Tha Crumb | Earthwing NLS Deck | Caliber/Indy Trucks | SK3 6374 Single Motor | Custom Mount | 10S4P | FOCBOX

I have been interested in this for over 10 years now. I have wanted to build one but gave in and bought an Evolve GTX. I had some problems with it but it is running well now. I joined this community so that I can start building my own. I would like to contribute to the community wherever I can.

I am an electrician and hobby machinist. I have a lathe with a milling attachment, drill press and some other shop tools.

I am going to start by building using a downhill setup I have. It is an Earthwing NLS with a Indy in the back and a Caliber 50 in the front. I would like to modify the Indy to accept the motor. Here are some pics of my progress. I don’t really have a plan at this point. I need my motor and pulley dimensions. The rough idea is to turn a bearing shoulder for the pulley and then a section with a flat for the motor mount.

I will keep my progress updated. Thanks for any input or feedback.


IMG_2401 IMG_2405 IMG_2403 IMG_2406 IMG_2395 Uploading… Uploading… Uploading…


I’d love to try some Indy trucks, haven’t ridden any in years but used to as a kid. Loved them.

1 Like

i need a lathe.


I like the indies on my shortboards. This longboard was my first. I started out with two caliber 50’s, took a hill and crashed from the wobbles. I did some research and found that by using a less turny truck in the rear I could quench the wobbles. Thats why I have the Indy in the back. It works really well and it feels like cheating. Same idea as the evo decks.

The lathe is a fun hobby. I will do small jobs for people on this forum sk8 related. I am in NE Ohio USA.

So I am wondering if I can mod my old abec 11’s with a pulley mount. They are currently at 64mm.

Whats the OD of a standard wheel pulley? 36t? So my evolve pulley is 32t and about 2" or 51mm.

I’m thinking I will go with 15mm belt, maybe 12 is ok. 6374 motor.


1 Like

Depends on your plans with the board. How are you going to ride this one?

I will probably gear it to go about 25mph. I would like to pull full on WOT 0 to full speed from time to time. Moderate hills here. I’m 220lbs. Otherwise mostly cruising with occasional shredding.

I decided to turn down my wheel pulley register to 0.4" OD at a depth of 0.825". This matches my evolve axle. The aluminum over the axle may wear over time since it could be soft. If it does then I can turn it off down to the steel axle. Then either use a standard skate bearing or machine a bushing adapter.

So I got down to some final dimensions and took some finish cuts. I ended up taking the wheel pulley bearing register down to .393" or almost 10mm. At that OD the Evolve bearing fits to a light hand press. IMG_2414

I then turned down a section for the motor mount. I ended up stopping at a .75" OD which left a couple flats from the casting. I plan on either matching this on the motor mount or just boring a .75ish hole and tapping two set screws to meet those flats. IMG_2417 IMG_2416

Next up is the motor mount. I am planning on mounting the motor inward to retain use of the kick tail. What angle the mount should extend from the truck? I think parallel to the truck base plate. I want it as close to the bottom of the deck without it hitting on the tightest of turns. IMG_2418 IMG_2419 IMG_2420

I swapped the wheels… neither look correct. I see there could be some abec 11 76mm flywheels on a shelf collecting dust somewhere or maybe 83’s. IMG_2421


Well I read the topic naming instructions…a bit late. I saw the Enertion FOCBOX on sale and picked one up for this build.

Made some progress on the motor mount. Started with a .3" plate of AL. Scribed some circles and lines as a guide IMG_2423

Made some saw cuts IMG_2503



To the belt sander IMG_2508

Having trouble seeing my lines and close to rough size, scribed some final lines on layout fluid. IMG_2519

To the drill press for a .750 hole IMG_2522 IMG_2526

And it slides on with a little hand press. IMG_2531

I’m going to have to figure out the angle here. I could have made it a bit longer, I actually shortened it .110 from my original sketch :roll_eyes:

I am concerned about clearance. I may just send it to the back. maybe add a wheely bar :smiling_imp: IMG_2537

I think I am going to run 83mm flywheels. I love that abec 11 but I am seeing how low I can keep the budget.

Am I wasting my time with anything but abec 11? Any recommendations?

Next up I need to mill the slots for the motor bolts. Set the final angle, secure in place with setscrew, will probably weld in final position. Then on to the pulleys. I wonder if I could possibly make the pulley on my lathe with the help of a spin index mounted to the cross slide…


Same favs as a kid for skateboard and roller skate baseplates. @akhlut hell yes! @MD84 Watching this one with a jealous heart. Good stuff.

Quick update, I slapped on my daughters 75mm big zigs. Went for a ride trying forward and reverse mounts at various angles.


Holy shrimp! Those big zigs are pure joy. Too bad I can’t slap a pulley on those…


I didn’t really have any problems either way. I tested rolling up a rounded curb that my evolve will sometimes rub if I’m feeling extra heavy. The mount actually had more clearance in the forward position.

At this point I am going with forward position at this angle:


So I’m going to narrow down the wheel diameter to either 76 or 83mm

How do kegels compare to flywheels? The pulley adapter seems easier to make…


So cool to see you using a Earthing DH deck! My roommate and I are huge advocates of Brain’s business. Those decks have amazing concave. I’m looking forward to seeing your board up and running so keep us posted. Also on wheels, if you’re ambitious you could try the 76mm abec flywheel in classic thane. I haven’t seen anyone use them because they force your drive system to be crazy low to the ground but I think you may like them because it seems like you want a more traditional board height and riding position. I just got some 83’s myself. Good luck with your project! @MD84

@GreasyGearsWRX Thank you for the motivation… I love the Earthwing brand, such a great company. My first and all time favorite longboard deck.

I’m just going to go for it and run the 76mm wheels. They are hard to find but I think I found a good source. I think I should be ok with ground clearance…If not, they will be a sick wheel for a gravity board.

Here comes some more progress…

Tap a hole for a set screw IMG_2629 IMG_2630 IMG_2631

It holds it in place ok, at least enough to for a test run later on and then I will weld it IMG_2633

Motor bolt pattern. Hoping the print is correct for the motor… Blue layout, srcibe, center punch, center drill, drill through, chamfer IMG_2637 IMG_2639 IMG_2643 IMG_2644 IMG_2645 IMG_2646 IMG_2648 IMG_2650 IMG_2651 IMG_2653


and for my next trick… IMG_2665 IMG_2666 IMG_2667 IMG_2668 IMG_2699 IMG_2682 IMG_2683 IMG_2684 IMG_2685

This is how you want your chips to flow… IMG_2686

No DRO no problem, better yet use a micrometer stop IMG_2691 IMG_2688 IMG_2695 IMG_2696

Chamfer edges and scotch bright IMG_2700

…Including more pictures of the machining process


How did you make that

@moon I submerged it in de-ionized water and then burned the material away using a 0.01" diameter brass wire pulsing around 50v :sunglasses:


Next up is the wheel adapter section of the wheel pulley IMG_2681 IMG_2674

The diagram helps me on the manual lathe, The two pieces will bolt together and a bearing will be shared between them to locate them concentric to each other

Can anyone tell me if a flywheel hub is straight through or is tapered? Not sure if I need to machine the portion that engages the hub on a taper or go in straight through. Also I am thinking the larger ID of the hub is about 1.56". Can anyone confirm?

1 Like

Just pulled the trigger on the 76mm wheels from Other Planet Skate


They have some interesting products, There decks look nice with a big kick tail option…

Other Planet Skate Decks


I am about to order the motor on hobby king, sk3 6374 192kv.

I found the xt90 antispark connector for a loop key. Is there anything else I need for this or anything good to get while I make a hobby king order?