[Emc-users] Fw: machine shop advice

[dave]

Begin forwarded message:

Date: Tue, 17 Apr 2012 06:43:13 -0500
From: John Thornton 
To: "Enhanced Machine Controller (EMC)"
 Subject: Re: [Emc-users] machine shop
advice


At least I can open up the stl files and view them in 3-D. There are 
several areas that are impossible to machine... they could be injection 
molded but not machined. Sharp inside corners in the Z axis are not 
machinable... if they have a radius they can be machined. The smaller 
the radius the longer it will take to machine as the tool would be 
small. I can only view a stl file and can't make a solid out of it...

Is there some reason you selected PVC as the material?

>From a plastics manufacturer:
. Materials that are resistant to bromine are few: titanium, fiberglass
reinforced plastic (FRP) and PVDF. PVDF was considered the best choice
because vessels made of FRP have been known to blister and fail
prematurely, whereas titanium is very expensive.

>From Cole-Parmer database:
Listed as very good; viton, pvdf, teflon, noryl, kel-f, hastelloy-c.
Ti was listed as poor. 

Another source listed stainless steel but did not recommend Ti

No one listed glass which is absolutely resistant to bromine but not
much of an engineering material. 

Clearly YMMV.  Good luck. 

Dave

John

On 4/16/2012 4:26 PM, Erik Friesen wrote:
> Ok, hadn't thought that far.  www.aercon.net/Public/Pumpitems.zip
>
> On Mon, Apr 16, 2012 at 5:13 PM, John Thornton
> wrote:
>
>> The dxf and pdf came through this time but too much detail is
>> missing. The alibre web site says the software can export to STL
>> which I can open.
>>
>> John
>>
>> On 4/16/2012 3:36 PM, Erik Friesen wrote:
>>> Try these again.The ad_prt is an alibre file.  I intend to get
>>> iges/step exporting, but currently only have alibre pe.
>>>
>>> For some reason, fireftp isn't doing its job, and was uploading
>> incomplete
>>> files.
>>>
 DXF
 PDF
 Alibre
>>>
>>> On Mon, Apr 16, 2012 at 4:26 PM, Joseph Chiu
>>   wrote:
 I've recently got a bunch of parts from FirstCut (Part of
 ProtoLabs, which started out as ProtoMold) that turned out well.
 Years ago, I used Rapid Sheet Metal for sheet work, and was very
 happy.  Their affiliate company, Rapid Machining, is working on a
 piece for me right now.  Their prices were better than FirstCut
 for 5-days turns, while FC was better for 1-3 day turns.

 With FC and RM, they used my exported STEP 214 files from Alibre.
 With FC, I use their online system to call out the threads.  With
 RM, I had a separate .pdf calling out my threads.

 Both places have a +/- 0.005" as a standard tolerance; but usually
 achieves much better than that.  FC only supports a limited number
 of threads.  RM appears to be more flexible.

 One thing about FC -- they claim they have a bed size limit of 7" x
 10" -- but it turns out for thinner parts, the supported bed size
 can be much bigger, depending on thickness.

 On Mon, Apr 16, 2012 at 12:46 PM, John Thornton
>>   wrote:
> Erik,
>
> I get invalid or incomplete for the dxf and bad file for the
> ad_prt file. Can you save the file as step or iges?
>
> thanks
> John
>
> On 4/16/2012 2:00 PM, Erik Friesen wrote:
>> The 3d pdf's created by alibre are a little flaky.
>>
>> DXF
>> PDF
>> Alibre
>>
>>
>> On Mon, Apr 16, 2012 at 2:47 PM, John Thornton
wrote:
>>> I can't see much on the pdf, do you have a cad drawing or 3d
>>> model of the part?
>>>
>>> John Thornton
>>>
>>> On 4/16/2012 1:42 PM, Erik Friesen wrote:
 Around 50 pieces each.

 On Mon, Apr 16, 2012 at 2:34 PM, Dave
 wrote:

> On 4/16/2012 1:35 PM, Erik Friesen wrote:
>> Has anyone here use e-machine shop, or anything like it?  I
>> am
 needing
>>> to
>> outsource some cnc work, but not sure where to go.  One of
>> the
>> guys
 on
> this
>> project had mentioned www.mfg.com, but I am pretty leery of
>> it.
It is
> all
>> plastic machining, pvc sheet.  Here
>> is one of three,
>> dimensions
>> are 4" x 2.35"
>>
>> --
>> For Developers, A Lot Can Happen In A Second.
>> Boundary is the first to Know...and Tell You.
>> Monitor Your Applications in Ultra-Fine Resolution. Try it
>> FREE! http://p.sf.net/sfu/Boundary-d2dvs2
>> ___
>> Emc-users mailing list
>> Emc-users@lists.source

Re: [Emc-users] Fw: machine shop advice

[Erik Friesen]

Its not pure bromine.  Its just enough to make some plastics brittle.  Its
in tablet form, so it is probably an occasional 10% ?? liquid?

