EEVblog 1456 - Sega Toys Homestar Planetarium REPAIR

Repairing a Sega Toys Deathstar, err, Homestar Flux Planetarium
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The designer Takayuki Ohira talking about the design: • Reaching the Stars: Ta...
10 minutes of the Casio FX-91W spinning: • 10 Minutes of the Casi...
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#ElectronicsCreators #Repair #Planetarium

[@feynthefallen]

The reason they use belts instead of cogs is usually slippage. This thing has a huge reduction, which means if it jams up near the end of the gear train, the small motor would build up enough torque to strip gears if it were directly geared all the way through. By adding a belt, the slippage can save the gears further down the gear train.

[@robbieaussievic]

..... Excellent, I only thought of noise dampening. I assume there would be a kit from the manufacturer, as those other belts are perishing at the same rate.

[@veronicathoms4979]

her availability is sure on What's apk ⤵️⤵️⤵️

[@veronicathoms4979]

(✷‿✷)†𝟭𝟱𝟭𝟮𝟲𝟳𝟳𝟵𝟰𝟲𝟮(✷‿✷)

[@geovani60624]

if it used gears instead of belts in the high speed section it would be as loud as a toy car, not good to sleep hearing that.

[@stheil]

@@robbieaussievic Sure there's a kit, it's called "Throw it away and buy an entire new one". Yeah it kills the environment but the shareholders like it.

[@wphanoo]

I think they use belts on the first reduction levels for noise. After two belts the speed in low enough so they can use cogs, they won't make much noise at low RPM

[@spudski100]

I once fixed a Walkman's snapped drive belt with a condom, i cut the thick band off the opening of the condom and it worked a treat!! that was the most action that pack of condoms saw however i was left very satisfied... with my MacGyver fix : )

[@3k2p6]

That's smart!

[@SeanBZA]

Dumpster PC CDROM drive will have those belts for the drawer mechanism.

[@rrrohan2288]

nah he said they dont

[@Mromfgtrololol]

Yup, I've replaced these belts on the tray mechanism of pc drives, Xbox 360, Philips hifi sets and Philips cd-i

[@picobyte]

Yep.

[@shvideo1]

Thank you for the video. I love these random product repairs on KZbin. You learn so much.

[@wilfred_chin]

Lifesaver, thanks for this video, my planetarium had the exact same belt problem. Now fixed with rubber band but have ordered some o-rings in case it happens again. Kids happy!

[@justinvzu01]

I think the belts are there because they can slip in the case of a mechanical failure. This'll save the gears if they ever get stuck. Usually rubber bands are actually quite good to replace bands like there.

[@TradieTrev]

When your brought out the casio my face totally lit up!!! The rubber belts are used to give a smooth motion relieving harmonics of the motor is my understanding. Bit like how mini splits when from direct drive to individual components.

[@atkelar]

CD drives and players usually have a belt in the drawer mechanics. - also: the belt on the "high speed" side is most likely to keep the noise down: gears at a certain sepeed are noisy and will probably also grind themselves to dust eventually.

[@jkobain]

@@sexygirls2778 hello, spammer.

[@jamesrizzo295]

BBC B

[@jamesrizzo295]

V,,,,v. Ok

[@atkelar]

@@jkobain keep reporting... these bots are a curse.

[@jkobain]

@@atkelar I keep doing so. And thank you for the reminder.

[@nigeljohnson9820]

Now we know why the universe is expanding at an ever increasing rate, it's not dark energy, it's just the rubberband stretching:-).

[@Treveliian]

Yes CD Rom drives do use a belt. but not for the drive of the disk, that's a direct drive to the motor, the belt is used for the disk tray to go in and out.

[@peterjf7723]

In one of his videos Techmoan mentioned that he had bought a mixed selection of tape deck drive belts.

[@michaelmoore7975]

The O-rings will dampen any ratchety movements that will be exaggerated when projected through the lens.

[@FrankGennari]

I have a big bag of at least a hundred belts like that taken from old motorized devices and tape drives, etc. I wish I could send you one. You can use a rubber band, but it won't last very long. The rubber will degrade after a few months if it's under tension, especially if it's turning.

