RE: 1/4-20 thread?

From: will pattison (
Date: Wed Mar 24 1999 - 16:32:44 EET

i have never actually built any threads finer than about 3/4-16, but i am
speaking from several years experience as a dtm applications engineer, and
more recently as a user of sanders, sla, and sls. given that the nominal
laser beam diameter in the sls process is 0.010"-0.020" (depending on
process parameters), and that the melt zone it creates will be similar in
magnitude, you quickly run into resolution problems with features like a
1/4-20 thread. the beauty of sls, though, is that it machines so well.
 so, save the hassle, not to mention the cad time to create the thread in
the first place, and just drill and tap that sucker.

remember, the key to rp success is first understanding your fundamental
prototyping requirements, then picking the right tool for the job...


-----Original Message-----
From: Doug Bucci
Sent: Tuesday, March 23, 1999 9:57 PM
To:; 'Ray Brandes'
Subject: Re: 1/4-20 thread?

In response to you & Ray Brandes, I want to build both the male & female
threads in my jewelry
that will eliminate my need for commercial hardware & fasteners.
I am also interested in why you are dissatisfied with the your result of
building threads in SLS?

Thanks Again-
Douglas Bucci

PS-I would like to thank everyone for their responses.

My MFA exhibition:

-----Original Message-----
From: will pattison <>
To: 'Ray Brandes' <>; Doug Bucci
Cc: <>
Date: Tuesday, March 23, 1999 12:41 PM
Subject: RE: 1/4-20 thread?

>i doubt you'll be satisfied with the result making this thread directly.
> other than with sanders and maybe actua, you will have a hard time
>creating this thread in any rp machine.
>you didn't say if it was male or female, but either way, i would recommend
>a secondary process. if it's female, model in a pilot hole, then drill
>tap post-build. sls nylon materials machine very well, so you should have
>no problem.
>will pattison
>product development engineer
>4d design
>-----Original Message-----
>From: Ray Brandes
>Sent: Tuesday, March 23, 1999 9:49 AM
>To: Doug Bucci
>Subject: Re: 1/4-20 thread?
>I assume it is a 60deg V thread, but is it male or female? What class?
>Make the male body .25" diameter to the theoretical sharp point then
>remove .001 to .002 from the diameter.
>Make the female the same .25" to the theoretical sharp but add .001 to
>.002 to this.
>Does it have to fit an existing part? Can you make it heavy and then run
>a tap or die on it?
>Doug Bucci wrote:
>> Hello, I need to create a 1/4-20 thread in SLS can anyone provide me
>> with the minimum tolerances for creating this? Thank you,Douglas Bucci
> << File: ATT00002.html >>

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