I am at the stage on my Bobcat were I need to mount the JetCat speed sensor Pitot probe some were. Where is the best location?

I would prefer not to mount it in the nose as it is to venerable to hangar rash at that location, the place I think would be best is in the front of the right boom. My only concern is that it might be in dirty air at that location. If I mount it in the vertical tail where do you mount the electronics as the long tube's that would be needed would seem that they could get kinked easily over that distance .

Mark,
I am just in the process of final mounting of the "Pitot Tube" as well.
I will be placing the tube in the nose and using a set up that John Redman had on his Bobcat. He made an 1/8" plywood
doughnut type bulkhead to mount a 1/4" wheel collar to and then he mounted the doughnut up in the nose using Aeropoxy. Drill a small hole up through the fuse bottom to access the set screw, and then you can slide the pitot tube back into the fuse for transport. I have done this on the first of a pair of Bobcats that I am building for a client and it works quite nicely. According to Bob Wilcox you need to be sure and keep the tip of the tube extended out of the fuse over 1.5 in. Or in other words out of the boundary layer of air. To slide he tube in you just loosen the screw and push it back until the black tip is flush to the fuse nose. To extend all you do is loosen the screw and the tubing that is attatched to the pitot will push the tube out enough to be able to grab the black tip and you then can extend out and just snug up the set screw. Quite simple and very effective.


Best Regards
Bill Brundle
AB Builders
Custom Built R/C Models

I saw Tim Redleman do that with a pitot tube on the nose of a bandit, seemed to work quite well. I had mine stuck into another tube bonded into the nose, with a thin wipe of rtv, cause as Bill said you have to push it in to get it into the jetcase.

I had no problem with hanger rash, just make sure that whatever you do it cannot hit the ground on a gear collapse, this includes putting it out on the wingtip or something.

I have mine in the vertical fin, that works well. I would think that on a BobCat you could go in the front of the boom or in the vertical.

As for the electronics, I mount them close to the pitot probe and then run a normal servo extension back to the ECU.

Of course with the new GPS unit you don't have to do any of this. And with a wireless modem you can read the speed with the handheld unit while in the air!

tell me more about this new gps unit..
is it jetcat mfg.?
how much added weight on board?
seperate battery?

Yes it is made by JetCAT, it plugs into an existing 4.0 ECU. No extra batteries.

I am not sure of the weight, I will have to find out.

Here are the menus:

Looks like this:


(to give you an idea of the size, those are the normal I/O board connectors at the top of the picture)

I retrofitted my Pitot in the right leading edge, just inboard of the right boom. Easy install because tube routing was a natural in front of the fuel tank. Access was the key. Seems to work great, and I have yet to bump it like you will in the nose!
Lee H. DeMary
AMA 36099

I put mine in the nose by first finding a plastic straw that was a perfect fit for the pitot tube. Then I sanded a flat spot on the nose of the airplane and made a hole to fit the straw. I roughed up the first 3 or so inches of the nose with 80 grit to remove the gel-cote and cleaned it with alcohol. I tack glued the straw into the fuse about 1 1/2" int the fuse with CA and made sure it looked straight with the fuse from the side and top. By sighting the fuse I determined a point to cut the straw which would be longer than necessary. Then I wrapped the straw and fuse joint with about two feet of carbon tow tacking both ends but leaving the middle unglued. I would estimate the whole thing was about 1 1/2 inches long. Then I mixed up some Pacer Z Poxy finishing resin and saturated the carbon tow. With the leftover epoxy I mixed in 1/2 micro balloons and 1/2 milled fiber until it was a thick enough mixture to stay where I put it without sagging. I built up this area longer than necessary to avoid doing this twice. Mix some more epoxy and pour down into fuse and hang fuse nose down until epoxy runs out the straw. When this has all cured pull the straw out. The epoxy will not stick to the plastic and you'll have a perfect fit once painted. Then start sanding until your happy with the way it looks. I drilled a hole from the bottom and tapped it for a 10/32 set screw from an old Bandit stab and installed the tube from inside the fuse. I also used retract air line for the pitot sensor and B.W. said this was fine. I think this gives the airplane a more streamlined appearance and has never been broken by the errant foot. I did this on a Bandit for Bob Wilcox and on my own Bobcat and will also add it to my new Super BANDIT . Hope this helps ,

Tim Redelman

Chris Huhn had the easiest setup for this I've seen on his F-16. The pitot tube simply slides into the nose and stops at the correct depth. It's held there by simple friction. In flight, air pressure assures the probe isn't going anywhere. Now.. to avoid damage, he pulls the pitot tube out further until it's free of the 'housing' in the nose and dangles by the flexible tubing.

-Doug

Hi Mark,

I have mounted the speed sensor several ways; in the nose, in the fin and on the side of the fuse in a mount. My least favorite is the nose. Everytime that you go off-road or when your NG fails to lock in the down position you will knock the speed sensor off if it is mounted on the nose. Of course, this shouldn't be an issue if you never have those problems. I'm not that lucky.

I really like the speed sensor mount that I purchased from Tad at Golden West Models for my BobCat. I have attached a picture of the mount on my BobCat. I will also include a photo of the speedsensor mounted in the vertical fin of my F-16. Both the vertical fin and the fuse mount are excellent solutions.

Gordon
http://www.gajets.net

Here is a photo of the speed sensor mounted in the vertical fin of my F-16. This worked out great because the full scale F-16 has a probe of this approximate scale mounted in the fin at this location anyway.

Gordon
http://www.gajets.net

Here's a Pic of where I have my pitot is located. You can see the tip of the pitot tube under the Remove cover------------
Lee H. DeMary
AMA 36099

PS can be retrofitted in about one hours time in this location!

Hey Gordon your not supposed to go 4 wheeling with that F-16. Get a Ford 150 4wd for that stuff! Just joking of course! See you @ Winamac June 26th - the 29th No excuses.

Tim

I liked the nose set up just because I thought it looked right. Making it movable makes life nice and easy. Mine didn't always ready correctly, but as time went on it ended up I had an ECU that had some minor issues. A new ECU and that was that.

Now for my good friend Gordon, I hate to break the bad news to you buddy, but on the real F-16's that probe is the inflight refueling light. The pitot tube is in the nose of the radome. But I promise not to tell the judges. <VBG>

John Redman
Team BVM, Jet Cat USA, Shultze Chargers

Hey Tim; You are right about the 4-wheeling. I just gotta figure out how to stay on the asphalt....

Good to also hear from you John! You are absolutely correct about the refueling light. FWIW, I didn't say that it was an air speed probe. I just called it a probe. It could be any kinda probe. . . . . It could even be a dildo or a proctoscope. Nevertheless, a probe is a probe. URGE... In and out.... You know what I mean....

However, since you brought it up, I posted a scale photo of the subject's vertical fin. So what if the probe is used as a light post instead of a speedometer. From an appearance standpoint it ain't far off....

Gordon
http://www.gajets.net

Now see what happens when I read more than one post at a time. For whatever reason I thought you had mentioned it was a pitot probe, but you didn't. Man do I look and feel stupid right about now.

You are right about it being the right scale and all, as well as being up and out of the way. Maybe I ought to put my glasses on before I read another post.<BG>


John Redman

Don't feel bad John, if you hadn't pointed that out, I would have!