Enclosed Track Bit???

[Mattedhead]

Hi guys...just looking to pick your brains a bit on the making of an enclosed track gun. I have a pretty good handle on most of this; however, I am having a tough time finding the corect bit for machining an enclosed track for a 5/16" shaft. I have found Amana bits down to 1/2" diameter, but I have yet to find a 3/8" or 7/16" bit for the task. Does anyon know where I might obtain the correct bit??? I have pretty mch scoured the internet. Also, does anyone have any pros/cons for delrin tracks. I noticed that Daryl mentioned that he did not work with these anymore for a number of reasons, but I am unsure as to their major downfalls. Any info would be greatly appreciated. I have found the parts/tools necessary for manufacturing a delrin track really cheap, but I am still short the bit to route the track.

Thanks in advance,
Matt Head

 

[Mattedhead]

Enclosed Track bits???

Hi guys...just looking to pick your brains a bit on the making of an enclosed track gun. I have a pretty good handle on most of this; however, I am having a tough time finding the corect bit for machining an enclosed track for a 5/16" shaft. I have found Amana bits down to 1/2" diameter, but I have yet to find a 3/8" or 7/16" bit for the task. Does anyone know where I might obtain the correct bit??? I have pretty mch scoured the internet. Also, does anyone have any pros/cons for delrin tracks. I noticed that Daryl mentioned that he did not work with these anymore for a number of reasons, but I am unsure as to their major downfalls. Any info would be greatly appreciated. I have found the parts/tools necessary for manufacturing a delrin track really cheap, but I am still short the bit to route the track.

Thanks in advance,
Matt Head

 

[ajwaverider]

Re: Enclosed Track bits???

Hey .Where have you been ? Kitto s' website has them and you can also get them here.http://www.leevalley.com/wood/page.aspx?page=30180&category=1,46168,46173&abspage=1&ccurrency=2&sid=

I know that the different expantion rates between the wood and delrin is one of the cons because delrin reacts more to temp and humidity than wood it can cause wood to crack if fasten to rigid. I've also found a place here that has delrin in speargun track sized pieces pretty reasonable but i'm not sure if I should use a round bar or cut a dovetail instead. Maybe Daryl can give us some input on it.

Matt.Hows the viz up there?

 

[Mattedhead]

Re: Enclosed Track bits???

AJ,
Thanks for the info...I looked everywhere and that is the first I have seen smaller than .5". If I get it at Kitto's site the the two bits run $235...my budget can't take that kind of hit! It looks as if I can get off for around $50 with your link. They should get the job done, as I certainly don't warrant the nice industrial level bits that kitto is selling.

I moved a few hours from the coast recently, but I was in the water last week. It was decent, but the surf was up...maybe 6-8' vis on the jetty, couldn't get offshore though, ended up surfing most of the weekend. I am going to try and get back next week. The grouper reports have been good at some of the offshore AR's, and if all else fails, the flatties are coming onto the inshore AR's and a few Striper have been on the Jetty.

Thanks again for the info...I was also thinking about the dovetail or even t-bar slot so I could only pin the track near the trigger mech, but machining the delrin sounds like a chore. I might just end up machining expansion slots. I was looking at this new PEEK, and Techtron PPS materials, their thermal epxpansion characteristics are closer to that of wood but HOLY SH@# they are expensive! It's nice to dream though...however my dreams more often than not include recurring nightmares of tuna mocking me from 25' with only my euro gun in hand! I can't bear to see another YF swim past unscathed this season, hence the new project.

Matt

 

[ajwaverider]

Re: Enclosed Track bits???

I'm sure Kittos' bit are good but I didn't knoe they are that pricey.Amanas' are pretty high as well.Viz inshore is St, Augustine was epic ,best ive had so far .6to 8 first day and 10 foot plus second day.Some sheeps I shot here http://www.ecfreedive.net/.

Good luck with your project.

 

[Bill McIntyre]

Re: Enclosed Track bits???

I don't know a thing about bits, or about making guns for that matter. But just in case machining the delrin turns out to be an obstacle, I have had no problems with a couple of guns with wood tracks.

As far as I know, the main worry with a wood track is breaking out the top if you drop the gun or shoot a fish so close that the shaft is still in the gun. Daryl Wong seems to provide for that by putting a block of micarta (I think that is what it is) in just the front end of the track as shown in the attached photos. In the all wood gun, the front part of the track is cut out and you can see the micarta block a few inches back from the muzzle. The other photo shows a hybrid gun with the micarta block in the front of the track in the wood butt section.

