Grizzly Rotary Table c/w DRO
- Thread starter Jmccrack
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I like old fashion rotary table
No electronics go bad I had mind for over 30 years.
I just think how many TV I gone through in 30 years
My rotray still works same as day I purchase it.
Dave
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I have a lot of the type tools and tooling. They sill works great the it was made.
I know that some can use and or learn how to use the old tools.
They pay the price
Dave
Nothing wrong with old fashion especially considering that some of use use century old machinery.
While true there us no dismissing the fact that something as simple as self feeding is usually better than manual feed.
On the other hand keeping sharp with the math involved in using a manual table is a huge benefit. The fact is there are trade offs both ways. If the controller is done properly it will save time at the expense of skill atrophy.
Ive seen mechanical devices break or wear out before the controls have failed. Of course this is a high end FANUC controller but the point is long lifetime for electronics is very possible.
If money to replace the electronic type buy one it only $650.00 for a ,4" rotray table.
If had I would too but and when stop just buy new one
That what I do with $100.00 electronic today.
Dave
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Once you get a little older and start to lose your irreplaceable faculties (arms, legs and brain), you will soon realise just how useful these NC controlled bits are.
Without them for power feeds on all my machinery and RT's, I would have had to give up model engineering many years ago.
It is only because of my lack of mental retention that I haven't gone the whole hog of full blown CNC.
Long live Divisionmaster.
John
Without them for power feeds on all my machinery and RT's, I would have had to give up model engineering many years ago.
It is only because of my lack of mental retention that I haven't gone the whole hog of full blown CNC.
Long live Divisionmaster.
John
Jmccrack
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The different thoughts and opinions are great. I am a machinist for longer than I care to remember. I am of two minds as well. Using a manual RT does indeed work the brain cells. But so does the NC RT. The one thing I do not have are index plates. All the work I have done to date on the RT is done using the vernier scale (which can be very accurate if used properly). I use a combination pallet and 3 or 4 jaw chuck on my RT now. That’s why I was wondering about the torque that is Nema 23 stepper motor develops. If it is enough putting a 1” Tk -pallet on the 4”RT say 6” x 6” sq maybe even 8”x8” sq would give me a lot of surface area to work from and having the mass of the 1” tk pallet should give me the rigidity I need. If all that did work it would sure make some of the flywheels I build now be a lot easier.
Jmccrack
Sizing a motor is a bit of an art and with steppers you get a variety of torque ratings in a frame size. Combine that with a worm reduction that can come in different ratios, you end up with a lot of variables. Given that i would have to say that you can power the rotary with a size 23 stepper. Remember the table is otherwise operated by hand from rather small cranks.
Will it work well? Again a lot of variables to consider. For one the power supply has to match the motor and that rating is based on motor inductance. The quality of the stepper driver is also a factor. A properly rated power supply assures that you can get maximum performance out of the stepper.
Max performance is pretty important due to the high gear reduction in most rotary tables as torque rolls off pretty quickly with stepper RPM. In other words you could be moving pretty slow under load if you can't run the motor under the best operating conditions.
In the end the most important thing for stepper driven systems is to avoid lost steps. Sometimes that might require a reduction in stepper RPM. Put a large enough auxiliary table on a rotary and eventually you will have power issues. Just realize that power demand is a function of depth of cut so there is more than one way adjust a system to run reliably.
As for rotary tables and having auxiliaries bolted to them, that is pretty common in industry. At least before the wide use of CNC. At the place i worked they use to have (all gone now) a few rotaries setup with permanently attached auxiliary tops. You do need to make sure the sub table is suitable for the job.
Sizing a motor is a bit of an art and with steppers you get a variety of torque ratings in a frame size. Combine that with a worm reduction that can come in different ratios, you end up with a lot of variables. Given that i would have to say that you can power the rotary with a size 23 stepper. Remember the table is otherwise operated by hand from rather small cranks.
Will it work well? Again a lot of variables to consider. For one the power supply has to match the motor and that rating is based on motor inductance. The quality of the stepper driver is also a factor. A properly rated power supply assures that you can get maximum performance out of the stepper.
Max performance is pretty important due to the high gear reduction in most rotary tables as torque rolls off pretty quickly with stepper RPM. In other words you could be moving pretty slow under load if you can't run the motor under the best operating conditions.
In the end the most important thing for stepper driven systems is to avoid lost steps. Sometimes that might require a reduction in stepper RPM. Put a large enough auxiliary table on a rotary and eventually you will have power issues. Just realize that power demand is a function of depth of cut so there is more than one way adjust a system to run reliably.
As for rotary tables and having auxiliaries bolted to them, that is pretty common in industry. At least before the wide use of CNC. At the place i worked they use to have (all gone now) a few rotaries setup with permanently attached auxiliary tops. You do need to make sure the sub table is suitable for the job.
Jmccrack
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Hey guys I got the unit today. It is all that was advertised. Workmanship is not bad. The table is flat to the mill bed in the .0002” range. The #23 Nima stepper motor has more torque than I imagined. More than enough to mill with a 1/2” endmill. I am definitely going to put my 6” 3 jaw on it along with a nice size pallet. I am pretty sure the rigidity will be there.
