the 12 foot table even though it fits in my space just barely. The main issue with the larger table has to do with the location of my breaker box. Now that I have extended the table to 12 feet I can no longer reach my electric panel when any breaker trips. I need to crawl across the table now to reset it.
Changing the rails was not that difficult. The total time to make the change so far was about six hours spread over the last two weeks. Finding the time to work on it was the hardest part. Keep in mind there is still more to do later but the rail change itself is complete and the X-car is running the full-length of the new 14' rails.
Changing the rails involves a few more things than just the rails themselves. My E-chain containing all my wires from the X-car had to be relocated to reach the additional 2' since there was not enough slack in many of the wires the easiest solution was to move the main control box 2 feet along the end of my table. I had luckily installed my control box on the outside end of the table making this change feasible. Had I mounted it under the table where it is suggested to be mounted I could not have done this as the reset and start button would be out of reach.
The last part of the equation to consider was that the vacuum hose had to be relocated. Due to the many obstructions and limitations this forced me to make another modification I had been contemplating for some time. That being to relocate my spindle motor. Relocating the spindle motor was done for two reasons. One was to change the routing of the vacuum hose up through the X-car rather than on the outside of the Y-car rail. This decreased the need to extend the vacuum hose less than 1 foot rather than 2. But the main reason I had been contemplating relocating the spindle was to eliminate some of the error that occurs when the cutting forces twist the Y-car pulling the cut line off course. This has been discussed in other threads. While moving the spindle closer to the Y-car motor will reduce the error some, it will not reduce the error as much as adding a second Y-car motor. But it is definitely a less costly fix. There is one more modification that I will be making to reduce this error more but I won't go into that at this time.
The first thing pictured here was to extend my C-channels the additional 2 feet needed. To do this has simply welded an additional 2 foot piece of C-channel pictured here.
305
The most time consuming part of changing the rails was re-drilling all the holes. It just so happens that the 12 and 14 foot rails are mounted using the same number of bolts so naturally the holes did not line up.
Here is a picture after the change. As you see at this point I do not yet have any of the table parts constructed. Aside from extending the table I will also be mounting my indexer in this location. Hopefully I will find time in the next couple of weeks to complete the rest.
306