Pre-Roll Master Class: Part III – Pre-Roll Manufacturing Best Practices

Welcome back to Part III of the Custom Cones USA Pre-Roll Expert Master Class where we are covering the fundamentals, as well as tips and tricks, of creating high-quality pre-rolls at scale.

We’ve spent years studying what goes into making perfect pre-rolls and our mission is to revolutionize and enhance pre-roll products by setting a benchmark for excellence and innovation in the industry by sharing that knowledge.

In Part I, we covered Paper Science 101, looking at the basics and science of what goes into making the rolling papers that make pre-rolled cones.

In Part II, we covered the Importance of Proper Grinding and Sifting.

Now it’s finally time to start talking about packing those cones.

While early on in the industry, many companies filled pre-rolls by hand. However, today, most use a cone-filling machine of some kind to produce consistent, high-quality pre-rolls at scale.

Three of the most popular machines are the KnockBox, the King Kone and the Fill N’ Fold. All three are tabletop machines that use vibrating motors to help pack dozens of cones at one time, but there are some important differences between the machines that can affect not only your final product, but your production times as well.

Let’s take a close look at these three popular tabletop cone-filling machines.

The KnockBox

The KnockBox, available in multiple sizes, uses a vibrating motor to shake the flower into the cones and create a relatively consistent pack throughout. The KnockBox was one of the first cone filling machines and the name has come to be almost a generic term for cone-filling machines, though it is a specific machine with its own pros and cons.

The KnockBox uses glass tubes to hold the cones and comes in multiple sizes, ranging from 50 to 500 pre-roll slots that can be filled per run. But those glass tubes are vertical cylinders. Because of this, it does not always hold the tapered cones snuggly so during filling, the flower can fall around the cone instead of into it, leading to spillage and wasted time by employees cleaning it up.

And while some companies swear by it and use it extensively, it is a relatively expensive machine, with the smallest model running for $3,000 and the KnockBox 100 costing more than $6,200. Attachments for it are also often expensive, compared to other, similarly sized pre-roll filling machines.

The King Kone

Next up is the King Kone machine. Made of metal and plastic, instead of glass, the King Kone is a solid, heavy-duty machine, leading to better overall filling. This model is extremely versatile, easy-to-use, and budget-friendly, starting at less than $1,700.

The King Kone also differentiates itself by using an adjustable vertical bounce motor to pack up to 169 cones at a time, instead of vibration. The vertical bounce creates a tighter pack at the mouth end, providing a superior pack with just the right amount of flowability for a smoother, even burn.

The King Kone pre-roll machine comes with several attachments, so it can pack half-gram 84mm pre-rolled cones, 3/4-gram 98mm pre-rolled cones, and 1-gram 109mm king-sized pre-rolled cones right out of the box with no extra attachments required. All you have to do is set up the proper cone filling trays, load the cones, and start filling the top tray with your ground flower. There is also an available tube conversion kit, which is compatible with tube inserts to pack pre-rolled tubes. Plus, its fully modular design allows it to come apart for easy cleaning and maintenance.

The Fill N’ Fold

Finally, there’s the Fill N’ Fold, another durable tabletop machine. Like the KnockBox, it uses a vibration motor to pack up to 121 cones at one time. It comes with the vibrating motor and a single size work tray, as well as a matching volumetric metering tray, though it does require the purchase of different work trays to produce different sized pre rolls. It is a little more expensive than the King Kone.

However, what makes the Fill N Fold unique is the included tamping and closing tool, which allows workers to fold over 11 filled pre-rolls at a time into what is called a “Dutch crown” style finish (as opposed to a twist). Many of the pre-roll companies we talk with list the pre-roll closing process as the biggest hassle of the process, taking more employee time than any other part of production. But because of this tool, the Fill N’ Fold has the fastest start-to-finish time of any cone filling machine we’ve seen.

This is part of what we call “the holes fallacy” that many operators fall into when purchasing cone filling machines.

