Automatic toolchanger or custom machine

[team08]

So I have a dilemma, and would love some second opinions on my options. I have a shopbot that I love for my work, I have dialed it in perfectly for everything I need to cut. There are three "stations" on the table, each for cutting different parts. Unfortunately, each station requires different bits, and one requires two. So in total, I have to do 4 tool changes to get everything cut. I can batch process to a degree, but ultimately, I have to change bit and zero multiple times a day. My question is, what is my best option to speed this up? Should I buy a spindle and toolchanger (more on this later), another shopbot, or, create a new, custom machine.

The station that requires two tool changes basically planes a piece of wood in 3D, then cuts it out. For a custom machine, imagine I would take a shopbot and put a planer head on it so it could ride in the X direction, and change Z depth (I know, I am crazy). This would make the planing a quick operation, since right now I have to raster back and forth the width if the piece. Is the idea of a shopbot with planer head crazy (15" head probably)?

As for the toolchanger, why do people here say they are $16,000 upgrades? I asked for a quote from HSD for an ATC spindle and they quoted roughly $4000-$5000 with VFD. So I assume you then just buy collets and make a holder for them (and some programming). Is there something more that I am missing? Its basically just a spindle with some sort of air actuated clamp for the collets right? I am not worried about the programming


Thanks for any help!

[gerald_martin]

Hi Greg:

I'm probably not very well qualified to respond to your post...but, there are a lot of botters that are interested in tool change automation.

I visited ShopBot in NC this spring and had the opportunity to discuss several things including toolchangers with Ted. Shopbot has a machine set up with a toolchanger. If I understood Ted correctly, the most cost prohibitive part of building a toolchanger is the electronic air activated tool release system. The spindle itself is not the highest expense.

Maybe an expert can chime in here. Brady?

Gerald

[knight_toolworks]

you can change the bits manually that would save some programming. one thing I see as an issue with a tool changer is home never can be moved without having to change the programming. some of shopbots competition charges 10,000 for a tool changer setup.
my issue is how long would it take to pay for the upgrade?

[harold_weber]

Greg, the ATC setups I've seen need a toolholder, a collet, and a collet nut for each tool you want to change to. The collets are the least expensive pieces. Then you need an electrically operated air valve and a nozzle to blow chips and dust from the toolholders before you pick them up. You need another air valve to actuate the toolchanger mechanism on top of the spindle. Probably also want a local filter/lubricator/regulator for the air supply. Then you need to spend time and get all this installed and working properly.

Don't underestimate the time or the cost of the time. The rule of thumb that was used when I worked in industry was that for every dollar you budgeted for capital equipment, you needed to budget $1.50 for expenses to get the equipment installed and working.

[gabepari]

Steve, "Home" should be able to be where ever you want it. As long as the tool changer uses "base" coordinates for its routines. You can re-zero all over the table, and then return to the table base coordinates that you set with your proximity sensors.

Gabe

[knight_toolworks]

that would be pretty slow though right? I don't know ofr sure but a tool changer would be best if you never changed where the machine is zeroed.

[team08]

Well that is where my programming experience comes in (software engineer by trade). I already have a program written that keeps track of where each "station" is, and knows where the ultimate "home" is. It can change coordinate systems on the fly and keep track. Now if you lose steps, that is another story. So the additional cost is the logic/control of air? So slap on some relays (cheap) and air solenoids (~$100) and we are good to go! Sounds like I need to start making one and a little DIY page for this....

[stevem]

Tool changers work most efficiently when the tool holders are located on the Z axis. The second most efficient place is on the gantry, so that the spindle only has to move to the end of the gantry.

As for the pneumatic system to operate the tool gripper in the spindle, it only needs an output signal to open an air solenoid. Many hobby machinists are currently building auto tool changers for their table top mills. Since I just bought a couple of Taig mills, that's on my to do list.

[cabnet636]

ekstrom carlson has a quick change spindle, i looked into it runs 5500.00 before collets and parts, i am having another machine built with 10 hp atc and yes it's ten grand. the quick change was interesting because you preset z to a tool number set program to recognize need for tool # 3 then just snap bit in ( has a release pin) and move on i am convinced it would work with shop bot jim

[weslambe]

As most of you are aware, I built my own CNC machine after having 4 prior to this one. BTW, I still consider myself a shopbotter since they gave me my start.

