I had a hand rivnut gun for installing rivnuts and due to it being a budget priced tool, I only got to use it maybe 30 times before it failed. It was fine for the smaller M4 & M5 sized rivnuts but when installing M6 size or M8, the gun struggled to get enough of the rivnut compressed. Upon inspection, the internals of the gun were made of non-hardened steel and a section of the mandrel puller inside the gun was worn out, rendering it useless.
I've liked having this tool and couldn't justify the $150-200 for a good quality version and wondered if there was a DIY version. I found a design online which I could easily replicate on my lathe. It is a design where each piece is for a specific bolt thread size so I made four of them - for M4, M5, M6 & M8 rivnut. The design is simply two ~20mm diameter steel pieces machined on the lathe with a really small thrust bearing in between them. A high tensile bolt passes through the entire assembly.
To install the rivnut, it is first screwed onto the end of the bolt and the rivnut placed in the sheet metal hole. The bolt head (and therefore also the rivnut) is held in place with hex key or spanner/socket, then the nut (also high tensile) is tightened with a spanner which draws the bolt upward and compresses the rivnut. The most important part of the tool is the thrust bearing which makes the tightening of the nut surprisingly easy.
The total cost was approx $25 for all the high tensile bolts and nuts, thrust bearings and a small amount of steel bar. I have since used them to "tighten" a few of the rivnuts I've previously fitted. It does take slightly longer to use these tools as opposed to a commercially available plier type tool but it's not a tool that I need every day, and at least I know that these ones should last.
I've liked having this tool and couldn't justify the $150-200 for a good quality version and wondered if there was a DIY version. I found a design online which I could easily replicate on my lathe. It is a design where each piece is for a specific bolt thread size so I made four of them - for M4, M5, M6 & M8 rivnut. The design is simply two ~20mm diameter steel pieces machined on the lathe with a really small thrust bearing in between them. A high tensile bolt passes through the entire assembly.
To install the rivnut, it is first screwed onto the end of the bolt and the rivnut placed in the sheet metal hole. The bolt head (and therefore also the rivnut) is held in place with hex key or spanner/socket, then the nut (also high tensile) is tightened with a spanner which draws the bolt upward and compresses the rivnut. The most important part of the tool is the thrust bearing which makes the tightening of the nut surprisingly easy.
The total cost was approx $25 for all the high tensile bolts and nuts, thrust bearings and a small amount of steel bar. I have since used them to "tighten" a few of the rivnuts I've previously fitted. It does take slightly longer to use these tools as opposed to a commercially available plier type tool but it's not a tool that I need every day, and at least I know that these ones should last.
Comments
Post a Comment