Rotary Question

[John W. Love]

Hi all,

I've got an order for some champagne glasses for a wedding but we do not have a lens that will allow us to do flutes. My manual says the minimum diameter we can do with our lens is 3". My question is does anyone know how written in stone this is? I was looking at some tulip glasses with a 2 7/8" diameter but wondering if the 1/8" is gonna break me (literally). The manual says the reason for the restriction is to prevent the lens colliding with the item. I haven't done anything on the rotary except for a few wine glasses and I tried suggesting regular wine glasses but they want champagne flutes... Anyone know??

Thanks,

~Alicia

[Niklas Bjornestal]

I have engraved stuff about 1" in diameter with rotary on a laserpro mercury, and i think the rotary attachment should be simular. You just have to keep the engraving far enough from the rotary attachment so that the lens doesnt hit it.

[Brian Robison]

Are you going to engrave all the way around the glasses?

[John W. Love]

I will be engraving text with simple graphics on the glasses...kind of a weird deal but they want 4 names and a date. They are for a wedding and the bride and groom each have one child whom the other is also "marrying" ...not sure how that works lol. Anyway on a flute type glass I'm not really sure how that much text will look, I havent gotten the details yet and I'm kind of hoping for short names...but I'm guessing it's going to go at least most of the way around the glass.

[Darren Null]

Should be OK...I've done pens on mine. You might need a spacer though:
http://www.sawmillcreek.org/showthread.php?t=71197&highlight=rotary

[Rick Irwin]

Perhaps on the base or bottom of the glass?

Make the type circle around the base. Remember to reverse type when engraving on back side of glass.

[John W. Love]

So, if I'm understanding this correctly, the problem is not the head hitting the glass and breaking it but the head hitting the rotary attachment itself and thus causing an x motor error? If this is correct then shouldn't I be able to do champagne flutes since they are long and thin?

Here's a pic of what I'd like to use since I can't find the 9 oz tulip glasses anywhere that won't require me to buy an entire case and I only need 4...which means I'd either have to charge the customer more for the job than I think they will pay or I wouldn't profit on the job. I can get these locally pretty inexpensive and they sell them individually if this will work...

[Garrett Nors]

I don't understand this very much... what does your rotary attachment look like? I can do pens on the rotary all day and my laser still has room to move. The rotary attachment itself is under whatever item I'm engraving, thus that would make it the "table" and it would be impossible for me to hit while engraving anything that wasn't a negative curve (which would be impossible :D)

[Darren Null]

So, if I'm understanding this correctly, the problem is not the head hitting the glass and breaking it but the head hitting the rotary attachment itself and thus causing an x motor error?
If your rotary is like mine, then yes. (see side view, below)

If this is correct then shouldn't I be able to do champagne flutes since they are long and thin?
Yes indeed. With the only proviso being that -if your rotary is like mine- you don't go too near to the top of the glass. Too near being defined as being the distance between where the laser beam comes out of the head and the left edge of the head, plus a bit for ramping. That's assuming your glass is in the same way as the diagram. And you can always use spacers if you want to laser the top of the glass.

@ Garrett- The Mercury (and presumably Pinnacle) rotary is different to the 'rest upon' type from other manufacturers. It's a rotating rubber chopped-off-cone-thing at one end, and a freely-rotating rubber pad at the other. The rubber pad moves in the x-axis and locks in place to secure the item to be lasered. There's pluses and minuses to the design. the big minus is that you ARE, at some point, going to smack the head against one end or another (I've done both) and earn yourself an x-motor error.

[John W. Love]

Thanks Darren! My rotary attachment is, indeed, just like the diagram that you posted. I will go with the regular champagne flutes and probably make a spacer so that I have less risk of hitting the head against the attachment.

One other question, John just informed me that the theme of the wedding is centered around the Texas flag and the customer wants a graphic engraved on the glass that is in the shape of Texas but shaded similar to the flag...Does anyone know if this type of shading would show up at all on glass? I haven't engraved anything except text and simple graphics before on glass so I'm just not sure. I guess worst case scenario is I buy an extra glass and try it but thought I'd ask since you all are so knowledgeable about so many things!

~Alicia

[Darren Null]

Glass engraving shows up white. The closest you're going to get, I think, it to use 2 different (densely packed) textures to represent the colours. Or if you wanted to be smug, you could use coloured rub'n'buff. Or glass paint.

EDIT: Reconsidering the size of your glasses and the shape of Texas, the result is going to be too tiny to mess around with like that. I'd just put the lines and the star in and leave it to the customer to imagine their own colours.

EDIT AGAIN: I noticed your glasses curve in a little. You can get 'round the bend' as it were by adjusting the head up and down a little and running the job several times. If you're not careful, it's possible to go too low and knock the glass out. Done that. Also if trying to go low, I unscrew the autofocus probe and stow it in the 'up' position (while being incredibly careful to remember to put it back down again when finished!!!!).
This bit may not be true for your rotary because mine is vintage; but if I use the up/down on the rotary, mine can't find the home position again. So I don't.

