Midhandle Gun Build.

HEDS · Nov 13, 2008

Ok here goes , firstly a bit of background.
This was my first build so i aint no expert! I have tried to keep a record of the fundamental steps to building my gun - if i was to build another , many things would change! both in the design of the gun and in the manufacturing process, i might post some 'on hindsight' ideas again.

My personal brief was to build a midhandled gun of approx 85cm. The gun will be used with a single 16 or 18mm, or double 14mm bands.

These are not step by step instructions, but a record of the building process based on information I collected from various sources [thanks Pastor] coupled with my own experiences, and [hopefully] a little common sense chucked in for good measure.

Cutting list.
Iroko ,sawn and planed [for the gun laminates] :x1 1000mmx50mmx10mm
:x4 1000mmx50mmx8mm
Iroko , for the handle. approx :x1 200mmx100mmx50mm
Hardwood Dowel. :x2 8mmx50mm
West systems Epoxy.

Trigger Mechanism, bits of brass for the trigger and pushrod [hopefuly more details on this will be provided soon.!]

First , I bound the rough sawn laminates together with masking tape so that they all aligned together.
I worked out my waste on each end , and drilled 8mm holes all the way through the laminates.[For a locating dowel-this will stop the laminates sliding around when pressure is applied]
On a flat solid table I laid out a bin liner, then my laminates.
I had a straight solid piece of mahogany to use under my clamps.
I made a mix of west systems epoxy resin , and glued the laminates one by one [I had the 10mm laminate in the middle] . Then I tapped in the hardwood dowels to align all the laminates before clamping them down.
This was left for about 24hours.

HEDS · Nov 13, 2008

I planed the blank by hand, to remove the epoxy and to straighten the edges for accurate routing.
I then used a router table to cut a half round groove for the shaft and also a quarter round on the top edges as channels for the bands to sit in.
The groove for the shaft finished where the trigger mechanism was going to be. Also the depth of this groove was decided upon to ensure that the shaft rested high enough to get the wishbone in the shaft notches without scraping against the rail.
Two 14mm holes were drilled for the bands. These were drilled lower down than the band channels to ensure that the bands would hold the spear down to the rail.
I used some carving chisels to merge the holes into a slot. Also I drew a line from the bottom of this slot to the trigger end of the band channel and carved this out carefully to reduce friction between the bands and the gun.
I cut the muzzle of the gun to a pointy sort of shape , witch resembles a head shape associated with the shark family .

HEDS · Nov 13, 2008

I then marked and morticed the trigger slot. Stopping to check size and depth often . [but not often enough in my case] I had to glue a piece of wood back in as I had gone to deep on one cut.
At the same time I morticed for the handle positioning and routed for the pushrod between the trigger and the trigger mechanism.
Aligning the shaft groove on the trigger with the groove on the gun is important. I did this, but the top of the trigger mechanism was proud of the gun about 5mm, also the top fixing pin would get next to no hold on the gun. So I decided to glue on an extra fillet of wood to surround the trigger, I pinned this down with hardwood dowels to ensure added strength.
I glued two pieces of wood together to make the handle and cut two tennons in this at a slight angle to fit the mortices in the gun, I then cut a very rough shape for the handle using a bandsaw , the handle was then glued onto the gun with west systems epoxy , wrapped in cling film [to reduce the mess/also keeps the glue from running out if you have gaps in the joint] and lightly squeezed in a vice.

HEDS · Nov 13, 2008

It was then a matter of shaping the handle with a rasp to fit my hand.

HEDS · Nov 13, 2008

Apologies for having to post a load - couldnt think of any other way , hopefully this will be an ongoing thread with some more pics of the finished gun to follow and some nitty gritty details if i get some time.
I might also embark on another build over winter!

HEDS · Nov 14, 2008

This is the finished gun - as you can see from some pictures , i didnt manage a good finish , and i never achieved a good finish - shot some fish with it though

alexrom1207 · Nov 14, 2008

Didn't achieve a good finish!!! Are you kidding? That gun is beautiful!!! Any idea on total number of hours for the build?

Pastor · Nov 14, 2008

alexrom1207 said:
Didn't achieve a good finish!!! Are you kidding? That gun is beautiful!!! Any idea on total number of hours for the build?

