Lathe Owners - Make a Notos hammer for me?

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EmptyTin_Tim

EmptyTin_Tim

Member
Dec 8, 2022
477
331
Midwest, USA
Hello,

I had a mishap with my Notos.. I let a friend shoot it but I didn't instruct him on the manual of arms for it. I handed the Notos to him after cocking the lever back, inserting a magazine, but not pushing the lever forward so I didn't hand over a loaded gun.

Well... he didnt know so when he shot with the lever back it rounded off my hammer in a spot where the sear catches. I've tried rotating the hammer in there to get a "fresh" spot where the sear attaches but it seems to keep rotating around after X amount of cocking/shooting and has cause dangerous situations from the lever not holding back and shooting a shot to not holding back but me catching it but it double feeding.

This needs replaced.

So of course I asked Umarex for a hammer but.. they said "We do not stock or sell parts for that model. If your gun is experiencing a manufacturers defect please let us know and we will set up a return case."

Even if it were a manufacturer defect I couldn't return cause I have the OEM moderator chopped off and Buck Rail kit on they wouldn't do work on it. Lol

So here I am reaching out to any lathe owner who also has a Notos and is willing to make a one- off hammer for me. I just want it an exact copy I don't need it to be heavier or anything modified.

I can pay through PayPal.

Thank you!
 
I'm really amazed. I emailed Wes. He emailed right back with links to the sear and the hammer he added to the website!

Snowpeak/Artemis PP750 Sear

airgunarcheryfun.ca airgunarcheryfun.ca

PP750/Notos Hammer

airgunarcheryfun.ca airgunarcheryfun.ca

Yes this was much more affordable than doing a one off custom thing. Sorry to any future lathe owner who wanted to make a buck off of me!
 
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Motorhead said:
Yup, SNAG sears are the most troublesome when contemplating custom hammers in PCP's
Click to expand...

The general answer is to copy the OEM sear geometry on your custom hammer.

An example of this are the custom Bulldog hammers that Mackeral5 had machined, as shown in this GTA thread:

Bulldog .250 needed an MDS hammer w/adjustable striker - Airguns & Guns Forum

Bulldog .250 needed an MDS hammer w/adjustable striker, Air guns, Airgun Forum
www.gatewaytoairguns.org

I have Mackerl5's permission to copy and paste his GTA thread OP here, because the imgur hosted images will be visible on AGN. Better than me trying to explain Mackeral5's logic, I prefer to let him speak:

Mackeral5 said:
"I wanted to share a somewhat recent collaboration with a couple of GTA members.

Some time ago I crudely carved out an MDS hammer for my Bulldog, as a working prototype, proof of concept type of project. Initial results were promising so I decided to reach out to a couple of GTA members to see if they were interested in helping me take the crude prototype to a more refined, documented design, and make a couple using lessons learned from the prototype.

One member provided design support and developed the drawings/models. This included solving many details that were not part of my crude prototyping process such as angles, tolerances, defining the fabrication/assembly operations and sequences.

A second member provided additional refinement of the fabrication/assembly process as well as the actual fabrication and assembly of components.

My collaborators possess much greater skills than I, especially in the areas of attention to detail and precision. You will see that here when comparing the prototype to final design and execution.

Here are a few pics.

Various bulldog hammers. Skeletonized 46gram OEM far left, middle OEM with peek striker, right my prototype MDS with brass core and peek striker

GYyPzUd.png


The prototype was very light, right around 30 grams. Required too much hammer spring, even with my simplified balanced valve. But results were favorable enough to warrant further development.

A sampling of the documented design.

sSeG8NM.png


The prototype next to the final versions.

QrN1ZaL.png


2eoKwWu.png


4lpWe0o.png


We created 2 different brass core designs. The one with the smaller diameter hollow is the one I mainly use, it is designed to be compatible with my guide fixed at the rear SSG. The brass core with the larger diameter hollow is compatible with an OEM hammer spring configuration.

Both hammer designs weigh in the 40-50 gram range and are not necessarily suitable for an OEM unregulated bulldog. However for my balanced valve equipped smallbore .250 bulldog they are a perfect match. The adjustable peek striker was a game changer from a tuning perspective. It took a while to find a good combination of balanced chamber volume, HST, and striker protrusion. I am still learning how those adjustments all interact. I added a buffer system that functions like a bstaley mod, but doesn't rely on Oring's staying put. I do not have pics of that but it works very well so far and there is no concern about orings moving around. The Bulldog has a valve body retention nut, I drilled 6-8 holes and glued in sections of 90 duro Oring, like bristles protruding 1/16 from the valve nut's face, stopping the hammer's forward travel. I hope that makes sense to those familiar with a Bulldog's inner workings... At some point I will try to get a pic of this area.

All in all I could not be happier with the collaboration. 3 similar minded individuals living far from each other, who have never met nor heard each other's voices were able to achieve a desired outcome. All communication via emails and pm's, each contributing their time and expertise, and the end result actually working as intended. The journey was very rewarding, I appreciate the process equally or more so than the final output, the hammers themselves. "


If AGN members are interested in having such custom hammer made, ask Mackerl5 on AGN: https://www.airgunnation.com/members/mackeral5.16336/
You can also ask me to contact the machinist for you.

The machinist is not on AGN, but has the user name luge007 on the GTA Forum. He offers airgunners very reasonable rates for precision work:

Airgun Forum | GTA International Airgun Forum | 17,332+ Members

The Gateway to Airguns forum is the oldest, largest, and most active airgun forum & knowledge archive. Used internationally by airgun enthusiast and industry professionals to discuss and share all things related to airguns. From vintage airguns to the most modern PCP airguns.
www.gatewaytoairguns.org
 
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I've built hammers with nothing more than a drill and a dremel and a home-made jig, along with sandpaper for final polishing.

My hammers are LIGHT, 4-5 grams, but I also have made 20-40 grams. Not offering, just saying it's quite easy to DIY

My current valve only needs this 5 gram hammer along with 4 lbs of hammer spring to generate 60 fpe...

IMG_20230820_112116152_MF_PORTRAIT.jpg
 
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Got my new hammer and sear! Exactly same as Notos even though marked for PP750.

You can see the chip/gouge/mark left from firing out of battery in the right hammer. The left is new one from Wes.

The trigger now feels more crisp but a little heavier. That's okay cause it is safe now, no more ND-ing here. I adjusted the trigger sear screw cause it wouldn't catch after the swap. Guess the dimensions were off enough to warrant the need to back out that screw a turn or two.

Anyway, extremely pleased with our buddy Wes up north for sending out these parts when even Umarex said nope. Also thank you for directing me to him! Finally have my Notos working safely again!!

20231030_221148.jpg
 
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