[@JN.0_o]

belt kits for tape decks are readily available, check eBay

[@andarthome142]

I love the disco bals with the litle mirows on it, in the 70's ☺👍

[@veronicathoms4979]

her availability is sure on What's apk ⤵️⤵️⤵️

[@veronicathoms4979]

(✷‿✷)†𝟭𝟱𝟭𝟮𝟲𝟳𝟳𝟵𝟰𝟲𝟮(✷‿✷)

[@veronicathoms4979]

⤴️⤴️⤴️💯👆

[@pocoapoco2]

For those o-ring kits somone gathered together all the possible o-rings that don't fit anything and assembled them into one convenient kit.

[@DrTeddyMMM]

There is a memo on the Service Manual for this device, it states: "When opening for repair make sure you have the proper containment device to collect the Galaxy Gases inside so they can be replaced when reassembling" :P j/k

[@XantheFIN]

@@sexygirls2778 You b*tch mispelled "collection".

[@Brian-L]

“I’m a bit of a watch aficionado.” Proceeds to show off a $20 Casio. 😝 You kill me Dave, I hope you’re here all week!

[@SeanBZA]

You are forgetting the Bulova Accutrons he also has a collection of....... Not to mention his own watch designs.

[@basshead.]

Aficionados aren't snobs. Only snobs wear expensive watches.

[@veronicathoms4979]

(✷‿✷)†𝟭𝟱𝟭𝟮𝟲𝟳𝟳𝟵𝟰𝟲𝟮(✷‿✷)

[@veronicathoms4979]

@@basshead. ⤴️⤴️💯👆✅

[@mikemike7001]

Nice use of a #10 rubber band, my favorite size for decades. Perfect for bundling fan-fold paper tapes in the 1970's. Perfect for bundling small cables and lengths of wire for storage now.

[@Damien.D]

Belt drives allows a smoother, vibration free primary drive. That's why there's all the fuss about belt driven audiophile turntables for playing vinyl records. Any motor vibration would ruin the smooth rotation of the night sky effect.

[@michaelmoore7975]

Exactly true. That's why I posted almost the same answer

[@redtails]

meanwhile HDDs are direct-drive and are one of the most highly precision vibration-free engineering marvels in the world

[@Arachnoid_of_the_underverse]

If the rubber band is anything like those used by the UK post office, it will be designed to deteriorate after a few months.

[@Knight8365]

If you want a rubber band that lasts for longer, cut up dish washing gloves - fingers thumbs, palm & wrist give different sizes. Very long lasting and durable.

[@michaelmoore7975]

Try a rubber fuel bowl seal for carburetor on a Briggs & Stratton engine. Comes in a kit or even by itself at your local hardware/lawncare shop. Rubber band will work a treat.

[@henricoderre]

I also thought about using an elastic to replace the broken belt. This is a really COOL device. I'm just a old kid at heart. Unfortunately, these are expensive.

[@che1602]

I'm sure it's been mentioned but cd players use belts. Some of the old high-end Sony's used multiple belts for the tray and clamping mechanism, not the PU which used a linear motor. Rubber bands are a very temporary solution as they dry out and crack quickly.

[@ericgoldman7533]

After doing a bit of quick math, it looks like that broken belt/loop could be imperial- 1in (25.4mm) diameter, 1/32in (0.79375mm).

[@NordriOfUthgard]

DVD Players use belts. Needed one I couldn't exactly determine the size of so now I've got a full set with a decent range for other stuff that comes up.

[@brainbuginfestation8548]

I bought a sega homestar because of this video and it arrived today! But, as soon as I turned it on, I noticed that there were rings in the projected image that were unfortunately not the rings around Saturn, but concentric ones spreading throughout the whole image. On closer inspection, I figured out that these were the rings on the Fresnel lens! The bl**dy thing was put in backwards from the factory! :-p But thanks to your excellent video, I already knew how to take the device apart, and did so without further hesitation. Now it is working the way it should and I'm waiting for the night to come so that I can enjoy the constellations of the northern hemisphere... Greetings from Germany :-)

[@zer0b0t]

finding the right belts is really annoying, wish there was a way to make them at home

[@andrewwalsh5837]

In a CD player they use a belt for the drawer mech in most cases, the spindle is direct drive

[@kenfung2121]

you can get a little drive belt in cd/dvd drive, check the drawer drive part :)

[@SwapnilV]

You need to get rid of the rubber band soon as they will chemically react with the plastic!

