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Ric.Fallu
The 'Few Tools' approach is to build a gun the simplest way, with the cheapest materials and fewest tools, but to apply design that produces a safe, efficient and aesthetically pleasing result.
One of the challenges is the trigger mechanism. Most mechs cost a bit (this is not to say you don't get value for your money). Is there a way to make a safe and smooth operating mech that isn't too too expensive? (Expensive
in money terms that is ' it might take time).
It seems to me there are several ways to go:
' purchase a cheap mechanism and design the gun around it
' purchase the internals of the mechanism and make the housing
' build a mech from scratch
Do any forum members have expertise on this??
Ric
Ric.Fallu
Cheap mechanisms
I have successfully used the Simontal/Picasso mechanism in single rubber guns. This mech has the big advantage of being cheap, and its also shallow, allowing you to keep the handle close to the axis of the spear. But has some features that require design solutions.
' The casing is an unusual shape and it takes some matching to the gun body. You also have to be careful when setting how high above the stock it sits to ensure proper spear alignment.
' The shooting line release is complex, and if there is a lot of pressure on it, it bows the spear upward. You can address spear bow by inserting a stainless pin through the casing, just above the spear, and it will stop the case flexing. I normally use this mech in closed muzzle guns, and use a wooden line clip to retain the shooting line, so I don't have a problem.
' Sometimes, the mech will let go when loading. RA addressed the problem by increasing the spring tension within the mech. Personally, I have solved the problem by placing a support under the spear just in front of the mech
Ric
spearq8
I went that route and found out it simply is not worth the trouble or effort. Today there are so many excellent triggers out there that it simply is cheaper to just buy one and build your gun around it. There are also safety concerns ... you really don't want to find out the hard way that the metal you used for your sear was not strong enough.
One day when 3D metal printing will become more common, you will be able to send your design somewhere and get your custom trigger in the mail. But even then my bet is that it would cost you several times what a normal trigger would.
phil herranen
The 'Few Tools' approach is to build a gun the simplest way, with the cheapest materials and fewest tools, but to apply design that produces a safe, efficient and aesthetically pleasing result.
One of the challenges is the trigger mechanism. Most mechs cost a bit (this is not to say you don't get value for your money). Is there a way to make a safe and smooth operating mech that isn't too too expensive? (Expensive
in money terms that is ' it might take time).
It seems to me there are several ways to go:
' purchase a cheap mechanism and design the gun around it
' purchase the internals of the mechanism and make the housing
' build a mech from scratch
Do any forum members have expertise on this??
Ric
I have built a few triggers ,and it's really not that hard . But I won't post how to do it for safety reasons . Reliable triggers are far to cheap to recomend or help someone build one that can't figure it out on their own .
popgun pete
Many years ago I experimented with making an inverted second trigger mechanism for an "under and over" gun and you need precision in the right places to get a reliable action, especially with the drilling of the pivot holes in the sear box housing. If anything the levers had to be made to suit the final spacing of the holes in the housing rather than the other way around as if that spacing is even slightly out then you need to adjust the levers, provided that there is still enough meat in the right places to be adjusted. One method is to make a pivot pin mounting template and use that to create both the levers and the housing, but the holes can still be slightly out if the drill cuts off center in the job or at an angle, i.e. not perpendicular to the vertical faces of the levers. That has repercussions for the contact width, side to side, across the rubbing surfaces that are under load.
Probably the easiest thing is to copy a known mechanism and use it for your templates, but by the time you get it right it may have been easier to just buy one. Plus there is always the prospect of "will the Defendant explain to the Court why he created the most critical part of the weapon involved in this tragic accident and not used one obtained from a reliable and proven supplier". "To save money your Honor".
Ric.Fallu
The comments of the preceding three are valid (and come from people who's advice I respect). Normally, I would give the same advice - its a lot of trouble, and there is the safety/legal liability factor to consider. If your goal is to make the most efficient and safe gun as easily as possible, there is no doubt in my mind that purchasing a mech is the way to go.
However, sometimes its good to set yourself a challenge just for the heck of it. You might spend hundreds of dollars in time to save yourself ten. But you learn in the process.
I have sometimes speculated about re-housing pre-existing moving parts. The sear and trigger of some mechs can sometime be separately purchased quite cheaply. Examples would be the Picasso mech sear, and the internals of the Undersee mech. It might be possible to make a housing, into which the internals might be fitted.
Seems to me that bending-up a sheet metal housing would be a difficult job to do with few tools ' especially if you wanted to do it precisely. Popgun Pete's comments about the need for precision compound the problems ' but there may be ways and I would be pleased to hear ideas.
My preference would be to attempt the housing with a block of delrin (AKA acetal plastic). You could possibly route a groove from the bottom up. The internals could be held in place with through rivets. The groove could be the width of the spear, or narrower but meeting a drilled hole to fit the spear. The 'Few Tools' problem with this is that it requires a router.