The Holes Fallacy

At first glance, it may seem like the quickest way to produce the most pre-rolls would be to simply pick the machine that produces the most pre-rolls in a single run, right? But the number of holes, or slots, in any given cone filling machine is NOT a reliable estimation of output or throughput for the machine.

We call this “The Holes Fallacy.”

At Custom Cones USA, we have conducted experiments using different pre-roll filling machines and we have found that this is not necessarily the case because of the closing process. In fact, our surveys of pre-roll manufacturers routinely show closing pre-rolls as the primary pain point, greatly slowing down the production process.

During our “Battle pf the Pre-Roll Machines” experiment, we ran full cycles three times on each of the KnockBox, King Kone and Fill N’ Fold with one operator and then three more times with two operators, including closing the pre-rolls to make sure we recreated the entire production process.

What we found was that the Fill N’ Fold easily outpaced its rivals in per-hour production and did so because of the special tamping and closing tool. And for operators, the whole process must be considered, including removal and closing of the cones, when factoring throughput, proving the holes fallacy wrong once and for all.

Interestingly enough, King Kone recently introduced a Dutch Crown Closer Machine of its own, which has the ability to give a Dutch Crown-style finish to an entire tray of pre-rolled cones in a single use. Though not as simple and elegant a solution as the Fill N’ Fold’s unique tool, the new machine will drastically speed up the pre-roll closing process, particularly with a dedicated operator.

Using Volumetric Metering Trays for Consistent Pre-Rolls

One way that pre-roll manufacturers can speed up their production process is the use of volumetric metering trays. Available in most sizes for most machines, a volumetric metering tray is a tool designed to help producers dose the same amount of flower into each pre-rolled cone in a cone-filling machine.

Since table-top pre-roll machines don’t have scales to weigh the amount of flower going into each cone, the metering tray helps ensure the same volume of flower falls into each cone. This saves tremendous time over simply dumping flower on top of your filler, hoping for the best and then adjusting once you get them to a scale.

But the key word here is "volume" - the metering tray does not weigh the flower, but since each hole is the same volume, in theory, the same amount of flower should be getting dropped into each cone.

For example, each slot in a half-gram, or 84mm cone, metering tray has a volume of about 3 cubic centimeters, which equates to about a half-gram of flower, give or take. The exact weight, however, always comes down to differences in the flower itself.

So while the metering tray is a helpful tool to achieve consistent pre-rolls, it’s only as accurate as your input material, which, once again, boils down to a consistent grind, proper sift, and careful handling of the raw materials over time.

To use a metering tray, simply push the ground flower over the top of the tray and into each of the slots by hand, then place the tray on top of your cone-filling machine, pull out the metal sheet holding back the flower and turn on the motor.

The biggest sticking point when using a volumetric metering tray is, well, the stickiness of the flower. Because the grinding process breaks open the trichomes and releases the oils inside, freshly ground flower is often stickier, which can cause additional resin build up and gunk up your machines, as well as restrict flow through your trays.

That’s why we recommend not using freshly ground flower in these trays and instead always advocate for letting your ground flower sit for a few hours before using it, to let the oils re-absorb into the material.

Automated Cone-Filling Machines

The final category of cone-filling machines is the automated filling machine.

Automated pre-roll machines can take boxes of cones and ground cannabis and automatically fill, weigh, pack, tamp, twist, and even weigh the final joint, delivering a level of consistency and automation unmatched by other pre-roll manufacturing methods.

They also rely on consistency, so proper grinding and sifting are even more important.

Automated pre-roll machines can typically produce between 1,000 and 2,000 pre-rolls per hour depending on the size and level of automation, so they do not usually make fiscal sense for smaller companies or producers just starting out.

We have found that the math for most companies begins to make sense at more than 50,000 pre-rolls a month, which is pretty rare for a producer; less than 10% of companies make that many.

However, for large-scale pre-roll producers, automation vastly speeds up the production process even further and can free up employees for other tasks.

Next, in Part IV, we’ll get into Pre-Roll Infusion Methods and Automation.