New Ball Lift Design by Rockston Engineering !

[rockston]

Thanks for the encouragement ! I am going with a Delrin sprocket ...nice and quiet, less moving parts...no ball detent...should be a piece of cake ... I'll have a proto this week.

[alphaminor]

You'll get it!

[Card Shark]

Very excited to see the results.

[mxfaiman]

I am going to have to abandon this entire design, it's just too loud.

It might be loud but it has a nice rhythm to it.

All it is missing is some train whistles.

[Moparformances]

i would not abandon this just yet..

you have a lightning fast device there..

i would build a thin plywood box around all the moving parts and try some insulation to quite the sound some... I dont think its loud at all.. but the Vid could hide some of the noise...

[mxfaiman]

i would build a thin plywood box around all the moving parts and try some insulation to quite the sound some... I dont think its loud at all.. but the Vid could hide some of the noise...

I was thinking along the same lines.

[rockston]

We will see about deadening the first design because the entire box acts like a speaker ... but first let me ask you guys: On an orange lifter is the sprocket split to allow for a divertor to get the balls out to the tube or does it work just on centrifugal force to the outside to eject them?


Thanks a ton guys !

[daverob]

I've also been playing around with gear based designs, and have just got myself a rotary table for my milling machine to try my hand at cutting my own gears , so this is what I have to offer on the subject...

The sprocket is indeed split. It has 10mm diameter semi-circular teeth, and a fairly deep groove in between. This has two functions, a tongue fits into the groove to guide balls out to the lift tube, and it also helps to centre the balls in the gear as the 11mm diameter balls have to sit partially in the groove, this means that they are nicely aligned as they meet the tube.

The other challenge with gear based designs is preventing balls from jamming as they feed into the gear, the orange lifters have a small sprung section of the track just under the gear (right where the balls from the hopper first meet the gear) so if a ball meets the gear and would have got stuck under the teeth, the sprung section flexes out of the way and allows the ball to move into the next gear segment without jamming.

You'll also need to have a switch to cut off the motor when there are no balls present. With an empty gear it will constantly push the stack of balls in the lift tube up, and they will then fall back onto the next gear tooth and before long you'll have a toothless gear. You could probably use a non return spring for the same effect, but I find that stopping the motor is easier (and quieter!).

Hope this helps...

[rockston]

Thanks Dave, very helpful and good luck with your lifter !

[rockston]

Sharing some progress promising - YouTube

[rockston]

Show Time ! sprocket drive 101 - YouTube


I could have done some actual work for customers today but what fun is that?


It is quieter, most of the racket is the balls hitting the box. I modified an off the shelf sprocket from Grainger.

Notice the sprocket is unconventionally mounted, I am using gravity to feed straight down into the side of the sprocket which

has several advantages. I am still experimenting on feeding this hungry beast but my guess is that the perfect shape inlet will allow

for jam free operation.


The speed of motor 2 is great however it's a bit short on torque at 9 Volts and I will most likely have to find a more powerful motor now.

In theory: 9 balls per rotation times 60 rpm 540 however the motor is bogging down a bit already without even hardly lifting and it's probably closer to 500

BPS.

[mxfaiman]

Hmm...

Looks good.

But you might find BPS increase by changing that 90 into two 45's. So it has a shallower slope to push balls up trough.

[rockston]

Hmm...

Looks good.

But you might find BPS increase by changing that 90 into two 45's. So it has a shallower slope to push balls up trough.

Absolutely that will help some, I plan on using long sweep 90's if I ever get to the plumbing supply house. However, I still need more torque, you can stop the motor easily by pinching the 3/4 hub underneath without any balls at all in it. It pushes balls up to 32" but slows down to about half speed by the time it get there so I need at least twice the torque at the same rpm. The cool thing is 8 or 9 balls a second is no problem. Now I am on a quest for an inexpensive 60 rpm motor with about 6 or 7 inch pounds worth of torque.

Thanks

[cardwwi]

Not sure if this helps motors start around page 140

https://www.surpluscenter.com/CAT284/Catalog284.pdf

Absolutely that will help some, I plan on using long sweep 90's if I ever get to the plumbing supply house. However, I still need more torque, you can stop the motor easily by pinching the 3/4 hub underneath without any balls at all in it. It pushes balls up to 32" but slows down to about half speed by the time it get there so I need at least twice the torque at the same rpm. The cool thing is 8 or 9 balls a second is no problem. Now I am on a quest for an inexpensive 60 rpm motor with about 6 or 7 inch pounds worth of torque.

