Canard Aviation Forum  

Go Back   Canard Aviation Forum > Chapter Specific comments, questions, tips & tricks > Chap 4 - Bulkheads
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 09-14-2011, 10:17 AM
egstrong's Avatar
egstrong egstrong is offline
Member
 
Join Date: Jul 2010
Location: Houston, TX
Posts: 45
Default Cutting out engine mounts

Boy, I can tell I'm going to be on here a lot. I've got the firewall bulkhead cut out and am getting ready to cut the holes (squares?) for the engine mounts.

What's the best way to cut out the 1/4" aluminum sheet? I could have at it with my jigsaw, but I've found my abilities in cutting a straight line with it are somewhat limited. I don't want to spend an hour or so trying to file it down to a straight line.
__________________
Ed Strong
Houston, Texas
http://edscozy.blogspot.com/search/label/.Introduction
Reply With Quote
  #2  
Old 09-14-2011, 10:51 AM
kjashton's Avatar
kjashton kjashton is offline
Member
 
Join Date: Jul 2006
Location: Concord, NC
Posts: 620
Default Re: Cutting out engine mounts

Suggest buying a cheap Harbor Freight bandsaw or better if you can afford it. Hit the pawn shops or Craigslist. It will cut aluminum just fine with a fine-toothed blade although the speed is too fast to be ideal. Remove cut marks with a hand-held belt sander inverted on your table secured with something. Even better is a 2-speed bandsaw you can slow down for steel cutting.

If you contemplate working with steel (there is not much steel on a Cozy that you can't buy prefab'ed), then you might want to go this way. The blade can be erected and used like a HF bandsaw but the blade is wide and will only cut straight lines.
http://toolmonger.com/2009/04/20/hot...tting-bandsaw/
__________________
Kent Ashton
Cozy IV N13AM
Reply With Quote
  #3  
Old 09-14-2011, 10:57 AM
RPR RPR is offline
Member
 
Join Date: Jul 2007
Location: Kingwood Texas
Posts: 30
Default Re: Cutting out engine mounts

Hi Egstrong, if you are close enough to make it worthwhile taking a trip over to Kingwood I have a large bandsaw which will make short work of any cutting requirements. Will be glad to help.
Richard
Reply With Quote
  #4  
Old 09-14-2011, 11:21 AM
ZG4Me ZG4Me is online now
N14ZG reserved
 
Join Date: Sep 2006
Location: Colorado, KLMO nearest
Posts: 1,020
Default Re: Cutting out engine mounts

Quote:
Originally Posted by egstrong View Post
What's the best way to cut out the 1/4" aluminum sheet? I could have at it with my jigsaw, but I've found my abilities in cutting a straight line with it are somewhat limited. I don't want to spend an hour or so trying to file it down to a straight line.
Tools are good! More tools better!

I picked up a 1x30" Delta belt sander at a garage sale, it gets used a lot. I also bought a wad of HF belts for it, they only last a minute or two compared to the higher priced belts from Norton/3M/etc. YMMV of course.

Use Dykem layout fluid on the metal, scribe the lines (a hat pin will work in a pinch), cut with a coping saw (wood blade works just fine) or hack saw just proud of the line, sand to the line. It's not that hard to cut a straight line with hand tools, if the tools are of fair quality and rigid.

If your AL stock is 2", make your engine mound hardpoints 15/16" square. 1/16" is the saw cut and sanding allowance.

Or just cut the hole in the bulkhead to match the slug, even if out of square or small/large. Flox will take care of minor irregularities.

Rick
__________________
Rick Hall; MK-IV plans #1477; my canard at: http://cozy.zggtr.org/ My hobby at www.zggtr.org/
Build status: It flies! Airworthiness 10/7/2016.
Reply With Quote
  #5  
Old 09-14-2011, 11:34 AM
TMann's Avatar
TMann TMann is offline
Got Foam?
 
Join Date: Mar 2007
Location: Omaha, NE
Posts: 3,604
Default Re: Cutting out engine mounts

Just a note/tip.
You don't want to mount your firewall in anything other than a temporary fashion until after you mount the center section spar.

