Notos or p-rod
- Thread starter DrToboggan
- Start date
If you want your Notos a lot quieter, this thread may be of interest:
[quote author=Firewalker link=topic=206735.msg156434800#msg156434800 date=1680571204]
I got the two new moderator inserts today and since I had 1-1/2 hours clear before I had to be off so I pulled out the dB meter, moved it 30 feet away inside the shop, opened the door and proceeded to take some noise samples.
First up was the original red split insert. 5 shots, 87, 86, 87, 88, 86 decibels, 87dB average.
Second was the lilac insert, 5 baffles, it knocked off 2 dB with the 5 shot sample of 80, 81, 80, 82, 80dB with an average of 81dB.
Third was the long Lilac insert but first, I had some work to do.
I promptly too took the Notos apart, chucked up the barrel/moderator housing and bored the housing out to 1". A few items to note, the housing interior was not centered on the barrel, the housing was molded out of round and the cap no longer seals tightly as it is now too small.
It took four passes to open up the housing to 1", there was a lot of chatter due to the soft material but it worked fine, I just had to take smaller cuts. I cut the housing down all the way to the interior base then pushed the insert into the housing to get a dry fit.
I got it about 2/3 in and the insert would no longer budge.
I went and got one of my 18" gauntlet leather gloves, put it over the end of the housing after mounting the barrel in the gun again and pulled the trigger!
POP! Out it came into the glove with no harm. I had to sand down the insert to make it fit but it was too long and I had to cut off the taper to fit it all the way into the housing.
The 5 shot sample was 78, 77, 78, 78, 79dB. This was noticeably quieter with much less 'snap' when fired. I even took a few more samples and shot an open housing shot to make sure the meter was working and yes, that seems to be the number.
Finally, I got the 8" black insert fitted by cutting off the last taper and sanding it down smooth. I then marked and drilled the pin holes, mounted it up and shot this jaw-dropping string of 5 samples, 66, 67, 64, 68, 69dB.
This a quieter than a finger snap. I also measured the dB at my ears using the long insert and I got 70dB on both sides which was interesting since the sound at 30 feet was 67dB on average.
Thanks to Mike and Subscriber for their work providing the designs and the printing. I am leaving the 8" insert in the gun since my POI didn't change from an empty housing and am still able to make 1/4" groups at 10m and this thing is just mouse-fart quiet! ;D
[/quote]
If you are looking for similar performance without permanently modifying your Notos, this may be of interest: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435148#msg156435148
Umarex Notos CRK Review - Airguns & Guns Forum
Umarex Notos CRK Review, Air guns, Airgun Forum
www.gatewaytoairguns.org
I got the two new moderator inserts today and since I had 1-1/2 hours clear before I had to be off so I pulled out the dB meter, moved it 30 feet away inside the shop, opened the door and proceeded to take some noise samples.
First up was the original red split insert. 5 shots, 87, 86, 87, 88, 86 decibels, 87dB average.
Second was the lilac insert, 5 baffles, it knocked off 2 dB with the 5 shot sample of 80, 81, 80, 82, 80dB with an average of 81dB.
Third was the long Lilac insert but first, I had some work to do.
I promptly too took the Notos apart, chucked up the barrel/moderator housing and bored the housing out to 1". A few items to note, the housing interior was not centered on the barrel, the housing was molded out of round and the cap no longer seals tightly as it is now too small.
It took four passes to open up the housing to 1", there was a lot of chatter due to the soft material but it worked fine, I just had to take smaller cuts. I cut the housing down all the way to the interior base then pushed the insert into the housing to get a dry fit.
I got it about 2/3 in and the insert would no longer budge.
I went and got one of my 18" gauntlet leather gloves, put it over the end of the housing after mounting the barrel in the gun again and pulled the trigger!
POP! Out it came into the glove with no harm. I had to sand down the insert to make it fit but it was too long and I had to cut off the taper to fit it all the way into the housing.
The 5 shot sample was 78, 77, 78, 78, 79dB. This was noticeably quieter with much less 'snap' when fired. I even took a few more samples and shot an open housing shot to make sure the meter was working and yes, that seems to be the number.
Finally, I got the 8" black insert fitted by cutting off the last taper and sanding it down smooth. I then marked and drilled the pin holes, mounted it up and shot this jaw-dropping string of 5 samples, 66, 67, 64, 68, 69dB.
This a quieter than a finger snap. I also measured the dB at my ears using the long insert and I got 70dB on both sides which was interesting since the sound at 30 feet was 67dB on average.
Thanks to Mike and Subscriber for their work providing the designs and the printing. I am leaving the 8" insert in the gun since my POI didn't change from an empty housing and am still able to make 1/4" groups at 10m and this thing is just mouse-fart quiet! ;D
[/quote]
If you are looking for similar performance without permanently modifying your Notos, this may be of interest: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435148#msg156435148
Upvote 0
If you are looking for similar performance without permanently modifying your Notos, this may be of interest: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435148#msg156435148
[/QUOTE]
Thank you for making the Notos silencer inserts !
I just downloaded the STL files and want to print at least one.
1. Is there any modification required to the Notos?
2. To use one of the 3D printed inserts I assume that you need to:
-remove the 2 pins which hold the original Notos insert
-remove the original Notos insert
-insert one of the 3D printed inserts
-add back the 2 pins
Is there anything else needed?
I will update here on the entire process.
Upvote 0
Nobody1,
If you downloaded the STL from the second link I provided above, please know that the pin location may need to be refined, so you may be able to provide feedback towards that. You would be one of the first people to try this exact design.
