Ogre 4x8 turn key plasma table

[_Ogre]

tried the rotary head today with out any luck. loaded a cope program in the rotary mach3 program. the y axis took off, y axis should be centered on the tube and all cutting done with x and a axis. tried the tube cut program y axis took off again. so quit that and left you a voice mail. i'll try to call bulltear on monday.

on the plus side... table is working well. cut the mrtbronco4 door roll bar signs and a receiver mounted 3rd brake light cover for the 66 bronco we have in the shop. also cut out some hole test and line test drawings. everything working well. thumbs up on this table. :D

mrtbronco4


line test (drawing not to scale)


hole test (drawing not to scale)


did some testing on cutting holes in 16 ga 304 stainless exhaust tube just using the x,y,z axis's and the dthc with moderate success.
this is for welding in the H on an H pipe exhaust; normally we'd use a 2.25'' hole saw at $12 per for maybe 10 holes (5 systems)
had to use settings for 10 ga steel to complete the cuts down low. lots of dross, but it's easy to clean off.
the holes are 2.25''x1.75'' elliptical





hoping to get the rotary head going on monday to cut out the actual H pieces

[jeepsr4ever]

We may not be open on Monday. To use the rotary you must first open the rotary button and not the bladerunner button. Our weather is going to be in the 30s below zero and our state governor shut down all public schools. This means no workers. I may be in briefly so leave me a message.

[_Ogre]

the cold weather is headed our way too. had to leave the water running or we lose water in the shop around zero.

i used the rotary program. probably a setup issue to lock out y axis. i did not find any info on the rotary program in on the mach3 website or in the mach3 manual. i had to manually load the pierce height in the setup tab. i entered the tube diameter in the main screen and zeroed z axis on the tube surface. is there any documentation for the tube program?

[jeepsr4ever]

If you check the setup area and there should be a blurb on it from your desktop (Setup rotary). If Y axis is moving then we most likely have to toggle the outputs in Config/ports and pins and make sure the X is moving for Y movements for rotary only(But I don't believe that is ever setup wrong). The A axis and X axis move the gantry down the long travel. The A axis is hardware slaved to the X axis which is unique to rotary cutting machines only. So if Y is moving we need to verify the output for rotational movements are not outputting to Y BUT my suspicion is that the interface for testing it looking for a Y axis limit switch. So if you go through to the final test you can opt out of finding the limit for calculating diameter through the test button. This opts out of looking for a Y axis limit switch. The reason we don't use the Y axis home switch for rotational machines is because you can mount it anywhere and often it will not be parallel to the X axis.

[jeepsr4ever]

Rotary also requires attention paid to acceleration rates. So when you get your tube diameter and go halfway through the test you need to go into the config/motor tuning and see what A axis says for acceleration. The deal is that if all axis are not tuned to the same acceleration rate your cut geometry will not be accurate. So you will need to change the X axis to the same acceleration as the A axis. Often times the wizard will drop acceleration so low it doesn't work well with THC on. Tweaking the acceleration to a usable number with THC will allow you great cuts. At a 2" to 2.5" diameter that should not be a problem. The ratio is 21-1 on the rotary so the max cutting speed on a 2" diameter is around 200ipm and less as the diameter decreases.

[_Ogre]

not sure how to ground the rotary head, i assume grounding to the table would weld the bearings in the rotary head.
similar to welding on a rearend with the ground clamp on the bumper

this is the interface i'm dealing with (image borrowed from the internet)
i have the round pipe/tube active, diameter set for 2.55''.
though instead of the calculate/touchoff/setup buttons on the right,
there is a tube cutoff function that you set the length and number of pieces.
the rotary read out does not change as the head rotates either

[jeepsr4ever]

If the rotary doesn't move then its mapped wrong. You can go to config/ports and pins/Motor outputs and map A axis the same as B axis.

[jeepsr4ever]

My guess is your not using the Rotary post processor in sheetcam.

[_Ogre]

no, i wasn't using the rotary post processor. am now

but when i do it swaps the axis's. i did a tube cutoff and instead it slit the tube lengthwise.
i rotated the dxf in sheetcam -90* and it cut semi correctly.
the dxf line is 7.96'' long, which is the same as the circumference of the 2.54 tube
but the straight line cut lacks 5/8'' of cutting the tube. is this more motor tuning issues?



back on the axis swap issue with x and a axis and not rotating enough.
i cut a circle out of 2.5'' tubing and it cut as an oval, not enough rotation again
also the cut should have started on the left of this picture instead it started at the top where the torch is.

notice my ground strap. 1/2'' copper tubing hammered flat and clamped to the side of the water table with the ground clamp.



also want your opinion on the chuck location; should it be over the water like this
water splash is already rusting the chuck and makes that end of the table of limited use.



the dthc needs some tweaking too.
for some reason the torch is diving and hanging on the rotating tube and x axis movement.
the cuts above were done with the dthc off, with the dthc on the hole is G shaped

will call you in the morning, just wanted to post these pictures so we could discuss them tomorrow

[jeepsr4ever]

I will check out the numbers for reduction (It is either that or your loosing steps in the rotary motor (shouldn't be the case) or your lines aren't long enough (DXF)). Also with a chuck mounted you may never get full travel it just doesn't work that way with rotary cutting and sheet cutting. You could modify the mount to sit back further but that limits short piece cutting. There are a couple of ways to deal with running a full sheet. One is to take the chuck off the shaft by removing the 4 3/8 bolts and the other is taking the whole rotary off. You probably loose 1-2"s of travel in 99"s so theoretically maybe an inch of travel if that. If you move your gantry all the way back how much travel do you loose?