Novice- Need Help With Motorized Display Disk - Page 1
Forum section: electronics / projects

author: newbie123
author_rank: Newbie
timestamp: July 09, 2022, 10:41:32 pm
content: Hello!I am very inexperienced- and have no experience with electronics of any kind.I would like to buy or build 3, low profile, motorized rotating display disks for a display case. You can see the mockup for the display case attached.Ideally, I would have the rotating display disks rotate at a slow pace, controlled by a switch built into the display case. If it doesn’t sacrifice the profile, I would like to have the speed be variable and adjustable by a knob on the switch, with a high bound cap on the speed. The disks will be supporting a series of statues. The largest of which is Width: 20.5” Height: 22.5” Depth: 17” Weight: 30 lbs. Note that I would just buy a rotating display disk, however they are all to high. I can drill into the ¾ inch wood platform the disks sits on to reduce the height if need be.My primary questions are:• Ideally, the rotating disk and motor would be less than an inch high, if that isn’t possible, I am wondering what the lowest form factor as possible would be? I am not sure if anyone has any ideas of small form factor motors?• What are all the parts I would need to buy in order to make this? Do you have any recommendations?What is the best way to wire everything together?I am of course open to any and all suggestions, or better ways to build the project. Thank you so much in advance for your time and help, it is much appreciated.

author: Benta
author_rank: Super Contributor
timestamp: July 09, 2022, 10:53:15 pm
content: Anything's possible if you throw dollars at it.How thick are the shelves where the disks are?

author: ledtester
author_rank: Super Contributor
timestamp: July 10, 2022, 12:01:10 am
content: Quote from: newbie123 on July 09, 2022, 10:41:32 pmIn this video the turntable assembly is about 1.5 to 2 inches high. You can tell because at 1:32 it show the dimensions of the sides as being 2.5cm high.How to make 360-degree Rotating Display Stand simple at Home use Gear motor and cardboard -- Mr. H2https://youtu.be/Z37_PjU0vWUAnother idea is to use a belt so the motor doesn't have to be placed directly underneath the turntable.Update:QuoteWhat are the dimensions and weight of the other statues? Perhaps you can adjust the shelf spacing to give more space to the tallest one.

author: pqass
author_rank: Super Contributor
timestamp: July 10, 2022, 12:23:34 am
content: If you're up to it: glass turntable + twisted belt + 3D printed mount + hobby motor + PWM controller.The glass turntable that's about 1" high (I have one). There are two 1/4" (height) halves to the bearing; the upper half is enough for a belt to rest on. The motor may be flat enough to fit under the glass. A 3D printed mount will need to keep the belt taut via sliding mechanism+spring or bow. The motor shaft will need to be augmented with a 1" long (or so) cylinder to accomodate the "V" shape of the twisted belt at that point. A pair of wires can then be run along the back and to the bottom of the cabinet to a PWM controller. You could share one PWM controller with all turntables but they'll all move at the same rate.EDIT: Hmmm. On second thought..... This may be fine for a cake but not your rock collection.

author: themadhippy
author_rank: Super Contributor
timestamp: July 10, 2022, 12:44:16 am
content: my first thought was a microwave turntable,but 30 lbs might be a bit much to cope with

author: MikeK
author_rank: Super Contributor
timestamp: July 10, 2022, 12:55:32 am
content: Amazon sells them. "Motorized Rotating Display Stand". And ones on eBay for under $9.

author: ebastler
author_rank: Super Contributor
timestamp: July 10, 2022, 07:05:45 am
content: Quote from: Benta on July 09, 2022, 10:53:15 pmQuote from: newbie123 on July 09, 2022, 10:41:32 pm

author: ebastler
author_rank: Super Contributor
timestamp: July 10, 2022, 07:12:00 am
content: Quote from: MikeK on July 10, 2022, 12:55:32 amCould you be a bit more specific please? I could not spot any models which are 1" thick or less.

