Home Tournaments Calendar Weather Merchandise Sponsors

Go Back   Spearboard.com - The World's Largest Spearfishing Diving Boating Social Media Forum > Spearfishing Gear > All About Guns

All About Guns What's your weapon of choice, and why? Discuss the beloved speargun here!

Reply
 
Thread Tools Rate Thread Display Modes
Old 05-26-2018, 09:44 PM   #1
Straits
Registered User
 
Join Date: Jan 2018
Posts: 26
Straits Cray Gun Build

Hi all,

Building my first gun and hoping the collective wisdom here can help guide me through it. Thanks in advance.

Workshop is coming together. Tools/equipment include: thicknesser, drill press, router, router table, table saw, chisels, hand saws.

I've got 4 x lumps of merbau (kwila) wood that are 90mmx90mmx600mm. The blocks float in fresh with approx 20% above water, without any parts attached. From another thread on this topic I understand this short gun won't float, but as it's a cray gun this isn't an issue.

I'm hoping I can ask questions in this thread and continue to add to those questions as I go through the build.

Gun plan:
Shaft: 600mm length, 7mm diameter, short flopper 25mm from point, aiming for shortest overhang possible. Square cut Riffe style with 2 x shark fin tabs.
Band: single 14mm small ID.
Components:Neptonics reef trigger mechanism, handle undecided at this stage.
Barrel: open track, 550mm from butt to tip, see question below about volume/dimensions.

Questions:
1) How much space do I need behind this trigger mech to the butt of the gun? I'll keep this minimal, and loading will be off the chest, with wooden butt square and clean.
2) How wide should the gun be but still fit the trigger mech with enough wood on both sides? Neptonics lists width as 12.5mm (0.5 inch). I'd like the gun to be bulky and solid so was thinking 40mm width.
3) How deep should the gun be? Neptonics lists height as 25mm (1inch), and I expect it to sit flush with the top of the gun so only the shark fins are above the top surface. How much wood is required beneath this to allow handle attached and trigger protrusion? I was thinking of 50mm, but just guessing here.

Thanks again.
Straits.
Straits is offline   Reply With Quote
Old 05-27-2018, 08:40 AM   #2
Mendicant
Registered User
 
Join Date: Feb 2018
Posts: 93
Re: Straits Cray Gun Build

I am afraid I am not familiar with the term "cray gun."
Mendicant is offline   Reply With Quote
Old 05-27-2018, 04:48 PM   #3
Straits
Registered User
 
Join Date: Jan 2018
Posts: 26
Re: Straits Cray Gun Build

Cray=Crayfish=lobster. Sorry, should have explained.
Close range short gun for manoeuvring in tight ledges and caves.
Straits is offline   Reply With Quote
Old 05-27-2018, 11:41 PM   #4
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 321
Re: Straits Cray Gun Build

1) How much space do I need behind this trigger mech to the butt of the gun? I'll keep this minimal, and loading will be off the chest, with wooden butt square and clean. (2 to 3 in for me)
2) How wide should the gun be but still fit the trigger mech with enough wood on both sides? Neptonics lists width as 12.5mm (0.5 inch). I'd like the gun to be bulky and solid so was thinking 40mm width (depend on line release mine is 2 inch).
doyenofcastle is online now   Reply With Quote
Old 05-28-2018, 05:58 AM   #5
Straits
Registered User
 
Join Date: Jan 2018
Posts: 26
Re: Straits Cray Gun Build

Thanks Doyenofcastle,
I'll plan 50mm behind the mechanism to the butt, and go with 50mm width.
No line release for this gun. Line will be anchored near the snout of the gun with short bungie to mono. These guns don't need much range, and will have approximately 100cm from muzzle to spear point when shot. Basically you get right in front of the crayfish and shoot through it at point blank range.

