Need stronger Indexer for off center work

[SpearForBrains]

I have just priced out a new cobra and will be selling my stinger 3. I am upgrading for 3 reasons.

1)ATC
2)oscillatring knife for cutting prepreg fabrics
3)a better indexer

But I need some help from this forum. I run a 4th axis in my HAAS mill and it is rigid as can be. But when I use the recoil with a big bit, like a surfacing bit, the bit grabs the material and the stepper motor in the recoil just isn't strong enough and all hell breaks loose. I am not just doing 3D work on the centerline, I need to work 2-3 inches off the centerline. Lots of torque.

So I want to use a rotary from a milling machine on the Cobra. Maybe a 5C collet rotary so I can quick change fixtures.

I have searched the forum but cant find any info on beefed up rotaries. And I dont need a full indexer. I am essentially just doing flip operations but the parts require 9 tool changes and a flip. Each part. So I would like to load a blank and hit cycle start and walk away to run one of our other machines. This would also open up the options of adding a trunion type fixture plate.

Any help in integrating a solid indexer is greatly appreciated. Thanks!

Brad

[Logan Y]

I don't have anything helpful to add but let us know how it works out. Gary might be your best option for help. I know he's sold different add on indexer/lathe models in the past and he might have an idea on how to do what you are looking for.

Also you can try asking Camaster if that is something they'd be willing to do if you are buying a new Cobra anyway.

[TimPa]

if the indexer can't hold the piece in your hi-torque tool jobs, you may consider applying an indexing wheel to the material - between the centers. you would disable the a axis when using the wheel. the wheel would have holes at predermined angles of rotation, and you would pin the wheel at the needed position when machining, which in turn would hold the workpiece rock steady. my rockwell lathe has this feature built in.

i don't think it would be that hard to build and incorporate... my $0.02

[rcrawford]

You could use a servo motor, as it would then adjust itself to remain in the correct position. Go for a larger servo motor, or lower gearing if you need more holding power. Sound like you don't need speed, so you could really gear it down to get more holding power.

But might be easier to just use index pins, like you would find on a lathe, as TimPA suggested. I removed my indexer and bolted my lathe to the floor in its place and I find that a lot handier than the indexer. I just lock the lathe spindle in position when I need it fixed, then rotate it manually and lock it in again. Takes about 3 seconds, but you have to babysit it a little more than you would for a 4th axis.

I use the lathe because I like it to free spin while I cut from the side for round objects. WAY faster than indexing on a 4th axis.

[SpearForBrains]

Essentially this photo shows what I am trying to do. Camaster says they cant do it. They just want to stick with their ornamental recoil 4th axis. So it looks like I will be doing manual flips. Not the end of the world, but I was hoping to make al our parts in one operation.

[Jim Becker]

I can't see the detail in your photo because it's so tiny on a 4K monitor, but the recoil system does indeed have its limitations. There's no harm in you getting creative for sure, to make a solution for what you want/need to do. Russell did that for his particular application and it worked out nicely.

[kjoiner]

Regarding using a servo motor, you might want to look at Tecnik servos. They make a line called Clearpath and have some that are supposed to be drop-ins for stepper motors. The benefit is that you get an encoder that will provide feedback to keep the motor in position. The one caution is that if the bit snags and the motor holds its position, then something else in the rotary axis might give way.
We are using one of the Clearpath motors for an entirely different application but so far so good.

Kyle