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Anybody ever used the injection machine being sold here:
mediummachinery dot com (sorry, can't post web addresses as first post)
Looks like it's got good features for being sub $3000. I've never injected molded before, does this look like a good machine for short production runs of less than 1000 items?
Anything else comparable?
I can't say either way as I haven't tried it, but it is one of the ones I've been looking at myself for future projects due to the Max Mold Size(8x8x4) and Shot Capacity(2oz).
But at the same time look at pics of it I can't help thinking it might me cheaper for me to just buy the right parts and self assemble, because the frame work for the machine seems very straight forward(my dad actually has something VERY similar in his autoshop)
Mike
Hi,
I haven't played with the Medium Machine but I know the guy who make the LNS machine at LNS Technologies High Tech Products for Hobby, Education and Business, (disclosure: I make molds for him). I know the LNS machines work. They have good temperature control and cost less. Smaller shot size, but very flexible with mold size -- just about anything goes. The Medium design worries me a bit because it generally is good to inject quickly, and it looks like the machine injects slowly. But on the other hand, it should be good at packing the mold because of the high injection force.
Peter
I was actually thinking of getting that machine, and ordering it as a stop-gap since it's so inexpensive. I was also thinking of ordering a mold for the part I have designed until I can learn how to make molds on my own (and buy a cnc machine).Quote:
Originally Posted by Peter H
How much do you charge for molds Peter? Do I just send you a 3d model and you design the mold, or do I design the mold? Final question, once you CNC out a mold for a small part, how do you remove tooling marks? I was thinking glass bead blast, but I've never made one.
Hi Briphi,
If it is a straightforward, small part, then $500, but it varies. It is less often that they are straightforward. Injection molding has its own learning experiences. It is kind of given if you are on CNCzone you have aptitude for this sort of stuff. As you look around, you see plastic parts everywhere proving that a lot of people have figured the process out (but you probably also have had plastic parts fail proving that some folks didn't figure it out very well).
For parts to work in simple molds, they must have tapered sidewalls and no undercuts. It is possible to do undercuts but then the molds get complex. The part generally needs to be designed with the mold parting line in mind. There are a huge number of polymers available with different properties. The mold has to take into account material shrinkage if the part has to interface with other dimensional parts. Molds often are designed to specific materials or families of materials. There are several good resources on the web with design guidance for molded parts from a couple moldmaking/injection molding houses.
Finish requirements affect mold cost. If the part is used in a visible application, then mold finish is important. The material choice affects the finish needed too. No matter how well a mold is finished, a thermoplastic rubber part will have a matte finish (ever see a shiny rubber part?) so molds for those materials don't merit a lot of polish. On polishing, I do a lot of passes on the mill to get as good a surface finish as possible, then it is mostly thumbs and sandpaper (bless our technically advanced society). The Foredom and Dremel help sometimes. Blasting can be done if rough texture is desired. With a lot of polymers every surface flaw in a mold will be faithfully reproduced in every single part.
Having a good part design saves me time and saves you money. I work in Rhino which is good for shapes and curved surfaces. The native files are 3dm, but I can import a number of different file formats. Step files have worked well. Stl files sometime look a bit faceted from the mesh vertices. I design, fabricate, and sample the mold (provided the polymer is a common one or if you supply material) and will send you samples for approval. Upon approval you get both the mold and the g-code to make the mold. With the g-code when you get a CNC mill you will be able to reproduce the cavities. Terms are 50% down and 50% upon approval of parts prior to shipment of mold. Everything is done in the US.
Our first step is to execute a short non-disclosure agreement to protect your intellectual property. Then we can discuss the part and from that generate a quote.
Peter
Has anyone heard about Yizumi? I heard very bad machine and service. Don't know if it is rumor or truth. Can anybody confirm?
Don't buy Yizumi machines, ever!
I have been using Medium Machinery for about 5 years now made thousands of parts. Can't say enough good things about this machine it's Awesome, I did update a few things like added a gravity feed hopper onto the machine and an easier way of locating the molds . but these small updates you can get to over time to suit your needs.!