Lure Duplicator...looking for some help

[ravenlures]

After looking at what I see which I would like to make out of cedar but I see a lot of sanding and I will stick with making molds and turning on lathe.

Wayne

[JasonB14]

3 hours ago, ravenlures said:

After looking at what I see which I would like to make out of cedar but I see a lot of sanding and I will stick with making molds and turning on lathe.

Wayne

Wayne that’s ultra fine ridges and balsa ....sanding takes about 45 seconds. 
 

vodkaman...I’ll make it public...I thought the link would let you view it. 
 

here’s the public link 

Edited February 12, 2021 by JasonB14

[Vodkaman]

Jason - thanks for the video. That is excellent. The screw motor set to absolute minimum, the definition is not going to get any better. Very good job, inspiring.

The only issue is the end bearing mount for the master, somehow is off center.

Ravenlures - You cannot produce this type of lure body on a lathe and you cannot replicate the material density with a mold. The only alternative to this machine is hand carving, so I will take the short clean-up time.

[JasonB14]

1 minute ago, Vodkaman said:

Jason - thanks for the video. That is excellent. The screw motor set to absolute minimum, the definition is not going to get any better. Very good job, inspiring.

The only issue is the end bearing mount for the master, somehow is off center.

Ravenlures - You cannot produce this type of lure body on a lathe and you cannot replicate the material density with a mold. The only alternative to this machine is hand carving, so I will take the short clean-up time.

In that temporary master I didn’t get the pins dead centered which caused the wobble you see, however the end result was not affected at all as it is for all intents and purposes identical to the master...I’ll make me a 2 piece master and put a solid pin all the way through it and that should fix that issue, also the motor driving the ball screw can be turned down more, I started with it wide open but that’s only 3rpm, I slowed it down during that cut and the ridges got smaller. I think a round tooth blade would help some but haven’t found one yet.....maybe even a 4 1/2 chainsaw blade. Overall for no test runs I’m pretty pleased. Thanks for the advice along the way. I’ll probably pull it all apart and paint it this weekend and then work on some sort of box around it to hook my dust collection system to....balsa dust can’t be healthy as fine as it is. 

[Vodkaman]

Ah yes, I understand now. I used a 6mm diameter stainless rod to through mount my masters. I would fix the block on the rod before carving.

Agreed, a round profiled saw blade would be a good solution. I couldn't find anything locally. Perhaps it might be possible with some sharpening rig, I have not researched the idea.

I really like your rotating follower with what looks like a O-ring contact. This would eliminate the problems of master wear that I had. I do think that the follower needs some means of adjustment for the next evolution.

The precision ball screw is really doing its job, the only downside is the threads per inch count which prevents you achieving a finer definition. For my next iteration of duplicator design, I will be looking at M5 rod with a standard thread of 0.5mm pitch, in other words 50tpi. The carriage will run on rails and be pulled along by the rotating skinny threaded rod.

This design would allow me to either use a single motor with a 1:1 gear ratio between the spindles and still achieve a 0.5mm definition step, or, use two motors and balance finish against time. Sometimes time is not that big a deal. My design spec is also to produce 6 duplicate bodies per pass.

Dave

[fishordie79]

MIND BLOWN. Incredible thread everyone! 

[ravenlures]

Dave

"The precision ball screw is really doing its job, the only downside is the threads per inch count which prevents you achieving a finer definition."   Wouldn't just slowing down the screw make a finer cut, or is it a time concern.

Wayne

[JasonB14]

1 hour ago, ravenlures said:

Dave

"The precision ball screw is really doing its job, the only downside is the threads per inch count which prevents you achieving a finer definition."   Wouldn't just slowing down the screw make a finer cut, or is it a time concern.

Wayne

Wayne the ball screw is a 4mm pitch (4tpi)and the the drive motor is 3rpm max so that’s just under 1/2” per minute feed. I can slow that down to about 1/8” feed per minute but just gotta see if that improves the surface finish. I’m not overly concerned with time as I can do the sanding by hand while the next one is cutting...and of course version 2.0 will have multiple cutters and possibly dc powered grinders. This was fun to build and learn and hopefully I can make it even better and make some killer balsa cranks. 
 

The next step though is to make a back poured mold to hold the blanks perfectly square for cutting the the lip slots. I have a plan but I’m open to ideas.  I’m thinking about a dremel with a saw wheel held vertical and the blank sits belly down in the mold and slid across the saw blade at the desired angle 

[Vodkaman]

Ravenlures - yes, slowing the screw improves the finish.

I do feel some confusion. At first I could not see the video and only had the image to go by. To me, this image represented a finish similar to what I achieved with a 25tpi screw. So, I assumed a faster screw rotation to what I saw in the video.

For the main screw rotation speed in the video and the master rotation speed, I expected a much finer definition. I must admit that in my mind I was a bit disappointed as I wanted to go down this same route myself on my next duplicator design.

There is a limit to how slow a motor can go under Pulse Width Modulation control, but the slow speed in the video was VERY impressive. I look forward to a photo that shows what the best possible definition looks like, particularly over a sloping section of the master.

Dave

[Vodkaman]

Jason - I found a very simple solution to the lip slot issue.

