Using X axis table moter for knee X axis

[imatoymaker]

I have an old Bridgeport with an antique Southwestern Industries Trak controller. What I want to do with it is to basically make a horizontal mill out of it. We have done this on a manual level by just rotating the head 90deg. While this works on a 1 or 2 hole operation to do anything more than that is just a pain. We have several jobs that require mounting an angle plate, hanging the part off the table, and rotating the head which is equally a pain.

What I would like to do though is as we upgrade to newer equipment is to take that Trak and do this on a CNC level. Obviously this not only makes our end milling easier but opens us up to quote on jobs we would have previously not even bid on. Most of the mechanical I have already worked out but what I am not sure of is can I use the X axis table motor to power the knee which would now become the X axis.

Here are the questions I have. They are not in any particular order. If you have any that you can think of that I have not please let me know.

1. Would a larger motor be necessary?
2. If so, would this require some kind of interface to the controller?
3. I know the ratio is different. Would the controller be able to deal with that or would I need some mechanical solution for that?
4. I know that we would not be dealing with ball screws but would gravity take care of that situation for the most part? Most of the tolerance I have to deal with is +/- .005 or larger.

I haven’t done any concept drawings yet but would be willing to do so if anyone were interested in this idea. That is if it hasn’t already been done.

Thanks
imatoymaker

[greg b]

Hi imatoymaker it all sounds like it would work,I asked the same question about a bridgeport interact 1 mark 2 that i have ,the only differance is that my idea was to try and connect the 4th rotary axis up to the knee feed but no one seemed to have to much input on that idea.I cant see why it would be to hard with your idea once you work out the right ratios ,I know the motors that drive my interact table have quite a bit of grunt.I guess all you can do is give it a go, the upside of having a acme thread on the knee feed is that it can hold the weight of the table without winding back on the motor,with a bit of luck it will be the same pitch as your ball screws.Any ways good luck with your mod greg b.