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Marble Runs with the Gluckskafer Sunray Arch

December 09, 2019 4 min read 2 Comments


Yes! The Gluckskafer Sunrays Stacker is Great in Marble Runs!

Guest post by “BuildingWithRainbows


If you’re looking at expanding your marble run kit, slopes are a great set of pieces to add.  A common go-to for slopes in Grimm’s Ball Runs (for good reason) is the Grimm’s Slopes set:

It's great!   But we’ve recently found that the Gluckskafer Sunrays Stacker is a really nifty set for slopes as well.  The slopes from the Sunrise stacker set are super compatible with Grimms building boards for marble runs—we love that the rays are the same width as the Grimms building boards (unlike the slopes which are narrower).  In the picture below:  on the left is a piece from the Sunrays Stacker, and on the right is a piece from the Grimms Slopes set, each on top of a Grimms building board.  When the ball comes down the track a bit off-centered, the wider slopes are really helpful for catching the balls instead of letting them fall off the track. 

Another notable difference between the Grimms Slopes and the slopes from the Sunray Stacker is that the Grimms set has a range of angles while all of the pieces from the sunray are a similar low angle.  For a new (or very young) ball run builder, I’d recommend the Sunray slopes for this very reason.  It is beyond tempting to use the steepest slope to get the most speed in a ball run, but before long you have a ball jumping the track or worse, breaking it apart because it has too much momentum.  The shallow pitch of the Sunray Slopes is excellent for keeping this in check, and in most cases, the slope of an individual sun ray really is adequate to get/keep the ball rolling.

At first glance, it appears that one could stack a few sunrays to replicate the steeper slopes from the slopes set, but unfortunately this isn’t quite the case.  Here, in the foreground is a steep thick slope from the slopes set, and behind it three sun rays, stacked.  You can see that the curve of the outer edge of the pieces pulls the top of the slope away from the back edge making it quite difficult to get the ball to the top of the slope as it comes down the run.  The curve is slight enough to be inconsequential when using a single ray, but is too much with two or three.  The other challenge with stacking rays to get a steep slope is that repeated marbles (and even more so, small ball) strikes will collapse the slope (next picture).


If you know you need steep slopes, the Grimms set is the way to go--but while we’re looking at these pictures, notice the blunt drop at the end of the red Grimms slope, and how all of the sun rays taper to a very short drop?  This short drop at the bottom of the slope also helps maintain the ball’s momentum instead of losing a lot of it to the direction change as the ball drops off the end of the slope.

If you are planning to purchase a set of slopes and are debating between the Gluckskafer Sunray stacker and the Grimms Slopes set, one other thing that may affect your choice is storage options.  The Sunray stacker has a much smaller footprint, but is more likely to fall and scatter if bumped.  The Slopes have a very large footprint, but do come in a tray. Both are shown here, next to the columns from the colors and shapes set:

A couple more factoids, before we get on to some of the most fun features😊

The outer arch (check out that amazing wood grain!!!!!) of the Sunray stacker is comparable (but not identical) to the light green arch from the Grimm’s Classic Rainbow:

Here is how the arch and “semi-circle” piece from the Sunray Stacker compare to the Grimms 12-piece rainbow (both set on building boards).  The curve is not quite the same, and the Sunray Stacker arch is a bit thicker. 

And this is how the same two compare length-wise (in this picture, the Sunray stacker is complete, on its green base):

Speaking of the base, here is how it measures up to the building boards:

How does the base of the Sunray Stacker function when used as a ball track?  It was one of the first things I wanted to check out when I got it!  Have a look!


 I absolutely love the sound the ball makes rolling down the wavy board!

And check this out—this is the green base board from the Sunray Stacker set flat—and I love that it works with all three Grimms ball sizes!


 Small Balls


One thing I love with the slopes set is making a channel for the ball to roll down.  You can make a sort-of-similar channel with the sun rays, but the channel is shorter, and the effect less musical:

It takes a fair bit of momentum to get down the full slopes track, but I love it!  The Sunrays track works, and could still be a fun finish after any run:

The other day my 8 year old got out the Sunray stacker and made this nifty run on his own (he also used the Gluckskafer Slats, a lot of pieces from the Grimm’s Large Stepped Pyramid, Grimm’s Semi-circles, and a few other parts.  I love the way he used the Sun Ray pieces to make jumps (all his idea! And you definitely couldn’t do this with the Grimm’s Slopes without some careful planning) and I love that wavy board.  Under the wavy board he also used sunray pieces to set the slope.   We found the higher surface area of the yellow curve (as compared to its Grimm’s Rainbow counterpart) helped it slide around less when marbles bump into it.  Check out the second movie for a slo-mo of the jumps!

 Happy Building!

- Buildingwithrainbows

2 Responses

Vicki Vaughn Morrison
Vicki Vaughn Morrison

January 26, 2020

Thank you so much for all this great information! I loved getting to see the videos and the slo-mo was the best!


January 26, 2020

Ok, Sold! Love that wave board!

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