[@redtails]

12:40 dave finds out the ultimate plan of belt drive mechanisms: planned obsolescence

[@cids1599]

Wonderful video. Thank you for posting.

[@caterinarigo3713]

Thank you for this video: I have bought this projector for 10€ on a second hand store and unfortunately it has the same problem, it works but doesn't rotate. I'll try to fix it!!

[@gr2238]

I buy my O Rings from a place that repairs hydraulic drives and pistons for heavy equipment. They have the whole second floor filled with shelves and bins of O rings.

[@Starphot]

Rubber bands are a poor substitute for drives like that. Rubber bands are not cut accurately and the thickness varies throughout its circumference. Google tape drive belts. Customers tried to replace the tape drive belts with the rubber bands and they were complaining of bad sound. I had a lot of such repairs.

[@garbleduser]

This is not the Homestar Runner I clicked for.

[@brettito]

Well at least he got the homestar running.

[@welshwisdom]

I've been looking for one of these for years

[@AR-xy4jy]

As a kid in the late 80s early 90s i used those rubber bands to temp. fix my cassette player. It was only a temp. fix because the cheap multi colored rubber bands only lasted a year or so before they snapped again and had to be replaced with fresh ones.

[@fernandopaul1]

usually the first transmission in machines is done with belts to allow some slip between the motor and the other parts. This is done to accomodate strong inertial forces when the entire train is accelerating. Think of lathes, milling machines, etc.. they all start with a set of belts transmitting torque from the electrical engine to the second axis. After the first transmission, they all use gears.

[@psychtank8681]

Drive belt usually sold by bulk in assortment of different sizes. It was easy to find back when Radio tape was so popular. Serviceman usually have them.

[@szabolcs__]

I used tube oring for my old walkman , it worked fine

[@jschroedl983]

That cast metal casing around the motor looks like it is for noise / vibration absorption.

[@pedro_8240]

12:12 noise possibly, considering the ratio of the motor and the pulley, the motor would be spinning fairly fast, and the teeth engaging at that speed probably would make too much noise, who knows.

[@gkilm]

My lenses fell apart when I did this with my flux. Can you tell me if the lenses were turned inward into the plastic tube (so the flat end was on the outside of each time), or with the round ends facing out?

[@Julzilla]

Hey Dave, you can 3D print belts like this with flexible filament!

[@gregfeneis609]

Rubber band is an OK drive belt replacement as long as it's not a tape transport (capstan drive, etc.) where variations in the belt cross section can cause variations in speed, which could mess up playback quality.

[@firesurfer]

You can buy an assortment of replacement belts for like $10 US They give you several dozen asst sizes in a plastic case. In auto parts stores.

[@ovidiulu]

You can find belts in PC optical drives (CD-ROM units) at the tray mechanism.

[@KeritechElectronics]

Cool device. It's noce that the problem is so easy to fix.

[@danman32]

I've found rubber bands have too much of a stretch, especially long ones and when you need to transfer relatively large amounts of torque.

[@tubastuff]

Or use a large TPU hair band.

[@gower1973]

If it was an all cog system and it jams Dave the gears will strip, good luck finding a spare, the belt allows some slip

[@I.____.....__...__]

7:17 I've definitely seen belts in some CD-ROM drives. 🤔 11:12 Been there, done that. I've repaired portable cassette players with a rubber band instead of a proper belt. 13:42 Two issues with using rubber bands in place of a belt: • too much tension killing torque • slipping from not enough grip

[@MrCarGuy]

Dave, you should do a video on the Arcflash rifle and the numerous limitations of it all

[@Jenny_Digital]

CD Players with a drawer usually do. Also, many tape players have a small belt (besides the big one for tape transport) for the counter.