[John W. Love]

That's kind of what I was thinking on the graphic...maybe just an outline with the lines and a star...Thanks again Darren!

Our auto-focus seems to have gotten broken at some point so it's always in the up position and we manually focus anyway...but you are right I remember before it broke it getting in the way on objects in the rotary attachment.

[Andrea Weissenseel]

My Spirit uses the same type of Rotary attachment, like on the picture. I'm doing a lot of glasses especially champagne flutes for weddings and never had problems with them. My flutes have a diameter of 60mm (on the top) since the flutes are not straight at the top I don't get near the rotary with my laser head.

Just explain to your customer that you can't fit a bulldog in a dollhouse ;) and try to get a compromise by putting just the names on glasses and making an additional bottle of champagne or even better a champagne cooler/bucket where you can easily engrave the flag theme

these are the glasses I'm engraving

Andrea

[Albert Nix]

You had better watch the lens carriage. What lens do you have? If the longest focal length you have is the 2" that comes std with that machine, you may be pushing it. I have the 2.5" and 4" lens and if that is the glass that it looks like you may need the 2.5". I have raised the auto focus out of the way to get clearance but be careful doing that as it can get you in trouble later down the road. You can get close to the glass with any lens but what will get you is when the head is sweeping the y axis it will move past the image area and can hit the rotor head. focus on the glass then manually move the head all the way to left to be sure it clears.

[Garrett Nors]

If your rotary is like mine, then yes. (see side view, below)

Yes indeed. With the only proviso being that -if your rotary is like mine- you don't go too near to the top of the glass. Too near being defined as being the distance between where the laser beam comes out of the head and the left edge of the head, plus a bit for ramping. That's assuming your glass is in the same way as the diagram. And you can always use spacers if you want to laser the top of the glass.

@ Garrett- The Mercury (and presumably Pinnacle) rotary is different to the 'rest upon' type from other manufacturers. It's a rotating rubber chopped-off-cone-thing at one end, and a freely-rotating rubber pad at the other. The rubber pad moves in the x-axis and locks in place to secure the item to be lasered. There's pluses and minuses to the design. the big minus is that you ARE, at some point, going to smack the head against one end or another (I've done both) and earn yourself an x-motor error.


Excellent illustration!! :D

[Darren Null]

Thanks. If I could be bothered I should update it to contain a speech bubble with swearing; and also an arrow pointing to the x-motor error. Or not. Probably safest with the SMC TOS if you imagine your own swearing.

[John W. Love]

Thanks for all the wonderful advice. Darren, I was going to download your CDR of the spacer,but I keep getting an address not found error. Is that the correct address that is listed or has it been updated since it was posted? Would love to try that out and see if that doesn't make quite a few things easier for us.

Thanks,

John

[Darren Null]

The cdr was attached to the board, but it was a while ago. Must have been 'housekept'. I made another one for you. Tis easy enough. The circles should be the rim of your glass size + a little bit (couple of mm- enough that you get a grip, not so much that it's another thing for your head to thwock). The 50mm spacing should do you for most things.

[John W. Love]

Thanks Darren, That is awesome, I really appreciate it. I was trying to figure out when I was going to have time today to design a spacer, so you really came through. Funny, today is my day off, but I am busier than I normally am when I work. No rest for the wicked.

John =)

[Darren Null]

No prob. The spacer cdr is for 3mm thick material (I'm in europe and we do all the millipedes and centipedes measurements here). It's very +- friendly, so you can just burn the cdr with imperial stuff...the only thing you have to be careful of is getting the slots in the round bits symmetrical- everything else is open to interpretation and using your ninja senses in a "that'll do" fashion.

[John W. Love]

Thanks a million, Darren! We modified the spacer by sizing it down to the diameter we needed and adjusted the holes then used wood glue to put it together and felt on the ends...it worked like a charm! I did, however, earn myself one x motor error *insert swearing here*... My fault though, since I have not had the best luck with the rotary before and I actually managed to get the very first glass in there and position it correctly the first time without wasting a glass. Sounds great, right? But then I tempted the laser gods by patting myself vigorously on the back while I left the room to go get the other three glasses I needed. I came back just in time to hear that awful thwack and panic as I wondered if the glass broke when it fell out of the rotary. What happened was that it did just fine on the top edge where we had the spacer, but when it finished engraving the head moves all the way to the right side of the table...it couldn't clear the other side of the rotary attachment. The good news is that I saw what happened and was able to prevent it on the other 3 glasses by standing there with my finger on the stop button and pressing it the instant I saw the machine stop engraving and start moving to the right.

The glasses came out beautifully, I'll post pics after John gets home from work and tells me what he did with the cable to connect the camera to the computer! Again, many thanks for the help!

~Alicia