[skrubol]

Yeah, the nailing makes 3d printing less appealing. It could probably be made to work, but too much risk of either needing expensive consumables, high failure rate, or just not being optimal.
I still think a traditional 3 axis machine can do what you need, especially if you can split the lasts and glue them up after. You can put holes for alignment pins in the halves, etc, though it seems that getting them aligned by eye/hand shouldn't be too hard.

[pippin88]

If all he wants to make is shoe lasts, then I don't see the advantage of a standard 3 linear axis machine.

A machine like shown in the video would be more appropriate. Always better to do work in one setup where possible.

For a custom build there is no particular difference in difficulty. In Australia, there is not much available in terms of decent kits or prebuilt machines, so mostly we have to fully DIY.

[pippin88]

cuplinks:
What is the tallest shoe you would make / last you need (this will determine the diameter of the rotary axis space required and the travel of the Y axis)?

I've whipped up a very quick and dirty mock up of what a frame / machine might look like. Many things like tailstock and steppers etc missing. See attached.
Easy to make out alu extrusions. Easy to weld up and get machined flat.

[cuplinks]

cuplinks:
What is the tallest shoe you would make / last you need (this will determine the diameter of the rotary axis space required and the travel of the Y axis)?

I've whipped up a very quick and dirty mock up of what a frame / machine might look like. Many things like tailstock and steppers etc missing. See attached.
Easy to make out alu extrusions. Easy to weld up and get machined flat.

Hi Pippin,

That is similar to what I am thinking too. The biggest last I have is about 350mm long, 130mm high and 120mm wide, but that is only a size 14G. I would probably want a Y axis travel of about 450-500 to account for the extra wood at each end to attach to the lathe head and tailstock as well potentially even larger lasts. The max rotary diameter needed would therefore be somewhere around 200-250mm and I guess the desired travel for the z axis would be half that at 100-125mm?

I was thinking of getting something like the following lathe with an extra cast iron frame to use as the base for y-axis/z-axis. Im assuming I can replace the motor and gearing and aim for a 5:1 reduction for extra torque. I know people earlier in the thread said not to retrofit a lathe but what do you think? I'm liking the cast iron frames for rigidity.

Finally, the y-axis would never have to move very fast throughout the cut, and also never very far. However the z axis would be moving in and out constantly, quickly and would need to be super accurate. I'm assuming ballscrews and linear rails for both but was wondering if something cheaper could be used for the y-axis as it doesn't have to work too hard, it just needs to be rock steady when stationary.

[Happy Feet]

i am into the 3d printig for this too. .First of all there are several materials and i wouldn't go with hdpe ( no reason for that) .I am a ABS guy but i know that petg would work nylon plastics would also work and there is the abs-pc which would overcome the toughness of abs.
So you do have lot of materials to choose from .

About the nailing thing. The leather would take nails to the bottom of the show , isn't that right. The 3d printing needs a different approach during cad modeling.

So there are two things you could do . the one is to leave some holes, that will be used with screws or clips or whatever , and teh second route to go is printing a female inlet only at the bottom of the last that will be clapped to the last with the leather on the inside and will be left for a while to get the material formed.

Finally think the 3dprinted part in the same matter that you are thinking of wood. Solid . In this case you wont be able to pull the nail out. What i am trying to say is that palstics have similar mechanic properties ( and even better on nylon plastics) with wood. They even approach soft aluminum ( if you exclude temps)

Dont look out on pla. pla is just for fun . And also if you get a print that is not bonded well or easily tears apart then there is something wrong with ur prints.

3d printing is the future of cncs. the only thing in my opinion that will survive are the woodworkings cnc onluy because we cant produce wood bu any other way but from a tree.

just my thoughts

[cuplinks]

i am into the 3d printig for this too. .First of all there are several materials and i wouldn't go with hdpe ( no reason for that) .I am a ABS guy but i know that petg would work nylon plastics would also work and there is the abs-pc which would overcome the toughness of abs.
So you do have lot of materials to choose from .

