Edge and Wall Sensor for the Pink and Green Domino Machine II by Gzumwalt

This is an ACCESSORY for the Pink and Green Domino Machine II By gzumwalt.

It replaces "Mount, Battery.stl" and the two bolts that hold it on. The rest of the operational parts are Greg's genius work and can be found with his posting. It can be retrofitted to any existing Domino Machine II or new build.

Credits regarding parts:

1. For Consistency the BOLTS are ether modified bolts from Greg's train or copies of the bolts. To reduce confusion I have provided the bolts with their name in this project. Therefore for consistency you can chase any printed threads with a 6mm x 1.0 tap to clean them up.
2. The base of the battery mount is dimensionally Greg's design so it would fit properly.

The Accessory adds an table edge sensor and wall sensor in a forward assembly that, with blurry vision, may have some resemblance to a train. The wall sensor looks like a light and also acts as a more easily accessible ON/OFF switch. Do remember the Nose LIGHT switch needs to be pulled out and the edge switch closed for the motor to work.

I will also be adding to this library some treads I designed after the two local hardware stores could not provide me with the 8 O-rings I needed. Mixed results with the tread. I had to add teeth to the front wheel. Ultimately TPU does not have the grip of O-Rings... so now I own large quantity of o-rings. For your first train a Visit to Harbor Freight will provide you with a household supply... and 10 of the size you will need.

This project is very straight forward. I designed it around one switch type. The spring for the nose wheel can be a little touchy. I will talk about that more in that step. But I am adding a downward switch against really light plastic. Too much spring pressure and you lift the front drive wheels so they don't have traction. I have built 4 to get this dialed in... I think you should have good success.

I also designed a DOMINO STACKING tool for this train. Be sure to check that out BEFORE you print anymore dominos.

I print all the items for the train as Greg recommends. The front wheel shaft I print differently... I print it laying down so that it has more strength.

Non-Printed Parts

1. Some wire... 22 to 24 gauge is fine. maybe 150mm (6") of two different colors.
2. A Soldering Iron and solder
3. A hands width of 1.7mm filament.
4. A Spring.
5. I am using PEN SPRINGS, however, you need to find an OLD STYLE pen with the very narrow non-gel reservoir. The spring needs to have a pressure of LESS than 100g when pushed against a scale. I designed for about 22 to 25mm in length. You will want about 6-8mm sticking out.
6. Two Limit Switches
7. Some glue if you are going to add TEXT or an accent ring.
8. One 210 (.75 x 1 OD x 1/8) or 211 (.13/16 x 1 1/16 OD x 1/8) o-ring ... or print the TPU version for this.
9. Optional... a wire cap. You can alternately solder and cover the one connection.
10. Optional... if you want the nose assembly to be easily removable to put on something else, one set of jst connectors.

I use a limit switch from Temco Industries. I am sure there are many manufacturers of this type of switch. Whatever you pick the dimension and throw will have to match.

Here is the Temco dimension sheet I usually buy them in Temco ebay store where they normally sell them in units of 6 to 100 at a reasonable delivered price.

Printed Part instructions.

1. The only part that will need supports is the new battery holder. You will need to support that from the plate. All of the other parts should print without supports.
2. I have provided several Accent rings you can print and glue onto the front. I have also provided optional text.
3. Accent rings are very thin and may be hard to get off the plate if you don't have some releasing agent
4. To add text to the train, I add the optional text on the print plate overlaying the accent ring before slicing.
5. The TPU tires I am posting where an experiment that I thought worked well on my first train and then for some reason did not on the others.

Text is generated with a program I wrote that generates text on a breakaway bar. You are welcome to generate your own custom text with that program which you can get HERE.

If the "ew_Light_Shaft_Pin.stl" is too tight let me know and I will shave a little off its diameter.

Material: I have printed all 4 out of PLA+. I printed one with an accent of SILK PLA. It looked great. Be prepared to do a little more fitment as the silk printed with slightly different tolerances. It also has less of a tendency to seat quite as closely when printed as a screw. q

Clean the battery mount of support material. There is a little notch on one side toward the back, make sure that is clean of support material.

I recommend chasing the threads with a 6mm x 1.00 tap so the bolts go in easily.