I built my machine around the equipment that I had at the time, a colombo 5hp spindle. That said, I don't think that I would have added a tool changer for the money that it takes to do so. If I spend an extra 5-10 minutes changing bits per sheet it would take decades to pay for the tool changer by only saving those few minutes.

I have several friends with tool changers and they are fidgeting with them quite often. Sometimes I want one, but then I would rather spend the "extra" money on an in-ground pool for my kids.

[jdoug5170]

I think that I would consider a partial ATC...this means, get the ATC spindle and manually make the tool changes.

I seem to remember that we were able to release the tool holder holding tool with just the push of a button and then were able to insert the needed toolholder and bit. Quick and easy and we had already calibrated for Z axis when setting up..

Doug

[team08]

So I got a quote from HSD on a spindle with the changer and everything, so I am trying to figure out all the details before making the plunge. A VFD was included in the quote, an HSD DPL series. I do want to control the spindle speed from the shopbot, so I am wondering if it would be compatible with the shopbot Spindle Control Board? Looks like it specifically works with a Delta or Yaskawa VFD. Any ideas on compatibility? I am pretty sure I will need to control the ATC logic from the PC anyways (using DIOs on the shopbot) so I really think the VFD will ONLY be used to control speed. Not sure if any also incorporate ATC logic. I will try an post a flow diagram of what I am thinking later and you can comment. And yes, I plan on having all of this information as open source so others can follow my lead on ATC!

[thewoodcrafter]

I don't know for sure if things will be compatible but I would think so. Either a 0-5DCV or 4-20ma signal would be used. These are pretty standard control options.

You will have to turn the spindle or VFD off through the software for your ATC.

If you don't mind, what were you quoted for a ATC spindle and VFD? What HP were you quoted, 5HP?

[team08]

I think that the control board actually talks RS232/485 to the VFD. I just was not sure if I could use on of those VFDs (Delta or Yaskawa) with the HSD spindle I am choosing. Anyways, I will probably start a new post about the project but this is the hardware configuration I am thinking of thus far
8340

[joe]

There isn't a day that goes by when I didn't wish I had a TC.

Every time I look at a 3D file, I go into dream world wondering if I should bite the bullet. There is a need on most of 3D files for three bit changes. To save time, you have to be close by to keep everything running.

It's doubtful the casual router user could justify a TC.

Most of all, there's little knowledge about how complex these units are. I've seen what happens when one goes wrong.

I can't wait till I get one.

[marcus1234]

I have a 2 year old 4 X 8 PRT Alpha with a 9 position tool changer. I bought the machine used with the tool changer already on it.

It's seems pretty simple really. Your home can be anywhere. When it changes tools it just moves across the table until it hits the limit switches & then it sets the new zero for the tool change.

I'm not sure who wrote the custom commands, but they seem pretty simple . I have modified them to speed up the process. I've never timed it, but I think it takes under a minute to change tools. After it picks up a new tool, the new tool is already zeroed & it keeps cutting.

Works great. Don't know if I'd want to live without it.

I've only had the machine running since about January & most of this is still pretty new to me, but if anyone wants more info I'll try to answer the best I can.

[dubliner]

Somewhat off topic & I know its hardly even close to a tool changer, but what about adding bit collars to bits, Might it remove the need to zero bits ?

[steve_fedor]

What about this unit

www.midwestrapidtool.com (http://www.midwestrapidtool.com)

[khaos]

interesting that they have .sbp files... hmmm...

Has anyone used this? Hey ShopBot do you have an opinion on this product?

[billp]

Steve/Joe,
This unit was demonstrated at the Ohio Camp last year. if you go to the Flickr Camp page you can see pix of it in action;
http://www.flickr.com/photos/campshopbot/sets/72157602214378806/

[Brady Watson]

Toolchangers are affordable for those who actually NEED them - as in people who cut thousands of parts, with short cycle times and several bit changes during one setup. For 99% of the moneymaking jobs that you will do, a toolchanger simply can't be justified from a financial standpoint. Even for the price of a DIY toolchanger, you could still buy an entriely NEW CNC for the same price. In all reality, toolchanges take very little time...2 wrenches and a C2 command and you're back to cutting again.

