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What type of machinery will mass produce this shape?

ua101

Aluminum
Joined
Mar 21, 2013
Location
Toronto
Hi, I'm trying to figure out if there is an efficient and fast way to produce specific wooden tool handles with different designs. Sketch is attached:

The narrow section is always the same length, width, shape, corner radius....

The handle part needs to change based on large production volume per each design. It also stays the same length, but everything else changes.

The biggest issue is I need it to be hollow internally - most likely drilled from two sides, so the narrow section is always 1/4" hollow in width, but the wide section needs to change according to the handle shape, so there is a step there.


I'm not sure if there is a CNC machine that can drill that deep and that precise, and if there is, what type of jig needs to be there to produce about 60 of these per hour.

I'm not sure if a programmable drilling dowel machine can accomplish everything including hollow section, but I need something that is as automated as possible.

Cheers.
 

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You state that you need a constant wall thickness, same for all parts. Does the 3rd handle up from the bottom have a reverse tapered hole in it as well?

Other than that one, it may be possible to get dedicated MAKA chisel sets to do most of them, at least the ones with at least 1/2" internal width. The 5" depth is challenging. I'm not sure if the typical MAKA machine strokes 5"? But people make specials.

What kind of wood? makes a difference.

smt
 
Looks like it could be done on an automatic lathe with an active sub spindle Not sure if that is the proper terminology. Material indexes in, Template controlled milling head begins cutting the outside, part is cut off and transferred to an active spindle where a hollow chisel cuts out the center. May take two chisels. Only change in set up is a different template is mounted.

Tom
 
A second question (unasked . . . I know) would be what kind of customer would want those wooden handles?

I suspect you'll find a high percent of rejects or handles broken in service with the 0.2" wall thickness. The dimensions don't look an especially good fit to hand either, though that depends upon the application. Some of your handles will likely break or splinter in service unless you spend $$$ on a finish, possibly a ferrule, etc.

Just as one point of comparison there's a reason that makers like Henckels (kitchen knife handles) mold their handles. Cheaper to make in quantity, far more durable, easy to mold for a satisfying fit to hand, less likely to splinter, don't require a finish and then refinishing, predictable material properties, did I mention durable . . .. A $$$ hardwood (and even a cheap softwood may be $$$ once you get them out the door) may seem "classy." Which may be your motivation. Still, some pretty high end knives, tools, pistol grips, hand-held utensils, stick shifts, and most anything else hand held manage a premium without the wood.

Just a thought, before you commit to automating the heck out of the wood-handle-making process. Lot depends upon quantity as well.

If you're committed to wood you could also split the blank, machine it, and glue it back together.
 
Stephen good question, in this instance the hollow diameter is based on narrowest section of the handle so it's not reverse taper, I just don’t see how a reverse taper could be done with such precision, on such a flexible material like wood, so most likely scenario is it’s just a straight hollow all the way with no step.

Wood: I'd like to experiment with different ones, but main one is ash, but need an option for hard Maple, Poplar, Birch, Adler..... Mostly hard woods.

When you said Maka, which one or what type?

Main issue is the 5" bore and if the wood will bend, or the tool will bend with such small bore diameters, and if we start out with very thick wood blocks a lot of money is wasted.

I'm a total newbie when it comes to CNC lingo and types of machines are available but from logical point of view it seems to me that I need two machines in total for internal and external:

Tom many questions about the active sub spindle options:

1) Does the active sub spindle move in the Z-Axis?
2) Can it grab a 1.25” square block of wood in 7.5” length in full depth all the way through the spindle?
3) Does it have automatic tool change or basically one spindle grabs it another one drills it, once one end is drilled it changes to a different tool where it grabs it and then the other end changes the tool from grabbing to drilling?


Active sub seems like it would cover the internal hollow section. I’m not sure it will do external well on precision of corner radius and overall smooth texture or do it fast enough for large volume turn over, so for external I’m thinking some type of dowel machine like this one:

SHOVEL HANDLE MAKING MACHINE TYPE TS6 - YouTube


With different cutters, I know they can program them for tapered shape as well.

Pete, the wall thickens will change, the measures are not precise, I simply need a flexible manufacturing method then I can play around and find out the threshold of breakage on different wall thicknesses. I need the handle to slide on a proprietary device, so it’s not for conventional use where it will break.


