Pneumatic Air Graver From Bolt
Introduction: Pneumatic Air Graver From <PERSON>
This instructable is about making an air graver. In the past, I made the same tool but the working principle is completely different. That graver uses suction and compression while the one I am telling in this Instructables only uses compression, which means that the regular air compressor works without any hassle. Now one thing that is similar in both cases is that I am using a 20 mm bolt for the build. I do a lot of stainless steel work and I have a few of these bolts available from one of the repairs I didn't do a few years ago. This build requires quite a lot of precision and doing this without a lathe is a bit more difficult task to do but if you ask me it's definitely doable and the only thing you need is patience. To be honest the tools I have are not the best in their line and need to be replaced. But if you have a lathe then definitely this build is much easier to do without any issue. Although in a few areas you definitely need to improvise to achieve a certain level of precision. This particular tool is mostly made out of bolts but there are a few elements for which I need to use the punch which is made out of HSS. If you have some suggestions for me then definitely leave them down in the description section.
Supplies
Material Used
1. M20 stainless steel bolt
2. M8 Allen head bolt
3. M10 brass rod
4. M10 Punching Die
5. Grub screw M4X6 mm.
Tools Used
1. Angle Grinder
2. Drill Press
3. Drill Machine
4. 11.7 mm Drill bit
5. Sanding Pad
6. 20 mm core drill
7. 4,5 mm thread Tap with.5 mm pitch
8. 1/2" unf thread tap male and female die
9. 776
Tap Handle
Although to ease the work you can easily do the entire work with lathe and surely its hardly one day work, so how fast you can make this totally depends upon what resources you have.
Step 1: ​Drilling Hole to Construct Barrel.
The first thing to do in this is to drill the hole. There are two different hole diameters required for this tool. For the main barrel, the hole required is 10 mm and for the adjustment nut, the hole required is 11.7 mm for ½" UNF thread. To get a good start I first made both the ends flat so that the drill has a good start. Since we need to grind down the barrel from outside that's why a little bit of wobbling can be done easily. After that, I mark the center point and then center punch for the drilling operations. Started the drill with a 5mm drill and then reached up to 10 mm. Stainless is a work-hardened material and the one I have seems to be a bit harder that's why I decided to anneal it and along with this I also annealed the HSS blank because later on, I am going to make a piston with this piece and also the graver holder. To slowly cools down the material I wrap this inside the glass wool and it really worked. After 4 hrs later the bolt is ready to process. Once this is done I drill down the hole and prepare it to cut.
Step 2: Cutting to Required Length
After drilling work is completed it's time to cut down the piece to the required section. The first cut I made is for the adjustment nut and this will help to adjust the stroke length between the graver holder and the piston. If the striking distance is more the impact will be High and this will generally be used for the stainless steel engravings. The final required length for the nut is 14 mm. The next cut piece is used for making the graver holder. If I had a bigger chuck in my drill press then I definitely prefer to turn the entire piece from a single piece. The length required is 8mm. The last piece cut out is 47 mm. And then the bolt head which is left in the end which is going to be used for making the butt cap.
Step 3: ​Setting Up the Drill and Start Reducing the Size
Once I cut the piece to the required dimensions I started turning them closest to 16 mm and I first clamped them in the bolt and then clamped the bolt in the drill chuck. Once I started rotating the drill you can see the wobbling. Now I start the grinding process with various tools like an angle grinder, die grinder, and file. This is an extremely time-consuming process and once you remove the wobbliness then you need to constantly measure the size otherwise it's going to look ugly. I decided to use a fresh file so that I get the result a bit faster. During this process make sure that drill is rotating anticlockwise direction. 776