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

No, because they have to be assembled in a very particular way, then calibrated to TA’s meter (through “magic”) to give accurate results. Like he said before, even the orientation of the diffuser panels can alter the readings.

I am guessing that once he has finished construction and made all the final adjustments he will glue the pieces together to lock them into place. Perhaps with the exception of the 90 that the flashlight head goes into. He can mark the position that the 2 pieces need to be, then rotate the end 90° so it can be boxed up flat. When you get it, you rotate it back into position and be back at accurate readings.

That is my understanding of it.

Keep in mind that even different batches of pvc pipe from the same company can exist which might throw off the readings. The white pigment could differ slightly, the surface finish could differ slightly, etc… By TA doing it his way, he can compensate for all this.

Thanks Jason for the explanation. Didn’t realize he has to calibrate each setup.

If you will ship it to Sweden I’l take one/Micael

I’m in.

A calibrated light light box built by someone I trust for $100? You bet!

Thanks, TA, for doing this…

John-Galt

Got a question. I know ambient light gets through schedule 40 pvc. When doing any lumen check should the room be dark? Or does it matter?

I don’t think he means 5-6x the price of the entire unit…. just for that opening piece where the head goes. Correct me if I’m wrong….if so, $5-600 dollars is very expensive.
But if it’s about $50 more, id buy it.

In for one if @ $100 shipped
Thx

Keith

Yes, there will most likely be some calibration needed on a per unit basis based on my past spheres. Once I have built this batch I will have a much better idea of if making a kit would be reasonable.

When I have all my work lights on my desk on the lumen meter reads 0 or maybe 1 lumen, the 1 lumen is usually getting through the opening. ~1 lumen is not something I personally care about.

I spent the morning getting quotes for PVC from every place I could find.

Lets just say the price on the larger PVC is stupid expensive, I saw several pieces they wanted $200+ for!

I still need to figure out all the costs, they were higher then expected, I was hoping to get a discount buying in bulk but it seems that is not possible with only ~100 pieces ordered.

The raw material cost for the 4” is about 2.5x the price (including extra costs for the diffuser sheet and centering rings). So the 4” version would most likely end up around $150+.

They don’t have 5” but I did find 6” at the last place I went, it is closer to 7x the price of the 3” and would need some extra pieces to work adding more costs.

It would be AT LEAST $200-225+ for 6” plus MUCH higher shipping costs. Should I even spend the time adding it up more exact?

Another issues is actually getting the PVC in quantity at all, some of these pieces are hard to find and would have to be special ordered. They said it will be between 1-3 weeks at most of the places I went for this quantity. The lowes had only sold 36 of these in the entire last year! I am looking at buying ~100 in a single purchase lol.

I will be busy most of today but I will try to get the final details tomorrow and will most likely start accepting payments this weekend once I confirm everything.

It looks like the 3.5” version will indeed be $100, the only question is if I will have to charge for shipping or partial shipping.

https://www.supplyhouse.com/Spears-P302-030-3-PVC-DWV-Street-90-Elbow

You can order in bulk at all three stores. You should be able to get them for less than 4 bucks apiece.

The 4 inch is about twice as much
https://www.supplyhouse.com/Spears-P302-040-4-PVC-DWV-Street-90-Elbow

Very interesting, when I looked up prices online a few days ago they were all higher then local places.

I will have to check those out for sure. Thanks for the tip!

I’ll take one. Thanks.

DWV are the thin walled ones. Not sch40 like the regular tubes. These are always cheaper. They are made for low low pressure drainage rather than higher pressure like schedule 40.

That said, they may work ok after calibration. They just have a thinner wall and different composition. They are always cheaper though.

Dwv is drain, waste, vent.

Nope, these are all schedule 40. And the dwv is what TA is using in the first pictures. The high pressure elbows are a short bend. These are for drain but they are schedule 40.

Added!

That is a good point, I did see the thinner walled versions when I was shopping this morning but I think it is worth going with the normal stuff for the extra few bucks.

That said it is hard to tell in the pictures what these are, they say SCH 40 in the details on some of them.

I know very little about PVC, the ones I am using now are called a 90 degree street bend that you get at home depot.

Schedule 40 is thinner than Schedule 80. I believe HD sells the Sch 40 pvc pipe. I think they might have some SDR rated pipes too which is also different dimensions but I can’t remember.

For pvc scheduled pipe sizes:

I’m thinking if the pipe wall is too thin, there might be some light leakage for really high lumen flashlights

I haven’t seen schedule 80 pipe fittings very often and when I do they are grey and short radius bends. All those fittings at Lowes and Home Depot are schedule 40 except for the thin drain crap. The schedule 40 is the thickness. Dwv is a cellular core with pvc coating for use with Drain Waste and Vent. TA’s setup in the pictures in the OP says DWV. When ordering make sure you are getting schedule 40 dwv street 90’s cause the high pressure PVC elbows are short radius.