Hey everyone, welcome back to the blog—today we’re diving into something super practical for anyone running a scraper conveyor: adjusting the tail unit. If you’re working with heavy materials like coal, ore, or bulk grains, you know a scraper conveyor is the backbone of your operation. And let’s be real, if the tail unit’s off, you’ll run into all kinds of headaches—slipping chains, misaligned scrapers, even premature wear on parts. I’m Jake, part of the team here at [your company name, no need to make one up, just keep it natural], and we supply these conveyors to mines, farms, and construction sites all over. Today, I’m walking you through exactly how to get that tail unit dialed in, no fancy jargon, just real-world steps that actually work. Scraper Conveyor
First, let’s make sure we’re on the same page about what the tail unit does. Unlike the head unit, which has the drive motor and sprockets that pull the chain, the tail unit is the opposite end. It’s got the tail sprockets, the take-up assembly, and the end of the conveyor frame. Its job is two-fold: it tensioners the chain so it doesn’t slip as it moves, and it keeps the chain aligned straight so scrapers don’t get twisted or jammed. If you skip adjusting it right, you’ll end up with chain slack that causes it to derail, or too much tension that snaps the chain or wears out the bearings faster. Trust me, I’ve seen new operators skip this step and have to shut down production halfway through a shift—we don’t want that for anyone.
Before you even touch any bolts or nuts, there are a few pre-checks you need to do. You can’t just jump into adjusting blind; you need to make sure the rest of the conveyor is in decent shape first. First, shut off the power and lockout/tagout (LOTO) the unit—this is non-negotiable, no shortcuts. A running conveyor’s nothing to mess with. Next, inspect the chain and scrapers. Look for any broken links, bent scrapers, or wear on the chain pins. If there’s a broken link, replace it before adjusting, because a weak chain won’t hold tension right. Also, check the tail sprockets—if their teeth are worn down or chipped, that’ll mess with alignment even if the unit’s adjusted perfectly. I always tell our customers: adjust the tail unit only when the rest of the drivetrain is in good condition. It’s like trying to fix a flat tire while the car’s engine is sputtering—you won’t get it right.
Okay, once the pre-checks are done, let’s get to the actual adjustment. Most tail units use a screw-type take-up assembly—this is the most common design for medium to heavy-duty conveyors, which is what we supply 90% of the time. There are also hydraulic take-ups for high-production mines, but let’s start with the screw type since it’s the most user-friendly for smaller operations.
First, find the take-up bolts on either side of the tail unit. You’ll see two big bolts, one on each side, that connect the tail frame to the take-up bracket. These are what you’ll turn to move the tail unit forward or backward (moving it backward adds chain tension, moving it forward loosens it). But here’s a pro tip: don’t just turn one bolt. Always loosen both side adjusters evenly, or you’ll end up with the tail unit tilted to one side. That’s a quick way to get the chain misaligned and scrapers rubbing against the frame. I’ve had a customer do this last month—he turned the right bolt a full turn and left the left untouched, and by the time he started the conveyor, the chain was off the sprocket entirely, costing him 3 hours of downtime. Moral of the story: equal turns on both sides, every time.
Once you’ve loosened those bolts, you’ll need a way to measure the chain tension. The old-school way, which still works, is to check the sag in the chain between the head and tail sprockets. For every 10 feet of conveyor length, you want about 1 inch of sag. So if your conveyor’s 50 feet long, you want 5 inches of sag. That’s the sweet spot—enough tension to prevent slipping, not so much that it puts unnecessary stress on the chain and bearings. How do you measure sag? Grab a friend, stand at the midpoint of the conveyor, pull the chain down gently with both hands, and measure how far it moves from the top of the sprockets. If it’s less than that number, you need to loosen the take-up (move the tail unit forward a bit). If it’s more, tighten the take-up (move the tail backward).
Wait, but what if you have a hydraulic take-up? That’s for the big mines, usually conveyors over 100 feet long. Hydraulic take-ups have a pressure gauge that’s way more accurate than sag measurement. For these, you want to set the pressure to match the chain’s rated tension, which is usually listed in your conveyor’s manual (we send a full manual with every unit we supply, by the way). The good thing about hydraulic take-ups is they’re self-adjusting a little, so you don’t have to check them as often, but you still need to verify the pressure monthly.
Once you’ve got the tension right, the next step is alignment. Tension matters, but if the tail unit’s misaligned side to side, you’ll still have issues. How to check alignment? First, make sure the tail sprockets are straight with the head sprockets. You can use a string line or a laser level—super easy tools, no fancy equipment. Run a string from the center of the head sprocket to the center of the tail sprocket. If the tail sprocket is off to the left or right, you’ll need to make small adjustments to the side shims, or if it’s a bolted tail frame, loosen the mounting bolts on the frame and tap it gently to align. Don’t force it—small, gentle taps are better than yanking it, which can bend the frame.
Another way to check alignment: look at the scrapers. If the scrapers are rubbing evenly on both sides of the conveyor trough, that’s good. If they’re only rubbing on the left side, the tail unit’s pulled to the right, and vice versa. That’s a quick visual check you can do even before using tools—great for a fast pre-shift check.
