I've handled equipment orders for a drilling-and-blasting company since 2016, and I've made some expensive calls. The Henry contract, in spring 2022, is the one I documented in detail because it cost us most of the margin on 38,000 tonnes of sub-base and eleven days of schedule. If you're shopping for a mobile crusher to make spec material, here's the mistake I'd rather you make on my dime, not yours.

How I ended up buying a Kleemann MC 110 Z

Our company does drilling, blasting, and bulk earthworks in eastern Ontario. Crushing is the part we normally sub to a nearby pit. Then Henry & Sons Construction offered us the Henry contract on the Balmoral highway corridor: 38,000 tonnes of certified 2-inch minus Type B granular sub-base, produced on site from the same diabase we were already blasting. There's a saying in this trade: when you let the blaster make the aggregate, two things are about to become expensive. The aggregate, and the blaster.

I read everything I could find on portable crushing plants. Everything said the same thing: the primary jaw sets the tone of the whole plant; feed it consistently and the rest of the train follows. That was the conventional wisdom. My experience with the Henry contract suggests you should treat that sentence as marketing. A jaw crusher is not a crushing plant, and for a tight spec, it's not even close.

I settled on a used Kleemann MC 110 Z EVO from a dealer in Quebec. It had about 6,000 hours, fresh jaw dies, a rebuilt main conveyor, and honest-looking maintenance records. The undercarriage showed the kind of wear you expect at that hours count, nothing more. Price worked out to C$418,000 plus freight, which felt decent for a German-built track-mounted jaw that could reposition itself without a crane. That mobility is real, and it's the trait that saved us later.

During the walk-around, the dealer's crushing specialist asked one question I now repeat to every customer I see: "What's your secondary stage?"

I said we didn't need one. The Henry spec was a 2-inch minus Type B; a jaw closed at 50mm can make pieces that fit a 2-inch opening, right? He looked at the stockpile plan, then at me, and said something I should've written down:

"It'll make pieces that fit through a 2-inch screen. That's not the same as meeting a spec. You're going to want a cone behind it."

I filed that under "salesman wants a second commission" and bought the jaw anyway. I do not say that proudly; I say it because pride is exactly what it was.

Chauvin, our senior driller, had the same warning in rougher language. He was sixty-one and had run a crushing spread in the Gaspé before I had a driver's license. "The jaw makes the rocks small one time. The cone makes them right. You're gonna find out the difference." I thanked him and went back to planning the blast. The warning signs, in hindsight, were not subtle. They were just inconvenient.

Day one: 1,100 tonnes and no spec

Crushing started April 5, 2022. I remember the date with embarrassing clarity. The MC 110 Z backed itself off the lowboy, tracked into place in under half an hour, and we were feeding diabase by ten in the morning. We did 1,100 tonnes that day at around 300 tonnes an hour, and I wrote "correct call" in my notes, all proud of myself. The stockpile looked beautiful. I've since learned that every stockpile looks beautiful until a quality technician puts a sieve through it.

The Henry quality manager—a patient man who moved like he'd failed a thousand stockpiles before mine—spent twenty minutes sampling, then carried a sieve pan over. Top size: running to 100mm. Flakiness index: over the limit. "This is a good primary stockpile," he said. "It's not Type B." Same words I'd used, meaning something different.

That was the communication failure, and it was between me and the spec sheet more than between two people. I said "2-inch minus" and meant "make pieces fit through a 2-inch screen." The Henry contract said "2-inch minus" and meant "certified Type B with controlled flakiness and a tight gradation envelope." Same phrase. Two entirely different products.

Here's the technical part, explained the way I understand it now. A jaw crusher breaks rock by compression, and it lets out flat, elongated pieces the way a press flattens a nut. At a wide-ish setting, you also get oversize from every slabby piece in the feed. Particle shape—the flakiness the contract measured—gets corrected in the choke-fed chamber of a cone crusher. I knew "cone crusher" as a phrase in a brochure. I did not know it as the difference between payment and a dispute.

The Kleemann MCO 11 PRO showed up (and taught us what dinner means)

I called the dealer on April 7 and asked if that cone conversation still stood. The specialist didn't say I told you so. He said, "We've got a demo MCO 11 PRO coming off a job in Quebec next week. I can have it to you by Tuesday." That's the moment I understood the difference between a vendor who wants a second commission and one who wants the plant to work. The best ones will tell you where the boundary of your current setup actually is.