I agree that the idea of a toolchanger is downright sexy and one of the crown jewels of CNC inner geekdom...but day to day logic and experience tells me that it is just something else to break, and even though I have cut well over 750,000 parts on my ShopBots, there was never a time I needed one...maybe wanted one on 1 or 2 jobs, but never needed one to make a job profitable. So...as a worker and moneymaker, I don't need one. As a CNC geek, I would love to have one, if for no other reason than bragging rights.

For companies doing production, nearly all of them are doing 2D operations - drilling (which should be done with a dedicated drill), pocketing, profiling, and most utilized - edge forming with a shaped cutter. 3D applications are near nil since 3D operations tend to have long cycle times and changing out a tool automatically doesn't really reduce overall cycle time compared to a manual change.

The Midwest Rapid Tool unit is nice if you want to appeal to your inner geek & are in love with a Porter Cable. My feeling is, you can spend a few grand on a toolchanger and still be left messing about with a Porter Cable at the end of the day. The PC is great to get you going if you don't have much $$$, but it really has no business being on a CNC in the 1st place, in my opinion & experience.

-B

[joe]

I come to this subject for a totally different perspective.

Since I'm not interested in, or ever will attempt to do high production, lord be willing, one shouldn't preclude that us artists couldn't save valuble time and money with a TC.

Bit changes are, for me, like diaper changes. Necessary, but glad to have it over with.

Most 3D files use three bit changes. The first for for area clearance, called rough out. Second is the little detail bits. Last is the profile bit which cuts the image free. Waiting around for this chore is just silly.

The past is behind us, so keep looking forward.

Joe
http://www.normansignco.com/workshop.htm

[knight_toolworks]

but 20,000 or more in time at 80 a hour you need 250 hours in bit changing to break even if you can change a bit in 3 minutes thats 5000 changes to break even.
myself I can only see it in a machine that was designed with it built into the design.

[erik_f]

If you look at it from a pure business standpoint, yes most people won't make their money back on a tool changer. On the other hand...if you running a business that is making money, and it is something that isn't going to hurt you, then I say, go for it. I might have a hard time putting a 20K add on to a 15K machine, but then again I really have no right owning a cnc machine anyway. I guess bit changes can be a pain in the ass if you are running a super busy shop and have to keep an eye out for when the machine is sitting still because the file for the current bit is done, but then again...I think its a good idea to keep an eye on my machine anyway. I think, however, the spirit of this thread is in the same spirit as the "open source vacuum". If one wanted to go through the pain and madness of making their own tool changer...could it be done on a budget?

[Gary Campbell]

Eric, et al...
You can do it on a budget, but I am afraid that it's going to be a large one. Even a "homemade" setup will still require a spindle that is a couple thousand more than most of us use. Add the drawbar pneumatics, filter, regulator and hoses for another grand. Without figuring the costs of a custom toolholder rack, each drawbar capable toolholder (replaces collet & nut) will be $175-$350 per bit, each tool holder cradle will add another $30-$50 per rack slot and add another $100 each if you want electronically verified tool removal and replacement in the rack. Add the neccessary programming and an air blower nozzle or 2 to make sure bits are clean before pickup, and you should be good to go. I am not sure if a separate ATC control board would be needed, but this may surely use all existing I/O ports on the SB board.

I will be happy to change a few bits for that kind of money. However, should someone care to UPS me the parts listed above and a big check, I would love to do the development. I would do this for the fun of the project 10 to 1 over the need for the finished product.
Gary

[joe]

Thanks Gary for posting this message.

Most people would like to have a TC. However, for many, it falls beyond the budget limits. Nothing wrong in that. My budget's limited too.

I've always felt a TC is a factory job. Left to people who know what they are doing. And with support.

Professor Chapman, he has few limits but he relishes bit changes. I've never quiet understood him. Nice guy though.

Joe
www.normansignco.com/workshop.htm (http://www.normansignco.com/workshop.htm)