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Anyone know where to source an acme threaded rod locally/Canada?

Jimbojones

Jimbojones

Active Member
btw - Thread moved here from 'off-topic' area

On the hunt for a acme-threaded rod; trying to find a supplier in Calgary (or Canada) that has these on-hand.

Specs are as follows:
3 ft long
1"-10 RH thread
B7 alloy steel

Tried a number of suppliers I already get assorted metal from e.g. Metal Supermarket, Brafasco, Gregg's, Calgary Fasteners, Quest...nada.

I can get it from US but shipping/exchange makes it unattractive and some of my US suppliers have stopped shipping to Canada since business had dropped off.

Any places that I should check out?

fwiw - not interested in making one since it needs to accurate and the proper grade of steel/hardened
 
I bought a 3 foot length of 1-1/4" left hand threaded rod at the Bolt Supply House in Edmonton. They had to order it but it only took a week to get. It was about $40.
 
1-10 Acme thread w/ B7 spec metal? Not for $40 unless it was discontinued stock...found 1 place in Calgary and they sell it for $67/ft (yikes!)
 
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That was a good lead. Called them and they had 1"-5 on hand...is trying to source some 1"-10 so will update with whatever they find out.

I did have someone else call me back and they could get it....but min. 12ft length for $300. Per foot price was much better but can't justify wasting 3/4 of the material....anyone else want to build a lead screw from some of this rod?!?

UPDATE: Blackfoot Industrial could get it from Keystone in the US but needs $100 min order (piece is $50). Brian @ Blackfoot was easy to talk to/understood...would recommend them for other orders.
 
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Strange that this rod is so hard to find locally; 10TPI acme isnt uncommon, especially when you consider its used for a lead screw for a manual machines with SAE dials e.g. 10 turns = 1 inch.

So, I've updated my question:
1) anyone know of someone in Calgary that may actually stock this?
2) anyone else interested in some 1"-10 acme rod for stock/project, etc? I'd then buy a longer piece and get much better pricing...
3) or...does any know of somewhere in Calgary would stock 1" ball screw rod? I have no idea if you could get something with a 10TPI pitch but that would be a better solution since it inherently has less lash
 
I haven't done any builds requiring something like that, but just a gut feel that would not be a real hot seller in Calgary & maybe explains the lack of stock. I know its not what you want to hear, but lots of hits in USA or the CNC kit build suppliers through China. I found this link at 13 $U/ft., but of course exchange, shipping, dinger fees & time... If they ship to Canada by USPS you might be in the ballpark assuming they cut to length.
http://www.roton.com/Mating_Components.aspx?family=7059495

Ballscrews, from what little I've seen/know are very spendy in that diameter/length. Using same reference they sell 1" OD x 4 tpi for 39$U/ft
http://www.roton.com/Mating_Components.aspx?family=7059343
 
Another thought - what you are seeking is essentially a commercial lathe lead screw. Might be worth a shot to see how much a replacement part for matching 36-40" lathe would be? Again, might not be an 'in Calgary' solution, but maybe Canada. Maybe a call to Modern Tools or Busy Bee to see how much a spare would cost for their lathes. Sometimes people bend the lead screws with bad strapping practice during moves, so might be something they stock.
 
Jimbojones said:
$300+....already checked in to that avenue. Just about fell over...
Click to expand...
Thats too bad..

PeterT said:
Another thought - what you are seeking is essentially a commercial lathe lead screw. Might be worth a shot to see how much a replacement part for matching 36-40" lathe would be? Again, might not be an 'in Calgary' solution, but maybe Canada. Maybe a call to Modern Tools or Busy Bee to see how much a spare would cost for their lathes. Sometimes people bend the lead screws with bad strapping practice during moves, so might be something they stock.
Click to expand...
Very good thought though!

Isn't getting one machined a potential option? I personally haven't tried threading Acme, but it should be a pretty straight forward threading job, shouldn't it? Just need the right type of rod...

edit: 3' might be an issue for home lathes though...
 
Our F.T. real machinists are better to comment on real world jobbing prices, but I'd guess by the time you purchased/compensated the appropriate rod stock, had a machine shop set up & cut threads, 2-3 hours total time and/or Min charge... a finished $300 replacement lead screw might look like a deal. I'm really not qualified to speculate. I thought that lathe lead screws were precision ground, not just turn-threaded. But maybe that varies by lathe?

I'm also not clear what this particular project requires. A material/thread was specified but tolerance was not. Is lead screw overkill & 'threaded rod' is sufficient? This link specs +/- 0.0003 inch 'lead accuracy'.
http://www.3ders.org/articles/20151...inter-and-upgrade-to-a-lead-screw-z-axis.html
I'm guessing that term relates actual : theoretical pitch per lineal inch of screw? That's pretty tight if you ask me & maybe explains the cost. Another thought - a jobbed out lathe threading operation could only replicate its own lead screw accuracy. If its a worn out Betsy, it will faithfully replicate that on your machined lead screw. I can't see how it can improve to a tighter spec unless CNC lathe with compensation?