Use a short stub of PVC pipe as a mold, sitting on a ceramic tile or glass.
pour a Bondo filler mix into the mold.
grease up a duplicated blank and push into the Bondo, about half way.

Once cured, the greased body will easily pull out. On the side of the Bondo cylinder, a flat can be ground on the belt sander. This flat will enable you to cut lip slots on the band saw.

Plenty more jig opportunities will come to light once this basic jig mold is made. All holes and slots can be cut rapidly, with minimum effort and total accuracy and repeatability by using a series of jig molds.

Dave

[ravenlures]

Just wondering if it cuts Maple and Cedar nicely or burn up the blade on Maple, balsa is always easy to cut no mater on what type of tool. 

Wayne

[ravenlures]

Would it be better to use a motor and just gear it down instead of a pod for speed. I think it would work once you find the right gears set up and maybe cheaper in the long run, not sure. Plus you could set it up to run both feed and rotation of master lure. What you think? Also maybe easer to build.

 

Wayne

[JasonB14]

27 minutes ago, ravenlures said:

Would it be better to use a motor and just gear it down instead of a pod for speed. I think it would work once you find the right gears set up and maybe cheaper in the long run, not sure. Plus you could set it up to run both feed and rotation of master lure. What you think? Also maybe easer to build.

 

Wayne

Wayne I personally didn’t want to deal with gears and chains so I went with 2 separate motors and direct drive with PWM speed controllers...the ball screw has a very aggressive pitch and normally used with stepper motors or servo motors. The motor I’m using cost like 15$ from Amazon and it’s so small you could probably hide it in your hand 

[ravenlures]

I would be working with 8" lures out of cedar  so that's a long ball screw set up I will look into it would a motor that small work or to much of a load.

Wayne 

[JasonB14]

1 hour ago, ravenlures said:

I would be working with 8" lures out of cedar  so that's a long ball screw set up I will look into it would a motor that small work or to much of a load.

Wayne 

My ball screw is 300mm or 12” ish I’m not using nearly all of it. The motor is very strong, don’t think it would have any problems, but a wiper motor may work better for you. 

[Vodkaman]

Ravenlures - I built my second duplicator for cutting 8" bodies of meranti wood which has a density of 0.55g/cm³ to 0.68g/cm³. Cutting was no problem as the depth of each cut was less than 1mm. I was experimenting with multi section swimbaits at the time and needed a healthy supply of bodies. Hand carving soon became very old.

I used bicycle chained gears for my machines. The method was successful but very limiting. I used 2:1 ratio (88 - 44 teeth). I guess 3:1 would have been possible but the gear diameters were very large and bordering silly. Any future machines will definitely be motor driven.

If the motor can move the carriage then it is strong enough. Very little load is added from the actual cutting process. Depending on the dimensions of your bodies, you may have to mount a larger cutting wheel, I went with a circular saw tool rather than an angle grinder tool. I think the grinder will take a larger wheel.

Dave

[ravenlures]

Would the threaded rod 5/8"be ok instead of a ball screw I know that the ball screw is a more costly than the rod. I was at Menards and wasn't that bad and heavy enough for longer runs for longer lures. Time I have money I don't have  like most of the retired lure makers. Motors I guess I would go with two. I really want to make this for my one son to have to make his own after I pass on.

Wayne

[JasonB14]

The way I have mine built there is very little weight on the screw. So depending on how you build it would depend on the size of the threaded rod and how much deflection it has. And ball screw prices are no where near as costly as they use to be...with both end blocks the nut and nut cap was 54$ 

[ravenlures]

But what size or length was the ball screw 18" to 20" I am not looking at 12" or less ball screw. but will check on it. I would assume that the longer the more deflection there will be or am I wrong.

Wayne 

[ravenlures]

Dave

If I have two wiper motors for drive would I just need a AC/DC converter to run them and gear/chain/pod what ever needed would this work.

Wayne

[Vodkaman]

You could go with a converter, but make sure the converter can supply the power for the motors.

'Gear/chain/pod', not sure what you mean here.

Dave

[ravenlures]

What I mean is, which one  I would use coming off the motors, that would depend on how I set it up and what I have to work with. I guess I would need a converter for each motor. Can I use a speed reducer pod, would that work, or a speed reducer like I have on my router. I am no electrical wizz but I like projects, I will see need room in my shop first to start with base plywood.

Wayne

[JasonB14]

Wayne my ball screw is 12” long and 16mm diameter so it’s pretty hefty and like I said there’s practically no weight on mine because the bulk of my weight is riding on linear rails and bearings. 
 

as far as power, you could go with a converter or do what I did and source an old 12v server power supply. The ones I use out out 12.4 volts and 75amps, which is waaaay more than you’ll ever need and because of their purpose they’re super reliable and really cheap. 

if you go this route I can help you with the very slight modifications you have to make to get it to work outside a sever  

https://www.ebay.com/itm/193605326994

[ravenlures]

Jason Thanks I put that on my watch list and it is a lot of 2  so would I need one for each motor.  I am just getting what I need or think I need. to start with the drive then start with the screw set up.  First make room this will be a slow project for me, waiting for parts and money as I go along.

Wayne

[Munkin]