What's the best way to produce this?

I need to design a fixture that holds two rods at 90 degrees to each other. It must be something that is very cheap to produce. I'd love to use a standard plastic tee but they don't produce 5/16" tees.

I imagine something like a plastic cube with two thru holes drilled perpendicularly to each other. The holes are offset so they don't intersect. Size tolerance for holes and their relative to each other position must be no more than +-0.01"

How much such a mold would cost? Can I expect a Chinese manufacturer to machine these parts really($0.20) cheap if I order 1000 pieces?

Fill free to express any opinion.

Thanks, Alex

Reply to
Alex
Loading thread data ...

Well, you could start with some data vital to the answers that you seek. How big or small is this object? Exactly, with tolerances. Where in this object do the holes need to be? Exactly, with tolerances. Size of holes? 5/16 by itself says nothing other than a generalization. 5/16=.3125. Press fit for rods, or slip fit? .311 +.001/-000? How about .312 +.01/-.001? Will size of rod be consistant so assembly will be satisfactory, or will some fit properly, some loose, some not at all? If you can be very specific, you will get reliable answers. Vague descriptions usually get answers that will make nobody happy later when the price goes up because some feature needs to be better.

michael

Reply to
michael

You can't build a mold for only 1000 units. I'd get some UHMW (machinable plastic), make up some holding fixtures and drill the holes.

The only way you'll get 1000 for $200 is if you do it yourself

Karl

Reply to
Karl Townsend

WHY?? we do it all the time its called a prototype mold some times for 25 pcs. Ray Mueller

Reply to
SMuel10363

The mold will be an insert mold and you also need to build a stripper for the removal of the insert parts from the plastic. In addition, you need to make several sets of the inserts to get the production rate up. For a few parts, drilling plastic will probably be the best way. That will be just a pair of jigs to hold the parts in place under a drill press You may also want to look about at various products and when you find something that has the right size Tee, go pester the maker for some extra parts. Their plastic parts probably either come to them in fair size boxes and that will probably mean thousands of them or they are making them inplant and you can get a few hours of production for a lifetime supply. I'll note that I did find some threaded Tees at one site when googling and I'd suspect that shoving a rod into there would provide a lot of retaining force although they will probably crack when they get old.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works evevery time it is tried!

Reply to
Bob May

Perhaps you'd do better asking in a Chinese group..

John

Reply to
JohnM

Come on, guys!

All he needs is a 5/16 Swagelock elbow or tee.

Good grief.

Yes, they do. Brass Swagelock or nylon Tubelock.

It's a drill press job. 20 cents times 1000 is 200 dollars. I can buy the acrylic cubes at Acme, although I would rather have Delrin.

Why? In other words, with function, funding, form, fit, and finish, in order, what is the function, and who is funding it?

Yours,

Doug Goncz, Replikon Research, Seven Corners, VA Unequal distribution of apoptotic factors regulates embryonic neuronal stem cell proliferation

Reply to
Doug Goncz

Mcmaster Carr sells such a fitting for $1.44 each - not your target price but there is no large minimum and you don't have to buy the tooling... If you need a thousand, call them directly and see about volume pricing.

Part number is 50775K121 for an elbow.

formatting link

As for manufacture should you need something not already available - you would be much better off having a local moldmaker build it and run them for you. Shorter wait times for simple tooling (no ocean between you, nor customs paperwork), plus the benefits of being able to talk face to face with the person who builds your tool. There is a huge value in being able to go to the die shop, show them what you need and dialog about how best to accomplish it.

SMuel10363 could probably get you all the information you want, just don't tell him you are going to bid it to his substandard competitors. =)

StaticsJason

Reply to
Statics

Doug Goncz wrote: ...

...

...

Below are a few hints about this item. Alex (Kuznetsov, alexkuzn@pacbell...) has been reticent about what it actually is and does, presumably to keep all of us greedy-bastard r.c.m readers from stealing his invention and getting rich at his expense. I once presumed it was a motorized food-processing device [use of stainless and wood parts] intended for mass production [hence his continuing emphasis on low cost and hiding the details], but now imagine it's a knife or tool linear sharpener, probably intended to sell on late-night TV at an irresistably-low cost, per thread

formatting link

-jiw

  • Has a 3"x4"x1" hard, stable, water-resistant engineered-wood piece bolted between two metal bars, per
    formatting link
  • May need sleeve or flanged bearings for low-stiction "start and stop low speed linear movements" while "working in presence of some small amount abrasive dust in the air" per
    formatting link
  • Might instead use 5/16" 303/304 SS-rod slides, about 8" long, with
5" long sliding tube with bushings at the ends, and shaft rotates 1-5 rpm and moves linearly 1-2 inch/sec., and the tube is mounted in a 1"- thick wall, per
formatting link
  • Considered "ball bearings with the U groove in outer ring" but decided "Turned, ground and polished shafts are expensive. Especially stainless ones." and "Shafts must be absolutely parallel and at precise distance which makes the manufacturing expensive." in the thread
    formatting link
  • Planned on bending 1/4" SS-rod --
    formatting link
  • Will do "hundreds of 1 inch threadings on 1/4 stainless rod" --
    formatting link
    etc.
Reply to
James Waldby

Remember McMaster Carr is buying their item off the shelf from one of their suppliers - dig enough such as order one part & ck. for mfr. i.d. - and you can go direct as your qty. is large enough for the mfr. to be willing to deal with.

Reply to
Ted Walker / Strategic Industr

Please let me know what is exactly(material etc.) the tee you found on McMaster. I can't find any 5/16" tees on their website.

Thanks, Alex

Reply to
Alex

Our experience has been similar. Some things are just as expensive as the local high markup hardware store, but for a certain subset they must buy in staggering bulk...

Hard to beat the convenience of the big yellow book for flipping through looking for advance solutions to tomorrow's problems. =) Quite a bit faster than looking through the shelves and shelves of individual catalogs even if it doesn't quite have the depth.

StaticsJason

Reply to
Statics

Read the posting again. url listed with an example part number.

StaticsJason

Reply to
Statics

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.