About the nailing thing. The leather would take nails to the bottom of the show , isn't that right. The 3d printing needs a different approach during cad modeling.

So there are two things you could do . the one is to leave some holes, that will be used with screws or clips or whatever , and teh second route to go is printing a female inlet only at the bottom of the last that will be clapped to the last with the leather on the inside and will be left for a while to get the material formed.

Finally think the 3dprinted part in the same matter that you are thinking of wood. Solid . In this case you wont be able to pull the nail out. What i am trying to say is that palstics have similar mechanic properties ( and even better on nylon plastics) with wood. They even approach soft aluminum ( if you exclude temps)

Dont look out on pla. pla is just for fun . And also if you get a print that is not bonded well or easily tears apart then there is something wrong with ur prints.

3d printing is the future of cncs. the only thing in my opinion that will survive are the woodworkings cnc onluy because we cant produce wood bu any other way but from a tree.

just my thoughts

Hi Happy Feet thanks for your thoughts.

I really don't understand enough about the different plastics available in 3D printing these days. If you can point me to a link to explain it all that would be great.

That said; HDPE is the current industry standard for plastic shoe lasts and they are all cut with a CNC lathe.

Also I am finding it hard to follow your post in regards to leaving holes, screws, inlets, etc.

I already have a shoemaking workflow that I am not willing to change in any drastic way unless it reduces cost AND/OR increases quality. If 3D printing can produce a last that is superior to a wooden last and can be printed in a comparable time frame for a comparable cost, I would be interested. But my research suggest otherwise.

[pippin88]

Don't buy a lathe to convert. Not suitable and you will spend more time and money than just building right the first time.

Will look at the sizing and modify mock up later.

Did you have a link you can share to your shoes?

[Happy Feet]

Hi Happy Feet thanks for your thoughts.

please keep in mind that i may talking b****t.

I really don't understand enough about the different plastics available in 3D printing these days. If you can point me to a link to explain it all that would be great.

i looked around for a comparison but didn't find any site talking about these things. i am printing abs straight from LG Chem pellets, which is not sold as a filament and there are few that know it as a material for 3d printing ( this is what i know so far) . i am making my own filament and the cost for a kg of pellets are 3.5€ including 24% taxes. i think hdpe pellets a re at the same price range as the petg i know for sure. there are lot of materials out there most for aesthetics on 3dprinting but keep in mind that most of the thermoplastics would be 3dprinted till the end of the decade.

I am taking the infos i want about materials in the materials web library.

That said; HDPE is the current industry standard for plastic shoe lasts and they are all cut with a CNC lathe.

hdpe is a good plastic for food, for recycling and cheap to produce .it can stand temps little less than 100c. this is why if you look around you ll see many objects from low density or high density pe . i think the pet will overcome high density pe soon. There is no hdpe filaments at this time as it is difficult to print and doesn't offer any advantage ( except food grade ) over other ones. fifteen years ago it was one of the tops for a variety of uses. i think now it is not no more. i am talking only for high density . the only reason they used hdpe instead of wood is the cost. and the plastic industry is changing through 3d printing. so in a few years there will be no more wooden last at all i suppose. i dont know if there will be lasts at all :-)

On our days it is also cheaper to have a good to top fdm and maintain it from a heavy cnc machine. the savings on the material from the different modeling approach i told before would be huge and on materials size and weight cost even if it is plastics.

Also I am finding it hard to follow your post in regards to leaving holes, screws, inlets, etc.

if i cant nail something over something else then i have to find another way of doing it . sorry i dont know how the shoes production work but i imagine you want something to be formed on that last. forget what i ve said about holes. i was also referring to a mold inlay for the last to be pressed on and clamped there until you get it formed.

