Stohr OEM nose

[Blair Robertshaw]

Hi all, does anybody know what the OEM thread pitch is on a Stohr f1000 fiberglass nose? The thread pitch on the nose whiskers that the front main plane bolts to. They look to have never been drilled out or over sized drilled and then tapped but the first few threads are not really great, cant get a bolt into them really easy and I would prefer not to over size drill and then tap. I think if I can re-tap the OEM pitch I should be OK. Thanks all.

[Fred Michael]

Call Stohr

[Blair Robertshaw]

Tried that... anyway, looks to be a 10/32. there is such little material there I just don twant to over size drill the holes. Tap seems to have little to no resistance. at least hole 1

[99sh]

If you're talking about these pieces, it's 1/4"-20

[petawawarace]

Tried that... anyway, looks to be a 10/32. there is such little material there I just don twant to over size drill the holes. Tap seems to have little to no resistance. at least hole 1

Just a thought. Are you sure it's not an M5 x.8 thread? They will usually thread into each other they are so close to the same.

[Blair Robertshaw]

Pretty sure not metric but you’re right, really close and 99ish, my first try was a 1/4 x 20 but it had quite a bit of resistence when trying to turn in. This is a used nose and I think at one time it may have been over tightened and they had to run another tap into it. It isn’t a robust area to be sure. I chased the 10/32 and not much material on the tap, some granular stuck in the cutting fluid but not a lot. Not enough to think I was cutting new threads. I then put the bolt through a small stack of washers and tightened it up on all 4 points to see if I could get a small torque load on the bolts and they seem to be ok. Fingers crossed To the paint booth today. Thanks guys.

[JakeL]

Blair, probably best to post a picture.

Gen 1 Stohr noses were, I think, tiny 10/32 inserts in the nose.

Later cars had 4 little "hockey puck" things that inserted into the "tusks" on the nose, and those were 1/4-20, but as far as I can tell are designed to cross thread if you don't hold your nose with one finger and stand on one foot and pray to the Gods of McMaster-Carr just right.

Neither solution is particularly good, but the later ones are at least strong enough. the earlier 10/32 ones were prone to breaking bolts and the wing would fall off!

-Jake

[Blair Robertshaw]

Thanks Jake, yeah, Im thinking Im going to drill through the Tusks and use 2 Barrell nuts on either side and use 6MM bolts up through the Tusks into the Barrell nuts. The last one was like that so there must be a reason behind it. This is a Spare nose / wing assembly and the last thing a guy would want is to lose the wing because the bolts break after a guy just broke the primary nose assembly from whatever. I really am suspicious of the 10/32. And of course the nose is in for paint today... LOL.

Thanks boys.

[Dave Cutchins]

"...............Later cars had 4 little "hockey puck" things that inserted into the "tusks" on the nose, and those were 1/4-20, but as far as I can tell are designed to cross thread if you don't hold your nose with one finger and stand on one foot and pray to the Gods of McMaster-Carr just right."


I had the same experience recently. Trying to line up the bolts through the main plane, the holes in the "tusks" and the threaded holes in the aluminum pucks is a challenge. I found that by applying pressure on the tusks and pulling them toward each other just enough allowed the holes to line up and bolts to thread easily. The secret was to have an extra pair of hands applying the pressure.

[Blair Robertshaw]

Hi Dave, yeah those little hockey pucks you reference are known as Barrel nuts as far as I know. Funny thing. I had to find them at IKEA! They use them a lot in their furniture assembly. The ones I have are 6mm and yeah, a guy really does have to stand one foot, cross fingers, hold nose and yes pray to align. Lol. Thanks


QUOTE=Dave Cutchins;555921]"...............Later cars had 4 little "hockey puck" things that inserted into the "tusks" on the nose, and those were 1/4-20, but as far as I can tell are designed to cross thread if you don't hold your nose with one finger and stand on one foot and pray to the Gods of McMaster-Carr just right."


I had the same experience recently. Trying to line up the bolts through the main plane, the holes in the "tusks" and the threaded holes in the aluminum pucks is a challenge. I found that by applying pressure on the tusks and pulling them toward each other just enough allowed the holes to line up and bolts to thread easily. The secret was to have an extra pair of hands applying the pressure.[/QUOTE]

[JakeL]

meant to mention one trick: I took a band saw (cutoff wheel would work too) and cut a notch/slot in the side of each one parallel with the threads, so that you can hold it in the right orientation with a big flathead screwdriver as you try to thread the bolt in from the underside of the wing. Seemed to make a big difference.

-Jake

[Blair Robertshaw]

Yeah this has turned into a real PIA. Jake do you have a pic of what you mentioned. Unreal that an OEM part doesn't fit into the holes in the OEM main plane wing. Thanks.

meant to mention one trick: I took a band saw (cutoff wheel would work too) and cut a notch/slot in the side of each one parallel with the threads, so that you can hold it in the right orientation with a big flathead screwdriver as you try to thread the bolt in from the underside of the wing. Seemed to make a big difference.

-Jake

[JakeL]

Blair,

Such is the reality of hand-made parts I guess.

See attached photo. Stan posted this in the Stohr FB group just yesterday, I added the green line to show what I did. Make a notch/slot like shown in green. Put a flathead screwdriver in the notch, and that gives you the ability to manipulate the barrel nut to ensure it is lined up with the bolt coming up through the bottom of the wing.

-Jake

[Blair Robertshaw]

Thanks Jake. The Barrell nuts I have already have the slot in them for the Flathead. I thought you meant something else.The front holes from the nose whiskers line up with the holes in the main plane, the rear whisker holes do not line up with the holes in the main plane. Out by 1/8" on one side and about as much, maybe a bit less on the other whisker. And cant seem to get enough flex or any flex in the whiskers to try and softly persuade them to going in. I may have to make some sort of aluminum plate the whiskers bolt to and then bolt that to the wing from another set of holes. Looks like I may be SOL if that doesnt work. Out of ideas here on my end.

Blair,

Such is the reality of hand-made parts I guess.

See attached photo. Stan posted this in the Stohr FB group just yesterday, I added the green line to show what I did. Make a notch/slot like shown in green. Put a flathead screwdriver in the notch, and that gives you the ability to manipulate the barrel nut to ensure it is lined up with the bolt coming up through the bottom of the wing.

-Jake

[Blair Robertshaw]

Hi guys, I would like to clarify that the nose I am working with was NOT built by Dauntless. It is a generation of nose that I think was and may be in fact the first Generation of nose from Stohr. Don't want Dauntless to get a bad rap for something they didnt build.