author: beanflying
author_rank: Super Contributor
timestamp: July 10, 2022, 07:35:29 am
content: First thing to get sorted is load support. Something in the order of a 100mm Diameter thrust bearing assembly to carry the 30lb requirement 100x74x4eBay auction: #141776299274or better a bigger one at 150x120x4eBay auction: #222607383219This will give you plenty of depth for a steel or aluminium platter to sit over it.You will still need a bearing shaft and pin in the middle to carry and align the platter axially but the weight and platter support is a larger concern in this case.The biggest issue you will have is generating the torque required to get them rotating initially not so much when they are actually running. A Pancake motor (largish diameter) and simple oring or timing belt drive will make most sense but I suspect much under 40-50mm in height is likely going to be an issue. DC motors will give you good torque and bang for your $. So your 1" high platter might need to increase a little or you might need to route a rebate into part of your shelf for the motor and drive system.Electronically this is all fairly simple in particular if you keep it to low voltage DC to 12 or 24 V from a power supply and potentially something as simple as a re purposed Laptop one depending on what current you finish up needing.More detail please but there is some starter mechanical ideas.

author: Gyro
author_rank: Super Contributor
timestamp: July 10, 2022, 09:37:57 am
content: Quote from: pqass on July 10, 2022, 12:23:34 amFinished!To be honest, it's going to be difficult to produce a rotating display stand that doesn't look rather 'Heath Robinson' (^). Low height manually operated rotating stands (for dishes, condiments etc.) are known as 'Lazy Susans'. The best I can think of is to mount a slow speed drive motor to the underside of the shelf, somewhere near the back where it won't be visible, with the shaft protruding above, and a pulley and flat drive belt arrangement. The result isn't likely to be quiet though - Lazy Susan ball bearings tend to click as the free running ball bearings float about, and the 30kglb capacity, particularly if unbalanced, is a big concern.

author: beanflying
author_rank: Super Contributor
timestamp: July 10, 2022, 10:27:49 am
content: Got really really bored waiting for the Tour to startAs a rough idea the lower platen could easily be made from plastic as the load is pure compressive. I have 3D printed these for light duty in the past and I used Lasercut Acrylic for the upper ones but they were a very different order of load. But I can't see a major issue with Plastic here.The Upper one Aluminium or Steel would make sense as plastics will certainly buckle and deform. Without really pushing the vertical limits of the materials 32mm in Height should be ok allowing for a gear or pulley on the shaft between the axial bearing. The cutaway has 5mm vertically for the Pulley plus clearance.At this height I think the Motor will likely need to protrude below the lower Platten to make it work but I haven't remotely looked at options. Motor nominal speeds of 100-200 RPM then a small belt reduction of 3-4 to 1 and then electronic control it down from there. Maybe a pancake stepper motor might be worth a look.Anyway TDF time

author: ebastler
author_rank: Super Contributor
timestamp: July 10, 2022, 11:31:21 am
content: Quote from: beanflying on July 10, 2022, 10:27:49 amYou could use a small motor with a friction-wheel drive (in contact with the outer perimeter of the large turntable) -- like in the old cheap record players, before belt drive became the standard. The motor could either sit outside of the turntable's footprint, preferably out of sight behind it, or within and underneath the turntable.The transmission ratio should help with the motor torque and speed requirements, and allow use of a smaller motor.

author: beanflying
author_rank: Super Contributor
timestamp: July 10, 2022, 11:59:59 am
content: I did consider that but with the likely need to keep the motor inside the platten you would either need a secondary transmission loop or to widen the rim of the upper platten so the motor stays inside.The very rough model was to look at the height and with some re shuffling of the axial bearing higher near the upper platten then run the drive below it might also make more sense. So Motor with the shaft facing down to the drive.Ok add break over TDF is back.

author: tooki
author_rank: Super Contributor
timestamp: July 10, 2022, 12:35:02 pm
content: Quote from: newbie123 on July 09, 2022, 10:41:32 pmIf you search for the common names for these things — “turntable” or “lazy Susan” — with the word “motorized” you’ll find many commercial products and DIY projects to give you inspiration.