I already have a shoemaking workflow that I am not willing to change in any drastic way unless it reduces cost AND/OR increases quality. If 3D printing can produce a last that is superior to a wooden last and can be printed in a comparable time frame for a comparable cost, I would be interested. But my research suggest otherwise.

time is something relative ....! 3d printers cant beat cnc's at least not the cheap or in the price range i told before. but if you are willing to pay what you would pay for a cnc lathe or mill and add some more for research that will be ur gain after all, then i promise you time would not keep you back from doing it .

something last and my apologies for the huge post. ( i may have to be restricted to only some words during a week) . processors dont do faults . if you get something not scanned well it is not the process itself but something in acting. if you want to be on the route of custom shoes you need a reliable solution for 3dscanning.

[wizard]

Hi Wizard, thanks for your thoughts again.

The problem I have with 3D printing is of course the durability of the plastic. When making a pair of shoes I need to drive nails in the the last to hold the leather in place. It is probably hundreds of tiny pins over the course of one pair and I would be expecting the lasts to be used for dozens of pairs. The good thing about wooden lasts and even HDPE is that the nail holes don't chip away at the last.

I'm learning a lot about shoe making here. As such I would no have imagined nailing the leather in place.

I'm worried that the layers in the 3D printed last would chip away with the nails.

This is where you need a plastics expert that is strongly involved in 3D printing. There are so many resin out there that you can't rely upon hearsay. At work we use a couple of gaylords a day of plastic, I believe 4 different resins. We run the same resins in an injection molding process for years on end thus I'm not up on what resins might work in this situation.

Plastic resin technology is pretty interesting. These days you can buy resins with melting temperatures in the same range as zinc alloys. In any event the point is there is so much out there that you really need that expert to highlight the possibilities.

Also cast aluminium lasts are used for making sneakers as they can survive the vulcanisation process of putting the rubber soles on but are not useful for traditional shoemaking.

But maybe it is possible, I have found an amateur shoemaker who experimented with 3D printing on
and managed to make something work with PC-10 plastic. It was a 30 hr print and he said the cost of plastic was high. These are his lasts;

The price of materials and what one calls high will vary a bit. My big problem is the 30 hour print time.

First off I don't recommend leaving the many low end and DIY machines unattended when it comes to printing. This simply from the risk of fire. So that means you need someone to attend to the printer. I don't know what the going rate for a machine operator is down there but lets say it is $15 an hour, that is $450 dollars per last. Maybe that is doable in the custom shoe market I don't know. In any event no matter how you slice it the cost of operation of the machine has to be figured in.

By the way that 30 hours is likely trimable by a significant amount with modern commercial 3D printing solutions

Anyway, I am not likely to go against the industry standard and would prefer to use wood as I am used to it and can source it locally and relatively cheaply. (I have a contact who has a shed full of old wooden last blanks).

Finally, in regard to using 3rd parties. I have gone down this route many times in the past and unfortunately don't get the results I need. I have ordered lasts from the UK, India and China, as well as from the old company now closed in Australia and they all have problems. I send them my measurements and all appropriate data and the lasts don't fit the client. In one case I took the client in for a 3D scan of their feet and had the lasts made from that scan at considerable expense and they still didn't fit.

Since you have had this problem all over the world I have to wonder where the issue is. It could be software, errors in the measurement software, or in the translation of you data to the local machinery.

I look at it this way if the machinery builds an exact duplicate of your virtual model, in real material. then something outside the job shop needs to be fixed. It may be a case of specification errors, CAM or CAD errors or something else. In any event if the CAD model is valid the CNC should reproduce it exactly. If after trying all these different suppliers and not getting usable results I can't see you having any better luck in house. You need to determine where the 'last' went wrong so that problems become addressable.

I know I can fit my clients by manually adjusting a last so I just need to have more control over the process to get it right. And instead of wasting money experimenting with 3rd parties its time I just sorted it out myself.

