Big table/Small room-thinking outside of the (bar)box

fastone371

Certifiable
Silver Member
By the time this moving table project is completed I would guess that he would save time and money buying a different house. An option if he has adequate yard space is to build a "man shed" that would accommodate a pool table of his choice. Going this route would also give him the option of outfitting the interior as he sees fit as it would not affect the Mrs. home décor.
 

bignick31985

Life Long Learner
Silver Member
By the time this moving table project is completed I would guess that he would save time and money buying a different house. An option if he has adequate yard space is to build a "man shed" that would accommodate a pool table of his choice. Going this route would also give him the option of outfitting the interior as he sees fit as it would not affect the Mrs. home décor.
Yep, instead of adding on, just make another 400sq ft room out back for the table. Only runs $20,000 after it's said and done, but their is no price on your sanity.
 

jasonlaus

Rep for Smorg
Gold Member
Silver Member
Tear up the floor and install railroad tracks under the legs, make sure they are perfectly level and install a manual brake.

Good luck 🤔
 

ridingfree2001

Ridingfree2001
I’m posting this on behalf of my buddy, he hasn’t got his approval to post yet- I guess admin are too busy playing pool and that’s the way it should be!

....If I may I’d like to throw the problem into the forum and see if it elicits any new ideas or pitfalls that I didn’t think of. I’m half way through the project
already and of course I think my solution is the greatest solution ever devised. However, I’m 56 and have learned recently that there are people out there way
smarter than me (don’t ask about my mailbox key fiasco).

Background:
I play in a league with 9’ tables so I wanted a 9’ table in my basement. I only have 11’8” on the long rail sides so technically this isn’t enough clearance for even a 7’ table with a standard 58” cue.
So……. I went ahead and bought an 8’ table, telling myself that I would just use a shorty cue for the occasional shot. Well 40% of my shots required the shorty cue and within a
few days I decided to just move the cue ball by hand away from the rail. This of course negated any concept of positional play and I quickly found myself losing interest.

Then Covid shut us down and I had time to stare off into space and think a bit more about the problem. I could buy a smaller table (loser), buy a new house (nope), knock out a wall (What would the wife say?)
or build a device that could move the table into position depending on the leave of the cue ball. Obviously somebody on YouTube would have already designed such a thing so I cracked a beer and started searching.
Apparently this problem/solution is the only video NOT on YouTube. (teaser: we’ll fix that).

So, staring at the ceiling one night I summarized the following.


The solution needs to be integrated into the normal flow of the game. Ideally, you should forget that the table moves after a few games and just play as if it were a normal table.
This means that manually moving the table is not even being considered. That would affect the flow of the game and introduce human error into the equation (think mailbox key).



1: I need the table to move 12” left or right in order to have unimpeded play. Total linear motion then is 24”.

2: Table need to move into its new location in under 10 seconds. I chose 10 seconds because that’s the approximate time it takes from the instant
I hit the ball until I’m ready to bend over for my next shot. This includes pre-shot routine, staying down after the shot etc.

3: Table need to remain level at all times. My table is leveled now for the centre position. Will it still be level if it’s moved 12” away?

4: The balls can’t move at all. I know my buddy will call me out for cheating if the balls move even the slightest bit. He’ll say they always move in my favor when its my shot and against him when its his shot.
This probably would not have been a problem with the shag carpet that was originally on the table but we changed the cloth for a Simonis worsted cloth a few months back.
The friction coefficient is now VERY low and the balls can easily be disturbed.

5: Braking system: I weigh 200lbs. A rudimentary test with a scale between my belly and the table shows that I apply 15lbs of lateral force on the table when I’m stretched out over the table for an awkward shot.
Table needs to have the equivalent of an emergency brake applied when stopped.

6: Height: My table is 32” high. If I add some sort of mechanism under the table and raise the table X inches I’ll need to be able to lower the table by the same amount.

7: Control activation System: It seems obvious at this point that we are talking about some sort of electric linear actuator. How would it be activated?
Interrupt buttons, Hey Alexa MOVE TABLE LEFT, clapping, IR or Bluetooth remote control, etc. However its done it must not interfere with the flow of the game.

8: Noise: I don’t want the table to be heard over the background music. Mostly Burton Cummins and Gordon Lightfoot at the moment.

9: Lighting: My overhead lights are directly over my table. Lighting needs to be good wherever the table is parked.

10: Safety: A rogue motor powerful enough to move a 600 lbs table could wreak havoc on a table frame. Finished product needs to have safety features build in. E.g. Limit switch/homing sensor of some soft.


So, that’s the scope of the project. I purposely left out all my ideas because I wanted my fellow pool playing buddies (or just nerds as my kids keep telling me) to chime in with some ideas.
My current timeline will have the project completed in about 4 weeks. At that time I will post a “How To Video”. If you have a solution for any of the 10 listed problems then throw it in the mix. It’s not too late for me to change course.



Scott
 

ridingfree2001

Ridingfree2001
I always make the biggest room in the house my pool room and if its the living room...a Bedroom may end up as the living room! Priorities are easier when youre single!
 

MitchAlsup

AzB Silver Member
Silver Member
Well I give you credit for having an original post idea on these forums!

