Making Plastic Front Aperture Sight Inserts

It's been a while since I made an airgun post. As I mentioned in my previous entry, I recently bought a Diana 75 T-01 10M match air rifle. It only came with one front aperture sight insert, of 3.5mm diameter.
I was having a dickens of a time getting a good sight picture so I noodled around on the internet for information and found that most recommend around a 4mm aperture for 10M airgun. I could have bought either metal inserts or a set of plastic inserts, but I figured I'd save some money and have some fun making my own plastic inserts.

Some squares cut out of 1/8" thick lexan. Acylic might be slightly better optically, but Lexan is what I had. I drilled with a #32 drill bit (.116", just inder 3mm) for a #4-40 screw hole.

Mounted several on a mandrel with a #4 screw

I turned them down to 17.5mm (.689") diameter, which seemed to be the size that fits the front sight mounted on the Diana. Sizing of inserts is confusing, will the common 18mm inserts fit my rifle? I don't think they will, unless that refers to the thread root diameter. But I digress.

Sorry for the blurry picture, I snapped these rather quickly. I mounted the disc in the soft pie jaw chuck, and drilled and reamed to 5/32" dia. although the hole came out smaller due to the springiness of the plastic, .154" (3.9mm). Anyway, I'll have to make a bunch of different aperture sizes to see what works best for my rather amateur shooting ability.
I then countersunk the hole with a 90 degree countersink, figuring that it would transmit the dark tube reflection as a ring, by the same action as a periscope prism.

The finished insert, with the metal insert beside it.

As you can see, I get a nice dark ring, without the added distraction of the little arms on the metal insert sight. I snapped off a quick 5 shots to test and shot the smallest group thus far. So it works! All told it took about 20 minutes to make the one from start to finish, with several blanks left over.


UPDATE 2/28/08
I did a little more futzing around, and made some new inserts based on my experiences. One thing I found is that if the insert thickness is such that it is under the aperture insert slot of the front sight tube, light will enter the plastic insert, spoiling the black ring. The obvious fix is to get some thinner plastic, but for now a piece of electrical tape over the slot takes care of the problem. I didn't notice until I shot with the shop lights on.

I turned the new inserts about .006" under the 17.5mm (.689") size that I did the first one. It seems to center well and is much easier to get in and out. I also chamfered the edges as the blanks were on the mandrel, using a vee cutter, as seen above.

First op. was to gently and lightly chamfer one end of the hole, both to provide centering for the next op. and to debur.

Then I drilled with a 4mm bit at relatively high speed, so as to get a round hole (hard sometimes with a drill bit as they want to make a Reuleaux triangle.

Then I flipped the disc and put the 90 degree countersink in with a 90 degree center drill.

I'll put all this up on a dedicated web page eventually...

Helpful Handyman

I put together some (a torturous process) flat pack cabinets for the laundry room today.

Henry installed all four knobs himself, with no help.

Notice the concentration!

I'm plum wore out, the silhouette thing is a lot of extra work. I did get a bit of fun on Friday when our friend Mike came up to visit and check out the Benton County Library book sale. He also brought up an air rifle a friend of his had for sale. I bought it. A Diana 75 T-01. It reenforces what a poor shot I am. Read "The Owl and the Pussycat" to the kids tonight from the volume I found at the sale. I was quite restrained this year, only bought one box of books. Between the cabinets and the book sale I feel like I ran a marathon...

Silhouette, Alouette, Ohhhh

We had a custom silhouette we did for Stu at 3 Potato 4 receive a blurb in Cookie magazine. So now we are in the custom silhouette pendant business. Many to do, but here's the first one completed.

If you want one you can always contact us, they're an affordable $75.00 plus $15.00 for custom engraving.

This is the first time I've used the word "blurb" in a post.

Industrial Jewelry, Thrift Store Score and Family Fish Dealing

Might as well get this out to you for the weekend...It's been lovely outside lately, sunny and warm. Henry and I walked around Corvallis today soaking in the vitamin D and generally enjoying the crisp, clean air.


80/20 Aluminum t-slot extrusions.


I looked at them on end and thought, "why not make jewelry?"


I walked around town with Henry today and found this lovely Ulmia rabbet plane at the thrift store for $5.00! While I should sell it on Ebay, likely I'll just keep it in my plane collection.



My mother emailed Max with a picture of this blotter:
Dear Max, remember yesterday when you talked to me on the telephone? You said that you liked fish. I reminded your daddy that your great-grandfather (his grandfather Munden Allan) sold fish to supermarkets in Canada. Here is one of his advertisements. The business was his father's, and he worked with him. This fishing picture is on a blotter (which I used to dry the ink from my letters). Ask your mommy or daddy about blotters.