You're not wrong. To me that is the perfect UK gun and the more people that start using them the better

Awesome job Heds mate, I want a go next season bro :friday

foxfish · Nov 14, 2008

Heds thanks so much for posting this thread, fantastic write up & a great gun.
Can you tell us more about the trigger & the linkage?
What is wrong with the finish? I assume you mean the epoxy it not as smooth as you would of liked?

HEDS · Nov 14, 2008

Hours of build , took me about 6 hours to get the gun to shape , after the gluing period 24 hours. Then a couple of hours fiddling with the mechanism . and another couple for the finish.
So id say a total time [adding an hour or so to rip/plane the laminates t size] would be .35 hours.

The finish aint special [honestly] but i aint bothered as i know that its sealed - im pretty sure that this wood was unfinishable to somebody of my experience without a fluke. There where patches on the gun where the epoxy when nearly dry would pit and bubble!

Here is a diagram [ not good im afraid ] showing the basics of how the midhandle mechanism works , ill try and post some more pics maybe.

Pastor · Nov 14, 2008

That collet idea is awesome to adjust the backlash on the trigger :king

HEDS · Nov 14, 2008

Actually the adjustable collet was a temporary measure !! I didnt know the exact length of the pushrod for it to work, so i decided on a temporary adjustment - which stayed there because it made sense.
The 3mm pushrod goes through a 4mm filed out hole in the brass trigger as a pretty loose fit to allow for the change in the trigger angle when it is squeezed. I put a spot of loctite on the collet when preferred position was found.
By the way - this is where i sourced my collet.

foxfish · Nov 14, 2008

I just love resourcefulness-
Mate, I have tried & tired to get a decent epoxy finish but gave up years ago, I now use epoxy only as glue & use two pack polyurethane as a top coat.
What make of trigger did you use?

HEDS · Nov 14, 2008

Yep , i sorta gave up in the end as well.
Trigger Mech from
Pathos - Μηχανισμός σκανδάλης --- diveshop.gr

The only implication to using this trigger i found - that the top fixing point is at the same level as your shaft , meaning that if you grooved for the shaft on top of your blank [like i did ] the trigger mech is hanging out of your gun a good 8mm , and you wont have any wood to pin or screw the trigger in place. So i made an extra piece to put around the trigger , out of a waste laminate , and put this in place with hardwood dowels. Dodgy Diagrams and a pic supplied [this pic highlights the problem i had with the epoxy:head]

Pastor · Nov 14, 2008

Very robust triggers at a silly price, I've loaded them with a pair of 20mm bands with no problems. Worth buying then a dozen at a go. A nice feature of them is the wedge shaped front which when under load beds them down harder rather than being pulled out

fish impaler · Nov 20, 2008

Pastor said:
Very robust triggers at a silly price, I've loaded them with a pair of 20mm bands with no problems. Worth buying then a dozen at a go. A nice feature of them is the wedge shaped front which when under load beds them down harder rather than being pulled out

about how much US$?
?

Pastor · Nov 20, 2008

$32 at todays exchange rate

azapa · Nov 20, 2008

that's a beautiful gun HEDS, hearty congratulations. I'm sure 99% of the builders here would say it's one of the nicest first guns that anyone has seen!!

Whilst I can imagine how you routed the spear groove, how did you route or shape those diagonal band grooves?

Please let us know what else you build or fiddle with on that one.

HEDS · Nov 20, 2008

Ok have done some more dodgy drawings , hopefuly they will cure some curiosities!

Diagram.1-Cut a Taper in the underside of the blank , roughly from the handle area to the muzzle. Drill two 16mm [i think] holes for the band slot.

Diagram.2-Merge the holes with a chisel.

Diagram3-On a router table i made a quarter round 3/8th [i think] channel both sides of the gun from the predicted band maximum stretch [just in front of the trigger mech at the back of the gun ] to the band slot.

Diagram4- Spent some time with a spokeshave , chisel , pocket knife and some coarse sand paper making the channel wider to taper out to the band slot.

Diagram5- Morticed the trigger slot, Motices for the handle , pushrod groove and rear trigger area. All the accurate work done , started shaping the gun and rubbing down.

Diagram6- Cutting the initial band channels on a router table.

azapa · Nov 20, 2008

Perfect, the drawings are spot on. Did you mortice (step 5) by hand? Impressive stuff. I wonder if there are any decent books on this, although with your writeup alone I would be happy to give it a go.

Midhandle Gun Build.

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