Hole in middle centering ring?

[Iamtannorv]

Getting to building my LOC big nuke 3e and noticed there is a hole offset in the middle centering ring for the mmt, does anyone happen to know what it's for? It's not mentioned in the instructions... did they maybe just send me the wrong centering right?

 

[Sandy H.]

I'm not sure, but I've heard sometimes people put holes in confined spaces to allow pressure to equalize.

Either way, I think they might want to look for a different laser vendor, as the three rings you posted have various differences that would likely alert a typical vendor to a possible issue.

Sandy.

[edit 03/13/2022 @4:33pm: My comment above about laser quality has apparently ruffled feathers. That was not my intent. I am leaving the comment in place, as I'm not the kind of person who waffles or tries to hide behind a keyboard and change history, but my intent was to mention a possible quality issue and that was taken the wrong way. Additionally, the OP asked a question and my comment sidetracked the thread. I apologize for that as well.]

 

[mtnmanak]

I love LOC kits and have a bunch of them, but, as I have noted in build threads such as the Bruiser EXP, LOC basically has a bunch of generic parts and throws them together to assemble a kit. So, if they have a bunch of middle CRs and one kit needs a hole in it, it is often easier to put a hole in all the middle CRs of that size. I wouldn't get too wrapped around the axle if the parts you get don't exactly match what you think they should be. It also manifests itself in the fit of a lot of these parts. Be prepared to do a bit of sanding to make things fit. A Dremel is a good investment if you don't already have one.

In particular, see post #9 in the thread below:

https://www.rocketryforum.com/threads/loc-bruiser-exp-with-mmas-and-rnws.169277/

 

[Titan II]

Either way, I think they might want to look for a different laser vendor, as the three rings you posted have various differences that would likely alert a typical vendor to a possible issue.

You may want to do some research before you make such a statement. Hint...check the LOC site.

 

[Sandy H.]

You may want to do some research before you make such a statement. Hint...check the LOC site.

I run a laser every day. I would not ship product that looked like that. I see at least 2 issues with the product in the picture that can be resolved. If they outsource some or all of their laser work, they should audit the vendor. If they in-source all of the work, then they have an opportunity for improvement internally. I feel that I have done quite enough research to be extremely qualified to make such statements.

I was not attempting to bash LOC, as I own a handful of their rockets and enjoyed building and flying them. Every vendor has to question product quality every now and then and if they see indications that things are less than perfect, they should determine if there are areas for improvement. The set of rings posted show areas for improvement.

Sandy.

 

[rharshberger]

I run a laser every day. I would not ship product that looked like that. I see at least 2 issues with the product in the picture that can be resolved. If they outsource some or all of their laser work, they should audit the vendor. If they in-source all of the work, then they have an opportunity for improvement internally. I feel that I have done quite enough research to be extremely qualified to make such statements.

I was not attempting to bash LOC, as I own a handful of their rockets and enjoyed building and flying them. Every vendor has to question product quality every now and then and if they see indications that things are less than perfect, they should determine if there are areas for improvement. The set of rings posted show areas for improvement.

Sandy.

None of the rings pictured were unusuable, maybe some were prettier than others or whatever, but to most people they look just fine. I personally would have no issues using them, odds are they own their laser and it is not a high end commercial model but instead a larger hobby model ( (I maybe wrong, but rocketry vendors are not usually flush with cash for commercial grade equipment).

 

[Titan II]

I see at least 2 issues with the product in the picture that can be resolved.

My statement stands, regardless of your alleged expertise. What are the two concerns?

 

[David Schwantz]

I thought the CRs looked pretty darn ok.

 

[Sandy H.]

My statement stands, regardless of your alleged expertise. What are the two concerns?

The difference in text indicates a change in focus. As the beam focus affects the width of material burned away, inconsistent focus can lead to poor fitment of parts as the kerf compensation would not be correct.

There appears to be a fairly good amount of staining on the edge of the cut and the cut itself seems fairly black. That would imply that the speed, power, air assist pressure and/or pulse frequency of the laser could be improved to give a more clean brown/tan cut vs. a black sooty cut. That would reduce the amount of effort required to clean up the rings prior to epoxy.

No need to further derail this thread. I added a comment to my original post clarifying that I wasn't trying to derail the thread and I apologize for doing so here as well. The rings are perfect.

Sandy.

 

[crossfire]

Once their in the tube who is going to see them. Dose epoxy soak into the card plywood? I always try to sand some of it off.

 

[sharkbait]

Once their in the tube who is going to see them. Dose epoxy soak into the card plywood? I always try to sand some of it off.

To answer the OP’s original question, it appears that the CR with 4 holes would lend itself to be able to receive 2 U-bolts. The CR with 2 holes lends itself to be able to receive 2 Eye bolts. The CR with 1 hole looks to be set up to receive 1 Eye Bolt. This would give you options for whatever type of harness attachment you may want.
If you don’t want the holes then put a piece of tape on the back side and fill them with epoxy.
I cannot make any quality issue concerns from looking at the picture on my I-phone, from what I see they are fine.

 

[Titan II]

This is one of the 5 3/8 x 75mm sets LOC sells. And their quality is quite good.

Top picture on the left:

https://locprecision.com/collections/rocket-components/products/538rings