I suggest Aircraft Spruce or Aeromart. But, if you're looking for cheap prices, you might be better off at DeNault's Aircraft Supply.

If you think BV is expensive, start buying FAA approved parts! Try $50.00+ per bolt in some cases.

Daren

On a hex head bolt...Three lines is grade five, Six is a grade eight.

Kevin

Hi Guys,

I may have missed it if this was suggested already--I tried to read all the posts. The difference of $0.19 and $9.00 is so great that I would have called BVM and simply asked them to tell my why I need their bolt. I would do it now, but I'm not a jet owner (yet). It could very well be that there is a justifiable difference, then again, maybe not. If nothing else, it would be interesting to hear their response. Could the invoice have been in error?

Just a thought, or two.

By the way, I see no problem with the orignal nature of this topic. It's a legitimate question for such a forum.

Thanks,
Paul

Here's the deal on the bolt in question. So far, there have 79 posts on this thread so far, and everyone has missed the point.

I just went down to the shop, opened up the cabinet, and lo and behold, there is a box containing a brand new VioJet...complete.
Looking at the bolt, one thing is readily and very apparent. The BVM bolt has a 1/4" hex receptical, not the 3/16" that is standard on a 1/4 -28 allen bolt.
Looking at the Micro Fasteners on line catalog, I couldn't find a 1/4-28 NF bolt. They list 1/4-20NC, but not a fine threaded 1/4" bolt in sight. Maybe I'm blind.

Anyway, the McMaster carr catalog, all 3552 pages of it (Catalog 109, the most recent one) lists lots of 1/4-28 NF bolts in both carbon and stainless steel, but they all have a 3/16" recess.

The BVM bolts were designed by BV, and made especially for BVM by one of the major fastener manufacturers because a 3/16" allen receptical (standard) is insufficient for that job. BV tried the standard bolt, and they didn't cut it.

Go get some special bolts made up, maybe only a few hundred of them, and find out what it costs you. Please tell us on this site as soon as you find out. I'm curious.

I wonder if the originator of this thread has checked to see if his starter probe fits his new 3/16" bolt recess? Maybe that is in order before you return the specially designed, very hard, very straight, correct sized BVM bolts.

The bolt was not designed to separate anyone from their money, it was designed to perform the job for which it is intended.


Harley Condra
BVM REP

We have a winner! Harley has found the truth. I have recollections while working at BVM that the bolt was not and standard bolt, and was custom made to design. The hardening properties are very tight and specific to give the proper non-brittle bolt strength so it won't break, and the proper hardness in the hex so it won't strip. No one wants to have strip or break a bolt when they fire up for a round at Top Gun or the Scale Masters... and a broken bolt could release the fan and result in the loss of and aircraft.
So enjoy your 19 cent bolts, but don't propose they are the same as the BVM ones.
Design a custom bolt with special hardening, and order a few hundred at a time from a quality maker, and see what you investment is!

Dave
(I already regret participating in this circus)

Sounds like a very logical explanation to me. Harley, where were you 79 posts ago? Can we close this thread now before we find something else to disect?

Chris

Hi

The last thing I want to do is get involved in the meanness aspect of this thread (which is high, even for jet guys...), but I do have to say.....

Not out of an unwillingness to pay for the $9 bolt, but more out of the need for a quick fix--I went to a hardware resale shop (I forget the name, but it's right next to SoCal Guns, for those of you familiar with Convoy St.) and bought a package of what appeared to be the same size bolt as was in my Viofan. I had to replace it because my 15-year-old nephew tried to start the engine with a starter shaft from a helicopter (metric), and stripped it out (it only took a second, by the way). After cutting the bolt length down to size with a cutoff disc, I installed the bolt into the Viofan, and proceeded to get 85 flights out of it over the next several months (some with multiple starts). If memory serves, those bolts were $1.50 for a pack of two.

Does BV strive to and offer the best products and materials obtainable? I'm convinced they do. Can you find these items (and I don't mean IDENTICAL DOWN TO THE SCIENTIFIC NOMENCLATURE) like bolts, bubble-eliminating hopper tanks, fantastic glues and such elsewhere for less money? It would appear so.

