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Old Feb 03, 2013, 10:05 AM
Stick lift beats no lift
TexasJohn's Avatar
USA, TX, Arlington
Joined Mar 2003
147 Posts
Help!
Need ideas - tools for cutting a hatch in fg fuse

I'm pondering converting a pure glider to electric. Its a beautiful machine and I want to cut a hatch under the wing - in the belly - to move the tail servos back there, leaving the nose and near front of wing for battery, esc and so on.

The hatch would ideally be a smooth oval with absolute minimum kerf. Then I'd glue an inner lip inside and mount semi-permanently.

My notion so far is a tiny router bit and some kind of pattern to attempt to follow - something harder than fg so the bit will sort of follow the pattern.

I have some collets for small drill bits...now I think I need some tiny routers too.

Does anyone have any special suggestions or techniques for the cutting and guiding the cutter? My experience is they wander a lot. I'll start looking for the bits - may even have them at my local Hobby Town.

Here is a link to the glider if you want to see it before I do this really bad thing to it (bad if you are a glider purist!!). http://www.rcgroups.com/forums/showthread.php?t=1808352

Thanks.
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Old Feb 03, 2013, 10:40 AM
Registered User
Joensuu, Finland
Joined Mar 2002
1,457 Posts
I'd just cut the hole a little undersize and then sand it to the size and shape needed. Obviously I'd then need to make a new hatch from scratch. Or more likely just patch the hole up after installing the servos, accepting that any maintenance will require surgical operations.

If you decide to have a removable hatch, I'd recommend adding some carbon rovings around the hole to carry bending and twisting loads to the other side of the hole.
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Old Feb 04, 2013, 11:35 AM
The Prez....... again
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United States, IA, Rockwell
Joined Jul 2011
4,005 Posts
I have a large assortment of dental drills at home. Some are even carbide! Trying to find or build a pattern will be the tricky part. I assume you wan to save the cutout for the new hatch. It may be easier in the end to just build a new hatch. The time to do that is before you cut your fuse for the access hole. Mark your spot where you want the hole. Lay some saran wrap or other film on the spot and proceed to lay up some glass and epoxy to the thickness you want. Basically you are using the fuse as a mold for your new hatch cover. No need to be neat at this point. After you cut and finish your access hole take the new fiberglass part and trim to fit your hole.

Hope this helps.

Ken
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Old Feb 04, 2013, 09:29 PM
Stick lift beats no lift
TexasJohn's Avatar
USA, TX, Arlington
Joined Mar 2003
147 Posts
I like this. Could even make an extra hatch just in case. Yes I was hoping to use the cutout ....my first choice.
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Old Feb 05, 2013, 07:19 AM
-insert witty saying here-
Hemikiller's Avatar
United States, CT, Killingworth
Joined Dec 2005
1,792 Posts
Quote:
Originally Posted by kenh3497 View Post
I have a large assortment of dental drills at home. Some are even carbide! Trying to find or build a pattern will be the tricky part. I assume you wan to save the cutout for the new hatch. It may be easier in the end to just build a new hatch. The time to do that is before you cut your fuse for the access hole. Mark your spot where you want the hole. Lay some saran wrap or other film on the spot and proceed to lay up some glass and epoxy to the thickness you want. Basically you are using the fuse as a mold for your new hatch cover. No need to be neat at this point. After you cut and finish your access hole take the new fiberglass part and trim to fit your hole.

Hope this helps.

Ken
That's the "best" way IMO, it's how most guys make gear doors and access hatches.
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Old Feb 05, 2013, 08:10 AM
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rcav8r2's Avatar
United States, PA, Beaver
Joined Sep 2001
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Something to think about, although it may not be a problem here, is that the fuselage appears to get it's strength from the shape. By cutting a hatch in the fuse will weaken it. Size and position will dictate how much. Just something to think about particularly when adding a motor/battery

FWIW, a flying buddy cut a hatch in a molded fuse quickie 500. A few of us at the field, tried to tell him it was a bad idea due to placement and size. Well a few flights in, the plane told him it was a bad idea by exploding during a turn.
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Old Feb 05, 2013, 07:00 PM
Red Merle ALES
Curtis Suter's Avatar
United States, Mt, Helena
Joined Apr 2002
5,543 Posts
I use a place masking tape along where I want the hatch, draw a cut line in pencil and then very carefully and slowly cut with and Xacto blade.

To make the canopy and lip see here:

Read through post #110
http://www.rcgroups.com/forums/showt...7#post21097972

And here:
http://www.rcgroups.com/forums/showt...5#post17319543

Curtis
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Old Feb 05, 2013, 10:50 PM
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Wilfor's Avatar
Canada, BC, Williams Lake
Joined Jan 2010
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Check out this home made hatch cutting tool http://www.rcgroups.com/forums/showp...&postcount=287
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Old Feb 08, 2013, 12:03 PM
Stick lift beats no lift
TexasJohn's Avatar
USA, TX, Arlington
Joined Mar 2003
147 Posts
I thought the inner lip creation was brilliant.

I may have found a simpler solution.

It turns out that LiFe batteries in a line might fit where my ballast used to set...so maybe no need to shift anything around. Now I'm focusing on fitting a motor in there with the nose cone remaining removable. I think it might work with a folding prop if the prop will flip forward and I can bear to cut a big enough chunk off the nose cone to fit over the yoke...not sorted out yet.

Thanks for all the great ideas - I enjoy reading them.
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