Why the fuss over pvc?  It machines ok for me.  Its much better than uhmw.

On Tue, Apr 17, 2012 at 11:21 AM, dave  wrote:

>
>
> Begin forwarded message:
>
> Date: Tue, 17 Apr 2012 06:43:13 -0500
> From: John Thornton 
> To: "Enhanced Machine Controller (EMC)"
>  Subject: Re: [Emc-users] machine shop
> advice
>
>
> At least I can open up the stl files and view them in 3-D. There are
> several areas that are impossible to machine... they could be injection
> molded but not machined. Sharp inside corners in the Z axis are not
> machinable... if they have a radius they can be machined. The smaller
> the radius the longer it will take to machine as the tool would be
> small. I can only view a stl file and can't make a solid out of it...
>
> Is there some reason you selected PVC as the material?
>
> >From a plastics manufacturer:
> . Materials that are resistant to bromine are few: titanium, fiberglass
> reinforced plastic (FRP) and PVDF. PVDF was considered the best choice
> because vessels made of FRP have been known to blister and fail
> prematurely, whereas titanium is very expensive.
>
> >From Cole-Parmer database:
> Listed as very good; viton, pvdf, teflon, noryl, kel-f, hastelloy-c.
> Ti was listed as poor.
>
> Another source listed stainless steel but did not recommend Ti
>
> No one listed glass which is absolutely resistant to bromine but not
> much of an engineering material.
>
> Clearly YMMV.  Good luck.
>
> Dave
>
> John
>
> On 4/16/2012 4:26 PM, Erik Friesen wrote:
> > Ok, hadn't thought that far.  www.aercon.net/Public/Pumpitems.zip
> >
> > On Mon, Apr 16, 2012 at 5:13 PM, John Thornton
> > wrote:
> >
> >> The dxf and pdf came through this time but too much detail is
> >> missing. The alibre web site says the software can export to STL
> >> which I can open.
> >>
> >> John
> >>
> >> On 4/16/2012 3:36 PM, Erik Friesen wrote:
> >>> Try these again.The ad_prt is an alibre file.  I intend to get
> >>> iges/step exporting, but currently only have alibre pe.
> >>>
> >>> For some reason, fireftp isn't doing its job, and was uploading
> >> incomplete
> >>> files.
> >>>
>  DXF
>  PDF
>  Alibre
> >>>
> >>> On Mon, Apr 16, 2012 at 4:26 PM, Joseph Chiu
> >>   wrote:
>  I've recently got a bunch of parts from FirstCut (Part of
>  ProtoLabs, which started out as ProtoMold) that turned out well.
>  Years ago, I used Rapid Sheet Metal for sheet work, and was very
>  happy.  Their affiliate company, Rapid Machining, is working on a
>  piece for me right now.  Their prices were better than FirstCut
>  for 5-days turns, while FC was better for 1-3 day turns.
> 
>  With FC and RM, they used my exported STEP 214 files from Alibre.
>  With FC, I use their online system to call out the threads.  With
>  RM, I had a separate .pdf calling out my threads.
> 
>  Both places have a +/- 0.005" as a standard tolerance; but usually
>  achieves much better than that.  FC only supports a limited number
>  of threads.  RM appears to be more flexible.
> 
>  One thing about FC -- they claim they have a bed size limit of 7" x
>  10" -- but it turns out for thinner parts, the supported bed size
>  can be much bigger, depending on thickness.
> 
>  On Mon, Apr 16, 2012 at 12:46 PM, John Thornton
> >>   wrote:
> > Erik,
> >
> > I get invalid or incomplete for the dxf and bad file for the
> > ad_prt file. Can you save the file as step or iges?
> >
> > thanks
> > John
> >
> > On 4/16/2012 2:00 PM, Erik Friesen wrote:
> >> The 3d pdf's created by alibre are a little flaky.
> >>
> >> DXF
> >> PDF
> >> Alibre
> >>
> >>
> >> On Mon, Apr 16, 2012 at 2:47 PM, John Thornton
> wrote:
> >>> I can't see much on the pdf, do you have a cad drawing or 3d
> >>> model of the part?
> >>>
> >>> John Thornton
> >>>
> >>> On 4/16/2012 1:42 PM, Erik Friesen wrote:
>  Around 50 pieces each.
> 
>  On Mon, Apr 16, 2012 at 2:34 PM, Dave
>  wrote:
> 
> > On 4/16/2012 1:35 PM, Erik Friesen wrote:
> >> Has anyone here use e-machine shop, or anything like it?  I
> >> am
>  needing
> >>> to
> >> outsource some cnc work, but not sure where to go.  One of
> >> the
> >> guys
>  on
> > this
> >> project had mentioned www.mfg.com, but I am pretty leery of
> >> it.
> It is
> > all
> >> plastic machining, pvc sheet.  Here
> >> is one