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Experimenting With The Type 96 PDI Hop-up(Updated)

1662 Views 4 Replies 3 Participants Last post by  hidden187
I apologize in advance if some one has posted this already but I could not find anything like this anywhere so I said to hell with it.

Ok, so I was really bored today and I thought to my self as I was cleaning the gun, how can I make this hop-up better? So I came to this conclusion, even though there are 2 hop-up arms it still acts as if it is only one. Here is a horrible drawing done on paint....

Ok, this is the hop-up with the stock nubbin( in red because clear doesn't show up as easily ;)), as you can see there are 2 arms.

Now what would it look like in the gun with it pushing down on the BB, and say your bars are not set at the same level, due to a mean curve you are trying to fix.

As you can see, it does not sit with the hop-up arms there is a small gap from one level to the other. Now, you may be saying why would this matter its only 1/32 of a inch (made that up, I have know idea what the gap is ::) ). Well yeah at 100 ft sure it will fix the curve what about at 250 ft, or 300 ft. That small gap may be the difference between a 18 in grouping and a 9 in grouping at 150 ft( the distance used for this test).

So I came up with this DIY mod, and here is a basic drawing of it

Basically I cut the hop-up nub in half, witch in theory would eliminate the gap. But why stop there, when you can experiment with different type's of nubs that would use the same system (This is a endless amount).

So here begins the DIY mod, first here are the items you need, one Hop-up

Super glue and tweezers

and a pair of dikes ( wire cutters) , or even better a exact-o knife

Ok, so the first thing you want to do is have a stable platform to start. The first thing I did after removing the Hop-up was to take one arm and super glue the nub to the one are making extra sure that it was straight. I can not stress how important this is, it is the make or break of this. Use the tweezers to prevent your hands being glued to your $60 hop-up.

Next, I removed the arms completely to get the nub sized up on both sides. Now here was one of the more steady handed things to be done. You want to that your knife and as carefully as you can cut it exactly down the middle. Once you do that you will need the tweezers once again to glue this piece in place.

When you do that you want to let this set, and I don't mean for 30 min's ether. You want to let it set for minimum 8 hours, so over night is best. Now I can here people saying "But its super glue it sets in 10 min's." Yes, it does, but it is not set, and when bonding a little thing of rubber to a small metal bar you want to let it set. Also do not keep them together they will glue together. This is how I keep mine while I let them set.

I will post test results on Monday because I don't have the time to do it tomorrow, because I am going rock climbing. Also in the test I will post the grouping sizes, and how well it fix's bad curves at a distance. If there is a particular range you would like to see post it or pm me and I will try to get to it on Monday. So far I will do 50, 100, and 150 feet, if I can get it to go farther then I will see maybe 200.

Also a note if you find a grammar error or spelling error PM me, do not post it on this tread.

UPDATED Jan 16, 3:30 pm pst

Test Results

Test constancy's
-20 shots with a tuned hop-up (in 5 shot batches, and measurements done in circle diameter)

50 Feet

First batch- 8 in diameter (about 5mph to 15mph gusts)
Second batch- 9 in diameter (same wind conditions)
Third batch- 9 1/2 in diameter (" " " ")
Fourth batch- 7 3/4 diameter (" " " ")
Average circumference of 26.95 in^3

First batch- 6 in diameter (about 5mph to 10mph gusts)
Second batch- 5 1/2 in diameter (same wind conditions)
Third batch- 7 1/2 in diameter (" " " ")
Fourth batch- 7 1/4 diameter (" " " ")
Average circumference of 20.57 in^3

Conclusion for 50 feet there was a decrease of 6.36 in^3, what this means is that the accuracy went from a soccer ball to about a soft ball.

If wind is better tomorrow I will do 100 and 150. I took pictures but they do not do any justice to the math.

So I went out after I got back from work and was able to get the 100 ft test in while there was still light. Here are the results.

100 Feet

First batch- 15 in diameter (about 5mph or so)
Second batch- 14 1/3 in diameter (same wind conditions)
Third batch- 16 1/2 in diameter (" " " ")
Fourth batch- 16 3/8 diameter (" " " ")
Average circumference of 48.83 in^3

First batch- 12 2/5 in diameter (about 5mph or so)
Second batch- 14 1/2 in diameter (same wind conditions)
Third batch- 13 3/8 in diameter (" " " ")
Fourth batch- 12 1/4 diameter (" " " ")
Average circumference of 41.21 in^3

conclusion, there was a difference of 7.62 in^3, as you can see there is not much of a difference. As for 150 ft I will try tomorrow after work, but so far for a small mod like this it is very promising and pretty revisable if you don't like it.
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Not to bad man.

Should be a good little mod.

The thing that I was playing with, kind of along the same lines, but I used the shaft of a drill bit. I ended up just using normal glue, so I could reverse the mod if needed.

You could then, if you wanted, take a file and make a slight curve to the metal nubbin.

Also look at putting some card stock between the arms. Can use it like a spacer to try and get a larger area for the bucking to touch the bb.
This is somewhat similar to the mod I did with my PDI hop up chamber. I taped the arms together, to keep them even so they were not unbalanced, and both applied equal pressure on the nubbin.

Also, have you thought about possibly using a rubber band rather than the large o ring you have sitting there in the one picture? I found a rubber band applies much more pressure to the arms, and makes each adjustment more "sensitive" and affective. It also keeps the arms from wiggling around as the large o ring looses elasticity after awhile.

Just a thought, looking forward to updates.
Woogie; I do use a piece of a playing card to keep the arms spaced, I have also been looking at using a plastic mold and making a few different types of nubbin's (I have know idea if that's spelled right).

Fuzzy; I used to have a small piece of surgical tubing in there but it keep unscrewing from the pressure and vibrations
. I currently have a smaller o-ring then the one in the picture on it. The one there is the o-ring I use on the outer barrel to keep a good seal.

As for a up date when I got back from climbing there was to much wind for a valid accuracy test at 100 ft, and 150 ft. But I was able sort out all of my base lines before the mod and after for 50 ft, I have posted it on the bottom of my first post.
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I updated it today it looks promising for this little mod, cant wait to try different types of nub's. Would love to get some ideas for shapes or sizes.
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