[@nigelsears7191]

Most CD player use a small belt for the draw or loading deck slide , kits that size readily available

[@jkobain]

Don't you dare taking that ring from a Casio wristwatch!!

[@BradKwfc]

I tried replacing a broken belt from a toy with an oring... the oring put too much tension on the motor and it overloaded something in the motor drive circuit.

[@Not-Only-Reaper-Tutorials]

I had that Casio swatch when I was teenager :-D

[@오늘은-n5d]

hello. The rotation mode and shooting star mode were broken, so I looked for them and came across this video. The motor won't turn, I don't know how the shooting star works, is this even fixable?

[@JimTheCoffeeGuy]

For the majority of this video something felt off, then I realized there's a low pitched sound coming through the mic! Dave have a close listen, might need to add a slight filter to your audio perhaps? Only noticed as I was listening on headphones and not my phone speaker for once.

[@cspower7259]

Some of the Sony CD bays use a belt to open door and tray. common repair. Sometimes tray stops working just because the belts twisted. I suppose after time being twisted, it may snap.

[@rrrohan2288]

I think they use belts on the first reduction levels for noise.

[@LambertZero]

Rubber bands are made of some kind horrible shit that turns into a sticky mess that is very hard to clean up, in a matter of weeks, months if you're lucky. What you really want to use in a situation like that is a condom.

[@MrVinamp]

Shooting stars never stop, even when they reach the top

[@ruikazane5123]

Oooo we had a few of those over up Japan! Glad to see one reach down under and right on EEVblog it gone down! Anyways... CD and DVD players (and desktop drives too) that have motorized trays usually have a belt to limit torque transmission and not lock up the motor when someone does tug or push the tray in The extra large alloy block surrounding the motor is for cooling it down. Not that it helps a huge ton but for something that would have been ran for a day or something (one of our rooms was a night room and that was on 24/7 but it is Sapporo, cold) The belts were most probably for smoothing out the drivetrain. Plastic gears cannot really be ground to tight specs to minimize noise at such high reduction (which is caused by gear imperfection as they cannot be ground and mated to each other through wear, plastics) and what if someone jammed something onto the tray that was not intended to be...that would wear out the motor and the first two gears pretty quick. The lower one for the shooting star effect will be cost cutting. Bridging that far of a gap with gears would be a little more involved that what it is already... Proper belts for *most* tape decks and record players are square (regular belt) or rectangular (a flat belt) in cross section shape. The groove you see on the pulleys are designed to accept the square one which will be tilted to a diamond into the groove for maximum contact area (two sides of the square meeting the pulleys). Section thickness is about right where Walkman belts are at but if a 1mm section can fit then go for the thicker one...less likely to break than a thin one The time you can put a proper one in...please do the rest of the belts. Just to be safe. Don't forget to clean the pulleys before putting the new belts.

[@lasersbee]

12:15 Perhaps to keep the running noise down or alignment issues.

[@Hilmi12]

Normally you would use a belt drive to avoid backlash and also for smoother motion

[@petersage5157]

I'm sure Techmoan would be happy to send you a more appropriate replacement belt.

[@DGLAIndustries]

what disc have you, where the star constallations included? i like it and want it too. Very good Video, so i can fix my Flux Projector.

[@OfflineSetup]

A new belt needed! Only one man to call... step forward techmoan

[@henninghoefer]

You keep saying "FX-91W", but the watch is just called "F-91W". I think Casio uses the FX-prefix only for scientific calculators. The answer to the "why belts" question I believe is "noise"? (same reason most combustion engines use timing belts or chains instead of spur gears for camshaft drive)

[@AlexandriaH-qx8cx]

I have an issue with the brightness of the LED :(, is there any fix for this?

[@hestheMaster]

I always wanted to sleep beneath the Crab Nebula! Damn crappy rubber belts. Use a thin rubber band. Usually in the USA they are thin green ones and come with your newspapers that are delivered to your home or buy them like you did.

