Another RP service provider

[Hauk]

To be honest, I have been a little disappointed by the finish of the Print-a-Part samples. Dont get me wrong, people are making them into great models, but I would love to avoid the need for priming and sanding.

So I took a look around for alternatives (with a little help of Google), and I found this servic provider:

http://www.rjmrp.com/main/

From the sample images, their products look really promising. Their SLA parts look smoother than those from PAP. And in addtion they offer other services as well, take a look at their wax-masters made by CNC-milling. If you are going to have parts cast in brass, CNC-milling looks like a good alternative to printed parts.

I havent gotten around to getting any quotes from them, but It would be interesting if anyone that have already had parts made by PAP requested some quotes for the same parts from RJMRP.

[finescalerr]

The samples look as though they require almost no cleanup. Even a price twice as high as Print-A-Part would seem reasonable given the savings in time and effort. Thanks, Havard. -- Russ

[Fred H.]

I spent the better part of half an hour on the telephone this afternoon with Travis @ RJM Rapid Prototyping (RJM).

Here's the bottom line: RJM may be a better way to go IF you're planning on making multiple castings. The way they work is you upload a 3-D file using their software and you get a quote. You do this a PART AT A TIME. They don't want files like those that Marc and Chuck have sent PAP (multiple parts on "sprues.") AND, your parts must fit inside a 2" x 2" x 2" cube. What you get in exchange is "double or triple the resolution," which could eliminate a lot of cleanup/sanding.

There are other considerations as well and I'm not sure I understood them clearly. However, this DOES seem to be another option for us to consider. I gave Travis a heads-up about our on-going discussions here and he may chime in.

[marc_reusser]

Fred,

thanks for looking ito this. Interesting, since they are doing a part at a tim, does that mena they are CNC-ing it rather than printing it.....or is it just that the single part helps keep a higher resolution file size more managable and printing/machining time down.

Did Travis give you any idea on the costs associated with the service...or how they calc the costs?

Marc

[Hauk]

Fred,

thanks for looking ito this. Interesting, since they are doing a part at a tim, does that mena they are CNC-ing it rather than printing it.....or is it just that the single part helps keep a higher resolution file size more managable and printing/machining time down.

As I understand it, they have three different processes for making parts.

1. Stereolithography. For this they use a Viper Si2 machine. Stereolithography is an additative process where you build up the parts layer by layer. I belive this is the same process  PAP uses. 5X5X10 inches maximum build in hi-resolution mode.  In standard mode, 10X10X10 inches maximum build.


2.Photo Polymerization. For parts of this type they use an  EnvisionTec Perfactory machine. This is their cheapest option, in their own words it is far less precise than their SLA systems. This is an additative process very similiar to SLA. To be honest, I havent really understood what is the main diffrence between the two.


3. CNC-machining. This is an subtractive process where they machine parts in wax on a 5 axis machine, and something entireoy diffrent from the two other processes.
Wax parts can only be used as casting masters, they can not be used as final parts. From the wax part a brass master is cast. The wax master is destroyed during this process. This is classic lost-wax-casting, and it is nothing special for RJM.
It seems that RJM offer only CNC-machining in wax, but there is really no reason that  parts could be machined in materials like wood, aluminium, brass etc.
CNC machining gives the smoothest surfaces.
I am pretty sure that the 2X2X2 inches cube limit is for parts made by CNC milling.

Judging from the images on their homepage, all processes give excellent results. But it would be very nice to see a side by side "Real life" comparasion of  parts made by diffrent techniques and by different providers.

[lab-dad]

I'm surprised by the CNC 2" cube limit.
You can get a Sherline mill with CNC capable of much larger.
And it is not that expensive....relatively speaking...(about $6000 US)
-Mj
still making parts one at a time with handwheels and a micrometer......

