Swimbait Joint Slots

[RiverMan]

Anyone figured out a way to make the slots shown in the photo clean and even? I can make them work with a dremel but it looks like I used a rock to cut them. Any suggestions?

Thanks.

Edited December 9, 2014 by RiverMan

[BobP]

Why not just sand them smooth?

[RiverMan]

Bob, I'm talking about the small slots that the screw eyes are seated in.

[Vodkaman]

I have worked on this problem a couple of times, coming in from different directions. I will say up front that I didn't crack it. The solutions that I tried were, as you might expect, complex. But, don't fool yourself, this is actually a complex problem, so if you are looking for something simple, I am probably not your man.

 

The cutter, I decided had to be a 1/8” router mill.

 

From here you have two choices, either clamp the lure body and control the router or fix the router and move the body.

 

The first job, no matter which route you take, is to clamp the lure. This first stage is not so simple, as you do not want to leave clamp marks on the body. I made a wooden rectangular frame, clamping the body with bolts, screwed in from each side. Rubber pads to protect the lure. Already you will see that simply clamping the lure is tedious.

 

I will stop here now, as this could take a long time and could already be going in the wrong direction for you.

 

From here, you could simply bounce ideas off me, using my engineering background. You could ask for more and I will give it, with pictures too. What ideas do you have in mind? What kind of solution are you looking for? I think we should start by collecting as many ideas as possible, even the crackpot ideas.

 

Dave

Edited December 9, 2014 by Vodkaman

[Musky Glenn]

Vodkaman is on the right track but I would change the timing just a bit. I believe this, like a lip slot, should be done first thing while the lure is still square/rectangle. That would simplify the holding process. I would probably use a drill press and rig up a slide for the vise. Musky Glenn

[Travis]

Still haven't come up with a method?  Without shelling out big bucks the easiest way since I don't churn out numbers is just to start with square stock and mark center with a square and lay out the the positions. You should stick with consistent blanks then everything becomes a lot easier as you can generate lay out tools/jigs to speed everything.  Trying to clamp a lure shaped body isn't the way to go as Musky Glenn pointed out. Squared stock is by far the best method to start and makes generation of jigs easier and quicker.  I then just use my xy vise on the drill press and slot the hinge pin recess.  Now a drill press isn't ideal for this application  but we aren't really milling any hard stock so stress on the spindle is limited. 

 

http://www.tackleunderground.com/community/topic/27901-swimbait-joints/#entry217197

 

Using a router to route each one will get old quick and increases safety issues.  A trim router would really be the only option if doing this frequently as anything larger would get tedious/heavy.  Dremel with the router attachment could be used but essentially are a toy and frustrating at best.

 

If doing a lot of numbers then I would look at making a horizontal boring set up and cut both slots at the same time.  Something along Mathias Waddell plans.  Still the use of square stock the only way to go and you would would set up the table with a stop so the blank registers in the spot at the same time.  If you didn't want to work out the dual slot mechanism just lay the spacing so you slot the one hinge point flip the blank over and the slot the second.  However the drill press with x/y vise goes quick and if I couldn't cut them both at the same time not worth messing with unless you like this sort of stuff for fun.

 

http://woodgears.ca/slot_mortiser/index.html

Edited December 9, 2014 by Travis

[Vodkaman]

You guys are spot on. We cut lips and ballast holes from the square stock, so why not the slotted hinge holes. Everything gets easier from the start. Of course it wouldn't work for my application, as I would be cutting my bodies on a duplicator machine.

 

It would be desirable to carve the body as a one piece and then cut into segments. I guess the stock segments could be pinned together for the carving process.

 

Dave

[RiverMan]

The bodies are resin and already complete. I tried making a jig on the drill press and sliding the piece along with less than good results. I thought about a simple grinding wheel for a dremel but the problem here is once you start getting deep enough you also start getting a slot much wider than you need. What seems so easy is not so easy. I may be going back to the rock.