Once tension and alignment are dialed in, you need to secure the take-up bolts. Don’t just tighten them and walk away—use a torque wrench to make sure they’re set to the manufacturer’s specs (again, from your manual). If they’re too loose, the tail unit will shift over time, and tension will drop. If they’re too tight, you’ll warp the take-up bracket, which is expensive to replace. And always check that the lock washers are in place—those little guys prevent bolts from vibrating loose, which is a common issue with running conveyors.
Wait, let’s talk about regular checks, too, because adjusting the tail unit isn’t a one-and-done job. You should check the tension and alignment every 100 hours of operation, or after any major event—like if the conveyor got a big load of heavy rock, or if you replaced a link in the chain. Also, as the chain breaks in (stretches a little over time), you’ll need to adjust the take-up to compensate. That’s normal—chain isn’t perfectly rigid, so it will stretch a bit after the first few hundred hours of use. If you don’t adjust for that stretch, the sag will get too much, and the chain will slip off the sprockets.
Now, let’s go over some common mistakes I see operators make, because nobody’s perfect, and these are easy to slip up on. First, ignoring pre-checks—like I said earlier, if you skip checking for broken links or worn sprockets, your adjustment won’t fix the problem. Last year, a farm customer adjusted his tail unit three times because his chain kept slipping, turns out the tail sprocket teeth were worn down to half their size. He wasted time adjusting, but a $50 sprocket fix solved everything. Second, adjusting only one side—we already talked about that, it’s a quick way to mess up alignment. Third, too much tension. I’ve seen guys crank the take-up all the way to “make sure it doesn’t slip,” and they end up snapping a chain. Chains have a maximum tension, usually around 15,000 to 20,000 lbs for the medium-duty ones we supply—check your manual for your specific model. Fourth, not rechecking after adjustment. Tension can settle a little, so after you adjust, run the conveyor for 5 minutes, shut it off, and recheck the sag. If it’s off, make a tiny adjustment—no need for big moves.
What about if you have a new conveyor? The first adjustment is extra important. New chains stretch more in the first 50 hours, so you’ll need to do a couple of minor adjustments in that window. We always tell customers to check the tail unit after 25 hours and after 50 hours, because that stretch is normal, and if you don’t adjust, you’ll end up with slack that causes problems.
Now, if you run into issues and don’t want to mess with it yourself, that’s okay too. We’re a scraper conveyor supplier, and we offer on-site adjustment services for customers who don’t have the time or expertise. We’ve got techs that can come out, check the unit, adjust it perfectly, and even do a full inspection of all parts to make sure nothing else is wearing out. A lot of our customers prefer that for the first few adjustments, or if they’re running a high-production mine where downtime costs more than the service fee.
Speaking of downtime—let’s circle back to why this matters. A misadjusted tail unit can cut your conveyor’s lifespan in half. Worn chains, broken scrapers, damaged sprockets—all of that adds up to thousands in replacement parts and lost production time. On the flip side, a properly adjusted tail unit will make your conveyor run smoother, use less energy, and need fewer repairs. That’s not just a nice-to-have, that’s a cost-saver for your operation.
Wait, one last quick tip for smaller conveyors—like the ones used on farms for grain. If your conveyor is less than 20 feet long, the sag is a bit different: 0.5 inches per 10 feet, instead of 1 inch. Because shorter chains don’t need as much sag. And for light-duty conveyors, you might not have a big screw take-up—some use a simple end plate that you slide and bolt in place. The same rule applies: loosen both bolts evenly, adjust for sag, tighten.
If you’ve got any questions, or if you’re in the market for a new scraper conveyor, or just need help adjusting your current one, feel free to reach out to our team. We’re always here to help—no sales pitch, just actual advice from people who work with these conveyors every day. We’ve been supplying scraper conveyors for over a decade, so we know the ins and outs of every model, and we can help you get your tail unit dialed in right.
Before I wrap this up, let me make sure I didn’t miss anything. Lockout/tagout is non-negotiable, pre-check your chain and sprockets, adjust both take-up sides evenly, check sag or hydraulic pressure, align the sprockets, torque the bolts correctly, and check regularly. That’s the whole process. It’s not complicated, but it’s easy to rush and make mistakes. Take your time, follow these steps, and your conveyor will run way better.
Nonpower Powder Air Classifier References
- Society for Mining, Metallurgy & Exploration. (2020). Scraper Conveyor Operation and Maintenance Manual. SME Press.
- Conveyor Equipment Manufacturers Association (CEMA). (2019). Belt Conveyor Design and Installation Standards (7th ed.). CEMA.
- Agricultural Engineers Association (AEA). (2021). Grain Handling Conveyor Maintenance Guidelines. AEA Technical Bulletin.
ZXMC Environmental Protection Machinery Co., Ltd.
ZXMC Environmental Protection Machinery Co., Ltd. is one of the most professional scraper conveyor manufacturers and suppliers in China. Please rest assured to buy customized scraper conveyor made in China here from our factory. If you have any enquiry about quotation, please feel free to email us.
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