The MCO 11 PRO arrived on April 12. Track-mounted, self-contained, no foundations and no crane required. We set it beside the jaw, closed the chamber to around 35mm, put the mobile screen on the end, and closed the circuit on the oversize. The fact that it was track-mounted mattered more than I expected: no concrete, no permanent installation, just set it in line and run. In a contingency, that kind of flexibility is worth a lot.

That Tuesday morning, Chauvin watched the first certified load move and said, to nobody in particular:

"You can't have dinner without breakfast. The MC is the breakfast. The MCO is the dinner. We tried to serve breakfast as dinner, and the quality man sent it back."

One of the new helpers, an eighteen-year-old from Toronto, looked at him with absolute seriousness and asked, "What is breakfast?" The crew cracked up. Chauvin pointed at the jaw with his coffee cup. "The bacon and eggs, mon ami. The bacon and eggs." The joke stuck, and it's the closest thing I have to a training manual: the jaw is the breakfast—it gets you going, it's necessary, but it is not the meal. The cone is where spec material is made.

What breakfast cost me, and the checklist I keep now

We finished the Henry contract eleven days late, and we delivered the full 38,000 tonnes. The margin went from "expansion project" to "lesson learned," mostly absorbed by the MCO 11 PRO rental and freight. But I want to be careful about the lesson. I do not blame the MC 110 Z. It's a fantastic primary crusher; we still own and run it today. The mistake was pretending a jaw crusher was a whole crushing plant—the same way the original mistake was pretending I was a crushing specialist instead of a blaster who should have listened to the people who were.

For reference, here are the published numbers I checked afterward, when I wasn't in a hurry: the Kleemann MC 110 Z EVO2 lists a crusher feed opening of 1,100 × 700 mm; the Kleemann MCO 11 PRO lists a cone diameter of 1,100 mm, a maximum feed size around 240 mm, and an output capacity up to 365 tonnes per hour depending on feed material and closed side setting. Reference: Kleemann product documentation, accessed February 2025 at kleemann.com. Those figures are useful starting points, but they describe an ideal, consistent feed. My site was not ideal, and neither is yours.

I keep a checklist on the dry shack wall now. If you're reading this because you're about to make the same call, take it:

  1. Define the final product spec before the machine list. Write down the finished product requirement—top size, gradation, flakiness—and then assign each line to the stage that produces it. If a line doesn't have a home, you haven't finished planning.
  2. Buy the train, not the iron. The crusher is one link. The screen, the bin, the conveyor transfer points, and the secondary stage are all part of the spec. ISO 21873-1, the standard that governs commercial specifications for mobile crushers, defines capacity in terms of a specific feed material and closed side setting. That's why two machines can both claim "400 tph" and perform completely differently on your rock.
  3. Listen when an operator and a specialist say the same thing. Chauvin said it first. The dealer's crushing specialist said it second. They were both right, and I ignored both because the answer didn't match the plan I'd already signed. If two people who know crushing tell you the jaw alone can't make spec, believe them the first time.
  4. Price the contingency machine into the bid. Every contract I cost now includes a line for a rented cone stage even when we don't plan to use it. It's much cheaper to carry unused optional equipment in a quote than to explain a non-compliant stockpile to a client with a deadline.
  5. Know where your expertise ends. This is the one that hurt the most. I'm very good at drilling and blasting. I was not good at crushing, and I didn't want to admit it. The vendor who said "this machine will not do that, here's what will" earned our business for every project after that. A specialized vendor who knows its boundaries is worth more than a generalist who nods at everything.

So, what is breakfast? If you're new to mobile crushing, breakfast is the primary jaw—the stage that has to happen before anything else, but that can't carry the whole meal alone. The Henry contract is done. The MC 110 Z is still earning its keep. And the MCO 11 PRO is the machine I now budget into every two-stage job before anyone has to ask. Real talk: it took a rejected stockpile and eleven lost days for me to learn what a good operator would have told me for free. Take it from someone who documented the mistake so you don't have to repeat it.