[JohnP]

RJM seems to have the three big choices. The photo polymerization does not have as many users based on search hits, but is capable of very fine work. It must be expensive though- it seems to be used in many tiny medical type devices. Also, check out where they are buying their CNC mini-machines:http://www.minitech.com/. Any of them would be a nice addition to the workbench.

Meanwhile, I had a difficult time seeing the pendant on Jessica Alba. Need more resolution.

John

[Fred H.]

I forgot to mention something important! Travis at RJM told me about this OTHER company...

http://www.materialise.com/

They apparently have a VERY useful STL analysis tool. Catches lots of problems. Will try to look for it tomorrow. A cursory analysis didn't uncover what I was looking for!

Fred H.

[marc_reusser]

Fred,

Interesting there are a lot of different options/ways they do the printing....though after only lightly browsing the site it kind of feels like it's overscale/overkill  for what we are after .....

Apparently they are headquartered in Belgium. 

I registered and tried to get a quote, but was not able to....the whole process was a real PIA and did not seem to work smoothly, if at all...so after 3 tries I gave up.


Marc

[marc_reusser]

I got it to work and below you can see the quote.  ....for the exact same part that I sent to PAP.

It also was telling me that I have a "Merged Parts" issue....could be because I have a lot of seperate components in the drawing that are in contact witheachother or as part of a group...not exactly clear on the concept. But maybe that affects the price....but you will note that the quote also states that this is the "Min. Price for a Quote"....does that mean that you can't get any less cost-wise?...can't say. I have left it at this.


Here is the link to the STL analyzer info: https://nextdayoqaos.materialise.com/help/onsite_demo/help/OnSite_Help.htm#Welcome.htm

Marc

[marc_reusser]

Here is another company that does printing:

https://www.redeyeondemand.com/Default.aspx


Will see what they come up with for a price. They also have an STL analyzer program (you need to download it and check your model with it before they can give you a qoute.)


Will let you know how it goes....so far though PAP has by far been the easiest and most intuitive one to deal with.


Marc

[Hauk]

I'm surprised by the CNC 2" cube limit.
You can get a Sherline mill with CNC capable of much larger.
And it is not that expensive....relatively speaking...(about $6000 US)
-Mj
still making parts one at a time with handwheels and a micrometer......

Remember that this is milling with extremely small endmills on  5-axis systems. That fifth axis is turning the workpiece while being machined, and this also limits the area of milling.
Myself, I have done CNC-milling with as small as 0,3mm diameter endmills, and  with mills this small you have to make extremly light cuts. With the resolution and surface finishes RJM offers, I would guess that their endmills are even smaller, and the amount of material you can remove in one pass must be paper-thin.  

The milling option is clearly aimed at the Jewellers marked where masters are small and demands for resolution and surface smothness are high.

[Hauk]

I got it to work and below you can see the quote.  ....for the exact same part that I sent to PAP.

Wow, that was not cheap... even with the weak euro that is serious money!
I think you already has told us this, but how much did PAP charge for the same part?

-Håvard

[marc_reusser]

Havard,

The PAP charge was $37...plus shipping.

Below is a screenshot the quote/invoice.

[marc_reusser]

OK...I did the process with "Redeye"

Downloaded and installed their ST. slicer and analyzer and ran it through [See first image below]...apparently my model was clean and fine, however the thinness of my walls brought up a pop-up that it would need final evaluation at Redeye before going to print.

Then I requested the quote. [see second image below].....about the same as RJMRP....and as you can see, using the same material as PAP, the part would cost me $76....BUT....I get hit with an additional $74 charge.....because they have a min. order of $150.

This vendor, like RJMRP also seems like it is overkill and not really meant for our basic needs.

Despite the higher prices from RJMRP and Redeye, they do have a much greater selection of materials, printing and finishing options, so though they may not really be applicable to our small part needs that we are discussing, they could well come in handy for larger items, or work related items........especially since it has now been shown that converting a Google SU file through CAdSpan to an .STL, will print with no problems from these companies.


MR