3 Reasons for Rivet Mis-Feeds
When it comes to minimizing equipment downtime, it is important troubleshoot any issues as soon as they arise. In most cases, if the cause can be identified early, the solution is quick and can prevent any permanent damage to the machine and reduce scrap parts.
With track-fed rivets, typical of an impact riveter, manufacturers often have concerns about rivet misfeeds and how to identify the cause and correct it. It is important to note that there are many factors that can attribute to rivet feeding challenges, and some applications may be more prone to misfeeds then other. Orbitform works closely to identify these challenges early and provide solutions to mitigate the potential for rivet misfeeds.
If rivet misfeeds do happen, the cause may be tied to rivet quality, application challenges, or the machine set-up.
- Rivet quality. Seek a reputable rivet manufacturer or stocking distributor such as Jay-Cee Rivet
- Concentricity between the rivet head, shank, and thru-hole (if tubular or semi-tubular). Concentricity is important for reliable feeding and transitioning between the feeder, track, jaws, and rollset.
- Flatness of shank cut-off. A tapered or burred cut-off end can create tooling engagement issues, mis-feeds, and uneven form results. Check the cut-off end of your rivets, which should be square to the body and free from burrs.
- Change in rivet suppliers. If you’ve recently changed rivet suppliers, and immediately started experiencing a higher number of misfeeds, check to make sure the rivets are dimensionally the same as what you were using previously.
- Application Challenges
- Extremely small or lightweight rivets can get hung up in a gravity feed track due to their minimal mass
- Short rivets are prone to tumble into the jaws as the head is heavier than the shank
- Soft material rivets, such as copper, silver, brass, can get damaged in shipping or because of an overfilled rotary feeder. We recommend a vibratory feeder for certain applications because of this. Damaged rivets can cause downstream feeding issues
- Tight hole tolerance between the part ID and the rivet OD.
- Machine set-up
- Feeder reliability. If the rotary feeder has dirt or debris, or if it was not designed for the size and type of rivet being used, this may prevent rivets from feeding into the track.
- Track reliability. When debris builds up in the track, the rivets may not move through it easily and get stuck. Additionally, if the track, spacers and escapement were not designed specifically for the rivet type and size you’re using, this may present feeding challenges.
- Tooling design. If the tooling was not designed for the rivet being used or has been modified, it may not properly set the rivet.
- Tooling alignment. The rivet should stay engaged and be trapped and held in the correct orientation between the driver and the rollset pin until the rivet is clinched. A rollset with a broken or short pin could create a gap that the rivet will need to jump. Rivets do not free fall reliably. On the other hand, a long rollset pin can inadvertently push the rivet up and out of the jaws before the driver can trap it.
- Tooling wear. Check to make sure that the tooling is not excessively worn and that it is clean and free of burrs. In addition to causing rivet misfeed, badly worn tooling can damage machine components due to the increased force it will take to set a rivet.
To ensure impact riveters continue to function as designed, it is vital to perform preventative maintenance. In most cases, regular inspection of the equipment can identify potential issues before forming scrap parts or causing permanent damage to the equipment. If problems do arise, you can review the troubleshooting guide located in the equipment manual. We also have an in-house Service Department available to troubleshoot problems over the phone or visit your facility for a service call.
Again, it is important to note that there are other factors outside of this article that may attribute to rivet feeding challenges. If you’re experiencing rivet misfeeds with your impact riveter, regardless of the brand/make/model, contact your local Orbitform trusted advisor or our Service Manager, Mark Adler to discuss our solutions for your rivet feeding challenges.