Cheers
 
I don't like starting out asking people why they need the features they say the do. So i chose to assume you know what you are doing, are familiar with the materials and generally with tooling, and have some methods to analyze the constraints in the materials and process.

It sounds like that is not the case.

So lets start with a question everyone wants to know, why hollow, why uniform walls. You alluded to it sliding on "something else" to Peter, so that helps a little. Why change the profile, though? Why not engineer the smallest possible to work for everything, or conversely, decide to make the smallest one big enough to accept the machining process that would be more reliable for a larger diameter hole?

Next, how many of each are you going to make?

This type part is usually only made on cnc machines when there are expected to be relatively low volumes and you have to pay the extra cost because the volume won't support dedicated tooling and machines.
For high volume, low cost, they tend to be made on automatics, as has been partly explained. Like in machining where if you want high volume/low cost, multispindle screw machines beat cnc hollow. Transfer machines still do, too, for dedicated stuff that will run for a long time.

The OD's you show are relatively easy - as has already been noted by others, automatic lathes have been making shapes like that and more complicated, hopper fed, for a century.

I don't see any rotating tooling making the small rectangular cavities to a depth of 5" in wood and holding the tolerances you suggest you need to fit and slide on another part.

I see 2 ways around it that use recip tooling. In either case, drill the 1/4" hole straight through with a gun drill and high pressure air. It is a proven process.

Method 1.) size the cavity so it will work with a dedicated custom MAKA mortiser profile.

Method 2.) make the handle in 2 pieces, since you say the front section is always the same. The front piece would have a spigot and shoulder, and be glued into a counter bore in the rectangular section handles. The handles would be drilled with the largest drill that would fit, and then broached with a custom broach. They may have to be supported in a mould to constrain the sides against bulging or splitting while being broached, but it would work.

Why not plastic?

Certainly consider dymond wood, if you really want durable handles. I can't tell if Rutland is making any since the fire a couple years ago or not, but there are other similar products (resin & color impregnated wood)

smt
 
Stephen, I’m in a state of hypocrisy, on one hand I’m asking you guys for help, on the other hand I’m reluctant in sharing too much information publicly especially with potential Intellectual Property that could be explored down the road.

So I hope maybe I can still get some answers based on what I can share.

I need large production volumes of 20,000 to 50,000 units per year at low cost of about $1 - $2 per each unit, so most likely the CNC route might be out, this is based on calculation of finding a source or buying our own equipment and making about 50 – 60 units per hour.

Design issues.

1) It has to be one piece, can’t be made from two sections.
2) It has to be wood, and specific wood I mentioned, no other material.
3) Wall thickness, the goal is to shave as much weight as possible yet maintain structural integrity, so uneven wall thickness will provide more high stress points, that means the tapered design might be discarded in the end, and we only focus on even shapes. I’m starting with as many design options as possible and slowly shrinking to fewer design options because of limitations on cost per part and production methods for large volumes.



Questions:

1) Wood dowel or end shaping machines like this one:

WOOD ENDSHAPING MACHINE TYPE END5 - YouTube

Can these machines make square shapes not just round shapes, can they make different corner angle radius?

2) Mortiser, what is the maximum depth it can reach based on ¼” shank and what are shape limitations on the custom mortise shapes? Can they be automated or have 10 bits drilling 10 pieces at once.

3) Feeders, are they usually part of the overall machine design or generally produced separately and are very adjustable, taking into account my specific case.

Cheers
 
The 20-50k number of parts is not my expertise, but I have a few ideas that I would start with in my shop. I think that at these numbers the only reason to use cnc is the flexibility of changing designs or features. If you get it down to 1 or 2 shapes, then I would most likely make or buy plc or air logic driven machinery to do the job. I think I'd start with getting a blank to size and then have a hopper feed a drill machine with multiple spindles, so that you can have a slower more reliable operation but still meet your parts per minute.

So, put together a gun drill with 4-10 spindles and have it dump them out to a conveyor or hopper to feed a lathe type machine(s) that has auto load that locates it off the hole in each end to make it concentric to the through hole. As an option to the lathe, I'd look at a molder or shaper type machine that will follow a pattern, this might actually be a better method to cut the outside profile with the grain instead of against like a lathe usually does. It would require custom ground cutters, but at the 50,000 pcs per year, it would be an easy decision. I think that they are called a floating head shaper or something like that. With the design of the part, you may need to combine some of these types of tools, if you have an inside corner, the shaper tool will not work, you'd need the lathe.
Just some thoughts...
 