RM

Edited December 9, 2014 by RiverMan

[Nathan]

I know nothing about them.. or how they work...I've just seen them...but would a biscuit cutter work?...Nathan

[RayburnGuy]

If your already using resin to pour your baits could you make a resin mold that would hold the section of the bait your drilling? Pour it thick enough that you could leave the outside edges square so it could be clamped in a machinists vice. Then just chuck up a ball cutting bit of the appropriate size in your drill press and slide the vice to feed the work into the bit.

 

Ben

[mark poulson]

If your already using resin to pour your baits could you make a resin mold that would hold the section of the bait your drilling? Pour it thick enough that you could leave the outside edges square so it could be clamped in a machinists vice. Then just chuck up a ball cutting bit of the appropriate size in your drill press and slide the vice to feed the work into the bit.

 

Ben

 

I use a wooden Jorgensen's clamp to hold my swimbait parts while I drill the initial 1/4" holes for my screw eye recesses with a drill press.  The wood clamp has two wood jaws and two separate handled screws, so I can adjust it so the jaws aren't parallel.  I also use it to hold my tapered PVC bait parts vertically, even though it is only holding the very top part.  The wood jaws have enough friction to hold without so much pressure that they dent the PVC.

Then I use a dremel with a bit that looks like a porcupine to widen the holes to each side, so they have a V shape with rounded sides.  It's only 3/16" in diameter, so I can fit into my 1/4" pilot hole without it grabbing the sides too badly, like used to happen with a drill bit.

I ground off the burs that were on the very end of the bit, so it doesn't go any deeper than my initial hole. 

I got the bit from a local woodworking store years ago, and don't remember what it's called, but it looks like a corn dog with a bunch of spikes sticking out of it.  

It takes a little time, but once I'd done it a few times, I figured out how much I needed to remove, and it goes much faster now.

 

I just made a two piece glide bait, and I used a band saw to cut slots instead of the rounded V's, because I wanted tighter joints.  They show a little more, because I had to bring the slot all the way in to where the V of the bait section meets the face of the lure to get enough depth for the screw eye to move unimpeded, but there is much less vertical movement in the joint.

I hope to take it for a test swim today.

[Vodkaman]

This is about as simple as it gets, as Musky Glenn and Travis mentioned, the drill press is the answer. The frame shown in the image below can be slid along a clamped fence. Blocks could be added as stops, to limit the cut. The cut location adjusted with the fence position.

 

 

A better clamping method could be devised, using some kind of lever mechanism with rubber pads. This would be quick release. Such clamps are available off the shelf.

 

Dave

Edited December 9, 2014 by Vodkaman

[Musky Glenn]

If the bodies are resin, could you modify the mold so the holes are formed during the pouring. There fore the holes are already there when the part comes out of the mold. Musky Glenn

Edited December 9, 2014 by Musky Glenn

[mark poulson]

This is about as simple as it gets, as Musky Glenn and Travis mentioned, the drill press is the answer. The frame shown in the image below can be slid along a clamped fence. Blocks could be added as stops, to limit the cut. The cut location adjusted with the fence position.

 

frame clamp.JPG

 

A better clamping method could be devised, using some kind of lever mechanism with rubber pads. This would be quick release. Such clamps are available off the shelf.

 

Dave

 

You are a clever devil!

[Travis]

https://www.grizzly.com/products/Cross-Sliding-Vise/G1064

 

Similar to the vise I use.  As mentioned just need to mold a holder for the baits.  

[RayburnGuy]

Good find Travis.  That's the poor mans milling machine.

 

Ben

[Seeking 56]

Does the screw eye slot have to rectangular? How about inserting something in your mold that won't stick to the resin and subsequentaly allows you to pull it out once the resin has dried?  Like a plastic dowel? 

[RiverMan]

Some great ideas guys. Your suggestion Vodkaman is almost exactly the way I tried to do it originally. I took a router bit made for cutting slots and attached to my drill press, maybe that was the problem, Router bit on a drill press? Anyway, I clamped a fence to the drill press plate, secured the piece in a vice similar to what Travis posted and slid it along but it wanted to jump around some and ended up looking about like the rock method. It doesn't have to be a slot but I prefer it to be because otherwise you get to much up and down play in the joint. I only want left to right no up and down.

