Easy newbie question on rotary attachments (chuck vs. roller)

[Ted Liberty]

Hi,

I am about to order a laser engraver with the possibility of a small retirement business sometime in the future. Brand new to this (no experience, jumping right in), and although I've done quite a bit of reading, I'm a little confused about the rotary attachment. I thought I would need a roller style as I was considering glassware, bottles, etc. I read one post where someone said they never use their roller style, always the chuck style. It is not cost prohibitive to get both, but no need to have one collecting dust. And perhaps I may need both sometime in the future.

I appreciate any thoughts on this.

Thanks,

Ted

[Joe Hillmann]

Are you trying to start a fight with your first post? :)

I am biased, I have a jamb type rotary, with that said, here goes....

Some items are easier to do with a chuck/ jamb chuck type rotary, such as wine glasses, large glass mugs with a heavy handles, very light items, narrow disks, spheres, and items that need more than one pass (because it will always go back to exactly zero.)

A roller type chuck works much better for longer items such as baseball bats or pool cues, probably other items as well but those are the ones that come to mind.

Although with the proper jigs(made with the laser) you can do anything with either type of rotary.

With all that said, if you search the fourm you will find several threads asking how to convert a roller rotary to a chuck type but none asking how to convert a chuck type to roller.

Also, once you start using a roller rotary for something it wasn't intended for you need to do some math to figure out the ratio of the diameter of the item to the diameter of where it is rolling and stretch your image in the y axis by the same ratio, With a chuck type you just tell the laser the diameter and it takes care of the math for you.

[Ted Liberty]

Sounds like great advice, Joe. Thanks!

[Glen Monaghan]

Also, once you start using a roller rotary for something it wasn't intended for you need to do some math to figure out the ratio of the diameter of the item to the diameter of where it is rolling and stretch your image in the y axis by the same ratio, With a chuck type you just tell the laser the diameter and it takes care of the math for you.

Maybe that's right for a Universal, but it sounds bass ackward to me. There have been several discussions about rotaries and how a roller type works without regard for object diameter since the object's circumference moves the same amount as the rim of the roller moves, while the movement of a chucked object's circumference depends on its radius because the object rotates at the same rate as the chuck. With a roller, the object only rotates at the same rate as the roller if its the same radius (diameter) as the roller. Otherwise, there is a "gearing" effect on the rotation.

[Joe Hillmann]

Maybe that's right for a Universal, but it sounds bass ackward to me. There have been several discussions about rotaries and how a roller type works without regard for object diameter since the object's circumference moves the same amount as the rim of the roller moves, while the movement of a chucked object's circumference depends on its radius because the object rotates at the same rate as the chuck. With a roller, the object only rotates at the same rate as the roller if its the same radius (diameter) as the roller. Otherwise, there is a "gearing" effect on the rotation.


You may be right. I guess I am comparing Universal to Epilog I just assumed that Chinese machines with chuck type rotaries would have a driver programed to work with that type of rotary, if not ignore my last paragraph.

[Rodne Gold]

I paid about $300 for both a chuck and a roller setup..I have never used them as we do little rotary work and if we do , I do it on my GCC spirits , but it was so cheap I decided to get both just in case. If you DO intend to do rotary work of any sort - get both if they in that ballpark , it gives you maximum flexibility and having one at $150 or so gathering dust wont be a train smash..

[Peter Odell]

I have both I use the roller for large Items and use the chuck for pens and smaller Items. I would go with both when you order the machine

[Ted Liberty]

Thanks for all the great responses. Perhaps this wasn't quite as easy a question as I thought! I'll go with both and experiment.