Automated Mold Polishing

[Surfasys]

We are designing a new Polishing Machine specially designed to make automated Mould Polishing. Is there any people with good know how about polishing and machining of mould who would likes to give their opinion on the projects.

I love to share with you our idea and of course some questions.

Regards

Srurfasys

[MrMold]

I'll take a look!

[Surfasys]

Many Thanks,

Our Idea is base on Moulding a Tools inside the pre-machined mould (By EDM or Milled). Following that step we have a unique EDM Process that make the polishing. This EDM process is slightly different than curent EDM. We are using EDM in the air allowing very small spark energy so small crater and so on better surface finish.

Are you very knowlegable about Mold polishing work?


We have some questions

[spider]

how high of polish are you trying to get?

What would be an advantage of your machine?
I mean; you have high initial cost to buy another edm machine...cost of producing a carbon (carbon that you have to mount, cut, sometimes polish, QC)....carbon for entire part (like a bumper or facia??) and then pay a guy to stand there and watch it it (since this is fussy work).....lots of edm time....

On top of that i bolive there is a reason why handman polish the part in the direction of pull.


The only way it wold make sence is if it was a regular EDM machine that had the capability to produce high finish....and if it was to be used in condjunction with High speed CNC machine.

our High speed CNC, keeps on impresing me....I just love how the mold looks when it comes off....it's to closest we got to no handwork.

[Surfasys]

Very good remark, very smart,

Our technology is different, there is no need for Electrode or tool manufacturing we are using the your mold to manufacture the Tool. So it looks similar to what you are saying.

No need for machining,
Noneed for electrode polishing.

Regarding speed we are targetting 20min/sqInch for polishing from C3 to B1. Is t enough fast.

Q. What is the actual finish that you are currently having using your HSM and who is the manufacturer of this HSM.

[ImanCarrot]

What's the material for the mold tool plaease? if it's non- ferrous then I'd go for Diamond Machining- it'll produce an optical quality finish and can generate aspherical surfaces as well as sperical.

Send me a sample blank and drawing and I'll machine on for you if you like

[SORCHEROR]

lablond makinos cnc edm has a special fluid that pumps into the tank after the edm process than uses the electorde to polish the cavity,very high finishes acheived im told,but the costs are high and the time is lengthy,better machining finishes and a good hand worker is cheaper,the new high end edm machines finishes are good enough on most molds,we dont even need to polish most things,the small ribs we use ultrasound polisher on it
have you done any polish with this new process yet?
let me know
steve

[Surfasys]

I have been told by Makino engineer that their machine doesn't sell much because of price, but also because of the effect of the particules in the oil (actually Silica) that have an abrasive effect on mould corner and most Mould Makers in Japan are insisting on the sharp edge. Small details are also affected.

In the case of Makino you also need to machine and polish the electrode. In the design we are working on rigth now we are using EDM in the air so no rounding of the corners or details fading and the Machine would be substantially cheeper than a Makino machine.

Our tool is thermo-formed Carbon. It is thermoformed in the Mould that need to be polish so no need for Electrode machining or polishing.

What about Diamond machining? do you have a machine manufacturer name I like to check this technology.

Thanks

[spider]

Originally Posted by Surfasys Very good remark, very smart, Regarding speed we are targetting 20min/sqInch for polishing from C3 to B1. Is t enough fast. Q. What is the actual finish that you are currently having using your HSM and who is the manufacturer of this HSM.

i'm not sure C3 & B1 mean (I'm not a polishing expert ). but i do know that most of the stuff (95%) we polish up to 300 grit. The rest is eather specified by customer or grained (chemical etching?)

the high speed we have is this one;
http://interactive.fptindustrie.com/...3?OpenDocument


20 min/sqInch? I'm not really sure how that compares with current practices (again, it's not something i'm involved in.)

[Garypl]

Originally Posted by SORCHEROR lablond makinos cnc edm has a special fluid that pumps into the tank after the edm process than uses the electorde to polish the cavity,very high finishes acheived im told,but the costs are high and the time is lengthy,better machining finishes and a good hand worker is cheaper,the new high end edm machines finishes are good enough on most molds,we dont even need to polish most things,the small ribs we use ultrasound polisher on it have you done any polish with this new process yet? let me know steve

Yes, I have done this and it is pretty cool. It can generate a very fine finish like #2RMS 35 minutes for 1" area)
some things to consider though.
1. you need a electrode for every shape and each detail that is EDM'd.
For the very fine detail mirror or A finishes, each electrode needs to have a mirror finish, that requires additional time just in trode making. For the very fine detail better graphite is a necessity, Poco AF series is absolutly needed.

