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which two tubes from Titanium Joe
Posted: Fri Jul 27, 2018 12:37 pm
by kohalajohn
I have searched the forum for this.
Are there a pair of 1.500 OD Ti tubes that are commonly used by the good folk here?
I mean one for the outer tube and one to be cut up for spacers inside.
Say the outer tube is 1.500 OD with .070 width and therefore 1.360 ID, I would want the spacer tube to have an OD of say 1.350 so when I cut it into spacers, they fit snugly inside the outer tube.
I see Titanium Joe sells the above 1.500 OD tube and they also sell a 1.350 OD tube.
Those two should work. Shouldn't they?
Re: which two tubes from Titanium Joe
Posted: Fri Jul 27, 2018 3:19 pm
by garredondojr
I didn't use titanium but I did 1.5x.065" tube with 1.375x.035" spacers on mine. ended up having to clean up the spacers some they still ended up about .028" thick(the wall thickness on the 1.5" was a hair more than .065 so the ID was 1.366").
I machined an adapter for my live center with a scrap piece of 1.5" stock. used my center reamer on the inside after drilling a hole in it then machined a 60' cone on the other. put a light bevel on the spacer stock and dialed in the 4 jaw.
so in short unless you get lucky and your material is 100% on spec you may need a little extra and more work to get the correct fit.
Re: which two tubes from Titanium Joe
Posted: Sat Jul 28, 2018 8:52 pm
by fishman
I've bought from them for 4 silencers. I use 1.625"od x 0.065" wall with 1.5"od x 0.065"wall for spacers. The spacers need to be turned down to fit.
Re: which two tubes from Titanium Joe
Posted: Thu Aug 02, 2018 12:35 pm
by kohalajohn
Yeah, that's what I suspected, that sometimes the tube turns out to be not 100% to spec. That's fixable of course.
First question, has anyone found tubes that are in fact 100% to spec?
Second question, I like the above the above poster's point that he used spacer tubes that are only half the width of the outside tube. Makes sense, as the spacers only need to be strong from cone to cone. They don't need girdle strength to contain sideways blast force, as the outside girdle tube does that.
Seems a thin walled spacer would save weight without giving problems? Comments on that?
thx again
Re: which two tubes from Titanium Joe
Posted: Thu Aug 02, 2018 2:05 pm
by T-Rex
ASTM allows for seamless tube to have dimensional variations of +/- .005in.
So, even if it is 100% w/in spec, it may not be exactly the number you were shooting for.
Regardless of tolerance, if your tubing was had exactly as advertised, 1.5 tube would never fit inside 1.625x.065. 1.625-.065*2=1.495
Hence, why fishman had to turn down the outside of the spacer. Is it even .065? I'd think Ti that size would be .070?
As for spacer thickness, yes, go thinner. Save weight and money.
Re: which two tubes from Titanium Joe
Posted: Thu Aug 02, 2018 3:05 pm
by fishman
The titanium joe tubes are to pretty good spec. They just need to be turned down because you need 1-5 thou radius air gap to make it a slip fit instead of a press fit.
You're right, trex; it's .070" not .065" thou. Either way, It wont fit even with perfect tolerance. It's a 15 thou interference fit.
Re: which two tubes from Titanium Joe
Posted: Fri Aug 03, 2018 10:42 pm
by kohalajohn
So an up to .005 variation is to be expected.
So I'll go for a 5 thou radial gap, or say 10 to 15 thou interference fit.
So outer tube 1.500 OD with .070 width and therefore 1.360 ID, I would want the spacer tube to have an OD 10 to 15 less than that. So spacer tube OD of 1.345 to 1.350.
So that Titanium Joe tube of OD 1.350 that I was looking at, may be a wee bit tight. It probably would have to be taken down a bit.
Would be nice if tubes came perfect for this, needing no work, but I no longer think that's the case. Not that that's a huge problem though.
Re: which two tubes from Titanium Joe
Posted: Fri Aug 03, 2018 11:04 pm
by fishman
So that Titanium Joe tube of OD 1.350 that I was looking at, may be a wee bit tight
I'd be surprised if it didn't slide right in. I've been wrong before though.
Re: which two tubes from Titanium Joe
Posted: Sat Aug 04, 2018 11:49 am
by T-Rex
kohalajohn wrote:So an up to .005 variation is to be expected.
Variation is typical to OD and ID. Seamless is DOM so wall thickness is rarely larger.
So I'll go for a 5 thou radial gap, or say 10 to 15 thou interference fit.
An interference fit is when the female part OD is equal to or greater than the male counterpart. Hence, the measurements interfere with one another. 10-15 thou interference ain't gonna happen and isn't what you want. You want a 10 thou clearance fit. Slide nicely together they will.
So outer tube 1.500 OD with .070 width and therefore 1.360 ID, I would want the spacer tube to have an OD 10 to 15 less than that. So spacer tube OD of 1.345 to 1.350.
Would be ok
So that Titanium Joe tube of OD 1.350 that I was looking at, may be a wee bit tight. It probably would have to be taken down a bit.
Should fit
Would be nice if tubes came perfect for this, needing no work, but I no longer think that's the case. Not that that's a huge problem though.
Still need threads or welds so machine and/or fabrication skills are a must
Re: which two tubes from Titanium Joe
Posted: Mon Aug 06, 2018 2:41 pm
by kohalajohn
Helpful. Thanks.