Ric
manoa matt
Ric, I've done it on my scrounger gun. Re-housed Riffe internals in a custom made housing. Not sure how many "few" is when it come to tools used. Angle grinder, drill press, dremel, 5/16" hardened bolt, ball peen hammer, and a buffing wheel.
Bought a junk gun where the Riffe internals were re-housed in acrylic sheets that were glued together. The trigger and sear did not mate well if at all, however gun shows signs that it was in the water so maybe it worked, but I could not get it to. I used a section of a stainless box tube. Bent and formed it over the hardened 5/16" bolt (as seen in the photo before shaping and drilling) Then squared up the case and used a spare Riffe trigger mech to get the correct spacing between pivot pins. I'd like to say the case is hardened as it was not easy to bend and form compared to some flat sheet stock I have. Pivot pins are peened over on each side. Thin nylon washers are on each side of the sear and trigger to keep them centered and good engagement. This is one of the tightest mechs I have. A 9/32" spear will lock in, but a 5/16" would need the sides of the spear tail shaved to enter into the housing.
In the last photo the mechanism is labeled Riffe DIY.
spearq8
Now that is what I call devotion to cause!
lordyaussie
I was making mechanisms myself at one point, I made a bodgie roller gun which works well however I dont use it anymore - the build thread is on this site so check my profile and find threads I've started it should be there.
I made 2 more triggers however when it came to making the housing I gave up, it is like Pete said - you need to make the trigger and sear to the housing, not the other way around. But it was mainly that it was just difficult for me to bend sheet metal at the time, I think I could do it easily these days by hammering it around 8mm thick metal plate.
So after throwing a tantrum to conclude my diy mech adventures I raced to the computer and was just about to buy 3 neptonics reef mechs for $200+ dollars :mad: when I searched a classifieds site and found Kurt selling 2 rabitech-like cassets sheetmetal trigger and sear with bottom line releases for $10 each! and a riffe mech for $90. I was very pleased and have made 3 fantastic guns from them.
The best mechanisms were the rabitech-like ones, low profile, low height and length ... I loved them. Considering Kurt's make up(or cut) on the riffe I am guessing that they must have cost the him $15/20. I would love to get my hands on a few of these, if anyone knows where at a good price please let me know? :)
http://i.photobucket.com/albums/l518/lordoftweedheads/23gunbuild_zpsdce.jpg
http://i.photobucket.com/albums/l518/lordoftweedheads/14gunbuild_zpsac3e.jpg
I love using cassettes over most wood gun mechanisms because they are low profile and have a bottom line release... also the handles on the wood guns being shaped to the specifications of the pipe-gun cassettes generally end up looking like pipe gun handles which are awesome! Just check out the one in my profile picture, and the hardwear on that beauty cost me under $100 thanks to the generosity of Collin giving me an old mechanism(which I shaped a new sear for) and Daniel giving me the reel.
I am currently using RA cassettes in my 3 current builds.
However when I found the trigger mechanisms Ric used for the few tools build for $10Euros I bought 2 ( Picasso Asegai) and I bought another one(off the Picasso Skorpion) which looks even better(as it is easier to make up a side line release) for $7Euros!! :thumps:
When they arrived I released I had to figure out the line releases - use a peg, spinning gear next to the shaft or figure something out with the mech (I can realise something with the Picasso Skorpion mech but can't figure out the Picasso Asegai one). Havn't used them yet but when the newbie gun builders want to have a crack at gun building .. I can supply them with a cheaper mechanism if they want it :)
I purchased these cheap mechs from diveshop.gr
They are great, $15Euros postage for orders under $200Euro,
Picasso Asegai cassette $10Euro
http://www.diveshop.gr/index.php/catalog/product/view/id//s/product/category/14/
http://www.diveandfish.com.au/media/catalog/product/8/2/82d3b3a8-d310-40d1-b6c2-a4e763ac.jpg
Picasso Skorpion cassette $7Euro - I would suggest this one as you can 'figure out' the line release better (no line release included - you need to make one).
http://www.diveshop.gr/index.php/catalog/product/view/id//s/product/category/14/
http://www.megasub.pt/loja/images/CasseteScorpion.jpg
http://www.podvoh.eu/published/publicdata/CP71POGVODB/attachments/SC/products_pictures/DSCFo5_enl.JPG
I think one of the important concepts of the few tools build is to show that any one can create a gun with only a few tools and a small budget. Most gunbuilders on their first gun start because they want to make one cheaply and if they can't they may get discouraged and not have a go at building one at all.
I am example, If I didn't a spare spear and undersea handle I would never have even thought about making my first gun
but in me going ahead and building that first gun ( and groaning about the $50 cost of epoxy as the biggest cost :p ) I would never have started making guns and the spearfishing community would've never have received the write ups and inspiration that they provide.
