doghousesmith

Just got a B20 Hacker motor. Seems to be a real challlenge to mount the thing. I know you can use the small screws that are provided to mount through a thin firewall, but what is the best way to mount it in front of the firewall?
Any ideas would be helpful. Thanks

sierra gold

Are you talking with the Maxon GB? (I've only mounted that motor.)

You want it out front of the nose hanging in the breeze?

Sierra Gold

doghousesmith

Sierra Gold,
In essence it will be hanging in the breeze. I have installed it into an airplane with "cheek cowls" (my Doghouse eXtreme that I have scaled down to a park flyer electric size). I have had another brushless motor with a gear box in the airplane and I want to use the Hacker in the same airplane without much modification to the airplane. I am R & D ing. My Hacker does have the gear box. If I had built the airplane from scratch for the Hacker, I would have made allowances for the mounting of the motor.
I have made a mount that works but I was interested in how others have handled the mounting problem.

sierra gold

I have used my Hacker in two planes. Both were electric gliders and both were set up with a firewall on the nose. I used the 2 small bolts into the gear box for mounting and a spinner to finish it off.

Sierra Gold

BykrDan

I will have this same problem soon - I'm looking at a brushless motor for the front of a firewall (will go under a cowl, maybe behind a fake radial).

My current plan is to construct some kind of simple tube, front closed off to attach the motor to, and a flange at the rear to fasten to the firewall - think "top hat" and you'll see it. Motor goes inside the top hat, shaft pokes out the top.

Sounds heavy and complicated, I know, but it's what I'm dealing with. I will likely use aluminum, or even plastic tube, drilled full of holes. I don't want it to be too heavy...

So, what did you do?

Dan.

BlackCloud

My Feedback: (12)

Hi Guys,
You may want to try this. I just saw it in the instructions for the Funtana. They took threaded rod 6-32 ( you may look for whatever size you may have already in the firewall T-nuts, possibly 4-40. I will do my best to describe as my scanner is not hooked up. Insert lengths of threaded rod about an inch and a half lnger than the length of your motor from the back to the front of the gearbox. You should have 3 or 4 rods protuding from the firewall now. Next place regular appropiate size nuts on all the rods and snug them to lock the rods to the firewall. Now place 1 nut per rod about 1 inch from thr firewall. Next take 2 pieces of 1/8 inch ply a little bigger than the perpendicular shape of the rods. A pseudo firewall and brace. Drill both of the threaded rod bolt patterns into the ply so they can slide onto the threaded rods. On one piece of ply bore a hole for the aft end of your motor to slide through. Just big enough to hold the back end of the motor. Slide this piece onto the rods and snug with 3 or 4 more nuts. Take 3 or 4 more nuts and place them about 1/2" from the front endt of the rods. On the other piece of ply you need to drill it out just as though it was the nose on your other planes. One hole for the shaft to come through and 3 or for for you motor mouting bolts that go in the gearbox. Make sure you have those lined up with the holoe in the aft plate so your motor is straight. Bolt your motor to the front 1/8 ply plate you made and slide it onto the threaded rods inserting the aft end into the hole in the back ply plate. Now just add 3 or 4 more nuts tothe ends of the rods to hold the front plate on. There you go! The neat part is you can adjust the nuts and move the motor back and forth to change the CG.
I was able to get a photo of the installation in the manual with my videocamera. Lookss like I have to attach it since I don't have a hyperlink to it.
Good luck. Hope this helps.

ERCAV8R

Take a look at espiritmodel.com. They have a couple of motor mounts that are attractive and functional.

Henke Torphammar

hi

just make sure to mount the motor in the gearbox! NOT in the motor it self... tourqe will bend the frontplate apart if mounted the wrong way....

tailheavy

Your loosing me man. How do you mount the motor IN the gear box??? The gear box is already attached to the motor. The only two holes are in the gear box itself (which I don't use). Why not mount the motor to a couple of carbon fiber rods sticking out of the firewall? This is what I do on my fan fold planes. Works great & not a lot of weight. I just tie wrap it to the carbon rods.

Henke Torphammar

The motor end bell (with the BG mounted on it) is glued to the motor it self, if spinning a 12" prop at full RPM and making a snap roll there will be huge forces in the glued joint which might separate. (the glue get´s weaker when heated up)

well, this is a larger motor, but I would only mount the B20 simmular to this, by useing the mounting screws in the GB and let the motor is self hang loose to prevent any damage from the gyroscopcal forces.

http://www.rcuniverse.com/attachment...postid=1185683

pikebishop

hacker sells a nice light laser cut mount of light ply specifically designed to mount the b20. check out their add in man to see a picture of it. I have made similar mounts myself out of scrap. I think they charge six dollars for it.

tailheavy

I understand the difference now. But I am disappointed in the glued on gear box job by Hacker. I wondered how they attached it on there but now that I know I am real leery about it coming off even when mounted properly. After all the snap roll can be a pretty violent maneuver. The application I am using mine in is a fanfold trident and I just made it to practice hovering close to the ground so I think I'll be alright the way it is.

BykrDan

Hi guys;

This may not apply, or help with any of your projects, but I had to share...

Here's my plan to convert a PVC shower drain and pipe cap into a motor mount, to hold a brushless rotating can AXI 28xx about four inches in front of a GeeBee firewall. Excuse my rough drawings...

Dan.

BykrDan

The ovate hole under the motor is the battery path. The battery will pass uncomforably close to the motor!

tailheavy

My hacker b20-26s motor came with a small fiberglass disc with the holes drilled to mate with the maxon gear box. I just used a couple a 4mm carbon fiber rods fitted with those stand offs found in computer cases. I had a bunch of left overs from computer projects. See the picture for details.

Walt Thyng

My Feedback: (9)

It sounds like the original question was for a small motor, but I thought I'd throw my latest idea into the mix. I bought an 89 cent joist bracket from
ACE. They come in a smaller size for 49 cents. All I had to do was clip off a couple of locating pins, drill the firewall bolt holes and snip four strips of aluminum from some flashing. They're galvanized steel but the whole set up only weighed 3.5 oz and was probably only 1oz heavier than the mounting system it replaced.

I have an Aveox 36/38/3 geared 3.33/1 swinging and 18/10 prop off 25 cells mounted in it.. That's a fair amount of torque and weight. The mount handled it just fine. Not bad for less than a buck!
Walt
Illinois