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Thread: Cross Shaft / Rack and Pinion Upgrade

  1. #1
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    Cross Shaft / Rack and Pinion Upgrade

    I have a DynaTorch 5' x 10' Cutting table (not dropside) 5' x 10' AirHandler table, Gantry with cross shaft, Hypertherm 1250, Speedaire Air compressor and Speedaire Dryer. The table works well thanks to good tech support provided by DynaTorch. I bought it used and have upgraded a few components. What I am looking at doing is improving the movement in the x Axis, the Torch ratchets slightly as it moves. I replaced the gears on the cross shaft with Nylon gears and this smoothed the movement out considerably. However, I am noticing that that the gears are beginning to wear and the ratcheting is returning. I called DynaTorch and I can upgrade the machine. However, its too expensive for me at this time. I have been pondering some solutions to the problem and wondered if anyone has come up with a economical permanent fix. Some ideas I have are to replace the rails that the roller bearings ride on with linear guide blocks and rails , the cross shaft would remain the same with metal gears. The linear blocks and rails ( McMaster-Carr ) would have tighter tolerances like the Y axis has thus running smother. Please pass on any thoughts do not want to invest the money if this has been tried.
    Last edited by AZBBQGrills; 02-26-2011 at 11:58 AM.


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    AZBBQGRILLS,

    Having had the same table design as you I can understand what you are talking about. There is no easy fix. I would recommend you add a X axis slave motor and another piece of gear rack to match the master side. This would require very little work to add the rack.

    The gears and rack on your table do not have precision tolerences. This causes one side of the gantry to travel a difference distance than the other. In addition the gears are very noisy and rough as they travel along the racks.

    That said I did get alot of use from mine before I upgraded to dual motor X axis. With some fine tuning I got it to work pretty well. The 2 things that helped most were;

    1. Park the gantry in the middle of the table and adjust the cross shaft alignment so there is no wind up or (ratcheting). This will minimize the ratcheting effect when going from end to end of table travel.

    2. The cross shaft pinion preload is critical. Put just enough spring load on the pinion so it seats in the gear rack. This will require VERY light pressure.
    Keep the rack well lubed with a dry silicone type lubricant so it does'nt attract dirt.

    Magma-joe


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    What do you think it would cost to add the other motor and track? Would this eliminate the cross shaft? Would I need to by it through DynaTorch or is there another source I could go through. Would you consider modifying the roller bearings that the gantry rides on?


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    AZBBQGRILLS,

    I would not consider changing the V track / wheel setup. They work very well and are smooth. Dynatorch improved the later designs with the addition of 2 cam followers which hold the V wheels down against the V track. I included a picture.

    In order to add the slave motor you will probably need a bigger power supply, a new gear box with the same gear ratio as the master X axis, a new motor and pinion gear, an add a motor cable, fiber optics cable, V wheels & track and another gear rack. The added motor will eliminate the need for the cross shaft and double the power available to move your gantry.

    I would go through Dynatorch as they know eactly what you need and can help you through it. I bought all my upgrade parts from them and Leon's support made it all come together. It is a totally different machine with the dual X axis motors.

    As we discussed before you are welcome to stop and look at my machine to get some idea how the slave motor is added.
    I have seen your machine several times at the previous owners business. I sold him my torch slide when I upgraded to Dynatorch's latest style. As a matter of fact I purchased mine after his demo.

    Magma-joe
    Attached Thumbnails Attached Thumbnails Cross Shaft / Rack and Pinion Upgrade-cam_follower.jpg   Cross Shaft / Rack and Pinion Upgrade-c_follower_2.jpg  
    Last edited by magma-joe; 02-28-2011 at 07:45 AM.


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    Went in today and cleaned the rails adjusted the tension on the cross shaft and removed 80 percent of the ratcheting. Very pleased. I am going to give Leon a call and see about adding the other motor. I recently upgraded the interface console. The interface console is the power supply I believe. I did this with the intention that if I upgraded it would be one less component I would need to buy.
    When I spoke with dynatorch I was quoted 9 grand to upgrade the machine. I am very satisfied with how it runs. So when you saw the machine was the air table hooked up to a dust collection system? I have the dust collection system and intend on using the direct drive blower to hook up to the airhandler table. The dust is becoming unbearable.


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    Quote Originally Posted by AZBBQGrills View Post
    Went in today and cleaned the rails adjusted the tension on the cross shaft and removed 80 percent of the ratcheting. Very pleased. I am going to give Leon a call and see about adding the other motor. I recently upgraded the interface console. The interface console is the power supply I believe. I did this with the intention that if I upgraded it would be one less component I would need to buy.
    When I spoke with dynatorch I was quoted 9 grand to upgrade the machine. I am very satisfied with how it runs. So when you saw the machine was the air table hooked up to a dust collection system? I have the dust collection system and intend on using the direct drive blower to hook up to the airhandler table. The dust is becoming unbearable.

    AZBBQGRILLS,

    The dust collection system was always hooked up when I saw the machine. It was a very elaborate system with a huge Torit brand dust collector standing outside the building. They cut many parts from galvanized sheet metal so dust collection was extremely important.

    I still have a piece of 12' gear rack and pinion gears left over from my upgrade that are a match to your machine. I also have many other parts like the complete gantry, and drop side truck assembly which Dynatorch used to convert their tables to a drop side.

    Your machine is a testament to the durability of Dynatorch machines. The previous owner purchased that machine in either 2004 or early 2005 and it is still going strong making parts. I purchased mine in 2005 and when I added the slave motor I reused the existing XYZ motors.

    Dynatorch has made many improvements to their machines over the years but the improvements have been backwards compatable with older machines.

    Magma-joe
    Last edited by magma-joe; 02-28-2011 at 07:38 AM.


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