Bad news on triggers

[ivan]

hi boys

I have got some bad news about Ra Picasso triggers on the weekend, My mate has a picasso 100 it is less than 1 year old he recently fitted it with 2 16mm rubbers the rubbers are easy to load I can almost load it with one hand. He went spearing on saturday and the gun shot off the same way mine did a year ago. This news has hit me hard because I didnt think this would happen under 2 16mm. I am now worried about my new Ra 150 busting a trigger. I would like to know if anyone has knowlege about what is the absolute shortest I make my rubbers, currently they are 80 and 85cm and are relatively easy for me to load. I am thinking that if I run the risk of breaking a trigger that I should go for 1 20mm on my ra 150, problem then is it would probably be pretty hard to load.

cheers

 

[Abriapnea]

Hi Andrew , sorry to hear about your problems . Can't help you on the band lengths , don't even know what length I'm using .
I simply measure new bands against old ... I would recommend replacing the picasso grip with an omer , will solve your hassles .
(Where have I heard that before ?)
One 20 mm. band doesn't sound like such a good idea .

 

[Iyadiver]

Ivan,

Maybe u need to check out how worn out the trigger assy in the pistol grip. Think back how much use it has taken from what kind of rubber pressure since brand new. Maybe u can draw a graph of its estimated life span. 1 year is still too new to burst trigger but factory once in a while might received bad batch from production line. 1 grain of sand might do harm if it landed on the sear/s.

One last thing to inspect will be the spear. If it is steel, the portion that engaged the trigger sear, has it rust to a point where it cannot offer proper enagagement ? Spear can be the fault too.

Make a claim to ur dealer if warranty is still valid.

Remember, Jeremy of RA reccomended the following :


**************************************************
We have a graph of single band lengths that we use for various barrel lengths. By loading with two bands you can increase the power, but not by too much while still maintaining accuracy and penetration. We recommend two 16mm bands because of this.

We had a guy who overloaded his guns in our opinion. We measured the pull and it was in the region of 90 - 100 kg. He lengthened the bands to about 60 kg and was much happier with the results. The average guy uses a pull of about 45 - 50 kg with a single band on a 130 cm gun. We have never heard of
a gun misfiring without there being some fault with the mech or spear and have never been able to test a mech except by loading a tray held by a length of spear to about 150 kg ( in this case two people standing on it.

Cheers,

Jeremy

Dive Factory

181 Gale Street,
Durban 4001
South Africa
****************************************************


This info is where we guys were talking about in PNG + RA thread in June. We been thru this before and I still can not find proper answer on what is the safe limit of RA. A good 16mm band is 5/8" in the US. Good brand at this thickness is 50 kg of pressure if set at the regular 300-320% stretch. Two of these make 100kg. So which info from Jeremy make senses 2 x 16mm or 60 Kg ?
I would go for 60kg because it is a confirmed value. Band thickness/pressure will depend on manufacturer quality. One last thing is to measure the kind of strecth the original RA come with or set at, this define final pressure value.

My experience with my old JBL is, it has low modulus ( new one I heard better now ) rubbers. If I upgrade to Riffe rubber for their Woody Magnum, same length same thickness, the gun will need a hammer to release the trigger. It doesn't miss fire, but you will miss the fish cause ur trigger is to tough to push.

As for u having twice trigger failure on RA ( one is ur friend ) you better be careful. If 1 x 20mm + 1 x 16mm especially when shorten can break a sear as you were saying in that PNG thread, it sure doesn't sound like it exceeded the 150kg limit RA used as testing, but sure way above the reccomended 60kg.

I think you better stop pumping too much power on ur RA. If u can load a 150cm RA gun, I am sure you are either very strong or have mastered the technique well. With no butt like the RA, I don't think I can load that gun. This might cause you to add more power with ease and have another miss-fire. Triggers get worn out from rubber pressure you know. If this double rubber muzzle is new from RA, expect to hear more trigger failures in a few more years cause many spearos are nut-case, they will rig their gun to maximum......their own maximum, not factory maximum.

Also to consider RA retail price being very decent, I would not expect much super strength material or design. Research cost money & exotic parts cost money, RA must make their bucks to survive too. Stick to 60kg of rubber pressure, I hope all goes well in the long run. The next thing will be for all RA owners to write to Rob the man himself and voiced out the need for a 300 kg trigger which you guys are willing to buy as upgrade or something. Nothing is free my friend. I think RA has good future and reputation, I am sure they have a new trigger supplier or design on the drawing board. Manufacturer need spearos as testers too, if no demand from you guys, no new triggers will come to their line.