Stephen . . .

1) It has to be one piece, can’t be made from two sections.
2) It has to be wood, and specific wood I mentioned, no other material.
3) Wall thickness, the goal is to shave as much weight as possible yet maintain structural integrity, so uneven wall thickness will provide more high stress points, that means the tapered design might be discarded in the end, and we only focus on even shapes. I’m starting with as many design options as possible and slowly shrinking to fewer design options because of limitations on cost per part and production methods for large volumes.

. . .

Cheers


I'll be surprised if you get these made to a decent standard for $1 a piece. In addition to the deep square hole you want (all those chips to clear) and the two cross sections, you'll likely have to sand the outside and finish it.

As for one piece vs. two pieces -- if you saw a wood blank with a thin bandsaw blade it can be glued back so the glue line is essentially invisible and the whole likely stronger. This allows you to make most of the shape power fed on a shaper in something like 8' lengths. Glue the halves together, cut to length, and you have only the thinner section to cut down. Also very easy to play with wall thickness. Probably not going to do that for $1 a piece either, though.

By "specific wood" and nothing else was there something more specific than the list of light colored hardwoods you noted earlier? If this is an appearance issue rather than some arcane wood-related materials property issue, folks are regularly fooled by wood-grained plastic in auto interiors, floor materials, and handles: Plastic wood grain handle | Etsy
 
while its intellectually satisfying to make up a shape that is not available, and assume some machine exists to do it, its never a very good idea to also make up the price in advance. It has always been my experience that these sorts of imaginary exercises end up costing orders of magnitude more than you "think" they should. My guess is, in 20,000 part runs, you are going to be more in the ten to twenty dollar price range.
It makes much more sense to design around existing things, and modify as needed.

All that said, call (NOT email- people dont answer emails like this, because they are obviously going to be no-bids- you need to talk to a person, and appeal to their sense of feeling sorry for you for what a sad ignorant puppy you are) these guys.

They make handles, for a living, in more or less your price range (double or triple, but when we are talking a dollar versus five, thats still your price range)
They know what the machines can do, what woods are actually available in what quality, and they make handles.
They will give you a reality check.

https://www.househandle.com/
 
That's where I started by contacting companies that already produce similar products, at $1 - $2 per handle was not an issue - they can do it, specific wood and enough of it was also not an issue, the only issue was internal hollow section.

Just because it doesn't exist or never been attempted doesn't mean it can't be done. That's why I'm here, researching if it could be done, and at what price point or where do I have to compromise in the design to make it happen.

I repeat gluing or any other two-part operation is out, I can't explain it because of proprietary issues.

Let's focus on the internal part only for now. My plan is to find machinery that will cover the internal part needs, this way I can go back to the same companies and try to negotiate of possible 50/50 spit on investing in the machinery, or some other financial structure where it would make sense for both parties.

So lets focus on internal hollow part only for now.

Lets break it down to two sections cheap labor vs expensive labor. So if we had done in China where a person can insert each piece into a milling machine and hollow it out, will a CNC milling machine with some type of jig and chisel go deep enough at 5” with such small internal hole diameter?

Expensive labor, a machine with more automation or a multi station machine where it would drill X number of handles at a time, so still manual labor involved, partly because I’m looking at the cost of full automation, it looks like we’ll be working for 5 years paying off the cost of so many machines before turning a profit.

It seems to me that gun boring is based on lower speeds for metal not wood, and I don't see the spindles moving on any axis.

Cheers.








while its intellectually satisfying to make up a shape that is not available, and assume some machine exists to do it, its never a very good idea to also make up the price in advance. It has always been my experience that these sorts of imaginary exercises end up costing orders of magnitude more than you "think" they should. My guess is, in 20,000 part runs, you are going to be more in the ten to twenty dollar price range.
It makes much more sense to design around existing things, and modify as needed.

All that said, call (NOT email- people dont answer emails like this, because they are obviously going to be no-bids- you need to talk to a person, and appeal to their sense of feeling sorry for you for what a sad ignorant puppy you are) these guys.

They make handles, for a living, in more or less your price range (double or triple, but when we are talking a dollar versus five, thats still your price range)
They know what the machines can do, what woods are actually available in what quality, and they make handles.
They will give you a reality check.

https://www.househandle.com/
 
My plan is to find machinery that will cover the internal part needs, this way I can go back to the same companies and try to negotiate of possible 50/50 spit on investing in the machinery, or some other financial structure where it would make sense for both parties.

