Gravity Griff introduction and instructions


Gravity Griff is a model of a Ffestiniog Railway 3 ton iron frame slate waggon with brakes. It has a hidden motor, controller and sound card to simulate a gravity train. It is available in 16mm scale 32mm gauge and 7/8ths inch scale 45mm gauge together with matching unpowered slate waggons.

It has a 4 wheel drive motor/gearbox completely hidden in the chassis. It is controlled by a Loco Remote Mini B and powered by 4 standard AAA NiMH rechargeable batteries easily accessible under the removable slate load.

The kit contains everything you need including a Loco Remote Mini B to build a fully remote controlled loco. Just add batteries and a custom driver from the Clavey Models eBay store to get up and running with your smartphone.

It is 3D printed in PLA ST (super tough) grey and black. This means that while it is fine to run it anywhere, do not leave it standing outside in hot sun for any length of time, especially if it is unpainted. Above around 50 degrees C (120 degrees F) PLA can start to soften and so it may deform. Remember this is the temperature of the PLA which may be higher than the air temperature in the sun. PLA ST is more resilient than standard PLA.

The kit has been designed to have some of the parts friction fit together without the need for glue. Polystyrene cement (used for Airfix kits) works well on this PLA. We suggest Revell Contacta Liquid Glue with Professional Needle Applicator. Apply a fine line using the needle applicator and then hold the pieces together until set in a few minutes. Other glues including epoxy can be used but note that cyanoacrylate (super glue) may well leave a white bloom on the surface of the PLA that is hard to remove. This may be okay if you are painting Griff afterwards but otherwise best avoid it.

For the friction fit parts, a very gentle rub with wet and dry paper may be needed on some edges if they are too tight. Similarly some of the holes may need slight opening with a needle file or finger drill. Please do this slowly and gently. You should not need to open the axle holes on the wheels and pulleys at all as they have been hand finished already for a tight fit.

www.locoremote.co.uk

Gravity Griff 16mm scale powered slate waggon parts



3D printed parts
  • Black: chassis, 4 wheels, 4 axle boxes, 2 coupling hooks, 4 brakes, brake handle, brake handle support, motor pulley, motor holder, 2 axle pulleys on axles
  • Grey: 4 cage sides, cage top, switch holder, slate load bottom with 2mm bolt, slate load top, slate load holder
Electrical and other parts
  • Loco Remote Mini B
  • Combined motor and gearbox
  • On/off switch
  • Speaker (optional)
  • White power connector and cable for Mini B
  • 2 wire motor cable with Dupont connector at one end
  • 2 wire speaker cable with Dupont connector one end (optional)
  • PP3 type battery cable
  • 4 x AAA battery holder with PP3 type connector
  • 2 O rings
  • Clear heat shrink tubing
  • 2 50mm long axles
  • 2 pieces of brass coupling chain
  • Approx 2cm of 1.5mm diameter brass rod
  • 2mm allen key for the bolt on the slate load bottom

16mm scale unpowered slate waggon parts



3D printed parts
  • Black: chassis, 4 wheels, 4 axle boxes, 2 coupling hooks
  • Grey: 4 cage sides, cage top, floor, slate load bottom (optional), slate load top (optional), slate load holder (optional)
Other parts
  • 2 50mm long axles
  • 2 pieces of brass coupling chain

Wiring

Skip to the first photo in this section with a green background if you have the prewired version


On/off switch - 1
  • Locate the printed switch holder, on/off switch, power cables and heat shrink tubing
  • Cut the wires attached to the white Mini B power connector to 7cm and strip the ends
  • Cut the wires attached to the black PP3 battery connector to 10cm and strip the ends
  • Cut 4 pieces of heat shrink tubing to 8mm
  • Cut off the 2 metal tabs at one end of the switch - the middle 2 and 2 at other end should remain


On/off switch - 2
  • Bend the metal tabs on the switch out slightly to make soldering easier
  • Slip a piece of heat shrink tubing on both wires attached to the white Mini B power connector
  • Solder these wires onto the 2 remaining switch end tabs
  • Push each heat shrink tubing so they fully cover the soldered tabs and gently apply a soldering iron to shrink these in place


On/off switch - 3
  • Slip a piece of heat shrink tubing on both wires attached to the black PP3 battery connector
  • Pass the wires through the switch holder as shown - you must do this before soldering the wires to the switch


On/off switch - 4
  • Solder these wires onto the 2 middle switch tabs so that both reds are on the same side of the switch and both blacks on the opposite side
  • Push each heat shrink tubing so they fully cover the soldered tabs and gently apply a soldering iron to shrink these in place
  • IMPORTANT - make absolutely sure the soldered tabs are fully covered by the tubing and there is no possibility of any tabs or exposed wires touching and causing a short


On/off switch - 5
  • Gently bend the wires as shown and insert the switch into the holder
  • It is a tight but secure fit so wiggle it in carefully
  • Make sure the orientation is the same as the photo