Not only that but those cheap-skate builds taught me skills of making my own hardware, line anchors/guides, mechs, trouble-shooting and fixing mechs, line releases, trigger guards, tracks, handles, shark clips connections, lamination mech pockets, etc. And as a result I take pride that I can make something unique in all aspects.
Thanks everyone for replying to this thread of Ric's and showing how you have made few tools mechanisms. However I think one of the important aspects that still needs to covered is posting links to where mechanisms/parts can be sourced cheaply so that new people thinking about building a gun are not turned off by the $500 price tag.
Please post links to cheap mechanisms or parts :)
Good thread,
Best Regards,
Sam
Chuuken
Disclaimers. Disclaimers everywhere. It's understandable, I guess, since the first reaction to a problem in this society is to loudly and breathlessly argue over who's to blame(not me!!)... but it's just security through obscurity, and that's not much security at all.
I built a wood gun, open track (~90cm). The trigger mechanism is a simple, 2 piece affair. There is no mechanical line release, it's rigged with a Heinrich style extra tab on the spear and a slot on the gun body to route the loop of line through. One band, with a slot wide enough to accept one more band.
It's low power, compared to the cannons people make for the ocean, so it's friendlier to the first time gun builder. If I was making a multiple band cannon, I'd definately buy a cassette.
As far as few tools go... I made the two parts of my mech out of 3/8" 316SS using a hacksaw, a drill press and a hand file. It just takes a long time to get through that hard stainless.
The most important part of the build was actually designing the parts. That's where threads like this come in. I researched and researched and researched some more before I ever started trying to build that mechanism. The frustrating thing was running into disclaimers instead of useful info every time I found something promising. As a result, I ended up using pictures of Rene Potvin's guns, (prior to his website redesign. There was more up back then), a ruler and math. He had some good, clear pictures of his guns and his mechanisms. All it takes is one known dimension and time. (And a calculator.)
Only after I had that gun finished, did I find a truly useful thread on this forum by Popgun Pete on the engineering of trigger mechs. I wish I had seen that before I started, but it allowed me to look at my mech again and decide whether it was safe or not based on some actual data. It is.
If you want to make your own mech, do a search for Trigger Mechanism Design Rules. Read all 6 pages of the thread. If you get to the end and you don't understand why Pete praised some mech designs over others, read it again and again and again until you do. Otherwise, let the project die there.
To quote Pete in this thread:
Plus there is always the prospect of "will the Defendant explain to the Court why he created the most critical part of the weapon involved in this tragic accident and not used one obtained from a reliable and proven supplier". "To save money your Honor".
The answer has to be better than just, "To save money". For me, it's because I want to understand the weapon I'm using and be proud of it. I made it myself. I, (however belatedly), understand the forces acting on the trigger and sear enough to be confident that the gun won't just go off on it's own. I know I used steel that was thick enough and of a high enough quality that it will not fail under the stresses it will be exposed to.
Probably the easiest thing is to copy a known mechanism and use it for your templates, but by the time you get it right it may have been easier to just buy one.
That's the voice of experience there, I'll tell you what. If, however, the idea that making the the mechanism will be more difficult than buying it turns you off, just shell out for a mech. You'll be happier.
If it's just about money, get an AB Miller or JBL handle and muzzle for around $100 and use a shower rod to make a pipe gun of whatever length you want.
Ric.Fallu
Thanks to the people who have contributed
In times gone by I tried several times to make mechs: but never with success. I never used the circle analysis (detailed elsewhere in the forum in Popgun Pete's design rules) and that might explain my failure. But even if I had, and had the geometry right, forming a metal sear and trigger with a hack saw and a file is not an easy job. (In an Undersee-style two component mech, maybe only the sear has to be metal and maybe the trigger might be plastic?)
There may be other ways. Pacific islanders make a style of speargun that meets the 'Few Tools' criteria. I think there are two basic mechs used.
' One has a pin fixed vertically into the stock. The rear of the spear has a hole in it and it drops over the pin, holding it. The trigger levers the spear up over the top of the pin, releasing it.
' The other mech is a piece of heavy wire bent in an 'S' shape. The upper tip extends up through the stock, engaging with a slot in the spear. If you pull on the other end of the 'S', the trigger rolls on the bottom of the stock, pulling the tip down, releasing the spear.
Trouble is, the Pacific Islander mechs only work for low powered guns.
Somewhere else in the forum there is a thread on the 'Addict speargun' that had a handmade single sear mechanism that fit in the gun. I haven't had such a gun in my hands, so I don't know how smooth it is to load, and how easy it is to pull the trigger. But it provides a clear precedent for a hand made gun that (presumably) functions consistently.
