Igus Leadscrews/ TR16x2 LH

[Kram]

Has anyone used this company or heard of them? I want to order a leadscrew - they seem the only place to get TR16x2 left hand thread, but its either C15 or stainless.. stainless being very expensive. C15 does not seem good?

http://www.igus.co.uk/wpck/3810/DryLin_Trapezgewindespindel

Phoned them today, said a couple weeks wait, they have none in stock in germany but prices seem good.


Alternative is C35E, but only in right handed www.ebay.co.uk/itm/311357552380

 

[Luke]

Igus are very well known for plastics. Typically energy chain/drag chain and more recently plain bearings and bushes etc.

 

[Kram]

I ordered a TR16x2, 500mm from the ebay seller. Arrived with a 4mm pitch however he has already given me tracking number for the 2mm pitch replacement

I need to make a nut - Ill probably grind a straight toothed roughing tool then use a length of the thread as a tap/internal thread boring tool to finish it. Taps and nuts are extremely expensive.. However I did look on ebay and shops, I would buy an insert to do it properly but they dont seem to exist other than chinese auction sites?!?

 

[Wendelspanswick]

How about making an Acetal nut, no tap required:
http://bbs.homeshopmachinist.net
is one method but there are other similar methods.

 

[Kram]

Yes thats what Im thinking, though I already have a bar of nylon, any good? Id like to use aluminium but not sure how well it would cut with mild steel tool.

Problem with tapping, depth of cut depends on the taper I grind.. and mild steel screw with only work hardening from the rolling process is not much good for it. I have no experience threading on lathe but seems a boring tool can control depth of cut with cross slide and cut with the harder outer skin. I dont know if its possible to realign threads when swapping tools (on a small internal thread? ) but I could make a HSS grooving tool to rough cut the full depth and then make tap with the threaded bar to finish the nut, then the tap does much less work.

One major annoyance is that 2mm pitch is not standard for anything bigger than 10mm. Its not in machinery handbook and no one makes inserts (yet my lathe has TR10x1, TR14x2 and TR20x2 as standard!). It would help if I could find the thread dimensions somewhere!

 

[AndyStobbs]

A 60 degree wedge tool would cut it best. Can you find a half form insert rather then full form?

 

[Kram]

TR thread is 30 degree?

 

[AndyStobbs]

TR thread is 30 degree?

No idea to be honest. That was an assumption I shouldn't have made.

Any of these fit the bill? http://www.cutwel.co.uk/thread-maki...point-threading/trapezoidal-threading-inserts

 

[Flathead_Dave]

http://www.aliexpress.com/item/Bran...1725533511.html?spm=2114.40010508.4.74.jEo7zC


http://www.ebay.co.uk/itm/x1pce-Cyl...hash=item4842f64d18:m:mMQYc7rTWGR0B1g0mg_SZJw

 

[Kram]

Thanks for the links, inserts are 16mm doubt they will fit the 14mm bore, but it gave me the part number to search. Phoned up Posithread, and they have a 11mm insert. They also gave me the dimensions which are not in 19th edition MH:

Bolt 13.5mm minor (0.5mm clearance) 15.75mm OD (0.25mm clearance)
Nut 14mm bore, 16mm threads

 

[Pete.]

Trapezoidal thread is 30 degrees included as opposed to the 29 of ACME. Thread depth is pitch/2 so 1mm but you shouldn't really make a tap from a piece of leadscrew as you'll have no clearance at the crest of the threads (you can get away with making the moulded-on acetal nuts but not for cutting a thread).

If you want to make a threadcutting tool buy a piece of 1/2" silver steel and turn the thread profile into it by setting your compound 15 deg left then 15 deg right, then grind it down half way to create a cutter. Use that to cut the thread in your nut.

 

[Kram]

Good idea using the compound, I will try it.

 

[bricol]

You are aware of the page before? :

http://www.igus.co.uk/wpck/2371/drylin_trapezgewindemutter

 

[Flathead_Dave]

That nut no good then? If you weigh up the tooling cost and time involved,it doesn't look that expensive.
As far as I'm aware,the first metric edition of MH was the 27th.
I may be able to scan the page if it would help.

 

[Kram]

So that works, close enough angles, it was only a quick test so did not measure the width or depth.

 

[Kram]

The extra travel would have been very nice for some things I attempted on Saturday!

Had to sharpen new ccmt insert on diamond wheel before it would cut this. Needs to be really sharp with tons of pressure. Probably not good for the compound screw but I intend to replace that as well.

Right end is ready to grind into a TR2 tool, left end I only just started and will be TR4.

 

[Pete.]

Kudos for managing to turn down a piece of HSS, but usually people use silver steel and harden it themselves with a blow torch.

 

[Kram]

Ive tried silver steel and gfs before, very difficult to get enough heat in unless its very small.

Made a video of it cutting.
www.youtube.com/watch?v=BR0f5nOIDWA

 

[scott0031]

Ive tried silver steel and gfs before, very difficult to get enough heat in unless its very small.

Made a video of it cutting.
www.youtube.com/watch?v=BR0f5nOIDWA

Of course your heat source has a big role but getting some fire bricks will help you by a very large percentage. You need to contain the heat so its not escaping all over the place. It's often the difference of not being able to do a job and making it easy.

 

[Kram]

Finished turning, new challenge to grind it into a cutter. I bought a bench grinder last week - need to practise on scrap and dress the wheel.

Is the helix angle important? I think Ill need clearance on leading edge.