This may or may not work. What I do know is that developing a special purpose machine is none trivial. You need to determine if you are up to the demands and the impact that will have on your mainstream business. To put it another way if this will take you 1000 hours would it kill your business?

[wizard]

Don't buy a lathe to convert. Not suitable and you will spend more time and money than just building right the first time.

This I can not agree with. You would have to find a suitable lathe but if found there would be substantially less engineering work. The lathe would be a used CNC that has the swing and between centers capability and a cross slid assembly amendable to modification to run live tooling. The amount of time that would be saved over welding up a steel frame (even more time with a casting) would be significant and you don't need to worry about spindle design. You do need to worry some about the cross slide as that is where most of the action will take place conversion wise.

With a conversion of a used CNC machine, out of the metal working industry, you will get a very robust frame upon which to build your modifications. I might be biased here because I've seen some really strange modifications to old (some times brand new) metal working equipment to turn it into a special purpose machine. The technique is very common in industry to avoid major engineering projects.

Will look at the sizing and modify mock up later.

Did you have a link you can share to your shoes?

[Happy Feet]

if i may add something here. the electronics on printers from 2015 i got my hands on my first ( even then ) are very superior.

My board has some safety features and user calibration of them to identify a fault into thermocouples or thermistors or whatever. that means that if you want ( i didn't ) you can use all them and get some more safety.

Also you can install on the bed's thermal cutout switch which is safe enough. see the most dangerous thing at these days at a no low budget printer is the bed heater which usually are main power and enough watts ( mine is 600w or 700w). My board also can embed a camera ( the firmware ) so you can have an image through net anytime of what is going on. Finally i am controlling my printer through a web interface.
About the printing time . That was a problem to me and the solution i have found was to get bigger nozzles. If you are printing something with a layer height of .2mm or .3mm with a width of 0.3mm to 0.4mm would be much slower than a 1mm width and 0.8mm height. The problem is at the slow speeds the power that the printer consumes and here is the key.
All of the good solutions at these days comes with heated chambers. You cannot go 3dprinting with an open printer . So that chamber in ur case would have to keep high temps for the plastic to cool down slowly as it should . so that means more power and here in greece power is expensive enough...! so the reason i dont want the printer to go slow is to save a few euros every month.

I think it is necessary for you to find someone as wizard told and sort all these out. btw the unboding layers is common problem on newbies in printing . everybody solve this out by themselves.

about the scanning process . you were there when it happened ? the model ( the one who got his/her feet scanned) was standing or sitting. it was during midday morning or late night.?

there was a distortion on the model's feet as i can see which got multiplied by the exists of shadows ( 3dscanning is light and shadows) and the lack of multi direction lighting, that is what i think at least. i think there are laser scanners these days that don't do mistakes.

[cuplinks]

Don't buy a lathe to convert. Not suitable and you will spend more time and money than just building right the first time.

Will look at the sizing and modify mock up later.

Did you have a link you can share to your shoes?

roberts-hassett.com.au

look at the bespoke blog for recently made shoes.

[pippin88]

This I can not agree with. You would have to find a suitable lathe but if found there would be substantially less engineering work. The lathe would be a used CNC that has the swing and between centers capability and a cross slid assembly amendable to modification to run live tooling. The amount of time that would be saved over welding up a steel frame (even more time with a casting) would be significant and you don't need to worry about spindle design. You do need to worry some about the cross slide as that is where most of the action will take place conversion wise.

With a conversion of a used CNC machine, out of the metal working industry, you will get a very robust frame upon which to build your modifications. I might be biased here because I've seen some really strange modifications to old (some times brand new) metal working equipment to turn it into a special purpose machine. The technique is very common in industry to avoid major engineering projects.

Wizard, if you know of a small CNC lathe, I'd love to see a link to it.

I'd be surprised if the opening poster wants a multi-ton machine requiring 3 phase power.

Highly unlikely to find a working suitable CNC lathe. Which means retrofit. Which means lots of work.