[@joekenorer]

At a certain point plastic gear reductions need to use a belt to allow slip and save gear teeth.

[@DerStoeppel]

its all because of the sound, the first stage of gearing would be very fast and it would be impossible to make it sound pleasant...

[@abigailjoseph4190]

Mine is blinking on and off but won’t stay on consistently. Any tips??

[@TarasMartyniuk]

2:43 Some constellations that you never see in Australia :)

[@jkobain]

I've seen people using rubber bands or condom rings when needed to fix transmission in such devices and didn't have a spare belt.

[@tiberiopaoli9722]

I have a problem. the projector fell and the lenses came out. everything works but I can't put the lenses in the right sequence. does anyone know the order of the lenses?

[@techalyzer]

Ummm... do you really need a microcontroller for... turning a disc? Or is that just a motor driver?

[@gr4eme1975]

There is a high end cd transport made by a company called CEC that has a belt drive cd mech. It actually drives the cd spindle by belt not like some say the draw mech.

[@Palmit_]

this is why rings that are too big are made into a figure 8 (providing they are on different levels to prevent wear)

[@SidneyCritic]

Wagner Electronics (Summer Hill) are the drive belt experts.

[@mce_AU]

Chicken dinner in the dungeon under a starry starry night. Nice.

[@M0XFXUK]

What a cool device.. I want one

[@scottb721]

Is there a good equivalent these days?

[@erikdenhouter]

When you cut a piece from a larger belt, perpendicular, and glue it together perpendicular, it will work. I don't think a sealing O-ring is the right material; one is for tension, the other is for pressure. Your elastic rubber baby bumper belt looks best for now.

[@DaruoshAghajaney]

You can 3D print the belt with TPU.

[@keithking1985]

LOOK INSIDE SOME OLD PRINTERS OR "CAR STEREOS", (if you you have some laying around) YOU SHOULD FIND WHAT YOU NEED IN THEM,! (with a bit of pulling apart) seeing that the belt that snapped on it isn't doesn't seem to be holding loads of strain you could put it back together with a bit of glue & heat-shrink tubing until you find the proper size. it should do as a quick fix util then.. ; )

[@derofromdown-under2832]

Go to WES Components for a correct belt replacement...

[@1BrknHrtdRomeo]

lol had exactly the same problem xD Thanks for the DIY fix! haha Edit: FUCK I wrote an extensive report for my fix and closed the window lol -.- 1st attempt - Found a sub 1mm oring, less than 1inch from an aluminum pill case. Result: Works to a point or won't even move at all, too tight where the motor doesn't have enough torque. 2nd attempt - Rubber bands used in packaging extension cables (USB-C, Lightning, etc) from Amazon. Were a bit thick so I cut them in half. Result: Works to a point as well. The bands were somehow too thin? They broke after 15-30mins O.O 3rd attempt - Found a rubber band with similar dimensions in the video from work. Result: Again, works to a point lol. It will get stuck eventually. You can either press the button to have it rotate the other way to unstick itself or open it back up again to fix. So, unfortunately, this is only a half solution? Going to test if this can run continuously where the stars rotate in the N position (band has more travel going this direction so it doesn't get stuck to the housing). Hopefully the band doesn't break (wtf is this thing made of seriously lol) but if getting stuck keeps being an issue, my next solution is to grind a part of that inner housing to give the band more room.

[@andymouse]

Aw, hardly saw it in use...cheers.

[@Huvada]

CD players are direct drive, but the loading mechanisms usually aren’t and have gears and belts.

[@TeemoDIY]

Such belts can be 3D printed using TPU filament.

[@scellyyt]

I had something like this when i was much younger

[@woosix7735]

Having shopped for these replacement belts for cassette players, Somme listings say CD as well so…

[@JessHull]

I think they add and use belts in parts of the drive mech to cancel out any gear lash that maybe present. Since it's supposed to spin slowly to project an elegant starfield and gear lash would cause the starfield to jerk around and make for an unpleasant viewing experience.

[@woosix7735]

The rubber bands will wear out surprisingly quickly