Be Safe,
IYA

 

[Hamrrhed]

Abriapnea,
... I would recommend replacing the picasso grip with an omer , will solve your hassles .
The RA trigger mechs are a little different that the Omers, have you done this mod on your gun? If so was it a relatively painless undertaking? Could you attach a pic?
My 130 RA trigger mech busted under the load of a 20&16mm band configuration (as purchased) the first time I loaded it.
Since then Ive gone with the dual 16's (no problem so far) but the memory makes me a little apprehensive . Needless to say Mike Damms was more than helpful when confronted witht he problem.
Thanks
Anthony
Torrance California

 

[Abriapnea]

Hi Hammrhd ; I have some pics of the omer grip under "RA guns"
I THINK it fits RA guns ...my gun was built by a friend (a copy o RA)
I honestly don't know enough about tech specs to asure you it will fit though:duh

 

[ivan]

hi

Nice info IYADIVER, one thing though I dont know how to measure my rubber strength in kilograms, 60kgs would my current set up be over that. Oh believe me im not very strong I will tell you a little story about loading spearguns such as RA. My mates and i went to the gym one day to see who was the strongest, one of my mates benched 90kg, the other 80kg and the other 70kg. then I had a go and could only bench 50kg. Then i got my Rob allen 110 and see if they could load it none of them could even come close to loading my 110, theres no hope on them loading my 150. So there it is you dont have to be strong to load short rubbers.

My experience on rubber strength is limited all I know is that I shouldnt be putting more than 2 16mm on my gun. But what if my 2 16mm are putting out just as much power as someone elses 20mm rubber. see i didnt think my gun was too overloaded until these triggers strarted busting. IYA if you could give me a rough Idea on how much pressure a 80 and 85cm 16mm are putting out on my 150 in kilograms. Honestly my gun dosent seem very hard to load so if it breaks I dont really know where I stand maybe I could just use it how it is and every time it breaks pay the $30 to get it fixed this could probably be a good idea cos then I get the power all the time and only have to pay out $30 around once a year or so.

cheers

 

[Wishbone]

Hi guys,

Don't know much about this tech stuff and kilos. But I got this year a new 100 cm OMER Excalibur Carbon. It came with a set of 25cm/16mm bands and a 6.5mm shaft. The gun was spitting the shaft, not shooting it...

I've replaced the bands with 18mm Beuchat bands of the same length and it was OK despite the fact that Beuchat are thinning the band so it can easily get into the rings (sorry for not knowing the right term). As a result the Beuchat bands are popping out of the rings often and may hurt you even if you're wearing gloves. Happened to two of my fellow spearos this year and we called the scars "Beuchat Scars" I got rid of those bands.

Now I am using a single set of yellow Immersion Megabooster 25cm/20mm bands and I am VERY happy with them! The rings are thicker but that's not a problem. And the gun finally shoots as it should and I may say it's quite accurate! So there's no problem for an OMER grip to hold a single set of 20mm bands. I am sure it will hold another set of 16mm...

I second Abri's opinion on the grip!

 

[Iyadiver]

Hi Ivan,

There is a good info on Internet Custom Speargun on various rubbers, but I don't understand all of it ...ha ha ha.

Anyway I use Riffe rubbers as reference cause their catalog stated the pressure and I measured a few Riffes with tape and see their website.

Rubber Pressure as per Riffe spec :
1/2" or 12.7 mm is 70 lb or 31.8 kg
9/16" or 14.2 mm is 85 lb or 38.6 kg
5/8" or 15.8 mm is 110 lb or 50 kg
3/4" or 19 mm is 135 lb or 61.3 kg

My friend borrowed my Blue Water Hunting book but I remember them well. The above figure as per Riffe spec is considered premium quality rubber as per that book. Never think all rubber are more or less the same quality.....NEVER !! The above figure is based on strecth of 300%, more or less. 300% strecth seems a favourite. I suppose power against reliablility is there.

I don't know if percentage of strecth is linearly equivalent to the increase of rubber pressure. Some info I heard, after 300% strecth, power increase is not linear. Let's assume 300-330% is the standard strecht gun builders are looking for. At least I know Riffe put it that way.

Here is an example taken from Riffe Mid Handle series:

# Bottom 38" (96.5 cm) Stock length. Rubber (3) 9/16" X 18"
rubber strecth 28" (71 cm)

#H Hawaiian 50" (127 cm) Stock Length. Rubber (3) 9/16" X 24" rubber stretch 40" (101.5 cm)

#I Island 62" (157.5 cm) Stock Length. Rubber (3) 5/8" X 28 1/2" Rubber Strecth 50" (127 cm)


Calculation as follows : Example is Riffe Island

Powerband length is 28.5". This is a measure of where the knot to knot end or terminated at the wishbone.The entire rubber length is always extra 2" cause that is where you get "useless" rubber length where the wishbone is attached. This useless rubber length plus wishbone length is about 3" total perside.
So one side on the rubber is actualy 17.25" long including wishbone, not 14.25" ( 28.5 / 2 )

It streches to 50". Thus 50" / 17.25" = +- 290% strectch.
Strecth is measured from muzzle to furthest wishbone tab/sharkfin on shaft.

