Simple Halloween project - Page 1
Forum section: electronics / projects

author: Jeff1946
author_rank: Regular Contributor
timestamp: October 19, 2023, 11:04:39 am
content: For those of you who celebrate Halloween, here is a simple project. We have a large spider and web in our front yard. I decided to put two red eyes on the spider. To make it spookier, I made a circuit to make the eyes brighten and dim every 5 seconds. Note the circuit uses the cmos version of the LM555. It will operate to less than 1.8 V at which point the LEDs are barely visible. This surprised me as the LM358 is only rated to 3 volts.

author: RoGeorge
author_rank: Super Contributor
timestamp: October 19, 2023, 11:14:33 am
content: Were spider?

author: Konkedout
author_rank: Frequent Contributor
timestamp: October 22, 2023, 03:12:38 am
content: 3V is the MINIMUM operating voltage for the LM358. It is good up to 30V.https://www.ti.com/lit/ds/symlink/lm358.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1697903197388&ref_url=https%253A%252F%252Fwww.ti.com%252Fgeneral%252Fdocs%252Fsuppproductinfo.tsp%253FdistId%253D10%2526gotoUrl%253Dhttps%253A%252F%252Fwww.ti.com%252Flit%252Fgpn%252Flm358BTW I think if I were doing this I would forget the 555 timer and just use the LM358. One half of the dual Op amp can oscillate very nicely, and the other half can drive the transistor.

author: antenna
author_rank: Frequent Contributor
timestamp: October 22, 2023, 03:24:13 am
content: Now that you have the spider at it's best, I will share a top secret haunted house trick for the best cobwebs ever. All you need is a hot glue gun and an air compressor!

author: Mr.B
author_rank: Unknown
timestamp: October 22, 2023, 04:06:06 am
content: Quote from: antenna on October 22, 2023, 03:24:13 amHow?Any chance of a video tutorial?

author: Mr.B
author_rank: Unknown
timestamp: October 22, 2023, 04:06:56 am
content: Quote from: RoGeorge on October 19, 2023, 11:14:33 amAgreed.Show us a pic.

author: antenna
author_rank: Frequent Contributor
timestamp: October 22, 2023, 02:46:56 pm
content: Here are some pictures, but keep these few things in mind.I dont have an industrial glue gun that gets hot enoughI haven't done this in decades and I am way out of practicewhat you see here is shooting straight at the target, longer strings are possible from further away by shooting across the surface instead of straight at itThe glue should drop into the air stream, if the air hits the gun tip, it will cool it and clump upIt comes off of most surfaces easily by rubbing it.i tried getting a picture of the glue coming off in strings, but that wasn't working out by myselfjust to be clear, im using a junk glue gun from way too close from the wrong angle and it could look way better with practiceAnd in the age of huge server racks filled with TB hard drives, I can't upload more than one pic at a time because they are too big lol.

author: antenna
author_rank: Frequent Contributor
timestamp: October 22, 2023, 02:49:50 pm
content: another pic, not sure why the thumbnail is the same as the last pic, its not. This one I should have been further away and at a better angle, not straight at it. Practice helps, its been a while

author: RoGeorge
author_rank: Super Contributor
timestamp: October 22, 2023, 03:12:02 pm
content: That DIY spider web looks very nice, though, I wouldn't dare to use it over light bulbs. Seems flammable.

author: antenna
author_rank: Frequent Contributor
timestamp: October 22, 2023, 10:43:08 pm
content: Quote from: RoGeorge on October 22, 2023, 03:12:02 pmWe dont use that light and I had removed it right away anyhow. It was just something to shoot webs at for a picture. That halogen light would melt the glue pretty fast for sure!

author: Mr.B
author_rank: Unknown
timestamp: October 22, 2023, 11:48:09 pm
content: Quote from: antenna on October 22, 2023, 02:46:56 pmThanks for that.The effect looks pretty good.I have a few spare cartridge heaters for my 3D printer.I might try to machine up some sort of an aluminum head that can hold the air nozzle and dribble the melted glue in front of the air stream.Looks like a project for next weekend.

author: Piper259
author_rank: Newbie
timestamp: October 23, 2023, 05:27:35 am
content: Looks natural. That arms race with neighbors forces to look for something new every yearThanks