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Vman rocking beam duplicator
40 replies to this topic
Posted 15 October 2009 - 08:46 AM
Here are some pics of the Vman rocking beam duplicator. Pic1 shows the master with the dummy cutter follower, pic2 shows the cutter end, pic3 shows the result with another that I cleaned up with a flap wheel on the drill press.
I am satisfied with this first attempt, but there are problems. The main problem, which I did foresee, but did nothing about, was spindle alignment. This is critical in order to achieve a one to one copy, the slightest error and you create a different shape.
Spindle alignment is impossible when hand making such a unit from ply wood, but there are solutions. I overcame the problem with floating bearing plates (on the far side, not visible). These are bolted in position, once everything is aligned.
For the mark 1 effort, I decided to make the machine a hand crank, but it can be driven by a motor.
For mark 1, I chose a plunge router cut. The advantage of this, is that there is no bounce and the follower can be set very light, which reduces wear on the master.
There are several disadvantages though. As you can see, the cutter ridges require a bit of cleaning up, but this only takes a minute or so with a flap wheel. The main disadvantage was that progress was slow. I was reluctant to push the feed, as you have to listen to what the machine is telling you. The cutter bit was not new, but seemed fairly sharp. I think this is mainly because the machine is cutting end grain, never a good thing. If I allowed the cutter to follow the 6mm dia spindle, the block would snap, so I had to start the nose with a larger diameter than I would have liked.
However, I have designed the machine so that can easily be adapted to other cutter methods, such as turning the router through 90 deg and ‘lay on’ the cutter, or use an angle grinder with a saw wheel.
On a point of safety, I was very satisfied and felt comfortable operating the machine. With the guard down (removed for photo’s) the cutter area is enclosed and nothing can fly out.
I would appreciate any feedback on this project, particularly on cutters.
Posted 15 October 2009 - 09:07 AM
This may not mean much but I'm impressed. I could not build that machine with you reading step by step instructions. I will have to stick with the old hand carving method.
Posted 15 October 2009 - 11:17 AM
Cool tool Dave. Nice craftsmanship. Have no doubt you will come up with solutions for the issues you mentioned in your post.
Posted 15 October 2009 - 12:07 PM
Dave, fine job my friend! Are you cutting the bait in one pass?
Posted 15 October 2009 - 12:12 PM
Vary nice Dave looks like a good one . Any chance of getting video on the operation. I do better with moving visuels. (is that spelled right?) I want the plans if there is any. Frank
Posted 15 October 2009 - 12:23 PM
Looks to me if you reduced the stock size it would help with the feed. Seems the height could be reduced significantly. If the bait is being cut in one pass, perhaps leaning the cutter in the direction of travel could help also. As far as cleaning up the bait tumbling with an abrasive has been known to work well in the past
Posted 15 October 2009 - 02:00 PM
Thanks for the nice comments.
KC, you are absolutely right. After a night playing pool and consuming alcohol, my mind never left the project. I occured to me that I am cutting far too much wood.
Reducing the stock wood to the parameters of the master would vastly reduce the load on the cutter. This just needs more accuracy in locating the stock. Not a dificult problem to overcome.
The part is cut in one pass. Pointless in making two passes, as the cutter would follow the same path. Also, the cut can be done in both directions, without breaking the rules of routering.
Turning the router cutter through 90 degrees, as suggested in my previous post, would not solve the problem of the end grain, but it would minimise the ridges. I am leaning towards the idea of using the angle grinder method, first shown by Redg8r. The advantage of this is 40 cuts per revolution compared with two cuts of the router bit, a significant advantage in tool wear. Also the cost of a router bit is seven times more than a saw blade with theoretically, 20 times less wear with the saw cutter.
KC, the tumbling abrasive system, which we have discussed before, is a serious consideration, which will be explored, should I solve all the innitial duplicator problems.
My next tast is a total re-design and re-build, carrying foreward much knowledge acquired from the Mk1.
Frank, I am reluctant to put a video out until I solve the problems, same goes for plans. The last thing I want to do is inflict a migrane on my friends. This is a first draft, not a solution.
Edited by Vodkaman, 15 October 2009 - 02:06 PM.
Posted 15 October 2009 - 02:12 PM
A design out of the norm Dave. To be LaPicky, your stylus and cutter are traveling in an arc (longer and longer arm will reduce the arc to a manageable "straight" line); but I do foresee problem with cutting speed this way. The slight arc will introduce different cutting depth along the front and tail end. It could introduce binding of the cutter bit as it attempts to cut deeper and the head and tail end. Would be more obvious if it's a longer lure or if you are to cut a series of lures lined up (say 3 or 4 lures in a row). JMHO
Posted 16 October 2009 - 02:57 AM
V-Man, you've been busy! :yay:Nice machine for a starter. I am sure that you will be able to solve the problems that you spoke of. Good luck with this project. Can't wait to see your next one.
