Need Kraken spline to 1/2" hex adapters (WCP-1118)

Hi all, my team is in need of 3 WCP Spline XS to 1/2" hex adapters for Kraken Motors. WCP has had this product out of stock and on backorder for a long time now and my team has not been able to order any.

We are willing to pay for the product as well as shipping it to our school! If anyone has some spares, we would be greatly appreciative if you could contact us. We are located in NYC.

@team334 on Instagram

I have never seen them listed as available. There’s a good chance that they have not shipped any and therefore nobody will have any they can give to you. We ordered some early in the season to use and had to pivot to a different setup once we realized that they may not arrive in time.

We 3D printed ours and it seems to be holding up fine so far.

CTRE had a few in stock like 3 weeks ago so some teams may have some.

Some teams near us have some but don’t have spare to lend to us. Teams do have some though.

What have you been using it for?

We also needed them and never found them in stock. The CD thread about the motors indicated they were having a manufacturing problems and hadn’t receive any stock from the manufacture at the time.

We downloaded the CAD file for that part. We have access to a metal cutting laser and cut many “washers” with the same profile. The spline on the inside and hex on the outside. Then stacked them up. Been working pretty well for us.


We actually use it to drive our scorer 1:1 with a Kraken with .25" compression. It is a low torque, high rpm application. Never had any slippage or anything. We actually designed a slightly different adaptor with a slot to get compression with a shaft collar, but we never really needed it.

We’ve had great luck just printing spline xs bores into pulleys. They hold really well so far.

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Definitely caution against doing this on anything that moves fast/has agressive acceleration (honestly just in general). Tiny bit of heat and the PLA will fail, that bore is gonna become a circle.

The best thing to do is to print a pulley that has the bore for the 8mm SplineXS to 3D Print Adapter (WCP-1021). These are currently backordered but I know a lot of teams have them and I expect they will come back soon. If you need something you can buy right now, the 10t Steel Spur Gear (10 DP, 8mm SplineXS Bore) (WCP-1005) works as a stand in, although it won’t support smaller pulleys.

As for the hex adapters, as far as I can tell they had production issues and were never shipped to anyone. If CTRE had stock of them that’s news to me.

This is not true, we shipped quite a bit of these. We had an issue with our shipping carrier misplacing these… We have plenty in production and will be arriving beginning of April.


This is really cool! I will look into this and see if we can do this. I want to do a 3d printed spline, in fact we had already printed them and when press fit on the shaft it seems like it would work (for a shooter 1:1 ratio). Unfortunately, out mentor is not allowing us to use the part because he is afraid of failure when it comes to comp.

Our comp is on April 4-7, so unfortunately by the time they come back in stock on WCP it would be too late to get.

I appreciate all the replies though, very helpful stuff!

If you’re using an outer 3d print, you can print for other profiles besides a hex. In the past I’ve used gears with great success. You could get an in stock kraken gear and imbed that instead.


We use them on our shooter motors, which spin fast and accelerate and decelerate at extremely high rates, multiple times a match. Also used on our intake motor which is cycled the same way. Both PLA and nylon prints, never had an issue.

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That’s fascinating, the conventional wisdom to not print splines developed around falconspline, which definitely have a subtly shallower profile.

That’s all on a bambuLabs with a 0.4 nozzle?
Layer height, # of walls, infill?

Edit: stator phase current limits?

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All on bambu printers. 0.4mm nozzle, 4 walls, 35% infill. So far most of our tests on 3D prints find the failures are in the infill before the walls fail (when designed correctly and loaded appropriately).

Definitely goes against the grain in the conventional wisdom, and I think it’s only something I’d trust to work on long pulleys. Our printed spline bore fits are intentionally tight for maximum surface contact.

20mm+ / full length of motor shaft?
With a 9mm wide belt or a 15mm?

Our intake motor pulley is the 15mm wide WCP kraken pulley printed out, our shooter pulleys are 9mm wide.