I suppose going 50mm deep will make it a nice square prior to any further shaping. Would a gun this deep allow for enough trigger to protrude?
Straits is offline   Reply With Quote
Old 05-28-2018, 02:40 PM   #6
Hpwatson
Registered User
 
Join Date: Apr 2016
Location: Gulf of Mexico
Posts: 73
Re: Straits Cray Gun Build

Some of those questions can answer themselves once you buy your parts. I would mock-up the trigger mech first, then hold whatever handle you choose underneath it to make sure it all lines up correctly. One way to get the right trigger protrusion is install the trigger mech, then start shaving material away until it looks and feels right. Your handle frame will determine how far back you can mount the handle/mech, so I would make that decision when you have parts in hand. Keep ballasting in mind when you mock this stuff up, you'll have to hide some lead in there once the gun is shaped and built.
Hpwatson is offline   Reply With Quote
Old 05-28-2018, 05:09 PM   #7
Charles dT
Registered User
 
Join Date: Nov 2017
Location: San Francisco, CA
Posts: 115
Re: Straits Cray Gun Build

Hi Straits,

the design you describe looks a lot like the hole gun I built.
I'm attaching a picture here as well as a competitor Riffe 00 that shoots the same shaft so you can compare.

my gun has minimal overhang, actually I even carved out the end of the muzzle so that the flopper can be resting on the gun and still have the shaft lay flat. If I would start over I would have it rest even more or not at all.

If you really want a compact gun, go with a reverse mech, look at my gun and you will see that the mech is all the way back and yet the trigger is in front. Compare that to trigger/mech placement on the Riffe 00. That's part of the reason the shaft protrudes so much on the Riffe vs mine. With the reverse mech you reduce the length between the butt and the tip of the shaft so you have a more compact design. My speargun is shorter and yet the length from band to tab is longer so in theory packs more punch (not that it is required at that distance)

My gun is very bulky because it was built from 3 pieces of wood bolted together basically ( I didn't have any tools at the time and still don't have many) so you can disregard that aspect however from butt to tip etc it should give you an idea of what you are looking for.
Can take a few pics and measurements if you want. I remember that the width on mine is 40mm and that is way more than a Riffe, it already feels plenty bulky. 50mm sounds like a lot, but just personal opinion.
Attached Thumbnails
Click image for larger version

Name:	Ikea speargun.jpg
Views:	110
Size:	44.4 KB
ID:	238175   Click image for larger version

Name:	riffe 00.PNG
Views:	45
Size:	77.2 KB
ID:	238176  
Charles dT is offline   Reply With Quote
Old 05-28-2018, 11:14 PM   #8
triponempa
internet troll
 
Join Date: Jun 2013
Location: florida
Posts: 67
Re: Straits Cray Gun Build

Quote:
Originally Posted by doyenofcastle View Post
1) How much space do I need behind this trigger mech to the butt of the gun? I'll keep this minimal, and loading will be off the chest, with wooden butt square and clean. (2 to 3 in for me)
2) How wide should the gun be but still fit the trigger mech with enough wood on both sides? Neptonics lists width as 12.5mm (0.5 inch). I'd like the gun to be bulky and solid so was thinking 40mm width (depend on line release mine is 2 inch).
a gun this short does not need to be fat or bulky at all- also - it should be muzzle heavy - since you will be shooting down all the time

what you want - is a finished dimension of 1.5"x 1.5""
the track should be open deep - right?
if you do that - use a neptonices reverse mech - and use either a mortise in style - or flat plate style ar handle frame system
neptonics has two types - the flat plate allows for a smaller gun behind and below mech - by 1/4"
but the mortise in type allow for round gun profiles and sleeker look in general - but if your gun is wide enough at the back to allow the flat plate style - then you can make the gun a bit narrower in back.