Ric
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Ric.Fallu
Line clips
Some of the mechs discussed have flash arrangements for line clips, and this can make them difficult to install. I have got around the problem by making a separate line clip arrangement out of wood (what else).
In closed muzzle guns, you don't need a lot of tension on the wrapped shooting line, so the release hook doesn't have to be all that sophisticated.
The first gun I built was following instructions given by Ben Cropp in Handbook for Skindivers. He suggested making a line clip from sheet brass (stainless was much more expensive in those days). It was essentially a strip about 5/16' wide and about 1' long. It was screwed down at one end and loose at the other. There was natural spring in the metal and the line was pushed in under the loose end. Before attaching to the stock, the strip was bent with an upwrd lip at the front of the loose end to facilitate slipping in the line. In the middle, an inverted U was bent to give a little wobble room for the cord.
A similar arrangement was to wrap a rubber band around the stock behind the mech. The shooting line was stuffed under the rubber band ' this was a b*tch with gloves though.
Anyway, some years ago I was putting out washing on the clothes line. We had old-fashioned pegs ' the kind made from one piece that relies on the natural flex in the wood, and the jamming effect of a slowly narrowing gap. I had a minor epiphany (and without beer that time!) and it occurred to me that I might be able to make something similar for a spear-gun line clip.
Ric
popgun pete
Here is the "Addict" speargun mech. One of the "few tools" needs to be a drill press, either that or be prepared to discard a few attempts where the hole is not quite right!
manoa matt
As with most production methods there is a critical step path you must follow in order to assure accuracy of the components. I've never had the most expensive tools, and even some of the tools I own are homemade. Sometimes having less tools or standardized components allows you to break free from standardization and common practices. "Necessity is the mother of invention"
I learned a few things when I was making and modifying film cameras and darkroom equipment which require a level of precision greater than a speargun trigger. When making precision fitting parts with simple tools, you must follow critical step production methods. The pivot hole is the first thing you do, then measure roughly off the hole for the outline of the part. Cut it out leaving plenty of extra material. Grind, sand, file the part to its ultimate and precise dimensions. If you try to shape first, then drill the hole last, it will almost always be off as drill bits like to wander.
An alternative method, which I used to drill the pivot pin holes for the mech case is to start with a small diameter 1/16" bit and get it as close to the center of where you need. Drill successively larger diameter holes while forcing the part in the appropriate direction to make the hole move where you need it.
Ric.Fallu
if you have precision tools with massive frames and adjuster screws, it is easier to do precision work. But as Manoa Matt says, it is possible to do nice work with hand tools. This is especially true if you are prepared to throw away something that didn't go right (as pointed out by Popgun Pete).
The traditional process used by cabinet makers is to start with a "face" side, and orient others from it. Seems to me that with spearguns, this is not the way to go - I use the "middle" as the reference line. When I drill holes, I come in from both sides. Initially I had trouble getting my drill holes at right angles, but with practice I got better. Centre punching helps orient drill holes in metal.
And, you design around the constraints you have - the addict mech is a good example - it was designed to be made on a vice in a garage, not in a machine shop.
Ric
popgun pete
Here is an interesting tip from Jack Prodanovich as was explained to me by John Warren, respected metal sculptor, big game speargun designer and fabricator and himself a veteran spearfisherman. To put the curved lower tip on a trigger hook you can cut the lower trigger profile straight and then bend the end to create the curve that you require. Thus a smaller metal blank produces a trigger that would otherwise have required a bigger piece of metal.
It is worth looking at the early vintage guns of Jack and Wally Potts as there you can see gun evolution from first principles, including the use of clothespegs for passive line releases. These icons of the sport were way ahead of us in exploring how to make spearguns when such a thing had not been seen before and a close study of their work is a great way to learn how and why things have developed as they are now, especially for shooting the big ones!
hau
This ^^^^ is spot on information IMO. Thanks popgun pete. :beer:
spearq8
Saw this on youtube
Trigger mechanism for a speargun. Part 1: The Housing - YouTube
Trigger Mechanism for a Speargun. Part 2: the Trigger and Sear - YouTube
Home made Trigger mechanism for a Speargun. Part 3 - final assembly! - YouTube
theonetruerat
Seems to me that bending-up a sheet metal housing would be a difficult job to do with few tools ' especially if you wanted to do it precisely. Popgun Pete's comments about the need for precision compound the problems ' but there may be ways and I would be pleased to hear ideas.
Ric[/QUOTE]
I'll admit I haven't read through the whole thread. (I'm perusing spearboard while waiting on a delayed flight) I've avoided the whole housing issue by mounting the trigger directly in the stock. Since I don't have a router I cut the slot with a table saw and glue a filler in to form the back. Works for me but I'm making guns as a hobby and have no time constraints.
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