Don't let that little black thing to the left of the track in the wood gun confuse the issue. That's just an Alexander cable keeper for keeping the slip tip from falling off.

Again, I don't make em, I just use em, but I thought I'd pass this along for what its worth.

 

[Daryl Wong]

Re: Enclosed Track bits???

Hi Matt,

I used to be able to get the balls bits for routing the enclosed track for only 18.00. Now you can't even find them anywhere. I had to have a special order made up for me and they ended up costing about 50.00 /bit and I had to order a minimum of eight. At least I have enough for awhile. I wish I had found the site for the 15.00 ball bits before I got the eight I had to order.
As far as delrin tracks go, There really is no significance in performance by using it or similar plastic materials. About the only thing you will gain is less chance of chipping out the track. I don't get very many if any requests to repair the tracks on the guns that are out there.
If you are going to put in a Delrin track, there is an easy solution without having to dovetail or routing a bigger hole for a delrin dowel.
Just cut a channel to match the size of the delrin piece you want to use and then cut two shallow grooves on the sides of the Delrin piece. Then just laminate it in and you will have mechanical as well as parallelism to hold the Delrin in the stock. It will not come out. It beats pinning the delrin and looks so much cleaner. You may get small craze lines between the Delrin and wood interface, but you will get that no matter what plastic material you use. And it doesn't happen all the time.
I have also done the graphite filled epoxy in the track, but that is all hype and not nearly as strong as using a delrin piece. How can a thin epoxy edge in the track be as strong as a wood or Delrin edge. Been there done that and repairs are very difficult.
I used to use Micarta inserts like Bill's muzzle less ono gun, but I have since switched back to Delrin. I use it on all the freeshaft guns and also small strips on the semi enclosed hybrids like the one Bill uses.. I haven't noticed any problems with using a small piece so far. The main function for the inserts is solely to protect having the wood tract from being worn away when loading the gun.
I'm sure you will hear the same thing from Steve Alexander since he told me the same thing many years ago when I used to use his parts.

Aloha, Daryl

 

[Mattedhead]

Re: Enclosed Track bits???

Mahalo Daryl!

And thank you for the timely email as well. I am by no means sold on the delrin insert, I was just looking into the possibilities. I might do as you said and merely add an insert where the track opens up a bit. If i am putting this mch time and effort into a project it had better last. I would be sick if I chipped out part of the track. I will probably be making 2 or 3 guns, one in the 60-65 range for myself and then two in the 48-50 range, one for myself and one for a wedding gift to my best friend It would make it a lot easier to do a few at one time...I was alos thinking about laminating some pine to use as a practice dummy. I will apply all of the machining processes to this one first so that I don't learn from my mistakes on the good wood. I'm sure I will have a few more questions in the future, but as soon as I get the wood in, and laminated I will begin he "ordering fest" so that I have something to do during the aging process! Thanks again Daryl, Bill, and AJ for all of the help.

One question on the alternative method of laminating in the delrin...could you add a couple more sentences on this as I am unsure as to how you are suggesting doing this. Thanks.

Matt

 

[GilbertG.]

Re: Enclosed Track bits???

Woodline is another source. 12 bucks for a 3/8 bit. It should fit well for a 5/16 shaft but it will be sloppy with anything smaller.

http://www.woodline.com/scripts/prodList.asp?idcategory=120

gil

 

[Mattedhead]

Re: Enclosed Track bits???

THanks gilbert...i have vastly overestimated my internet search skills! You guys are good.

 

[ajwaverider]

Re: Enclosed Track bits???

I should spend more time spearing than on the computer but I guess it's ok since i'm able to help you.

 

[icarus pacific]

Bill Kitto sells the bits.

On Delrin, the cuurent fad is to pour a track with epoxy and either carbon or a low coefficient of friction filler, then machine the track. The thinking is that it doesn't rquire pinning or fastening the Delrin track to the stock and all the differing expansion rates that it involves. West Epoxy has the stuff, but get ready for the $$ hit.

I like my delrin tracks though they're on the guns that get the least use around here.

 

[Copro]

Try,

http://www.carbidebur.com/?OVRAW=carbide burrs&OVKEY=carbide burr&OVMTC=standard

I got two custom cutters from these guys. One (.751) to mount 1" round delrin, the other (.391) to cut the track for a 3/8 or 5/16 track. Basically for my gun I only mounted 12 inches of delrin for the muzzle and it is working well.