2 This type of machine is specialized Mits and Makino both have this technology but they cost 150k plus the additive is relatively short lived and costly to maintain. I believe that they make way more money burning in the B type finishes (10 +- minutes per 1" area with just a basic electrode non directional finish) or just standard finishes that require no trode polish.

3. Every EDM creates a hard surface called recast, yep lots of arguments here but it is there to some degree. These machines do have a very fine recast layer. Every surface that needs manual polish should have a vapor or bead blast. A very low pressure with fine grit will not harm corners but removes this, you will not believe how nice your polishing will go after this.

4. A good polisher still may be required. After all the trode polishing and care in handling of those precious trodes, you will find that not all of the detail will be perfect and those areas, small they may be, still can be molding issues.

[Surfasys]

Originally Posted by Garypl Yes, I have done this and it is pretty cool. It can generate a very fine finish like #2RMS 35 minutes for 1" area) some things to consider though. 1. you need a electrode for every shape and each detail that is EDM'd. For the very fine detail mirror or A finishes, each electrode needs to have a mirror finish, that requires additional time just in trode making. For the very fine detail better graphite is a necessity, Poco AF series is absolutly needed. 2 This type of machine is specialized Mits and Makino both have this technology but they cost 150k plus the additive is relatively short lived and costly to maintain. I believe that they make way more money burning in the B type finishes (10 +- minutes per 1" area with just a basic electrode non directional finish) or just standard finishes that require no trode polish. 3. Every EDM creates a hard surface called recast, yep lots of arguments here but it is there to some degree. These machines do have a very fine recast layer. Every surface that needs manual polish should have a vapor or bead blast. A very low pressure with fine grit will not harm corners but removes this, you will not believe how nice your polishing will go after this. 4. A good polisher still may be required. After all the trode polishing and care in handling of those precious trodes, you will find that not all of the detail will be perfect and those areas, small they may be, still can be molding issues.

Dear Garypl,

Did you get 2rms finish in 35 mn per 1¨ Area by starting from a D3 machining or by starting from Zero milling.
1- How many electrodes you may need to get so exlcelent finish. Whats the price of those AF electrode. Do you know how long it takes to polish the electrodes.
2- I heard that AGIE has one as well.. But I also heard that the price is more around $240k, I may be wrong..

Many thanks for replying, it is really interesting.

[Garypl]

Dear Garypl,

Did you get 2rms finish in 35 mn per 1¨ Area by starting from a D3 machining or by starting from Zero milling.

(We started with a milled surface usaully for every surface - pocket and some times we used cutters as small as .015" Diameter down achiving at least 32 or better finish. I always used 2 electrodes for all burns and added one for "HQSF"polish.
The first was stopped at a 10 Umrmax. this was a standard for large surface area large metal removal. Exception (1), for small areas like those < 1" square trode we stopped at 14 Umramx. This was always followed by a second trode reguardless of finish requirements and stopped at 10 Umrmax. Exception (2), depending on the amount of hand electrode polish and the amount graphite removed by polish we might use this second trode for a couple of minutes of High Quality Surface Finish ("HQSF" polish). For high quality surface finish we would add one more trode (Note *Identical and perfect polish is required for this exceptional finish) and burn from 10Um to 4Um plus into HQSF for the required time per surface area of graphite and add .001 to the finish depth. This depth change allowed the absolute contact of the trode during polishing.
Ok, we always checked our first burn and if necessary change of process and possibly but very rarely added one more trode. I believe that the few times I did add the Fourth trode it was because of problems of consistancy in electrode size because of polish or coolant heat problems. When achieving such high finish any small area really shows up..)
1- How many electrodes you may need to get so exlcelent finish. Whats the price of those AF electrode. Do you know how long it takes to polish the electrodes.
(Read above, one more, almost always.)
2- I heard that AGIE has one as well.. But I also heard that the price is more around $240k, I may be wrong..
(our machine was exactly that much 5 years ago, don't forget to expect a very costly additive to your coolant)

Many thanks for replying, it is really interesting.

If some of the terms used are not making sense just ask, tell me what machine type you are using or what details you would like I will get much more detailed. Once again, I feel that this technology is best used for lesser surface finish. It was easier to achieve an "A" type finish , add only a few minutes to each burn and still hand polish. Every burn that makes up a cavity has multiple burns and just a .00005 differance in trodes or depth makes steps and most all efforts usless for a smooth finish.