I would recommend - making 42"gun - anything shorter - is just lacking in power
go 1 7/8" x 1 7/8" x 44"for the rough lam - then mill down to 1.5"x 1.5
flat straight square and true (hardest part of the whole build)
triponempa is offline   Reply With Quote
Old 05-28-2018, 11:32 PM   #9
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 321
Re: Straits Cray Gun Build

Quote:
Originally Posted by Hpwatson View Post
Some of those questions can answer themselves once you buy your parts. I would mock-up the trigger mech first, then hold whatever handle you choose underneath it to make sure it all lines up correctly. One way to get the right trigger protrusion is install the trigger mech, then start shaving material away until it looks and feels right. Your handle frame will determine how far back you can mount the handle/mech, so I would make that decision when you have parts in hand. Keep ballasting in mind when you mock this stuff up, you'll have to hide some lead in there once the gun is shaped and built.
100% accurate
doyenofcastle is online now   Reply With Quote
Old 05-29-2018, 06:33 AM   #10
Straits
Registered User
 
Join Date: Jan 2018
Posts: 26
Re: Straits Cray Gun Build

Thanks all.
Makes a lot of sense.
Mechs haven't arrived yet, so I'll do the mock up when they arrive.
CharlesDT, that's a great looking little gun.
Straits is offline   Reply With Quote
Old 05-29-2018, 11:38 AM   #11
Mana'squal
Registered User
 
Mana'squal's Avatar
 
Join Date: Jul 2016
Posts: 108
Re: Straits Cray Gun Build

https://r.tapatalk.com/shareLink?url...9&share_type=t


I just finished a 42" mid that might be something to work off of. Minimal volume with maximum band stretch was the goal of the build. The only change I would make is I did not set my mech deep enough and their is about a 1/8" shaft drop from mech to track, I also already had the reef mech or I would have used the neptonics reverse mech. Gun has power for its size, I took a 30 pound fish this weekend from 7-8 feet out.

Sent from my SM-G900V using Tapatalk
Mana'squal is offline   Reply With Quote
Old 08-11-2018, 11:05 PM   #12
Straits
Registered User
 
Join Date: Jan 2018
Posts: 26
Re: Straits Cray Gun Build

Finally getting somewhere.
Blanks have been squared up and planed/thicknessed down to 40mm square.
All componentry except shafts have arrived (7mm diameter 575mm long).
Neptonics reef trigger mechs.
Handle is https://neptonics.com/product/ar-15-...n-handle-rear/ and I'm having some trouble finding information on the dimensions of the insertable part. With a couple spanners it measures between 15mm and 15.8mm. Does anyone know the definitive width? I'll get a router bit specifically for this insert, and keen to get it right first time. I don't particularly trust any of my spanners to tell me the truth.

All your earlier advice was spot on. Once the bits arrived, it was easy to see how it would fit together. I'll try get a photo uploaded.

Thanks.
Straits is offline   Reply With Quote
Old 08-11-2018, 11:23 PM   #13
Straits
Registered User
 
Join Date: Jan 2018
Posts: 26
Re: Straits Cray Gun Build

Attempting to upload pictures.
Attached Thumbnails
Click image for larger version

Name:	IMG-1050.JPG
Views:	42
Size:	111.4 KB
ID:	239231   Click image for larger version

Name:	IMG-1051.JPG
Views:	40
Size:	117.9 KB
ID:	239232   Click image for larger version

Name:	IMG-0812.JPG
Views:	38
Size:	94.9 KB
ID:	239233  
Straits is offline   Reply With Quote
Old 08-12-2018, 01:40 AM   #14
Mike N
Registered User
 
Mike N's Avatar
 
Join Date: Jan 2009
Location: Sacramento
Posts: 945
Re: Straits Cray Gun Build

I use a 5/8" bit for that handle insert.

MN
__________________
Never let a good crisis go to waste.

manmidhandles@gmail.com

https://www.facebook.com/ManMidHandleSpearguns/
Mike N is offline   Reply With Quote
Old 08-13-2018, 05:32 AM   #15
Mikel_24
Registered User
 
Join Date: Nov 2016
Location: Bilbao (Spain)
Posts: 160
Re: Straits Cray Gun Build

I think you need some more wood behind the mech. Otherwise the lower lip of the handle will contact your body before the butt pad (non existent in the picture) does, and loading will be awkward.
Mikel_24 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 06:51 AM.


The World's Largest Spearfishing Diving Social Media Forum Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright ©2002 - 2014 Spearboard.com