Speaker (optional)
  • Separate and cut the blue and green wires to 5cm and strip the ends
  • Solder them to the speaker tabs - do this quickly and carefully since if you leave the soldering iron on the tab for too long it could loosen the tab and internal wires


Motor
  • Separate and cut the yellow and orange wires to 5cm and strip the ends a SMALL AMOUNT
  • Slip a 8mm piece of heat shrink tubing on both wires
  • Orient the motor as shown - locate the top which has a half width piece of brass support in the gearbox circled
  • Solder the yellow wire to the tab on the same side as the half width piece of brass (bottom in the photo) - the tab is very small so do this carefully and make sure the solder or wire do not touch the metal case of the motor
  • Solder the orange wire to the other tab - the tab is very small so do this carefully and make sure the solder or wire do not touch the metal case of the motor
  • Push each heat shrink tubing so they fully cover the soldered tabs and gently apply a soldering iron to shrink these in place
  • These connections can be fragile so don't bend them until you are ready to put the motor in the chassis later
  • If you accidentally attach the yellow and orange wires the wrong way round don't worry - it just means you will need to connect them to the motor output pins of the Mini B the other way round so that the waggon runs forwards correctly


Preassembled wiring
  • If you ordered the preassembled wiring it will come packaged like this
  • Carefully remove the optional speaker which is only lightly held in, Mini B and battery holder
  • Carefully unwrap the Mini B, motor and switch
  • The connections on the motor and speaker can be fragile so don't bend them until you are ready to put them in the chassis later

Connecting the electronics



Components
  • Locate the Mini B, switch, motor and optional speaker
  • The Mini B in the version without sound does not have the top green board


Connecting the Mini B
  • Make sure the switch is set to off - the black handle should be pushed so that it does not go over all 4 wires
  • Connect the white power plug into the white socket on the Mini B - it is keyed and should only go one way with the red wire on the outer side
  • Connect the 2 wires from the motor to the 2 pins on the edge of the middle blue board with the yellow wire plugged onto the outer pin further from the white socket so that Griff goes in the correct direction - if you get this wrong you can always swap the wires round later
  • Connect the 2 wires from the speaker to the 2 pins in the middle of the green board marked Speaker - it does not matter which way round
  • The other 4 pins on the green board are for LED lights which are not used


Connecting the batteries

IMPORTANT! Only use 4 x AAA NiMH rechargeable batteries. Do not use Alkaline as their voltage may be too high and definitely do NOT connect a 9V PP3 battery even though it has the same clips as this will destroy the Mini B. Please download and read the setup guides from the links below before proceeding further, especially if you have not used a Loco Remote before.


Electronics check
  • Check everything works by connecting 4 x AAA NiMH batteries and turning the switch on. The bugle should sound.
  • Connect your smartphone to the Mini B as described in the Mini B setup guide. The Mini B has already had it's 'Shutdown on low battery' preset to off since you are not using a lipo.
  • Run the controller from your screen. When going Forward, the motor shaft should be rotating anti-clockwise as you look directly at it. If it is rotating clockwise reverse the yellow and orange motor wires.
  • Tap the sound buttons to play the 4 sounds. 2 are bugles and 2 background running noises - note these are not related to motor speed.
  • You can change the name on the screen (mine is Gravity Griff) and password if you wish as described in the Wi-Fi connection and controller operation guide.
  • Once you are happy everything is working correctly, turn the switch off and disconnect the components.
  • Always remember to switch the power off when you have finished running so the batteries do not fully drain.

Assembling the waggon

The photos cover assembly of the powered Gravity Griff waggon. The unpowered slate waggons go together in exactly the same way, but clearly without the brake parts, motor and electronics. The unpowered slate waggon has a flat floor that can be glued to the chassis inside the cage. The optional slate load is removable and sits on this.


Cage - 1
  • Locate the cage sides, ends and top - note the sides are different with one having brake handle mounts
  • If there are any fine strings on the rivets left over from printing, gently remove these with your fingers and a sharp knife - don't cut off the rivets though!


Cage - 2
  • Run a fine line of glue along the inside edges of the cage top and on the lugs at either side of the cage ends


Cage - 3
  • Note the orientation of the sides and ends so that the narrower strips attach to the top
  • Attach one side to the top
  • Attach the 2 ends to this and the top
  • Attach the other side - the top is a deliberately tight fit so you need to squeeze the end between your fingers a little bending the end as shown so that the side sits in the gap of the top - you should feel it clip in place
  • Make sure the sides ends top are inside the top all round, squeezing them as needed - they may bow a tiny bit until the pegs are added in the next stage - key is to make sure everything is in correctly and level on a flat surface


Cage - 4
  • Use 6 or more wooden pegs to clamp the sides and edges to the top as shown, again making sure they are all in the grooves under the top and not bowed
  • Use a rubber band round the bottom of the sides and edges to keep these tight and alined while drying - make sure it is not so tight it bends the ends or sides
  • Make sure the bottom is square on a flat surface and put the cage aside to dry