One beautiful link for Friday:
The Vibrating Lever 1/2 Trunk Steam Engine of the U.S.S.Monitor

Privacy Policy

Privacy Policy for mechanicalphilosopher.blogspot.com

If you require any more information or have any questions about our privacy policy, please feel free to contact us by email at nickandfelice@gmail.com. At mechanicalphilosopher.blogspot.com, the privacy of our visitors is of extreme importance to us. This privacy policy document outlines the types of personal information is received and collected by mechanicalphilosopher.blogspot.com and how it is used.

Log Files

Like many other Web sites, mechanicalphilosopher.blogspot.com makes use of log files. The information inside the log files includes internet protocol ( IP ) addresses, type of browser, Internet Service Provider ( ISP ), date/time stamp, referring/exit pages, and number of clicks to analyze trends, administer the site, track user’s movement around the site, and gather demographic information. IP addresses, and other such information are not linked to any information that is personally identifiable.

Cookies and Web Beacons

mechanicalphilosopher.blogspot.com does use cookies to store information about visitors preferences, record user-specific information on which pages the user access or visit, customize Web page content based on visitors browser type or other information that the visitor sends via their browser. Some of our advertising partners may use cookies and web beacons on our site. Our advertising partners include Google Adsense, . These third-party ad servers or ad networks use technology to the advertisements and links that appear on mechanicalphilosopher.blogspot.com send directly to your browsers. They automatically receive your IP address when this occurs. Other technologies ( such as cookies, JavaScript, or Web Beacons ) may also be used by the third-party ad networks to measure the effectiveness of their advertisements and / or to personalize the advertising content that you see.

mechanicalphilosopher.blogspot.com has no access to or control over these cookies that are used by third-party advertisers. You should consult the respective privacy policies of these third-party ad servers for more detailed information on their practices as well as for instructions about how to opt-out of certain practices. mechanicalphilosopher.blogspot.com's privacy policy does not apply to, and we cannot control the activities of, such other advertisers or web sites. If you wish to disable cookies, you may do so through your individual browser options. More detailed information about cookie management with specific web browsers can be found at the browsers' respective websites.

This and That

My dad emailed me this picture taken in October 1944

(L to R) Lewis, Lawrence, Muriel, Laney, Rev. John Franklin Carter, Michael, Alice and Nick

and their relevance to me:
(L to R) My Great Uncle Lew, Great Uncle Larry, Grandmother "Nona", Cousin Laney, Great Grandfather John Franklin, Uncle Mike, Aunt Alice and my Dad

My dad has great ears.

I bought Henry a "new" computer at the OSU sale, a CTL desktop P4, 3 Ghz, Win XP with a 19" CRT, for $165.00. It was unused, which again reminds me that not all my tax dollars are actually at work. Often they are just wasted.

This meant that stuff had to be moved out of the way in the computer/dining room. So I moved all of the Lapidary Journals into the bedroom. I need to sell them to someone who needs an entire bookcase full of magazines. I just don't refer to them any more, having extracted the knowledge I needed. That's 13-1/2 feet of magazines. (Any takers? I'm open to offers from anyone who will pick them up!)

Henry and Max each have their own computer now. The sound that dueling Wiggles Youtube videos makes is incredible. Cat 5 cable is everywhere. But now we can all surf the internet together.

I spent some time watching episodes of "Earth 2" on Netflix "Instant Watching" last week. Not a bad, if somewhat cheesy, series. What struck me is how similar the story is to "Lost" I googled around and it turns out I'm not the first person or even the second to notice the connection. I probably watch too much Sci-Fi.

I also fixed our refrigerator problem. The freezer door was popping open when the main door closed. This is actually good, as it means the seals are working. The fix is to tilt the fridge back by about 1/2 a bubble on the level (adjust the feet) and oil the door hinges.

Links:
Historical Globes of the Red Planet

Prof. Alexander Slocum's Fundamentals of Design is now online for free.

noformdesign bought some Taig parts from me, didn't realize at the time that he was also on Etsy. He makes awesome industrial jewelry. His DeviantArt page has even more cool stuff.

George's Whatzit and Brackets Under a Tarp

So this is what George brought over to Open Shop on Thursday. I know what it is, but do you?

It's steel.

It has parts.

Internal parts.

The back end.

Today our friend Maria came over with her son, Hunter. She needed me to fix her old treadmill so she could give it to her mother. I decided that it was easier to work on it it in the bed of her truck, under the tarp she had wrapped around it, around than to drag it in. That's why the pictures are so blue.
It was raining, which is why the tarp stayed on. I'm still a bit damp.

The bad bracket. Both sides needed replacement.

The bracket had fractured.

The new bracket, lovingly crafted from rusty angle iron.

You can see the vibration mount it fastens to.

I used lock washers, not the best choice, but I am out of 1/4"-20 nyloc nuts. Maria was pleased.

Hunter and Henry played while I worked.