'Custom' Tool question: Measuring Manifold nut inside angles?

[T. Cotten]

DANG ! That is a good idea, Bob. The only downside I can see, is that it would magnetize your chuck jaws and collect chips. However, the benefits would outweigh the deficits.

Just need a big de-Gausser, that's all Eric!

....Cotten
PS: I have two of these, and have never tried them. But I de-Gauss floatvalve needles with a jeweler's coil.

[ryan]

That is a new, great idea, to me as well Bob. Thanks for the tip!

[BigLakeBob]

DANG ! That is a good idea, Bob. The only downside I can see, is that it would magnetize your chuck jaws and collect chips. However, the benefits would outweigh the deficits.

I have not had that problem, the small magnets I use don't seem to have enough to induce magnetism into the larger mass of the jaw.

[exeric]

DANG ! That is a good idea, Bob. The only downside I can see, is that it would magnetize your chuck jaws and collect chips. However, the benefits would outweigh the deficits.

[BigLakeBob]

DSC05687.jpgSometimes I'll use magnets to hold a part at the front of the jaws, quick method that saves a lot of indicating, assuming the front of your jaws are in decent shape. Just wanted to add that if I want the part to not be flush with the jaws, I put a gage block (or equal thickness of any material) under each magnet. This way if I want to machine .05 off a part I might stick .100 blocks under the magnets. I find this method to work well on thin parts.

[ryan]

Cotton,
I sure would report findings, but I do not have any parts to check.

[T. Cotten]

Ryan!

Graciously,
When the nuts are held in a three-jaw chuck against their 'back', the run-out of the 'front' face is readily apparent.
Most all have been quite parallel, front face to back, and if there is any run-out on the front face, it only takes a gentle nudge to true it within the jaws.

Once again, the mass-produced seal's failure was due primarily to reproduction nuts with gross error on the angle.
Considering how many of these nuts I fitted with my own seals without any reported issues, I must attribute success to my different parameters for PEEK.

Now I can measure all the various nuts for a much more accurate fit.

It was surprising that fresh brass seals from the same producer as the nuts were similar in error, so as long as you didn't mix sources of nuts and seals, they had a chance.
(At least as much chance as any brass seal, anyway...)

The age-old question comes to mind: If somebody is going to the trouble to make a part, why not make it right?

....Cotten
PS: I hope to measure OEM and reproduction nuts for Sport Scouts, Chiefs, WLs, etc. soon.
If nobody else wants to contribute their findings, I guess I shall keep my own as "proprietary".

[ryan]

Cotton,
Sorry to jump into this thread late into game. I have been away visiting the spirit world for a week by having a ketamine infusion pain control treatment. Boblakes quote sure has a lot of validity after going through that treatment.
Now to get back on track, I will call the angle side the front side of the nut. One thing I have noticed is that the readings, using the flat on the back side of the nut, to take the measurements on the front side of the nut will give you a trigonometric sine error because the angle machining process is machined from the front side of the nut. Now this would be fine if the front side and back side were completely parallel, which I am sure they are not because the back side is not a critical measurement and does not have to be held critical, to the front side of the nut, while being cut off. My whole point being is that the front side needs to be indicated in flat to get a proper angle measurement, this can either be done on each individual part before the angle measurement is taken or check each part first to see if the front and back side are completely parallel with each other. The backside must also be burr free by either running a new flat Norton stone across the surface or by running a fine file lightly across the surface. If the front and backside are parallel, then the backside can be pushed against a stop to measure the angle.

If this makes sense to people on this thread, I will continue on how to double check boblakes compound measurement mathematically. It is very easy to do, but you have to use a scientific calculator.

Ryan

[T. Cotten]

If Bob and Mark and others would like to contribute, Folks...

We could all start sampling various nuts, and compare our findings here.
Then everybody could benefit.

....Cotten
PS: As a follow up, it now appears that the failure I mentioned earlier in this thread was due to a very high angle (whatever the lathe says it was...) nut used with a seal that was most likely patterned off of originals at a much lower angle. Such geometry biases the force of the nut against the inlet nipple at the very outside edge of the seal. The critical sealing is needed inside against the spigot.

[T. Cotten]

If it's that critical send it to me and I'll put it on the CMM and send you a digital drawing of it. B

I appreciate the offer, Bob!

But I get a wide range of manifolds constantly (four different ones this week), and you never know what nuts they will show up with.
Its hardly practical to mail nuts off and wait for them to come back, and I couldn't expect you to do it for free from here on out!

From the sampling I already have, its obvious that neither OEM nor reproduction nuts (for Harleys anyway) can be assumed to be perfectly consistent.
BigLakeBob's simple suggestion is quite accurate, and I only have to get up to speed where I don't lose much more time that I can't charge for: I'm too expensive already.

(But its obvious that my prices must rise eventually, if only to cover the rising cost of material.)

....Cotten
PS: I googled "CMM", and found I could neither afford one, nor find space for one. Once again, low-tech rules!
PPS: Its now six different manifolds this week, and the UPS man isn't here yet. I'm going to have to lock the doors 'til after Davenport...

[knuckcrazy]

If it's that critical send it to me and I'll put it on the CMM and send you a digital drawing of it. B

[T. Cotten]

Its a matter of tactile control measuring what's left, Bob!

Eyeballing a sliver of anything with a protractor isn't accurate enough.
(Needle points are a treat.)

With the nut chucked up and an indicator on the toolpost, the lathe does the rest. Don't even have to turn it on.
The operator is pretty slow though.

....Cotten

[knuckcrazy]

You don't have to fill entire area just a section hold nut at 45* give a couple squirts let harden then peel out.
I'm sure 1000 ways to skin it as long as it works.
Glad you got it!
B

[T. Cotten]

Bob!

Most nuts have a relief inside of the threaded portion, so anything cast-in would be locked from un-screwing. That led to my comment about breaking out sealing wax.

BigLakeBob's suggestion solved the problem most eloquently, although opening up many other questions.

Like: How have seventeen years of my own seal productions succeeded inspite of reproduction nuts!

.....Cotten
PS: I've got all of the glue guns, stored away. She doesn't use them either.
PPS: My seals were cheaper in 2000. Now they must go up again.

[knuckcrazy]

Just a thought, hot glue from your wife's hot glue gun then unscrew it and measure?
I use it for all kinds of quick molds to measure and fixture fragile parts for machining.
B