Edited December 10, 2014 by RiverMan

[Travis]

Have you tried a different bit.  Drill presses RPM are so slow that they don't work well with drill presses.  The router bits can be used but really have to go slow.  I have used them but find some of the dremel bits better for this type application.  The two bits I have used with success are the following.

 

http://www.dremel.com/en-us/Accessories/Pages/ProductDetail.aspx?pid=114  (better performing)

http://www.dremel.com/en-us/Accessories/Pages/ProductDetail.aspx?pid=194

[mark poulson]

Here are two pics of the bit I use.  It doesn't grab and run nearly as much as other stuff I've tried, so I can hold the work piece down on a bench and widen the slot with my hand held dremel.  The bit originally had spikes on the end, too, but I ground them off so it wouldn't deepen my pilot hole.

Edited December 10, 2014 by mark poulson

[Travis]

Here are two pics of the bit I use.  It doesn't grab and run nearly as much as other stuff I've tried, so I can hold the work piece down on a bench and widen the slot with my hand held dremel.  The bit originally had spikes on the end, too, but I ground them off so it wouldn't deepen my pilot hole.

 

I have used a few of those styles also for some power carving stuff, mine were very aggressive when it comes to stock removal.  

 

http://www.saburr-tooth.com/toolsShank18.htm

Edited December 10, 2014 by Travis

[RayburnGuy]

The bit in the picture at the first link Travis posted was what I was referring to as a ball mill. If you have a cross slide vice you should be able to anchor it down to your drill press and then feed it slowly with the vice. That should take out any wobble or bit chatter providing you run the drill at the highest rpm and feed it slowly.

 

Ben

[KelpKritter]

This was my least favorite and hardest part to get right when I was using wood and PVC to shape my jointed swimbaits.  When I changed to resin I incorporated the slots into the mold and they are clean and perfect every time.  My method was to take a piece of schedule 40 PVC pipe and ripped it lengthwise on the table saw.  Once I had a two foot long section of now crescent shaped pipe I slowly heated it with a heat gun and when it became pliable I pressed it between two sheets of plywood and let it cool.  Now I had a flat piece to work with. I then ripped the flat stock to the desired width. Then moving to the bandsaw I cut small sections to fit the mold. Before the mold was cast in RTV I cut the slots in the master with a Dremel bit, inserted the PVC, and filled any gaps or imperfections around the area with filler. Now I was ready to pour the mold.  Once the new mold had cured I removed the PVC from the master and could then use them in the mold with a little Vaseline brushed on.  After pouring the resin and having it set up the PVC pulls right out.  My molds hold everything to make the final bait including tow eye, ballast, hinge screw eyes, hinge slot "pins", and the hinge pin as well as a "key" to make the tail slot. Once poured and removed from the mold all that needs to be done prior to painting is sanding the parting lines and adding the tail.

 

DaveB.

KelpKritter

[RiverMan]

I will try the drill press again tomorrow. I think I have the round ball bit that Travis showed. I will report back and let you guys know if it worked.

Kelpkritter, sounds really cool.

Thanks again everyone for commenting.

RM

[Vodkaman]

Yes, router bits have a need for speed. Also there is always a bit of play in drill press spindles. It was a shot that had to be tried and part of the learning process.

 

This is where is starts to get more complex. I still think the plunge router bit is the way to go. Look at the ease of cut, in the videos linked above. We are cutting into end grain, which probably won't help much.

 

Basically, you have to replace the drill press with a sturdy jig that will mount a high speed router. You will need to be able to raise and lower the router with a lever or wheel.

 

If you are going to this much trouble, then an adjustable fence, possibly on two threaded bars would be nice.

 

Or forget about the fence and replace it with a lure carriage mounted on the same two threaded bars, and drive the carriage across the cutter with another threaded bar.

 

The lure carriage jig could be removable, so that a fence could be installed for other jobs, though I cannot think of other jobs that would use this machine.

 

I like the lure carriage idea, as it keeps the fingers well away from that temperamental high speed router bit. I wish I had a workshop now, as I think that this is one that I would like to build.

 

Complex but not rocket science, and can still be manufactured from stock wood, so still economically sound.

 

Dave