author: MikeK
author_rank: Super Contributor
timestamp: July 10, 2022, 01:06:07 pm
content: Quote from: ebastler on July 10, 2022, 07:12:00 amOP says "Ideally, the rotating disk and motor would be less than an inch high, if that isn’t possible, I am wondering what the lowest form factor as possible would be?" Key phrases are "ideally" and "if that isn't possible".Amazon has one that is 1-3/8" high. If that doesn't satisfy him it almost certainly can be modified to remove some height.

author: beanflying
author_rank: Super Contributor
timestamp: July 10, 2022, 01:10:57 pm
content: Quote from: MikeK on July 10, 2022, 01:06:07 pm30lb capable?and a link might be useful even if it is just for design ideas.

author: MikeK
author_rank: Super Contributor
timestamp: July 10, 2022, 01:51:47 pm
content: Quote from: beanflying on July 10, 2022, 01:10:57 pmMy mistake. It's not for 30 lbs.

author: beanflying
author_rank: Super Contributor
timestamp: July 11, 2022, 02:54:13 am
content: Coffee Break.I have used some of these cheap and cheerful right angle gearboxes in the past.eBay auction: #403750289913Heaps of torque in the low RPM versions. In stock form as the output shaft is bushed not really up to 24x7 use but dropping a bearing in would be possible, motor loads are light so the brushes and motor should be 'ok'. Also had the CAD model on hand from the other project. Output shaft would need to be shortened a little but as shown overall Platter Height is 34.5mm and this could be shaved another 1 or 2 I guess.Hello OP you still there because I am having 'fun' with your project

author: newbie123
author_rank: Newbie
timestamp: July 15, 2022, 08:39:33 am
content: Thank you to all who have replied thus far! It has been insightful to say the least. Due to all of your great input, I have what I believe to be a more sound design (attached). My main concern is still the size of the motor. I am thinking a small DC motor, that has 1 RPM. It is for a display so the thing is great if it's slow. As stated, it has to turn a 30lb statue, with a height of less than .75 inches. I looked into microwave motors, which would work well- many are just .4 inches tall, but they cant turn 30lbs. If anyone has any links to motors they think will work it would be much appreciated.@ beanflying- thank you man! Apologies for the late replies, I didn't get email notfis for this thread but will be checking back on it. That right angle motor looks great- I hadn't considered that! I am a bit concerned with that one though as its 3 inch or so wide, which will be a heck of a time fitting that into 3/4" thick plywood platform. That is the closest thing I have seen to a solution though, so thank you for that. Note this motor only needs to go at 1 speed- 1 RPM is fine, even slower is great. I think the gear motor has variable speeds? Not sure if a single speed will allow some reduction in size- but I don't know what I am talking about lol so any help is appreciated.I look forward to finding the right motor and am open to any suggestions there, and thank you all again!

author: beanflying
author_rank: Super Contributor
timestamp: July 15, 2022, 08:51:26 am
content: Nice you are still thereWith DC motors in particular don't be worried about a speed turndown from a 'nominal speed'.Not sure where you are at with DC Motor theory but if you start with a 24V motor/gearbox rated at 6RPM (from the evilbay link above) it will more or less turn at 3RPM at 12V. It is to a point a linear relationship.From there if you buy or make a small PWM (Pulse Width Modulation) speed controller 'generally' 20-100% speed control will be ok so you can get under your 1RPM and upto 3RPM at the 100%. Random link but plenty of Power limit available and forward and reverse switchingeBay auction: #313397702155unless you are really keen buy one rather than DIY.Point bieng don't be bound by an absolute RPM on a spec sheet. I haven't done anymore looking at motors or gearboxes so enjoy the googling

author: newbie123
author_rank: Newbie
timestamp: July 17, 2022, 05:16:21 am
content: You the man Bean- thank you my dude this is fantastic. I am totally lost on all this- I don't even know how to connect these things together properly- do you have any recommendations on where to learn the basics on hooking this stuff up? Thanks again you have been a huge help!