Wheels and axles - 1
  • Locate the wheels (disc or curly as ordered) and axles
  • Drive pulleys have already been prealigned on the axles - note they are correctly in slightly different places on the axles


Wheels and axles - 2
  • Push the axles onto the wheels, being careful not to move the pulleys


Wheels and axles - 3
  • Back to back wheel spacing should be 28mm


Chassis - 1
  • Locate the chassis, 4 brakes, 4 axle boxes, 2 axles with wheels, 2 O rings, 2 coupling hooks and 2 pieces of brass chain
  • Check the axles move freely in the axle boxes


Chassis - 2
  • Glue the 4 brakes into the holes on the underside of the chassis
  • Push 2 axle boxes into the holes on the side of the chassis with the motor block - these are a deliberately tight fit and should not need gluing so they can be removed for maintenance later if needed
  • Put an O ring onto each axle - don't forget!
  • Put the axles into the already fitted axle boxes with the pulleys on the side away from the motor block as shown - it does not matter which axle is which
  • Fit the axles into the remaining 2 axle boxes and push fit these into the chassis
  • Make sure the brakes are accurately aligned and do not touch the wheels before their glue dries - a good reason for not using instant glue!


Couplings
  • Slide a piece of brass chain into the chassis coupling hole
  • Slide the coupling hook onto this making sure the hook is oriented as shown so it faces the chassis
  • Use a small pair of pliers to close the chain loop
  • Repeat for the other end


Motor and pulleys - 1
  • Carefully push the motor into the hole on the top of the chassis with the orange and yellow wires oriented as shown
  • It is a secure fit so try to avoid taking the motor in and out of the hole as this may weaken the joints to the wires


Motor and pulleys - 2
  • Keeping a finger on the motor to stop it falling out, turn the chassis over
  • Slide the motor holder through the hole from either side


Motor and pulleys - 3
  • Push the motor holder all the way through the opposite hole to secure the motor
  • The motor holder should not be glued so it can be removed for motor maintenance later if needed


Motor and pulleys - 4
  • Slide the double motor pulley onto the motor shaft noting the flat part
  • Carefully stretch the O ring on the axle with the pulley closest to the middle onto the motor pulley nearest to the motor - you may find a pair of tweezers helpful but be careful not to damage the O ring
  • Stretch the O ring over the pulley on the axle


Motor and pulleys - 5
  • Repeat the process for the other O ring and axle


Attaching the cage and brake handle
  • Align the cage with the side with the brake handle mounts with the side of the chassis with the brake mount hole on the bottom - it's the same side as the pulleys and O rings
  • Glue the cage onto the chassis - the cut outs on the ends should fit over the buffer loop
  • Glue the curved brake handle support onto the side with the mounts
  • Fit the brake handle using the 1.5mm brass rod to the hole in the chassis - it should be a tight fit and movable
  • Check the cut out on the handle fits over the curved brake handle support throughout its travel, adjusting the support if necessary before the glue dries


Preparing the slate load bottom
  • Locate the slate load bottom, switch, speaker, Mini B and allen key
  • Use the allen key to remove the black 2mm bolt in the load bottom corner


Speaker (optional)
  • With the slate load bottom on a flat surface, push the speaker firmly into the hole with the wires pointing towards the Mini B mount as shown


Fitting the slate load bottom
  • Carefully feed the motor wires through the hole and seat the slate load bottom in the cage - make sure they come stright through and do not get trapped
  • Do not glue the load in case you need to access the motor and make sure the motor


Connecting the Mini B
  • Make sure the switch is set to off - the black handle should be pushed so that it does not go over all 4 wires
  • Connect the white power plug into the white socket on the Mini B - it is keyed and should only go one way with the red wire on the outer side
  • Connect the 2 wires from the motor to the 2 pins on the edge of the middle blue board with the yellow wire plugged onto the outer pin further from the white socket so that Griff goes in the correct direction - if you get this wrong you can always swap the wires round later
  • Connect the 2 wires from the speaker to the 2 pins in the middle of the green board marked Speaker - it does not matter which way round
  • The other 4 pins on the green board are for LED lights which are not used


Mounting the Mini B
  • Position the Mini B on the lugs and then secure it in place with the 2mm bolt and allen key


Mounting the on/off switch
  • Push fit the on/off switch into the corner of the slate load bottom held in place by the speaker mount


Checking the electronics
  • Fit the 4 x AAA NiMH rechargable batteries in the holder and connect the PP3 clip
  • The complete slate load bottom should look as shown
  • Check everything works as described in the section above


Slate load top - 1
  • Run a thin line of glue round the gap in the slate load top


Slate load top - 2
  • Fix the slate load holder into the gap
  • Turn the top over and push down on a flat surface so that the loader goes in evenly
  • Fit the slate load top in place - don't glue it as you need to access the batteries


Final comments
  • Griff is capable of pulling a few lightly loaded waggons
  • Power it up and enjoy
  • Always remember to switch the power off when you have finished running so the batteries do not fully drain
  • Remove the batteries and recharge them in a standard AAA NiMH charger