Broom stick threads
I have a project
A proto type of a paint roller type device and need the form and thread dimensions for the screw end broom stick
The customer had a drawling and the 3/4 -6 acme thread is wrong.
what I tried to reverse engineer from some threader sticks and nothing is a standard. all different some are 6 thread 5 1/2 and 5
The thread form the same too !
I look in the machinist"BIBLE" found nothing..
Can use some feedback on this
I think the length of engagement is the thing with the broom handle.
With 5 or 6 tpi and only an inch of "nut" that is a fairly soft material ie wood,
this is not too critical.The wood will deform to match.I would look at some existing paint rollers and see how their threads are .I have some rollers attached to old
broom handles.Pretty crude.
I think that some plastic moldmakers would probably know.
The ones in China ???
Originally Posted by rmsfla
Some broomsticks have a cast metal end now too.
I got a replacement handle a few years ago that was black plastic over metal thinwall pipe, with the cast metal threaded end -- and a hex ferrule to tighten it with. Got it at Lowe's in the bin with shop brooms. You might check there for something to model. It's fit a few different brooms well.
I went thru this a few years ago. After searching and trying various threads on different handles we came to the conclusion there was no standard. Even managed to talk w/ a custom tap & die company who said they had looked at the problem and could not come up w/ a standard. Now more and more they are making the threads from plastic or some form of alum./pot metal/ mystery metal.
We solved the problem by redesigning the attachment and us a clamp.
If you come up w/ a solution please post here I would love to see it.
'Bout 6 months ago I went through this nightmare of a special project of making a quite intricate device to fit on the end of a plain ol' broomstick handle. Customer had no idea what the handle was going to be made out of, but he absolutely needed that interface.
I can tell you that after testing approximately 20 different makes and models of female devices ( brooms, pushbrooms, cheap paintrollers, expensive paintrollers, polesanders, brushes and you name it ) by far the most were the closest to a 3/4-5 ACME.
The only problem was that using the ACME thread specs, they did not tighten up. My app was 1" deep blind hole, so imagine the chip issue.
Nonetheless, what I came up with was to reduce the major dia by .02 and give it a 5 degree taper.
Since the handles are made of all kinds of garbage using all kinds of garbage specs ( if any ), the taper had allowed something ( and I could not care less what part of ) the thread to lock up and tighten.
Anyway, this was my experience with the broomstick female thread. Straight bore, .02 under spec for the major and a 5 deg. taper.
If this is an internal application, I've found Micro100 the only supplier of a tool which can fit inside the bore and create the thread. Found no taps or threadmills to make a blind 3/4-5 ACME.
And lastly, my app was in Aluminum. If you have steel or anything else, either walk away from it or kiss your butt goodbye! This thing is one deep thread for it's size and the tool!!!
Sorry guys, I've just checked my notes on the program and noticed that the minor dia also had to be opened by .03! Still straight bore, but .03 over the spec.
Courtesy of ME Thread Pal, these are the specs I've used a starting point:
Minor Diameter Min,0.5500
Minor Diameter Max,0.5600
Pitch Diameter Min,0.6500
Pitch Diameter Max,0.6562
Major Diameter Min,0.7700
Major Diameter Max (Ref),0.7900
Flat At Root,0.0690
Thread Height (Basic),0.1100
Last edited by SeymourDumore; 10-28-2011 at 09:45 PM.
Reason: Update of comments
Is it possible that they purposefully get the threads off on the handles? The soft material would make up the differences but mostly the threads would bind a bit more fully engaged, helping to keep your paint roller tools from spinning off too easily if a bit loosened.
I don't know how useful these links are but they might be worth a look.
Originally Posted by rmsfla
Wood Thread Cutting Tool
The Beall Tool Company
Wooden Broom Handle Stick America screw/thread products, buy Wooden Broom Handle Stick America screw/thread products from alibaba.com
The thread on this looks like most of the threads I've seen on wood. It looks like a tapered Rd (round) thread. i.e. a knuckle type thread
International Thread Standards
I bought one of those wood threading kits in the early 80's. Back when Jerry Beall was working out of his basement. Worked surprisingly well. Still got it, just don't use it anymore. Back then, the whole kit was 100 bucks. Once set up, you can make some serious threads. Instead of scraping the wood, the router ''machines'' them. Excellent results!
I think alot of the problem is propriatary, they want you to buy their device and their handle to mount it on.Most will work if you twist their tails enough. Frank C.
Originally Posted by SeymourDumore
Thanks Guys for all the help,,Made a automatic taping machine for wooden blocks
Made the tap up and it works fine.
The fit was "just right"
how about using a taper either with a spline or draw bar type mechanism, or how about a taper on a square shaft? you might need a cam lever or a threaded nut to pop the two apart. . The regular threaded extension handles allow the roller to rotate. Many times I have shot a screw thru these connections when doing serious painting.