...... and you don't want to mount the spar until after you mate it to the wings.
__________________
T Mann
Long-EZ/20B Infinity R/G Chpt 18
Velocity/RG Restoration
EAA #390365
Got Foam?
Mann's Airplane Factory
We add rocket's to everything!
4, 5, 6, 7, 8, 10, 13, 14, 19, 20 DONE
Reply With Quote
  #6  
Old 09-14-2011, 11:55 AM
David Clifford's Avatar
David Clifford David Clifford is offline
Member
 
Join Date: Apr 2004
Location: Howell, Michigan 48843
Posts: 1,349
Default Re: Cutting out engine mounts

A good carbide tipped blade in a miter saw works great for cutting aluminum,, especially bar stock. I cut 1" square and 1/2 aluminum" plate with excellent results. On most miter saws there is too large of a gap between the blade, fence, and blade kerf insert. I use an "L" shaped piece of wood to hold against the fence that the piece to be cut rests in. Ease the blade in after it reaches full rpm and use slow steady pressure.
__________________
Van's RV-10
N959RV
Flying: 12/29/2013 and having a blast in Phase 1

Donation due: 12/2013
Reply With Quote
  #7  
Old 09-14-2011, 07:43 PM
Steve parkins's Avatar
Steve parkins Steve parkins is offline
Member
 
Join Date: Apr 2004
Location: daly city
Posts: 2,796
Default Re: Cutting out engine mounts

i cut out mine from a old bent 0300 mount a found at osh.
o wait, this was from a new builder and he ment hard points,lol
mine are in there some were and was cut from the left-over stock of a 747-400
Attached Thumbnails
Click image for larger version

Name:	oshslushphone 056.jpg
Views:	170
Size:	105.5 KB
ID:	5975  
__________________
edited by steve for a good reason
Reply With Quote
  #8  
Old 09-14-2011, 08:15 PM
Big Steve's Avatar
Big Steve Big Steve is offline
Plane building junky
 
Join Date: Aug 2006
Location: Filer Idaho
Posts: 565
Default Re: Cutting out engine mounts

A good carbide blade on a table saw will cut aluminum. Steve build on
__________________
Lovin Life in Idaho
http://websites.expercraft.com/bigsteve/
Plans #1466 on Chapt. 23 baffling
Reply With Quote
  #9  
Old 09-14-2011, 08:38 PM
David Clifford's Avatar
David Clifford David Clifford is offline
Member
 
Join Date: Apr 2004
Location: Howell, Michigan 48843
Posts: 1,349
Default Re: Cutting out engine mounts

Quote:
Originally Posted by Steve parkins View Post
i cut out mine from a old bent 0300 mount a found at osh.
o wait, this was from a new builder and he ment hard points,lol
mine are in there some were and was cut from the left-over stock of a 747-400
Looking good Steve. I need to get out over to KVLL to see your project along with Dusts. Summer vacation is over for me so I am back home in the shop again.
__________________
Van's RV-10
N959RV
Flying: 12/29/2013 and having a blast in Phase 1

Donation due: 12/2013
Reply With Quote
  #10  
Old 09-27-2011, 11:38 AM
egstrong's Avatar
egstrong egstrong is offline
Member
 
Join Date: Jul 2010
Location: Houston, TX
Posts: 45
Default Re: Cutting out engine mounts

Thanks for all the inputs. I got a wild hair last night and had at it with the jig saw with new metal cutting blades. The blade did wander a bit, but not as bad as I had feared, and filing the edges flat didn't take nearly as long as I expected. Of course, they weren't exactly 1" square as someone else has already noted, due to the kerf of the blade. I'll have to double check my measurements later today and make sure they are at least 15/16" square.
__________________
Ed Strong
Houston, Texas
http://edscozy.blogspot.com/search/label/.Introduction
Reply With Quote
Reply

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 02:12 AM.


Powered by vBulletin® Version 3.6.7
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.