[Azalin]

OK I've find them and sent out my inquiry. Thanks.

[Azalin]

I bought (4) ballscrew locknuts from intra trading in the UK.
N-04. 3.65£ each (+10.50 min charge).

They were ground, of excellent quality.
Shipping to spain approx 15.
Fwiw..

Wow. Their prices are expensive as SKF.

1 pc INTRA Lock Nut KMT 9 Price: - £ 33.00 each
1 pc Self Locking Nut GUK 45 x 1.5mm NYLON INSERT Price: - £ 11.00 each
CARRIAGE: £ 16.00

[Azalin]

Hi again,

The labyrinth is almost complete. The gap between 2 parts is 0.04mm. When the spindles is complete I'll use a double layer of 0.01mm thick steel sheet to install the main labyrinth part to have a nice round gap.

[RotarySMP]

Really nice work. Please post a picture of the Trepanning tool you used to cut the groves.

Mark

[Azalin]

Thanks Mark. I grounded a parting tool insert down to 2.1mm. I'll take a pic today.

[Azalin]

Cutting high carbon steel is a pain indeed. I broke some cutting inserts but finally finished the work. I'll use M6 socket head hex bolts for on the main part but I cant decide whether use 6 bolts or 8.

I'll cut the chamfer on the main part later, when the main housing is complete.

I have a question on powering the drawbar. Does anyone seen a linear actuator that is powerful enough to push about 5kN and short stroke (max 10mm)? The reason I lean towards this way I hate my air compressor because t's crazy loud.

[Dingenman]

Hi Azalin,

Something like this?

Cheers - Ard

MSI Motors Linear Actuator MSI 1000 Adjustable Stroke 1300lb Load | eBay

[Azalin]

Nice. I think that kind of actuator is what they use in treadmills. Yes, that might work. Thanks Ard.

[pippin88]

I think it may just be worth buying a better quieter compressor. You probably want air for other features too, such as fog or MQL

[Azalin]

OK the parts left are the upper labyrinth and the main housing. Here's the problem. My desktop lathe is small not to turn a 140x200mm round stock. So decided to cut half the housing of a 100mm round stock and weld the flange to it. That's the best I can.

[mactec54]

Azalin

Welding a flange to the 100mm tube is fine, done it like that many times

[Azalin]

Hey mactec,

That's good to know. Thanks.

[Azalin]

100x200mm 303 stainless and 150x50mm 304 stainless. Let's see if I can bore the big part with my lathe.

[RotarySMP]

Ouch. That won't be much fun. I hate turning stainless. Horrible long sharp stringy swarf.
Mark

[G59]

Horrible long sharp stringy swarf.

Fun time. LOL

Azalin, why did you choose stainless? Even Aluminum would of been fine as a spindle body. The stresses are 90% radial. Unless you have major horsepower going through it, seems over the top. 1018 Steel would of been just fine.

I'd love to know the thinking behind it.

Great job you're doing though. Lot's of fine work.

[Azalin]

Come on people. Motivate me!

[mactec54]

Azalin

The 303ss machines just like free machining steel, the only problem is it is not a good candidate for welding, and welding is not recommended, 304 is good for welding but is a little harder to machine

[Azalin]

Mac,

What actually happens when you weld two 303 together? (in my case 303 and 304 together). The welding points are weak and break in time or does it not weld at all?

If welding 303 is a problem then it would be better not to add the flange so the spindle body remains 100mm. That's actually fine with me I'll just need a better mount on the Z axis for the spindle.

[Azalin]

Fun time. LOL

Azalin, why did you choose stainless?

I must have misread or I didn't know that 303 isn't considered weldable

[G59]

A quick search yielded this.

303 stainless steel is also called free machining stainless.

You know what makes it “free machining” ?

SULPHUR!! sulphur is added to 303 stainless to make it cut like butter. Machinists hate 304 stainless because it is tough and gummy and wears out tooling.

Sulphur is bad for welding…its Good for machining…but Bad for Welding.

The cousin of 303 free machining stainless steel is 12L14 free machining carbon steel.

The "L" in 12L14 indicates LEAD!!

Both sulphur and lead aid in machining but can cause cracking and lots of other problems with welding.