SUOMI Drum 22 L.R 3D Print Conversion

[Bianchi]

I do not know...we will see!
parts are all in place it's the last step testing this mag!





i tryed to get something a bit cleaner to lock the axis.

 

[Bianchi]

I looked at the spiral and located two place where ammo doesn't goes well i enlarged them! after that i played with the pre-tension to see if i can push the load correctly and with the double spring i had to inflige three laps and half to push correctly the dummies ammos and only 15 real ammos to get a correct pushing...

the spring be already too much pre-tensioned i cannot give more laps without break the drum...this double spring thickness she's not good she alway's too thin. i will go buy a different...but i can show you how he work by waiting the new spring.

 

[Uncle Billy]

yes ,the rounds have to be pushed up in a very tall feed tower, if you had a short feed tower that probably wouldn't be a problem and it would feed all your rounds up that short feed tower.

I know I had to pre-tension the tension on my PPS43 drum to something like 5 or 6 revolution to reliably feed all the rounds up a tall feed tower, whereas on the MP5 drum, that has a short feed tower, I just had to pre-tension it to like 3 or 4 revolution.

just throwing out a idea here, but maybe you have made the housing for the spring a bit too small, where you can't put a longer spring in it there, to give you that extra revolutions to say 4 or 5, so it can push the rounds up the tall feed tower.

 

[Bianchi]

i simply reduced the tall of the original 30 rds mag to get a reduced feed tower i made nothing inside to reduce the number of ammo.

I'd not posted a picture of the spring in the casing but the double spring be more longer and there is space to add material, the problem come from the outside spiral wall are thin at start and if i add more revolution i could break it or twist the axis.

the better solution to not add much revolution is getting a new spring thickness more hard.

 

[Bianchi]

https://streamable.com/civsmg

he load not perfectly for the moment but he will works better with a small spring adjustement and by using it a bit because the printing is not really smooth, i don't want to smooth it with sandpaper that could enlarge and create problem.

just throwing out a idea here, but maybe you have made the housing for the spring a bit too small, where you can't put a longer spring in it there, to give you that extra revolutions to say 4 or 5, so it can push the rounds up the tall feed tower.

i take note! if i had to put a larger spring i could place it at the rear of the drum to get more space and recreate an housing and rebuild an axis more thick with two bearings in the older housing.

PS: today I learned something! where we can find flat springs easely for free!! i must quicly verify if that is real.

 

[Bianchi]

if you want a flat spring without waiting that he come from china



look inside a car seat belt winder!

 

[jimdoc]

I just scrapped some small gas powered weed whackers, and they had flat springs in there for the pull cord. Lawn mowers should be the same.

 

[Uncle Billy]

now that is a great idea!

I'll have to remember that if I ever need a flat spring, since I never wear a safety belt anyway

 

[Bianchi]

I just scrapped some small gas powered weed whackers, and they had flat springs in there for the pull cord. Lawn mowers should be the same.

hello! a friend of me tell me the same but i didn't found one!

now that is a great idea!

I'll have to remember that if I ever need a flat spring, since I never wear a safety belt anyway

you will find many differents sizes! generally they are in 0.20 thickness.

 

[Bianchi]

That is the most compressed spring that i can made for the housing with the chinese spring (eight revolutions).



If he not work! i will listen Uncle Billy and i will rebuild the housing more larger that can containing a entire spring like those that we can found into a car belt winder.

 

[Uncle Billy]

here is hoping you have it solved

 

[Bianchi]

arf! "constant force spring" he have the right name i could add revolutions but that never add more force. i had a better result with the doubled spring...

all being in the thickness... i will do a new double spring more long.

 

[Bianchi]

i cut the last spring in half and do a doubled spring! this time the tension comes rapidly with this longer size i only added two revolution. i will change the dummies ammo's for something a bit bigger than what i used.

this is my fifth try i think? i did not break the lips of the feed tower for the moment... be hard to find the right compromise when you only having one size of material.

 

[Bianchi]

the new double spring is the more strong that i made, he's so strong that he push the follower after the end stop that i builded on the drum i will modify the follower to stop it again at the right place but he did not push all ammos... i will reduce the feed tower inside to get less ammos in it to reduce the weight like my super Billy expert explained me more early.

 

[Uncle Billy]

good luck on your modifications. a lot of battle is finding the just the right combinations spring tension height of the feed tower....but once you do you'll be happy and proud of yourself when it function like it suppose to

 

[Bianchi]

yes all have to be combinate! that's why i have to look elsewhere my feed tower is a magasine and ammos are too numerous i will thin it inside, ammos will be more positioned in a straight line. we will know a day if that can works or not..

 

[Bianchi]

hello! i taked the time to rebuilded:

. a complete follower that didn't goes over the endstop the first be too thin.
. twenty two dummies ammos that have the exact same length

after that i loaded all the dummies and ten ammos i made them goes up and down
onto a short distance many times to enlarge the passage by friction and i repeated
this operation by adding five ammos each time to end with all ammos loaded in the drum!
ammos are better directed when i loading or unloading it by hand.

I keep loading it and unloading it...

 

[Uncle Billy]

hi Bianchi, did you get a chance to fire the gun with the drum in it? interested to know if it works like you expected it to

how about a short video of you shooting it

 

[Bianchi]

Hi sorry i'm in a new flat i had the internet yesterday this is why i disappeared! i also have to made a desk...to continue. i renewed my license and i will do a video when i can print the real new feed tower the first being a simple reduced magazine that works differently.

 

[Bianchi]

Now I have time to continue my experience! A video will come when I could go to my shooting club to take my new license.

after rebuilt the follower to stop him at the right place I remade a feed tower that is thinner inside but ammos does not goes up correctly...
now I have to make an head and ass rounded on all my dummy ammunition because they are cylindrical and i think they block.