I usually

1. give the bolts the slightest touch of lubricant so they go in easily.
2. do not trim the wires on the battery holder I buy so that it can easily be remove to change the batteries.
3. test the motor to identify the + and - that makes the train move forward.

Test your battery pack before installing (if you have meter)

1. The battery pack should put out about 4-6V and should not get hot.
2. if your battery pack ever starts getting hot, remove the batteries immediately. I had received one with a pinched wire around the switch that caused a direct short.... so test it first. If you have no meter, install the batteries, don't touch the red and black together... wait 5 minutes and make sure it did not get warm.

Solder a length of wire to each motor terminal. Leave enough wire to extend through the battery mount (ew_battery_rack_to_support_ew_nose.stl) and to one of the switches. I do this with the Red. The black just has to come out far enough to attach it to the (-) battery wire.

Run the wires from the motor through the hole in the bottom of the battery mount from the back and out the front.

Insert the battery holder wires into the battery mount and out the front hole at the bottom so you now have 4 wires coming out the front.

1. Place the battery mount on the Train frame.
2. Install the ew_Bolt,_Battery_Set.stl short bolt to the right when looking at the front.
3. Install the ew_Bolt,_Battery_Set.stl long bolt on the left
4. Install the ew_Bolt_battery-to-top-frame.stl at the top

In this step we want to make sure the edge wheel shaft fits properly and has free movement.

1. Put the tread or o-ring on the ew_front-edge-wheel_65percent.stl
2. Insert the spring into the ew_shaft_17-5_spring_hole_Depth_5mm-dia.stl. It should stick out about 6cm.
3. Careful as you go through this process. The spring can fall out of the slot and jam movement.
4. Insert your ew_shaft_17-5_spring_hole_Depth_5mm-dia.stl in to the slot on the ew_nose.stl
5. Does the shaft insert all the way? Does it move up and down freely?
6. If it does not, inspect the slot for excessive bridging at the top of the arch (the shaft has that entire side cutoff so it should not be an issue). Remove some excessive bridging if it looks like an issue.
7. Check the slot on the side of the shaft. Look for feature transitions that may have created an elephant foot type protrusion. Trim those off.... I have seen them at the END of the slot.
8. Can try a little lubricant, but the shaft needs to move freely without jamming.
9. If the spring is a little short you can usually stretch it a mm or two.
10. Remove the shaft, set aside the spring and Install the ew_front-edge-wheel_65percent.stl and insert ew_front-edge-wheel_bolt.stl
11. Ensure the wheel spins freely
12. Set the shaft aside

Inspect the holes for the light shaft pin and make sure they are well formed and free of debris.

Test that your filament fits freely through the ew_Light_Shaft_Pin.stl before you install it. Any issues can be corrected with a 2mm drill (5/64").

1. Install the light shaft (ew_Light-Shaft.stl) through the front of the ew_nose.stl. The notch MUST be facing upwards.
2. make sure it moves in and out freely without hanging on anything.
3. It will be a snug fit, place the end of the section of the ew_Light_Shaft_Pin.stl into the hole for the light shaft in the ew_nose.stl.
4. Be careful not to break the hole mount.
5. Seat the end at an angle and then maneuver the other and to the furthest edges of the shell until it inserts into the hold
6. As you insert the PIN it needs to go through the SLOT in the ew_Light-Shaft.stl
7. Insert the SHORT side of the ew_Light_Shaft_Pin.stl into other hole until it is flush.
8. Install your filament rivet all the way through. Pull the first rivet head tight against the PIN head.
9. This rivet needs to be snug so the short end of the PIN does not fall out.

Test that the ew_Light-Shaft.stl moves freely in and out.

Choose a wiring plan. I only wired my first tow with removable connectors. Mostly because I was really in development phase. You can use the removable connectors if you want to change out the battery mount or nose. Otherwise wiring direct is fine.