Let me do rough estimate for ur 150cm RA. If u are saying ur rubber is 80 cm, I am assuming u are measuring, termination to termination on the rubber, not the entire rubber length. So 80cm divided by 2 = 40 cm + wishbone length = +- 47cm. If ur RA is 150 cm muzzle to butt, the muzzle to furthest shaft tab/sharkfin is about 150 minus 14 cm ( rough estimate ) = 136cm.
So 136cm/47cm = 290% strecht. If ur rubber is Riffe quality that 16mm is already pumping 50kg pressure. So 2 of 16mm at 80cm length technicaly is putting you at 100kg and that is an overloaded situation as per Jeremy of RA info, if RA rubber is having the same spec as Riffe.

I keep thinking that Jeremy info does not make any sense. He reccomended 16mm x 2 but mentioned that 90-100kg is an overloaded situation. The only possibility is that RA 16mm rubber is only producing 31kg, like a Riffe 12.7mm, so 62 kg is decent, but this is not possible. Quality can't be that far off. Get RA to email u the graph that they have for their rubber loading, it should tell what they are producing.

If I were you, just stick to one of Riffe 3/4" (19mm ) and be safe at 61 kg. This is one mother to load !!!!

HOPE THIS HELP

Iya

 

[ivan]

hi IYA

Thanks for the info, im a bit worried now though cos you saying my gun may be putting out 100kg. Im seriously thinking about a single 20mm band but Abri said it may not be a good idea, Abri would you be able to verify that. A single 20mm band would probably have to be around 90 to 100cm long im not real sure. It will probably be a bit hard to load but I reckon I could manage. The part where you have to stretch the rubber so the butt of your gun goes on the chest is the hard part. I think i will try and email Rob allen and see what he thinks although I think my email is stuffed at the moment. anyone out their using RA 140, or 150 want to share what length of 20mm rubber your using.

cheers

ps I get more satisfaction shooting a fish with a single rubber rather than two.

 

[Abriapnea]

Hi Andrew ; listen Boet , that was only my personal opinion . I think I would pop something if I had to load a 150 gun with a single 20 band ...
The double 16's just work better for me . Whatever works for YOU is the right setup .

 

[sturgeon]

Ivan,

I used to shoot a RA 130 cm gun a couple years back. I had a single 35 inch 20 mm rubber on it. I usually add 2 inches per size, so my 110 cm gun had a 31 inch rubber and my 120 cm gun had a 33 inch rubber. My guns are pretty stout to load but I also need to be able to load them all day long (such as in a tournament) so I don't get too crazy with the rubbers.

Scott T.

 

[ivan]

hi

Thanks guys thats enough info for me to go and buy my new 20mm so Scott 35inch for a 130 so a 39inch for my gun. ill have to work that out in centimetres. One last thing im getting a new mask either a sporasub samurai aor cressi sub minima what do you guys reckon.

cheers

 

[Jay Styron]

Samurai

Just my opinion, but I use the samurai w/ the tinted lenses. I like the fit and the low volume.
Jay

 

[ivan]

hi Jay

Are they the ones with the red/brown coluured lenses

cheers

 

[Jay Styron]

Hi Ivan,
I think its more of a gray tint, and the outside is mirrored like a security mirror. Don't know if this helps w/ the fish not seeing your eyes but it looks cool. I like the tint because it seems to be easier on my eyes when its sunny and dealing w/ all the reflection on the surface. Also it seems that my eyes don't have to adjust as much when going back down where its generally darker.
Jay

 

[sturgeon]

Ivan,

I use the OMER Abyss. I have the tinted/gray, yellow, and clear lens versions. I like all of them but lately I've just been using the clear mask. If you're going to be diving in dirty water most of the time, I wouldn't recommend the tinted lenses (they're great in clear water though). IMO, the yellow lenses are good for all around use and the clear is the best for dirty water.

Scott T.

 

[ivan]

hi thanks guys

Scott I currently have a mask with clear lenses and will use that in dirty water on the coast 2 to 3m vis. But I will order the Mirrored samurai this weekend I will use this out at the reef vis from 30 to 200ft.

cheers