1st Multi-Piece Job Requiring Rotary Attachment

[Dane Fuller]

I wasn't exactly impressed. There were 24 pieces and it only took 17 seconds per. Before one was finished, I was able to have the next one ready so it didn't sit idle more than a few seconds between parts. The results were pretty good except on the last 4. It seemed to stop rotating toward the end of each one and the image was distorted. I was thinking it might be a stepper motor overheating thing. Is this a common occurance?

[Allen Isakson]

As for me, I would not think thats the problem on a epilog. Last Month I did 150 Pilsners glasses with double detailed logos. Ran non stop on a chinese machine without any overheating. Are you sure your having no slippage ?

[Dee Gallo]

Dane,

When I use my rotary, it always goes around and at the end of the engraving it rotates backwards to the starting point. Don't know if this is relevant, but it does not seem like your setup is working correctly. The only time I've seem distortion of the image is when the workpiece itself slips. Maybe you need to take more than a few seconds to place them in the clip - it could be that simple.

~ dee

[Dane Fuller]

I'm sure it could have been slippage but I never saw them do so. These were shot glasses and I couldn't use the clip. I imagine it was operator error. I was just wondering if it might be a common thing to watch for.

[David Fairfield]

Sounds like slippage to me, especially since it started towards the end of a run, when the wheels get a little dirty or damp. Just a little (invisible) dirt or damp is enough to cause slippage. It helps to keep the rubber rings very clean and dry. When doing production runs, I periodically remove them to wash & dry.

Side note, I found the spring clip to be worse than useless. I've tried it on various glasses, but it only causes distortion.

Dave

[Chuck Stone]

another couple of things to consider (yes, sounds like it is slipping to me, too)
You want to make sure you clean the rubber parts with just water. No alcohol,
and this can dry out the rubber and it will start to lose traction. Also, making
sure that the rubber is clean is important. Rubber grips because all the little
valleys in the surface create suction. Dust can fill in those valleys and the
rubber can lose its ability to grip. A damp cloth pulls out the dust and you're
back to normal.
Another thing to check is any belts on the rotary (not sure how yours works)
and any drive gears. If a set screw works its way out or loosens, it won't get
full drive.. but it might not stop altogether, either. Same with a belt that loses
a tooth or two. OR if the belt has no teeth but drives by tension, that damp
cloth again...

[David Takes]

I'm not sure what type of glassware you were engraving, but it is not uncommon for a manufacturer of glassware to coat the finished product with a polyethylene wax for scratch resistance. I've received other products with what seemed to be a thin oil-based coating. If the glasses were not cleaned prior to engraving, these coatings could have accumulated on your drive wheels and added to the slipping problem.

[David Fairfield]

Yes, good point about the glasses being coated. I forgot to mention, I run my glasses through the dishwasher or rinse with a water + vinegar before engraving, and that helps some, too.

[Chuck Stone]

+1 on the coating point..
I thought I was doing OK engraving glasses without air assist
until I looked at my lens. looked like a snowstorm in there!

[Bob Davis]

The standard clip on the Epilog rotary isn't very effective. The wheel needs to be larger (for more spring pressure) and also needs to extend further into the mouth of the glass.
A quick and easy modification to achieve this is to cut a 30 or 40mm circle from 3mm acrylic, and include a hole in the centre that fits snugly over the protruding knob on the middle of the wheel. Use some double-sided tape to attach it and away you go.

The rotary attachment is a bit lacking in development in my opinion. They don't seem to have changed in 12+ years and I have often had to come up with special jigs, add weights or use bolsters to achieve the desired result on items that won't readily fit. I'd like to be able to lower the RHS wheels (as well as raise them) for a start, and I would also like the movement of the glassware to be more controlled rather than relying on friction against a tiny piece of rubber. See notes on slippage above. An extended clip (with wheel) would also help to exert pressure nearer the centre of the glass and avoid the twisting effect on longer pieces.

[David Fairfield]

An option to fit the Epilog rotary with something like a lathe head would be so great. The rubber wheel design seems perfect in theory, but in the real world there is wobble, slip and play.

Dave

[Dane Fuller]

Thanks for all the suggestions. I'm sure it was slipping now that I have read all the comments. I wasn't aware of glassware being coated before shipment or how a little moisture can cause problems.

BTW, my client was very happy with the results on the 20 that made the cut and, even though I offered, she didn't want me to replace the 4 bad ones. I guess I dodged what could have been an irate customer because she just called and is sending more projects later in the week. I'll chalk the shot glass job up in the lessons learned collumn.

[Wil Lambert]

One thing I do is run double stick tape wrapped on the rotary wheels. Works better than the rubber and saves all the cleaning problems.

Or you can find silicone orings to replace the rubber ones. Silicone is sticky naturally.