Example (not sure if this is correct but something to check out on your own).
A) 'good quality spec' lead screw like link: 400 turns of 0.1" pitch * 0.0003 in/in = +/- 0.012" potential linear deviation on 40" of traverse travel
B) 'lower quality spec' guestimate 0.001 in/in for die cut or rolled threaded rod. Same calculation yields 0.040" (40-thou) over same 40" traverse. Is this reasonable? I have no idea. I tried searching on threaded rod tolerance class but didn't find much. Just lots of links like this suggesting for precision positioning, one needs to up the game from threaded rod.
http://www.3ders.org/articles/20151...inter-and-upgrade-to-a-lead-screw-z-axis.html

I'm assuming because of hefty 1" diameter requirement, this is a big boy lathe or mill or ? Ball screws assemblies seem to be getting very reasonably priced & accurate, negligible backlash etc. but most of what I see in CNC kits is smaller OD & shorter lengths. Or its entirely CNC driven & maybe they can overcome this tolerance with some software compensation? My understanding is you would not want ball screws for a manual machine because they could self feed under cutting pressure because of nil sliding resistance (without perpetually locking down the carriage every pass.). OK, I've officially depleted my hack amateur knowledge level here. If I'm off base let me know so we can all learn. Be interested to se what you come up with.
 
this is my two cents, if your using it for a lead screw on a lathe you don't required any special alloy if your half nut is brass
a ball screw would not work.
 
Here's some info that folks might find useful:

1) a good rod is rolled, not machined, not ground. It is an unthreaded rod that has the the threads literally pressed in to it by rolling dies. This has the affect of work-hardening the threads during rolling to increase their lateral strength and wearability. These guys mention their 'custom' service but the process also applies to non-custom rod
More info: http://www.keystonethreaded.com/custom-roll-threading-services.html

2) an alloy steel is necessary due the to the pressures put on the rod, regardless of the half nut material. Dis-similar material between rod and half nut is a good idea but that inhibits galling only. There is a reason why you can buy acme rods in numerous materials and for machine use, 4140 B7 spec is what is manufactured/used, not carbon steel/stainless/aluminum/etc. This type of rod is somewhat 'pre-hardened' and when you put it through the rolling process mentioned above, makes a nice machine-grade rod that is suitable for repetitive/machine-level use

I 'm sure the import tools makers may not use that spec but that also explains why their machines start exhibiting additional lash after light usage

3) C2 spec (self centering) thread is required to reduce binding/lash. Again, this is an actual spec for acme rod in machine use and you won't get that spec from 'off the shelf' threaded rod

4) ball screw conceptually would be nicer but as folks have pointed out, does not inherently lend itself to manual machining since it would 'drift' from lateral pressure on the work/lack of friction on the rotation of the rod. I have heard guys using ball screws on manual machines and then adding components to create friction to stop that action but unless it can be turned off on-demand, would make turning the handwheel challenging

Overall, this seems to be another case of 'hard to get in Canada'; kinda sucks but many of us have run in to this scenario before and my original request for information was to ensure that I wasn't missing some 'local' suppliers that could have saved me a lot of hunting. BTW: 1/2"-10 and 1"-5 w/comparable construction/material specs seems somewhat more common here...just in case someone else finds that they need a product like that
 
I'm no expert, but I've come across a few references to some lead screws being ground. Whether that's old/new/precision/... seems to vary all over the map. Die rolling is another threading process but that in itself doesn't equate to precision and it does not preclude ground lead screws from being used. A form of die rolling is also how they make generic all-thread studs etc. That's why I was asking - how accurate do you need it to be? Then its a matter of confirming the output specs. The Keystone link you provided reference 0.008"/ft which is 0.0007 in/in (under jackscrew section) . Is that good enough? Is a ground spec of 0.0002 inch/inch overkill? That's really for you to decide. Some lead screw suppliers offer multiple processes under one roof (rolling, milling, grinding). Ballscrews seem to be predominantly ground, but I've also heard of good & bad ones, so probably same deal: what are the specs? Now I'm really curious, I wonder what is a standard issue lead screw is in a decent lathe? Amazingly hard information to find. (Guessing die rolled on an Asian import). I'm going to post a question on another forum where the dealer weighs in. Some links:

http://www.machinetoolonline.com/PMMillingMachines.html
(generic wording but no actual specs)
high precision leadscrews

http://www.nookindustries.com/Product/ProductLine/Acme-and-Lead-Screw-Products
Nook Industries manufactures precision acme and lead screws by thread rolling, thread milling, or thread grinding processes. Each process produces high precision screws.

http://www.abssac.co.uk/p/ACME+Leadscrew/101/#.VzTF9E2hqUk
The lead accuracy is 0.006" per foot max. (=0.0005 inch/inch)

http://www.practicalmachinist.com/vb/general/how-make-leadscrew-harrison-10-aa-184629/
Main leadscrews are usually ground on special purpose machines.

http://machinedesign.com/archive/how-rolled-and-ground-ball-screws-stack (ball screw related but similar issues)
A specific application is often the initial deciding factor for choosing rolled or ground ball screws. Rolled screws, for instance, are typically used in low-precision applications. Examples include some pick-and-place devices and actuators. Ground ball screws, on the other hand, drive precision machine tools, such as milling machines, lathes, profile grinders, and EDM machines. Ground ball screws are also recommended for precision X-Y tables, such as those used in semiconductor wafer-inspection equipment.

http://www.chaski.org/homemachinist/viewtopic.php?f=4&t=12397
As for the original question, rolled is better than turned. Think about the thread rolling process as something like a forging. It will tend to push the metal granularity in a circular motion around the threads, which lends strength. It may even be preferable to precision grinding, although you give up something in the way of precision. However, the specs say .009" per foot for rolled, and the table moves about 6", so I could be off by .0045", which is acceptable for me.
 
Jimbojones said:
They don't stock (most) acme rod and especially not the type I was seeking. Had to grab some from the U.S.
Click to expand...
Oh Darn! I must have lucked out or got my data wrong. I found from Canadian threadall acme 3/4 OD left hand thread 6threads per inch, regular mild steel. 6'
 
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