As a side note I have heard that a normal 3/8 inch cutter will work for both 5/16 and 9/32 shafts. I would be more than happy to sell you my .391 cutter and a short piece or Delrin for a muzzle.

Jody

 

[GilbertG.]

On Delrin, the cuurent fad is to pour a track with epoxy and either carbon or a low coefficient of friction filler, then machine the track. The thinking is that it doesn't rquire pinning or fastening the Delrin track to the stock and all the differing expansion rates that it involves. West Epoxy has the stuff, but get ready for the $$ hit.QUOTE]

The cast-in epoxy track thing. I gave this a whirl a while back with mixed results. Though it looks super slick once you successfully make one I'm not sure its worth the trouble. If someone else can pick up on this and get it to work out on their guns then all the power to them. Kitto and Klefstad have probably already found the secret. Dean K is also offering this type of track. (hey all these guys last names start with K )

My biggest problem was porosity. Friggin' air bubbles!! Frozen and hidden in the hardened epoxy only to be uncovered once you've machined the track.
An eye sore no doubt, but more like a pain in the butt. Then you are back to re-casting the track and re-machining.

The source of the air bubbles comes from two places. The act of mixing the two-part epoxy and within the wood itself, also called "outgassing". If you mix in milled fiberglass or graphite powder or whatever the problem gets even worse since more air is introduced into the mixture. The mixture also gets alot thicker, making it difficult for the bubbles to escape. You can try and work the air out with a toothpick or something but you only have a few minutes to do this. Once it starts to set, get back into the house and wash up because you're done.

I even went as far as building a pressure chamber to try a manufacturing process called "pressure casting". I basically capped off a piece of steel pipe threw the gun block in with the wet epoxy track and turned up the air pressure to about 130 psi until the epoxy cured. What this does is squeeze the air bubbles down to a size that's almost undetectable, ALMOST. I'd still find an air bubble here and there. So gave up on it and never looked back.

2 pennies.

Gil

 

[andyt808]

Is it just me or did this post just get a lot shorter?...I was reading it late last nite and I thought mr. daryl wong had posted some tips on how secure the track. Then again I might have just been dreaming I was half asleep.

 

[Mattedhead]

Yeah...what the hell. There was some great info on here. If the moderators have shortened this one, please return it to it's original form as there was information that was quite helpful and most certainly appropriate in this thread.
Matt

 

[Bill McIntyre]

Is it just me or did this post just get a lot shorter?...I was reading it late last nite and I thought mr. daryl wong had posted some tips on how secure the track. Then again I might have just been dreaming I was half asleep.

It sure did lose some posts. At first I thought that Daryl might just have deleted his posts, but I had one deleted too. Of course mine wasn't very useful, but since I know I didn't delete it, it seems to indicate that some third party did mine and Daryl's and some others.

 

[Mattedhead]

OK guys...looks like some of it was moved to another thread...

[ame]http://forums.deeperblue.net/showthread.php?t=60961[/ame]

Not sure why...but at least the info is still there. It seems as if there are two duplicate directories/categories:

Hunting Equipment>DIY/Homemade
Hunting Equipment>spearguns and accessories>homemade equipment

One or the other should probably be removed and have one directory that is listed as a subheading to each of the categories. That way it is accessible through either avenue, if it is posted on one it shows up on the other as well.

 

[icarus pacific]

My hats off to you Gilbert for going through all the trouble with the epoxy/graphite and the pressure vessel trying to obtain a bubble free pour.

A couple of things that have worked for me, not so much for pouring bubble free tracks but with other castings is to go with a slower hardener that allows you time to vibrate the form, in this case the gun barrel, much as you would with concrete. another tip is to warm the epoxy/graphite before adding the catalyst to thin it. Let it sit for a few minutes and then fold in the catalyst and let it sit some more. Obviously you'll need to do a little test batch to get the timing right, but it's about the only way I've been aware of.

Also, a few pin hole sized bubble are'nt going to affect the shaft leaving, as the holes will fill with water. Cosmetically and deep in your soul, yeah it's a bummer, but performance wise it's a non issue.

 

[Bill McIntyre]

Maybe you posted the original question in two different threads? I always wonder about that. You can end up with some answers in one thread and some in another, and they are not coordinated.