Thanks

[pachiwall]

Looks like you found an acceptable gear! However here are some pics I posted awhile back when someone else was asking about the orange lifter gear.ball lifter gear 005.jpg 1.910" tooth to tooth, angle of pic looks like tooth to root of groove...but it is tooth to tooth.ball lifter gear 006.jpg OOPS! same pic, holding a receipt over flash to control glare.ball lifter gear 007.jpg .554" thickness of gear.ball lifter gear 008.jpg 1.553" from root to root of gear teeth.ball lifter gear 009.jpg .345" inside dimension between teeth, I probably should have measured center to center.ball lifter gear 010.jpgAnother root to root measurment...1.552" in this pic, the caliper probably moved as I was positioning it for the pic! I got an orange ball lifter that was in bad, but functional shape. It is no longer orange!ball lifter 010.jpg But it looks better than when I got it!Ball lifter slot guts 010.jpgBall lifter slot guts 013.jpg There is 2 pressure switches in the orange lifters. One in the lifter, and one in your top tray. If balls get full in the top tray...lifter stops. If balls run dry in the lifter...lifter stops. If you need any pics of how a particular problem was addressed, feel free to ask!

[pachiwall]

By the way, I ran out of space for pics, but this seemed important!Ball lifter slot guts 011.jpgNotice the pawl that is spring loaded. this holds the balls in the tube and prevents gravity from backflowing the balls into the hopper. I expect that by holding the column of balls it could reduce stress on the motor!Ball lifter slot guts 017.jpgThis is a pic of the pressure switch that stops the lifter when the lifter runs dry!

[rockston]

Thanks for all the info Shark !

[rockston]

Thanks for the pics and info Pachiwall!

[Lord Manimal]

As a resident n00b I probably shouldn't be trying to post any suggestions, but if noise and pipe angle are the primary problem, have you looked into flexible water pipe?
clear-1.gif

I'm 99% sure you can find this in the internal diameter required for a pachinko ball. Heck, some pet stores have rolls of the stuff lying around for their fishtanks, in addition to lowes, home despot (that's not a typo in Cuba!) etc.

For the sound dampening, on the box, I highly suggest craft foam sheets from Michaels/Walmart etc:

la189_f.jpg


For the motor housing sound dampening, it looks like it could be a simple plastic cup, lined inside and out with the aforementioned craft foam, slit in the side to allow placement/attachment to box. Open bottom, and slightly perforated top to allow natural convection to cool the motor. The noise would be directed "down" possibly into a small batch of dynamat, or foam from a guncase (which works amazingly well as a sound dampener!).

Have you given consideration to the fabrication of your own nylon components/castings? The less metal the more better, imho. Casting is quite simply as easy as obtaining your medium, mixing a batch of inexepensive mould compound (100$ gets you gallons of high temp silicon rtv mould making compound) suspending your wheel, arm and soon to be derelin bolt in the medium, pouring and waiting. Benefits include being able to use that first mould to generate say 10 or 12 copies, then using them all to make one master mould to pour 10, 12, or 50 at a time. Components are durable (depending on your exact selection of medium of course) and MUCH quieter. Plus, overall costs are greatly reduced. Precision water milling, or even general machining aren't cheap as you're obviously aware of!

Just wanted to toss out some ideas! I think you're really onto something here hoss.

[daverob]

have you looked into flexible water pipe?

I have. It's great for balls that flow downwards due to gravity, but it doesn't work that well when you're pushing upwards as there's too much friction.

As there needs to be a little clearance on between the balls and the side of the tube, the balls don't sit exactly on top of each other, so the weight of the balls above pushes the balls below a little bit sideways. With hard wall tubing (solid plastics and hard metals) this isn't that much of a problem, with soft wall tubing (flexible plastics and soft metals such as copper) the combined friction of a stack of 50+ balls means it's much harder to push the balls up the tube.

Have you given consideration to the fabrication of your own nylon components/castings?

I'm planning on trying something like this for my ball lifter design. I think that you'd be better off machining the gear from a strong dense plastic such as an acetal polymer (delrin), but for the other parts where strength isn't so much of an issue resin casting might be the best option (unless you're making enough to justify the tooling costs of injection moulding).

Precision water milling, or even general machining aren't cheap as you're obviously aware of!

Unless you have your own machine tools in your workshop