And we’re back with our fourteenth installment of Your Comments. Here are our favorites from the past week, from Make: Online, our Facebook page, and Twitter.


Todd Harrison shared an, er, alternative to Kip Kay’s Lily Pad Pool Warmers Weekend Project video:

My DIY redneck pool heater would be a lot less fuss.

There was quite a strong reaction to the video demonstration of free Climbing a 1700 foot antenna tower. Over on Facebook, Kenn Mileski summed up the reaction:

I had to stop watching when the climber said ‘free climbing’. Every professional climber I know would be fired IMMEDIATELY if they violated the 100% tie-off rule. He should have been climbing with TWO fall arrest lanyards with at least one tied off at ALL TIMES.

Also on Facebook, Randolph Bean admits to working at a slightly longer time scale than that demonstrated in the video How fast can you take apart and put a Jeep back together?:

Wait…what? You have to put it back together?!?!?! I better get to work, so far I’ve only taken about 15 years….

Dave reiterated some basic safety tips to keep in mind when making a DIY ultraviolet laser from scrap aluminum:

Nyle made some good points about safety in the original article, but said only a little about laser light concerns.
UV lasers are dangerous, perhaps more so the IR, as the invisible beam is of higher energy. Wear some appropriate goggles when working with a TEA laser. At the very least, dark, UV blocking sunglasses!
Running the beam through a mason jar of fluorescent liquid is a wonderful way of visualizing its path, but there will be a strong, invisible reflection from the glass, where the beam enters. Beware!
And, one wonders if the high voltage had its way, since Nyle’s article is almost three years old! Hopefully, he is still with us!

Simon appreciates a good set of Dual-reading calipers with Imperial/SI units on same dial:

Those would be very handy. Although after such a long time at not having something like that I find I can convert from metric into imperial reasonably well now (how many thou in a mm again?). I find I prefer the analogue ones. Sometimes I want to take a smidge off something when machining and don’t bother using the scale on the lathe but I get a good feel for how much a smidge is by how far the needle on the calipers moves.
I have also dropped mine and had them skip but I was able to take them apart and reset them.

Logan, co-creator of the DIY Underwater Bubble Room, chimes in to answer the question everyone was wondering about it:

Hello Logan here, I am the co-creator of the bubble room (along with my brother Jordan).
The maker of the mustache wax is “Firehouse Mustache Wax” ( If you go to the last page in their galleries there is a picture and a paragraph about Jordan and Dan (Dan is the guy in the video).
I agree a 50 ft wide bubble room would be amazing… The biggest problem I can see (possibly even a bigger problem than obtaining a dome that big) is that a hemisphere 50 feet across, full of air, underwater would have 2,042,954 pounds of lift (yes 2 million). That’s about 1,021 tons. I’m sure it could be done but the physics and material behind that structure would have to be very intense.
Also a tunnel to the surface would not work at all unless you had an air lock.

Commenter kinderdm shares some insider knowledge about vibrating conveyor belts:

My father works as an engineer for a company that produces vibrating conveyors (among other things) on an industrial scale. They have been doing such business for as long as I can remember, at least 25 years. As I understand it these systems are very useful in applications that involve small items, which could be lodged in the moving parts of a traditional conveyor. They are also useful in the food and pharmaceutical industries where lubricant contamination could be a concern. A vibrating conveyor can be made from a solid piece of metal so that the parts that contact the product require no lubrication. They also lend themselves well to sterilization as there is no where that contaminants can hide.

Salec had some sort of advice about how to make use of some of the parts being stored in the binder part storage post:

Yes, too often 555 pushes 4017 around, poor 4017 having no negative feedback on 555 whatsoever, which would be … hey, now when I think about it, quite an intriguing idea, thank You!
Here, try this: let 555 (as astable) clock the 4017, then make jumper-selectable decoded output of 4017, over a resistor, change the frequency of 555. Tap audio from 555 output to some sounding device. See what sounds it can produce on a speaker when you change the selected 4017 output to another one.

Inspired by the Simple method for constructing a worm gear, Dean W. Armstrong had a few more tips on how to make them:

Cool! Another interesting way some telescope makers make worm gears: they apply partially-set JB weld to the outer rim of the worm wheel, then put a nylon rod in the goo and let it set. The JB weld doesn’t stick very well to the nylon. I think I have read another way is to drive the nylon worm and worm wheel very carefully during the gooey phase and you get a perfect match between the two gears.

Brushyfork was having trouble putting together an Hydrogen-Oxygen Bottle Rocket:

“Seriously, this is almost literally killing me. I want nothing more in life than to launch this rocket. Please help me figure out what is wrong.”

After the author stepped in and helped out with some advice about timing, they left an exciting comment:

“I’ve gotten it working!”

Like these comments? Be sure to sound off in the comments! You could be in next week’s column.