[Marti]

After all this time, I think I will be starting my cnc router soon even though my workshop hasn't been wired yet. I will be adding a 4th axis later so I'm taking that in consideration with my build. I like the front axis of landarts CRP PRO4848. Has anybody else built in a 4th axis to the front? I'm wondering how many inches are extended on the sides to accommodate mounting the lathe.

[B landarts CRP PRO4848][/B]

[ http://www.cnczone.com/forums/cnc-ro...-software.html

I really like this one mounted against the front wall


and alternatively this one which mounts across the front


At first I was thinking of having a 4th axis that I could mount and unmounts, but these would not take up much space and once it's mounted it's done.

Any ideas or opinions?

[pippin88]

I haven't done it yet, but I designed my machine for a front mounted rotary axis. Should allow approx 1200mm long, up to 150mm diameter pieces.

I think it is a good way to do it.

[aarggh]

The way you've shown the model the gantry sides will have a tremendous amount of flex, these need to really be stiffened up well along the insides, and on the front/back edges to minimise flex. Also, go for good quality limit switches, the amount of damage that will be done under load if the gantry hits the extremes can be pretty bad. Other than just beefing the supports in general, fairly simple design that should work well.

cheers, Ian

[Marti]

I haven't done it yet, but I designed my machine for a front mounted rotary axis. Should allow approx 1200mm long, up to 150mm diameter pieces.

I think it is a good way to do it.

Thanks for the reply. I figure I would lose 6-8” on each end to the motor and mounting. With 150mm diameter, are you talking about from the center or 75mm?
Do you have a build thread or link to your router? I'd love to see how you built for the 4th axis

The way you've shown the model the gantry sides will have a tremendous amount of flex, these need to really be stiffened up well along the insides, and on the front/back edges to minimise flex. Also, go for good quality limit switches, the amount of damage that will be done under load if the gantry hits the extremes can be pretty bad. Other than just beefing the supports in general, fairly simple design that should work well.

cheers, Ian

Thanks for the reply. This is my design, I was just using it as a reference to the front mounted 4th axis. I'm not using aluminum extrusion on mine, I'll be using wood because it's cheaper. I know what you mean about limit switches. On another project, I had the small switches and had to go back and use the ones with a long arm. It made a big difference too. Do you have a link to your build?

What is the height of y'alls machines from the floor to the table top?


I meant to say this "isn't" my design.

[landarts]

Here is where all the information about the indexer and table build are. http://www.cnczone.com/forums/cnc-ro...ftware-10.html
I would be glad to answer any questions about table and indexer. Also there is no flexing in the gantry while using it with the indexer.

Attachment 292770

[Marti]

Here is where all the information about the indexer and table build are. http://www.cnczone.com/forums/cnc-ro...ftware-10.html
I would be glad to answer any questions about table and indexer. Also there is no flexing in the gantry while using it with the indexer.

Attachment 292770

Thanks, I really like the way the indexer is mounted on the front. What is the heighth from the top of the base to the center? I'm not wanting to do anything really big.

[landarts]

Not sure if I understand the question. The indexer is mounted slightly below the surface of the spoil board table so that I have not lost any of my upper table surface cutting area.

[Marti]

I tried to upload a pic, but it wouldn't work. But on it from the center point of the "pivot"?? to the rail it's 2.55 inches, so I'm guessing it could only hold a block 4x4? What's the largest piece you can turn and would you make it bigger?

[wizard]

After all this time, I think I will be starting my cnc router soon even though my workshop hasn't been wired yet. I will be adding a 4th axis later so I'm taking that in consideration with my build. I like the front axis of landarts CRP PRO4848. Has anybody else built in a 4th axis to the front? I'm wondering how many inches are extended on the sides to accommodate mounting the lathe.

This is a cool idea! I would be concerned about any limitations it may put on cutter use.

I really like this one mounted against the front wall


and alternatively this one which mounts across the front

These are the first examples I've seen of such a fourth axis approach. For a bit of last in versatility you have a fourth that is always ready to go. I can see where this would be very handy for many users.

At first I was thinking of having a 4th axis that I could mount and unmounts, but these would not take up much space and once it's mounted it's done.

Any ideas or opinions?

The only problem I see is if you have work that requires a cutter to come into the work from a horizontal center line. Only you know what your intentions are here. The other thing is structural integrity and a robust mounting & positioning arrangement for the tailstock. If these things aren't an issue for you then it looks like an inventive way to deal with an axis that often gets in the way.

[Marti]

This is a cool idea! I would be concerned about any limitations it may put on cutter use.

These are the first examples I've seen of such a fourth axis approach. For a bit of last in versatility you have a fourth that is always ready to go. I can see where this would be very handy for many users .

It's the best idea I've seen. I think landarts did great plans for it.