author: beanflying
author_rank: Super Contributor
timestamp: July 17, 2022, 05:54:35 am
content: The best way really is to get some bits and have a play. Plenty of Youtube out there some good and some not so good. You don't need an Arduino or similar Micro Controller so avoid getting confused if you come across this sort of video. This one will cover a lot of the basics and moreWhen you get to the low voltage side of a power supply and away from the mains input you are fairly safe and the worst thing that will happen is you will release magic smokeIf you go with a Laptop supply then likely it will be protected against shorting the outputs or doing dumb things. Worst case will be off to the local secondhand shop for another $5 plaything.Power Supply to the PWM controller is the only bit to be careful about. If you hook up the positive and negative wires from the PS to the Controller reversed the magic smoke will almost certainly release. That one linked above is clearly marked in and out on the connections and has a + (positive) and - (negative) under the board. This is almost certainly going to be true of all controllers even the cheap bottom of the barrel ones.The Motor won't care reallyapart from if you get nerdy about brush timing (ignore this)if you get the connections wrong it will just run reverse.

author: newbie123
author_rank: Newbie
timestamp: July 20, 2022, 09:29:52 pm
content: Awesome thank you Bean! This video has helped a great deal- I will be buying parts now and I hope you don't mind if I reach out with more questions! Thank you again for all your help.

author: newbie123
author_rank: Newbie
timestamp: July 24, 2022, 01:56:19 am
content: Thank you everyone for your thoughtful replies, as I move forward on this project, I realized I have no idea how to wire the motors together? I will be running three worm gear motors on three platforms, 24 inches apart from each other, then running that into a cabinet that ahs a switch and an outlet to the wall. My question is- what type of wire / gage would I need? How do I connect them together? Should I connect them before connecting to the switch? Does anyone have any recommendations on a switch type? Is there anything else I need to make this work? (i.e like variable speed if possible- anywhere from .1 to 3 rpm- Ideally the switch would turn on all three motors at once, but that is not required.) What type of wire should I take to the power strip? Is there any instructional video on this type of thing as I don't want to electrocute myself lolI have attached an image with a mockup for visual. I am also open to any better way / idea to hook this all up if anyone has any thoughts. Thank you all again in advance!

author: beanflying
author_rank: Super Contributor
timestamp: July 25, 2022, 03:13:14 am
content: What you want to do FIRST is add up what you need to drive the three platters. So 12 or 24V or ?? and a likely total Current of the three so this will depended on load, speed and a bunch of factors but at a best guess 2A (total) at 12V (if that is what you choose as a voltage) or maybe 19V (higher speed from more Volts) if you choose to use an old Laptop Brick (likely will handle 3-4A maximum so plenty.As you are a newb with the electrical side avoid switching to much on the mains side for your safety apart from just a simple on off switch to the power supply. Even buy a switched power board and skip this completely.Then from the low voltage side split into three pairs of wires leading to the individual speed controllers (you need three as the loads will vary and cause the heavy one to likely not run well). ** As I mentioned earlier get your polarity right or the smoke will come out of your speed controllers.Switching these on or off is trivial and a switch rated at 1-2A will be plenty, not essential you put a switch on these but I would.For wire sizing 20 or 22 gauge will be plenty and you could go thinner but see what you can get locally even a medium weight speaker cable will do.

author: free_electron
author_rank: Super Contributor
timestamp: July 25, 2022, 03:36:31 am
content: look for pancake stepper motor.https://www.oyostepper.com/goods-496-Round-Pancake-Nema-24-Bipolar-18deg-6Ncm-8498ozin-1A-%CE%A660x96mm-4-Wires.html?gclid=Cj0KCQjw2_OWBhDqARIsAAUNTTGOHj_vE2FAq9FdeZYAfDRbX11WfJt_uUWJQzPMyrD8J5BSCrQl5EcaAlK2EALw_wcB1cm thick ... there are even skinnier ones.advantage of a stepper is that you can run it very slow with a microstepping driver without needing complicated gearboxes...