BV's trying to turn a profit. What's the big deal?

Hmmmm........................
Probably snoozing.

I get some of my best info from the source.

Harley Condra
BVM REP
Bolt measurer
Catalog Reader

Hi Harley!

You really jogged my memory. If I am not mistaken this bolt is one of the reasons that BV switched to the special machined nut on the newer 91s and 96s!! He wanted to get away from the special machined bolt!!

Ha! No good deed goes unpunished!! No wonder I cannot get BV back on these boards, look at the crap he would have to deal with!!

I went to the library (the can) and found this from the old Inlets, circa 1997.

Industrial Liquidators. Awesome place. Certainly tops the list of any San Diegan with pegboard. Gateway Electronics is up there also. They have a "thick" collection of bits and pieces of usefulness.

You feelin' me?

You sure must be blind.
On the Micro Fastener web site the bolt # is SCA 1440 1/4-20x2.5.
I e-mailed & call Micro Fastener and for everyones info. the bolts are Hardened alloy steel 12.9 grade Rockwell C39 to C45 equivalent or stronger then Grade 8.
Prove is in the pudding!
Now please Moderator close this thread enough said.
MB

CONDOE_WON,
The bolt required for the BVM fans is a 1/4-28 NF (FINE THREAD, NOT 1/4-20 NC COARSE THREAD.). A 20 thread per inch bolt will not work in this application.
I may be blind, like I stated before, but I know a little something about threaded fasteners. Here's your lesson for today.

The number after the majordiameter is the thread count per inch. In effect, 20= 20 threads per inch, and 28= 28 threads per inch.
EXAMPLE: A 1/4-20 bolt or screw, or a nut for that matter, has a major diameter of 1/4", and 20 threads per inch.

Micro Fasteners still DOESN'T offer a 1/4-28 bolt.
Here's the pudding you mentioned, and the proof is inside.
Please...don't try jamming your newly purchased 1/4-20 bolt into your BVM fan.

Check it carefully, and you will find that I'm correct.

Harley Condra
BVM REP

I guess the phrase (quit while you are ahead) does not apply in these forums. This has gotten to the point that the engines are dead, the wing is on fire, and we are smoking in. This is going to take us straight to the crash site and I guarantee you we will beet the fire department there by 30 minutes.


UNBELIEVABLE JUST UNBELIEVABLE.

Doug,
You are absolutely correct.
I apologize to all for being too harsh.


Harley Condra
BVM REP

Now THAT is why you gotta love you some Harley C.

Sean with you 85 flights, was that with a BVM motor or something else?

Just curious.

Matt,


It was indeed a genuine BVM .96 Special Edition eninge in a Viofan. No inflation on the numbers, the flights were witnessed by many..... :-)

Shaun
I believe the .96 has the new style crank and rotor mounting parts. The .96 never had the long retaining bolt he is looking for. I don't doubt you changed the short one on your .96. That short bolt is probably a normal hardware store bolt.
I agree with the crowd that says bv had the old-stlye-long bolt specially made for a reason. It also had a special washer too.

I have a few of those special bolts... maybe I should ebay them... sounds like I could make a buck or two!


Good luck on your search to find an aftermarket one.

Dustin

Got back again from flying and didn't have a chance to contact Micro Fastener.
But when Monday comes around I will find out about this 28 threaded bolt. The price for making 20 of them. Then either I will eat my dust or some of you in here will.
Have to do pre-flight checks.
Over & out.
MB

Dustin,


Cool. Thanks for the info. I never really paid too much attention to the ins and outs of the thread pattern or anything like that, I just pulled it out, took it to Industrial Liquidators, and eyeball matched it to a bolt. Once I cut it to the right length, it worked fine! The BVM starter probe even fit fine. Your info explains it, though!

McMaster/Carr has 1/4-28 socket head cap screws----But it won't have the same recess as the BVM screw.

Kevin

Time to close this one. I hope everybody had an opportunity to contribute.

Regards

Ben