Texas_Ace BLF Calibrated Lumen tube / Sphere No math skills needed - Several spheres still available

I have considered these options as well, for custom sizes that people may want or need this is exactly what I will recommend. Even cardboard will work, you just have to cover whatever it is in aluminum tape to make it reflective.

That said, I am considering other options.

I could laser cut some plastic sheets that would work for this, although they would not have a lip to hang over the edge of the PVC. They would work just fine though and I could knock those out myself in an afternoon instead of paying someone the labor to do it for me on top of the cost of the 3D printing itself.

What do people think? Would having a flat piece of plastic on top of the sphere be ok vs the discs that have a lip built in to remain in place?

For single measurements it should not matter, only for those like me that do many measurements or LED tests where you leave something on top of the sphere for long periods of time would it really matter.

If people would be ok with this I can look into this option, it will take a few weeks for the 3D printing to be finished anyways at this rate. I could sell the 3D printed discs that are already done as an upgrade for those that do a lot of testing. I think they have 10 out of the 150 done so far.

In fact the more I think about it, the more I like this idea if everyone is ok with it.

I sold these with the 3D printed discs though, so I will fulfill that promise if that is what people want.

I was doing some quick math and each print job takes between 45mins - 2 hours it looks like depending on the side. So figure 1 hour per print + 30 mins between print jobs for the swapping process.

That is 150 printing hours total, beyond that being some very expensive time, divided by 8 hour days and the fact that they would be lucky to actually be printing for half that time each day, and it could be over a month before they are all done unless they were really slow for some reason.

I am thinking that just for the sake of time going with a laser cut sheet could be the necessary option.

Opinions?

and 3 printers would be 1/3 of that time :slight_smile: - you saying this place has 1 printer?

What i’ve implemented in the paper-mache sphere i’m working on is made out of white abs plastic.

I am mounting an insert onto the sphere made of two rings, one slightly larger than the other. The one closest to the sphere is the smaller ID, same OD, and the outer one is an 8th of an inch smaller ID, same OD. Then i’m cutting basic discs with varied central openings for each light. The OD of the flashlight discs fits inside the “outer” ring. Each disc fits inside the “outer” ring and sits on the lip created by the “inner” one.

Sort of like a manhole, with a manhole cover for each light.

You could print one adapter from PVC to the circles, then hole saw the individual light opening discs pretty easily and cheaply.

I’ll try to grab a pic after work.

They have 2 working printers right now (it is a small place and this is just a side venture for them but they are nice $2500 printers that work very well even with nearly constant use).

They just don’t generally let 1 person use both printers at once unless they are sitting around doing nothing. Recently they are both generally working all day every day. They want to get more but they are out of room to put them.

The only other place I know of in the area that offers 3D printing is a membership place that is over an hour away from me 1 way. Might get it done faster but it would cost more.

Like I said, buying my own printer would be the next best option if I thought a cheap printer could handle this. I am looking into this but I have heard the stories of these cheap printers taking weeks or months of tweaking to get them working and then they break down all the time. Which would take even longer then what I am doing now.

Hmm, that is a pretty darn good idea. When only making 1 of these there was no reason to worry about this but now that makes a lot of sense.

I will have to look into that for sure. It would save some money but mostly it would be way faster.

Only caution is the cutting of the abs. It wants to melt on me, so i’ve cut them a bit larger and am sanding the edges with a dremel to fit. Not something you want to get into when mass-producing them.

I bet your laser cutter folks would be able to crank them out with perfect precision though.

Yeah, I would most likely use acrylic instead of ABS since it is laser cutter friendly and then just apply the reflective tape to that.

For my setup, I'm all for you doing whatever you need to regarding cost- and time-saving. I know I'll have a great product no matter how it's finally spec'd out, and optimization just makes sense as the process goes along :)

So yeah, mod/optimize as you see fit!

-Ben

I’m ok with whatever is more cost effective, easier, faster and achieves the same result. I know the product will be high quality no matter what you do.

I’m ok with whatever works. I’m sure it’ll be more than sufficient.

I’m ok with whatever you need to do.

I'm of the opinion - that I don't know enough about the alternative - to have an educated opinion.

:)

Ok, Tomorrow I am going to try to finish up the outstanding MT09R mods I have here and the next day I will see about making up an adapter for the sphere to use laser cut centering discs instead of 3D printed.

The end results should be the same either way, this will be much quicker and a bit cheaper for me as well.

Whatever works and is cost effective. I think nkresho’s idea sounded good too.

Here’s a couple of pics of what i’m working on. The centering rings are in here.

Overall sphere design is a copy of the “match sphere”. Match's Mods: Homemade Integrating Sphere

Copy of match integrating sphere.

I agree, I was thinking on it and I think I might of come up with an even better way of doing it, a bit more labor but should work good. Then just need to get the centering rings laser cut. I can do a 24” x 12” piece at a time and each sheet should take less then 15 minutes to cut. So I can finish it in a slow afternoon if all goes well.

If you go a manual route you could potentially clamp multiple together and knock out several at once depending on what your plan is

I found that a piece of 4” PVC pipe almost fits over the outside of the 3” perfectly, I just have to sand off some little nubs on the outside of the 3” fittings for it to fit and then cut a bunch of short pieces of 4” pipe. Which might actually be a deal breaker since I sold my miter saw a few months ago.

the 4” I would still need to 3D print either way, I will start off with that and see how things go.

For the laser cutting, I could possibly stack a few but this laser cutter is only 50w, it works great but does not like cutting through very thick materials.

I don’t have much time tonight but just wanted to give a quick update. Spent the afternoon working on the centering ring issue and nkresho’s idea is a far better idea for this situation I think, the end result could in fact be better then what I first panned.

I really like the materials I ended up with and while it takes a fair amount more labor, well thats what family is for when the skill level is low right? lol

I got some pictures of the stack of stuff, think small refrigerator sized pile of stuff. I will try to post them tomorrow.

What worries me is when they are spread out all over the place and then shipping. I never even thought about boxes for this many large items. That could prove a challenge. I am working through them though.

The lux meters will hopefully be here at the end of the week, possibly early next week. I want to have everything ready for calibration when they show up.