Posted 16 October 2009 - 09:04 AM
how small it can go? can this machine copy a smaller bait?
Posted 16 October 2009 - 09:57 AM
Thanks LP, I try to be different.
Regarding the arc, my thoughts are that both the stylus and the cutter are making the same arc, so duplication occurs. The radius of the arc is 277mm, so over the travel of the cutter, it is almost straight, 0.4mm from straight over 15mm depth. Not sure I understand the binding, but it could be part of the problem.
Sinyo. The problem with small lure bodies is the diameter of the spindle holding the master. On the Mk1, I used 6mm, but this snapped at the router end, with the light wood that I used (albasia density 0.35gm/cm3). On the Mk2, I intend increasing the spindle diameter to 8mm. This is still OK on 3" lures, but much smaller and there will be nothing left to duplicate.
KC, I did a run with the stock trimmed down. A dramatic improvement in cutter load and speed. Pretty obvious really, duh!
The main problem that I am having now, is the spring loaded spike plates, holding the stock. About one in three, the stock cuts loose. So I am now working on a new stock clamping system. A pity really, as the spring loaded clamp was quick and efficient to operate.
Posted 16 October 2009 - 11:54 AM
Good deal! I bet you have it cranking out the baits in no time
Posted 16 October 2009 - 12:21 PM
Brilliant! A truly ingenious machine.
If you can, cutting from the center toward eash end might reduce the tearout.
And that would let you go deeper on the head end, so there is less left to hand shape.
Also, if you hit the blank with a quick drying sanding sealer, or any clear lacquer, after it's roughed out, but before you take it off, to lock the wood fibers, and then pass over it again with the router, you might get smoother results on the second pass.
Posted 16 October 2009 - 12:41 PM
Thanks Mark. Seems like a reasonable suggestion, but it would not solve the ridges, as the end of the cutter is sharp/flat. Maybe a round nose cutter would improve things. I will try to locate one on my next shopping expedition.
I have come up with a design for the stock clamp. I think it might just solve all the problems. start building it tomorrow.
Posted 16 October 2009 - 06:28 PM
Dave - I am up in Queensland so I don't have access to my pictures BUT I had the same problem with the cutter when I was making 2" blanks years back.
I was always going to go to a half round bit at the smallest diameter possible for your blank, but never had the money to buy one - I think a half round with 3 or 4 cutting edges (not 2) and made of carbon steel (not tungsten) as they are much sharper. Also if you can't get carbon steel cutters, you can sharpen the tungsten bits with a honing stone, honing along the flat (not the beveled cutting edge). I think I have mentioned before the Russian guy who used a saw blade with extreme angles on the cutting teeth, this was supposed to work well @ about 2.500 - 3,000 RPM - but this would not fit a router???
Love the 'Rocking Beam Duplicator", the thing that stands out for me is it is exactly the same as your original drawings, something I can never achieve - Rock On Baby..pete
Posted 16 October 2009 - 11:39 PM
I agree with Pete I think you need a ball end mill. they are used for metal working but are really slick for wood. Is your router set up with a fixed size collet or is it ajustable? I use an 1/8"(3mm) four flute carbide bit to mill out the hinge area for my swim baits. These only cost about 8 dollars US . I would tell you how long they last but I am still using the first one. Also on these bits I turn them about 4000 rpm really slow for a router. I tried to get a link for these but the web site is to confusing. ENCO, MSC, RUTLAND TOOLS or any machine tool supply house. These come really sharp when you gut them and cut like butter. If you try these I think the ridges will be smoother.
Posted 17 October 2009 - 09:02 AM
Frank and Pete, I agree, this may be the way to go. Unfortunately, my router is fixed collet (1/2") and fixed speed (mega fast). I will see what is available. But what ever cutter is chosen, it will have to do the entire job, changing cutters is not an option.
The length of the cutter is important, it has to extend about 50mm past the router mounting structure as this structure has to clear the stock clamps. This is why I chose a 1/2" dia cutter. I feel a smaller diameter cutter of this length would introduce chatter or tool bounce, could even snap under the load.
I built the new stock clamp today. A vast improvement in performance. No breakouts of the stock and I was able to machine the stock thinner at each end, so I will probably stay with the 6mm spindle. However, the clamping process is very cumbersome and time consuming, with eight screws. I now have a better design in my head, that should be even more secure with only two screws. Better still if I can find a supply of wing bolts.
Timing is 7 minutes per blank, this includes loading and unloading. With the new design of clamp, I should be able to reduce this by a couple of minutes. Actual routering of the profile is only about 90 seconds, the rest of the time is making the initial cut into the stock, which has to be done with care.
Posted 17 October 2009 - 02:42 PM
Frank, I will make a vid soon, just don't want to embarrass myself just yet.
Posted 20 October 2009 - 04:13 AM
I was wandering what your engineering mind worked on lately, and here it is, nice job, my boxes full of machines are jealous on your workshop maybe we'll have a chat in the chatroom like in old times