Your friend's project sounds fascinating to me. I fool around with CNC machines on a hobby level. Here is what I would recommend:

-Put the table on linear bearings used for CNC milling machines. You can get them on eBay, or cheaper on aliexpress if you don't mind the 2 month delivery. I think you will need 25mm to 30mm wide linear bearing guides. The wider they are, the more weight they can support, but the more expensive they become.
-Put the guides on the floor, and the trucks on the table legs.
-The guides must be level and on a rigid surface, so when the table moves, it will retain its level.
-Put the guides in a recess in the floor, so that you won't trip over them, and you won't make the table much higher. (side note, if you are tall, a taller table won't be a problem. I have my table on top of 5" blocks and love the height. I'm 6' 3" tall).
-Use a ball screw to move the table. One on each pair of legs. You are only moving a frictional load, not a weight bearing load, so the screws can be on the small side (and cheap side). A 12mm or 15mm screw will be plenty. The larger the diameter the screw, the more expensive. Get the screws from aliexpress or eBay.
-Use a servo motor, not a stepper motor. The prices are almost the same now in the hobby world. A stepper motor will make a horrible ringing noise, especially at the low RPM needed for this application. A servo motor will be whisper quiet. JMC Servo motor is the cheapest. The model number you want is iHSVxx. where the xx is 57 or 60 depending on the size. But technic clearpath servo motors are easier to setup, and still cheap. If you use a belt reduction, a nema 23 size will be fine to move the table, as my educated guess. With no reduction, you might want a nema 34. I'd probably try a nema 23 to start as they are more compact, even without a belt reduction. Actually I take this back. I'd go with a nema 23, and design in a belt reduction. Servos work best at faster speeds (opposite of steppers), so having a belt reduction will mean the servo can spin in an rpm range that has more torque. This will give you more reliable service.
-With a ball screw, (and the servo's not physically attached), you will be able to back drive the screw. This means if you lean on the table, it will turn the ball nut because the friction in the ball screw and ball nut is so low. In comparison, if you used an acme screw or a v-thread screw, the table will be locked in place when you lean on it, even with no servo motor attached. That is an advantage in your situation, at the expense of significantly more friction in the system, and then a more powerful motor needed to turn it. Having used both v-thread leadscrews and ball screws, the difference is huge, and I think I'd still go with a ball screw in your application. With the system on, the servo will hold the table when you lean on it. But if the system is off, the table will move if you lean on it. There are also servo motors that have a break, so that when the system is off, they don't spin. That would also solve this back driving issue.
-You will need this whole system times two. One for each pair of legs. To couple them, tie the two servos together electronically. The other way to do it is use one servo motor and tie both halves together with a belt or a chain. Both methods are used in CNC machines, particularly cnc gantry routers. For your application, the electronic method will be much better, since you won't need a long mechanical system in-between the two sets of legs.
-Have a home and limit switch on the end of each rail.
-For deciding when to move the table, some sort of vision system like Bob mentioned would be nice, but I think that would be way to difficult to implement, unless your guy is an electrical engineer, and computer programmer, and does vision systems for his day job, and can take home the equipment needed from the dayjob. I think a simple button on the table rail that moved the table from one extreme to the other would be simple to do, and easy to operate. You could have it duplicated on both sides of the table. Push it once, and the table moves 24" from where it is. Push it again, and it moves 24" back. That's it. No other options. Nothing to think about. With the ballscrew and linear rails, I don't think it would be a problem to move it 24" in 10 seconds.
-Expect this project to a year to complete in a hobby situation. Unless your guy is very familiar with cnc, CAD, electronics, computers, arduino, etc. Each component in this type of system has a very steep learning curve.

Good luck:)

Basically this, with a couple of exceptions::

We don't know about the floor the table is on !!

I recommend placing the rails at a lower level than the floor, and having the vertical height of the trucks "seal" the rail from the floor.
The rails need to be installed and precisions shimmed to the table remains level as the table is moved (level down to the 0.001" (.025 mm))
As the table moves, you need some kind of seal to "follow the table movement" and keep crud off of the rails.

Shim both rails level in their run dimension (this will be difficult enough), and shim the trucks (on paired legs) level in the orthogonal dimension to get the table dead flat.

Finally, the table needs to accelerate up to speed and decelerate back to a stop without disturbing the table position.
 

Chili Palmer

323
Gold Member
Silver Member
I didn't read the whole thread but using linear actuators would work. The table may weigh 600lbs but on rollers of whatever type, you won't need much room to move it.

Other then that:

Use some sort of sensor that can tell when the CB stops and then have it move the table automatically.

I would want the table to move the entire distance each time because this way you can have it "lock" into the other side somehow so the table doesn't move. If the table moves 6" then it's basically "floating" in the middle of it's range and may or may not be stable.

Instead of lowering the table you could raise the floor. A guy I know had a great room in his house that was sunken but when you were shooting at one end of the table you had to stand on the stairs. He ended up building up the floor of the entire great room so now it's flush with the floor in the hallway and you just walk right in. The windows weren't full length top to bottom but they are now and the outlets are near the floor but it works. Good thing he had 10' ceilings :)

Fun idea.
 
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