Notes:

1. Leave enough slack to not make your life hard in wiring.
2. You need to make sure there are NO wires that are behind the light switch when you close it up.
3. This also means the wire from the top switch to the lower switch needs to have enough of a loop to stay out of the way.
4. You can test fit your switches between steps. I don't recommend soldering with the switch installed as the heat could soften the plastic.
5. The top switch, the forward wire may need to fit along side the rear post it is passing. I did add some cuts to reduce pinching.
6. Don't solder the wires to the top switch such that the solder joints make the pins taller.
7. I chose to use filament rivets for the switches. That leaves play as the switch holes are bigger. I believe I have compensated enough for this. You do have the option of slight bending the switch arm if necessary.
8. The switches have a very small movement between engaged and not
9. make sure you hear a click when opening and closing the light after you insert the top switch and set the rivet posts, but have not closed them up yet.
10. The top entry has two small squares protruding. These are to keep the switch from rotating when engaging. Avoid trimming them unless you absolutely need to for fit.

Soldering

1. Solder your wires to the switches per the diagram you pick.
2. Start with the top switch.
3. Attach both wires, insert the switch and better cut the wire to the lower switch making sure the wire arches sufficiently to not be behind the light sliding in and out.
4. Solder to the bottom switch.
5. Insert the switch and set the rivets.
6. Insert the edgewheel shaft and see that you are getting a switch click moving the shaft in and out.
7. Rivet the switches in place
8. Test the nose clicks as the goes from rest to an accelerated close.

The lead weight experiment

I added lead weights inside the nose of one model. It was the silk pla+ mix black and silver print. It helped, but it did not totally solve the problem. What solved my issue was adding a washer to a bold on one of the gears that had too much play. It was only in this SILK printed gear model that I had that issue. The same washer is too tight on an all PLA+ build.

Time to do the final install on the shaft (ew_shaft_17-5_spring_hole_Depth_5mm-dia.stl) we set aside.

1. install the spring into the shaft
2. Have the ew_Bolt_Holds_ew_Shaft_Slide_round_end.stl bolt handy.
3. Carefully install the shaft with the spring in the hole.
4. As the slot clears the hole for the bolt, insert the ew_Bolt_Holds_ew_Shaft_Slide_round_end.stl bolt and tighten.
5. Do not overtighten this bolt. The objective is for the stop to protrude into the slot to prevent the shaft from coming out.
6. After the bolt is installed, test the movement.
7. The shaft should move freely up and down.
8. You should hear a click within the first 4 mm of movement or so... so long as you hear a click.

TEST the MOTOR before ASSEMBLY.

Double check your wiring

1. Install some batteries...
2. Open the front light switch, momentarily push in the ew_shaft, the motor should engage.

Test 2

1. Push in the front light to the off position.
2. Push in the ew_shaft
3. Momentarily pull out the front light switch, the motor should engage.

Remove the batteries, or turn off the battery pack

If all your power tested fine, it is time to install the nose.

1. Collect all your wires to one side or the other of the inside of the nose.
2. You can tie them if necessary, but it probably will not be.
3. Make sure wires do not fall out the hole in the bottom.
4. The nose hooks over the lip at the top of the battery compartment
5. Align the holes on the right and left of the nose
6. Install the ew_Bolt_Nose_Print-Qty2 bolts on both sides.
7. Feel free to install them half way and then to test.
8. After re-testing your switches, close up the nose bolts.

I found you can spice up the nose a bit by adding a ring to it. You are restricted in that the ring cannot interfere with the light switch. The same applies if you add text.

I added three Accent rights I have tested. I personally like the thin one and the two level one that adds depth.

Some rings are very thin and may be resistant to releasing from your plate as they will flex with the plate.

ADDING TEXT

• I have added text after the ring... difficult.
• What I do now is add the text to the ring on the build plate.
• I use breakaway text, so you can in theory keep it straight.
• The breakaway text does not connect the dots on the i's and such so don't loose those.
• The downside is it is a lot of glue to apply and get installed before it starts drying.
• You CANNOT get glue on the text support bars... or they won't come off.
• Text should be placed as low as possible in the ring so it clears the light.
• If you don't like the way it looks after you print, you won't like it any better once you install it.
• In the intro I reference the link to the program I used to create the text.

Glue TIP

If you are using superglue... I find the glue does not wick as much if you place the piece in front of a fan for the glue to dry. This is because these types of glues put off vapors as the dry.

I added a graphic to one train I gave to a grandpa friend.... so that is an option too.