Components

Parts were excellent quality and include:

Construction

The instructions are well written with decent illustrations. Though building a cluster can be tricky, Semroc has made this about as simple as possible, and the skill rating of 2 is a fair assessment. Overall, I had less than an hour in construction, with a couple hours of prepping and finishing.

The motor mount consists of 3 18mm tubes, metal hooks for retention, and coupler-style centering rings for blocks. Each tube goes into a section of the main centering ring, though there's a neat trick to it--the centering ring has a larger, solid outer band and an interior section with three wedges to wrap around the motor tubes. When pulling the centering ring from the laser-cut sheet, keep it intact (outer and inner sections together). This allows for easy alignment and orientation of the motor tubes while gluing. Once the tubes are set, tack the inner wedges to the tubes. After everything's dry, you can then remove the outer ring from the assembly, and the resulting assembly fits perfectly inside the BT-60. Before gluing it in, though, plug the tiny gap in the center between the 3 tubes with some wadding and glue (or dog barf, or even the laser-cut section if you didn't already throw it out as I did...). Semroc even made sure there were slight notches for the hooks, which helps make sure the tubes are oriented in such a way that all three hooks pull away without interference, making motor loading/unloading quick and easy.

The BT-60 gets marked for fins and launch lug via a template on the instruction sheet.

The baffle is a relatively light duty design, consisting of a coupler section about 2" long and a single baffle disk (fiberboard with some holes). The disk goes on the forward end of the coupler, so a good glue joint is essential (or a good fillet when placing in the tube) to prevent it from blowing out the front of the rocket. The baffle also serves as the shock cord anchor point--slip the elastic through a slot on the disk and glue/knot to the other side. The completed baffle assembly is then glued into the body tube about 4-5" back from the forward end.

Fins are precut, just needed a light sanding before tacking on with CA then applying wood glue fillets.

Launch lug needs a small wood standoff due tot eh larger diameter payload tube. The supplied lug is 1/8", which in my opinion is a bit wimpy for a 3-motor cluster, especially if carrying an egg payload. At that weight and with that much thrust, a 3/16 would be a much better choice. 1/8" rod is just going to whip too much.

The payload is a simple assembly of a balsa transition adapter, the clear tube, and a balsa nose cone. Mine were very tight fitting, needed a light sanding to fit. If you're going to fly this with payloads, you'll need to consider how to keep everything together here. A friction fit could work, though external tape would be a better idea. If you're worried about the appearance, consider using a couple small screws through the payload tube into the cone and transition.