Yeah, they're really gonna be lining up to "invest" in your project when you tell them no details because it's proprietary information...you probably think it's an original idea, but most of the machine-shop owners on PM have heard it a hundred times, just before tossing the guy out. :rolleyes5:
 
Ok lets clear out people that have nothing to contribute here. I have thick enough skin where I can take as much criticism as you are willing to dish out. This or any other forum is to exchange ideas and provide some input on how to solve or tackle ideas, designs… …last time I checked you can’t provide input on someone elses behalf as far as who will invest in what at what price point or under what terms..

So if you have nothing to contribute the best you can do is either, say what worked or did not worked in your personal experience or simply not respond at all.

The companies I contacted I did provide more details because it’s not via public forum, I think I also provided enough details here, the only thing I did not disclose is the industry and specific product category, which is irrelevant at this point. I know the industry very well and potential competitors so my ideas are not out of the blue, it’s based on experience and research.

Cheers
 
Does your resistance to glue have to do with introducing a "foreign material"? Or some other factor. I do not see gluing up halves as contributing to speed or efficiency. I do see inserting a spigot end into a rectangular handle part that is broached in a form as making the whole job possible and cost effective.

BTW, 20,000 parts does not strike me as a large volume per year. Even at $5/part. Point being, you have almost enough parts to interest a jobber, but not enough money to tool up for it if the internal features require R & D to develop a "new" process.

Also, your apparently very specific options in wood are sort of baffling to a woodworker. Maple, Ash, and Poplar are vastly different woods with very different machining characteristics and physical properties, as well as obvious tactile differences (in the unfinished state) Birch is somewhat between hard maple and poplar in characteristics, in a very loose way :D (Any of the woods except maybe poplar would make adequate handles. However the emphasis that it can only be one of these 4 states that a vast range of properties is actually acceptable, open, and unimportant.)

I think the machine Jason may be referring to is know to me as a linear profiler. As he notes, the vote is still out whether that or an automatic lathe would be more appropriate, pending further input on specs. Tooling an automatic is not cheap, but for small parts may be quite affordable. Then you get into things like % of reject parts based on the substrate (which wood are you actually going to use) and which one will run the most parts between tooling maintenance

smt
 
My take on this is that it is highly unlikely any standard machinery exists to do this. In the past most companies making specialized wood parts either custom built equipment or modified equipment to suit. Each operation was done by a separate spindle or work station, usually in batches.

I am not in the professional woodworking business but if I were to "imagineer" a suitable process it would go something like this.

Starting with an oversize blank.

Deep hole drill, with vacuum extraction for chips to rough out the interior.

Custom carbide cutter to mill the internal profile, with either the work piece or spindle guide by template or cams. Again with vacuum extraction.

External profiling, using carbide cutters in high speed spindles, template controlled. An inserted mandrel would hold the work pieces in correct relation during milling.

Even if you did this in house, 20,000 pieces at $1 each does not allow for much in the way of machinery with labor and overhead still to be accounted for. Doing it via someone else who must add in a profit margin IMO makes it dicey even in a low wage country.

PS: Thoroughly agree with Stephan Thomas re various woods. In the good old days something like that almost certainly would have been done in Beech or other similar species.
 
I'd love to see what this is if/when it hits the market.

The outside is an easy job for an automatic shaping lathe. But and auto like mine requires a custom ground set of knives for each profile. The inside corner on them rules out the floating head shaper/ linear profiler without having a second op.

The internal hole really has me stuck, though. oscillating mortiser or a broach of some kind is what I see.

I too am hung up on why a cut apart and reglued piece wouldn't work. There are adhesives that will perform and be safe in almost any working conditions and a small enough cut will make the glue line disappear on matched pieces.

Also don't understand the species specified. Stephen's points about physical and machining charactartistics are spot on except that the OP said Alder not Ash. The are all diffuse porous species with properties kinda all over the map as far as wood goes.

Dan
 
Don't ask so many questions, this guy clearly knows his specs so that's why he is asking for help lol.

Sorry bud but come on, if you want help you have to be clear with your engineering needs. If you want to be all cloak and dagger then good luck to ya because you are gonna have to figure it out internally.
 








 
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