Other than that you probably will need to sand down the OD of the narrow section of the insert that goes into the Notos casing, the intent is as you said; to drive out the pins, remove the stock endcap and insert; insert the printed insert up to the shoulder, and reinstall the pins. You should sight through the pin holes in the casing, and chase the holes in the insert with a drill, if they look too small, out of round, or out of position.
If you find that the pin holes are out of position and cannot be chased into a usable fit, you might prefer to drill your own pin holes, I have added STL versions without the pin holes, here:
The reply just above the linked one contains some design notes, that hint at potential installation details. Please read them.
I don't own a Notos, or I would to take measurements and refine their location in the CAD model myself. So, I have to work through others. Now, the need for designing the insert in the first place came from Dave, the guy who started that thread. He challenged someone to come up with better than stock sound attenuation. He cored out his Notos casing to 25 mm ID, but the logical follow on was to provide essentially the same insert that would fit the stock 24 mm ID casing. This is what you downloaded.
The image below is of the an insert for the unmodified casing, just printed by Mike: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435531#msg156435531
If you or anyone else post comments or questions after 7 April, I will not be able to reply, or do any design changes for several weeks. I am going off to spend time with my aged parents in the old country. So, not actively ignoring you. Just far away, with no PC to do CAD on. And preoccupied with other matters.
If you downloaded the STL from the second link I provided above, please know that the pin location may need to be refined, so you may be able to provide feedback towards that. You would be one of the first people to try this exact design.
Other than that you probably will need to sand down the OD of the narrow section of the insert that goes into the Notos casing, the intent is as you said; to drive out the pins, remove the stock endcap and insert; insert the printed insert up to the shoulder, and reinstall the pins. You should sight through the pin holes in the casing, and chase the holes in the insert with a drill, if they look too small, out of round, or out of position.
If you find that the pin holes are out of position and cannot be chased into a usable fit, you might prefer to drill your own pin holes, I have added STL versions without the pin holes, here:
Umarex Notos CRK Review - Airguns & Guns Forum
Umarex Notos CRK Review, Air guns, Airgun Forum
www.gatewaytoairguns.org
I don't own a Notos, or I would to take measurements and refine their location in the CAD model myself. So, I have to work through others. Now, the need for designing the insert in the first place came from Dave, the guy who started that thread. He challenged someone to come up with better than stock sound attenuation. He cored out his Notos casing to 25 mm ID, but the logical follow on was to provide essentially the same insert that would fit the stock 24 mm ID casing. This is what you downloaded.
The image below is of the an insert for the unmodified casing, just printed by Mike: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435531#msg156435531
If you or anyone else post comments or questions after 7 April, I will not be able to reply, or do any design changes for several weeks. I am going off to spend time with my aged parents in the old country. So, not actively ignoring you. Just far away, with no PC to do CAD on. And preoccupied with other matters.
Upvote 0
Note that these parts must be printed with the wide end down on the platen, and the small end of the cones up. This is so that the internal structures are self supporting.
You need to select "supports off", else the inside may end up with a bunch of material you cannot remove.
The walls are thin, so set 100% infill.
Before you actually print yours, check back at the GTA thread to see if there are newer design versions, or more info about better pin hole locations: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435676#msg156435676
You need to select "supports off", else the inside may end up with a bunch of material you cannot remove.
The walls are thin, so set 100% infill.
Before you actually print yours, check back at the GTA thread to see if there are newer design versions, or more info about better pin hole locations: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435676#msg156435676
Upvote 0
With a 3625 psi fill the Notos doesn't sound hand pump friendly. What is the cylinder capacity (in cc) of the Notos?
Upvote 0
Nobody1,
A GTA forum member has provided more accurate retention pin location measurements. I have updated my CAD models for the insert. You can download the STL files from this link, if you are logged into the GTA forum: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435843#msg156435843
A GTA forum member has provided more accurate retention pin location measurements. I have updated my CAD models for the insert. You can download the STL files from this link, if you are logged into the GTA forum: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156435843#msg156435843
Upvote 0
Another insert improvement update: https://www.gatewaytoairguns.org/GTA/index.php?topic=206735.msg156436088#msg156436088
Upvote 0
AWESOME 64dB after mods and using the 8" insert. My stock moderator was hitting 87dB at the same distance.
Last edited:
Upvote 0
Thank you for doing this again.
I have read you posts on the gateway to airguns website.
I will print the insert when I do not need to change the Notos in any way.
Upvote 0
The Notos puts a smile on my face every time I pick it up. Yes, it is hand pump friendly, takes about 45 pumps to go from 2000 psi back to 3600 psi with my China pump. Yesterday, shooting a nickle size target at 35 yards with my 1X optic, 3 shots were covered with a dime using Crosman Premier Dome pellets. Average velocity is about 780 fps with the CPD pellets and the squirrels and yellow beaks can (well the ones left) testify to the accuracy and effectiveness when I do my part. Other than smoothing out the trigger, my Notos has no mods and will probably not get any in the future as I am very happy with how it behaves presently.
Upvote 0
Notos…it’s regulated and cheaper. The whole marauder line at the least needs a total price makeover to be competitive in todays market in my opinion. Just too many better options for a lower price.
Upvote 0
I’m not so sure Crosman would be able updat the Prod and even maintain price, much less be able to compete with China. They long ago decided they couldn’t beat them and instead added them to their lineup.
When the Notos hit the market, I was looking to buy a Prod. Being already invested in their others, 1701 and 1720, a Prod made more sense for me.
I do like the look of Notos.
When the Notos hit the market, I was looking to buy a Prod. Being already invested in their others, 1701 and 1720, a Prod made more sense for me.
I do like the look of Notos.
Upvote 0
