A friend is building a new jet and wants to do first flights with an IC engine BUT with the idea of putting in a JetCat P120 or P160 in it once the design is proven.

This is going to be a trainer for a new even larger scale jet.

He wants to drill the fuse for the JetCat and then build an IC mount.

Any help appreciated.

Rcbart

I have never seen drawings for the stock mount. Why doesn't he just go ahead and mount the turbine, take the mount off and match those holes?

Sorry if I am missing something.

Yup, he doesn't have a turbine, nore one to look at. The idea is to built an IC motor mount unit that will attach TO the screw holes where a JetCat WOULD mount - when he gets to buying one.

ie. he would 'match' the drill pattern so as to have the plane 'JetCat ready', when he buys one.

Matt,

Any luck with obtaining the bolt pattern, or suggestions as to who could give it to me?

Thanks
Bart

Hi Bart,

I completely dropped this thread. I checked with the shop and there are no drawings of the mount with the holes. I guess I could try to measure one, but candidly I am not very familiar with this mount as I have never used it.

I am not sure how accurate my measurements would be, but I can try to get them tonight

Well I tried to measure the mounts, but it is difficult, as the shape of the mount is somewhat affected by whether the motor is bolted into or not.

As best I can tell, the dimensions of the bolt pattern are

6 5/32 X 2 3/32 inches. The longer dimension is across the turbine, in other words parallel to the wingspan.

This is very rough and will likely require slotting of the holes, so be forewarned!

I found the exact same problem last night when I was going to measure one of my unused Jetcat mounts. Without something to tighten it around, any measurement is going to be rough.

I should be getting an engine back from Jetcat in the next couple of days - if it helps, I could temporarily put the Jetcat mount around that engine & take some measurements before putting the engine back in the BVM mounts that I'm using in the aircraft.

Lemme know if you would like me to do that. Also, rcbart mentions using a P120 or a P160 - are the cans exactly the same diameter, so that a measurement based on just one of these engines will be sufficient ?

Gordon

It sjust after a motor is bolted in it, you will need some kind of divider to measure it, and I did not have one this morning at the shop. If you have a way that would be great.

Okey-doke -- when my engine arrives, I will slap it in the mount & take the measurements for rcbart. I have various calipers that should be able to do the job quite well.

Gordon

Thanks guys, much appreciated.

Bart

Okay - the brown toy truck just delivered my engine - so here's my measurements. The measurements were taken in millimeters, so they are more accurate that the imperial equivalents which are close approximations.

Where Matt gets 6 5/32", I get:
Rear : 155mm = approx 6 3/32"
Front: 154mm = approx 6 1/16"

Where Matt gets 2 3/32", I get
54mm = approx 2 1/8"

This was with the clamp fully tightened around the case, and the measurements were taken with two different calipers just to double-check on the meausrement.

The above measurements differ form Matt's "rough" measurments by only a millimeter or two, so no big deal there - as Matt says. you can always slot the aluminum engine mount very slightly to account for minor tolerance variations.

Later,
Gordon

Thanks all, I will give this to the gentleman on Saturday, he is back on this projectt - he had one to finish for an upcoming meet- so might want to start this tomorrow.

Regards
Bart

As I suspected, he had the IC motor mount built, waiting for the base size. Attached is the picture. The pencil is sitting on the fueld tank/thorttle servo tray, the circle at the right is the engine firewall while the unfinished plate at the bottom is to mount to the plane.

Thanks again.
Rcbart