I can never seem to get nice round perpendicular holes cut in the foam for wheel wells. I end up with gaps between the balsa wells and the foam. I know it's hidden after sheeting, but I'm hoping someone can share a tip or two.

Thanks!

Hi Jeff,

The trick is to cut the wheel well in the foam before sheeting. Two identical template plates for the well and the channel to the fuse for retract linkage are placed at exactly same location at top and the bottom of the core. Then the cutout is made following the curves/lines on the template.

Hope this helps.

I cut my wells before sheeting. The top/bottom template is an obvious oversite.... Thanks!

I needed this answered as well... Thanks!

Brian

I cut the wheel well with a hole saw before the wings are sheeted then line the wheel well with 1/16 balsa. Iinsert a foam rubber donut in the wheel well to hold the balsa in place while glue drys.

the donut is a good idea!
Hmmm.what if i use an actual donut ?
then i could eat it after i was done.
i always cut the hole after sheeting but i think i will try the before idea it sounds like it might work better
Dave.

A soldering gun and 1/32 piano wire looped from one side of the iron to the other. just watch the heat with the triger.
I use furnace tape on the edges of my templates to keep from burning soft templates.

Possibly you could share with the class the method you're currently using. Hole saws do a really good job making round holes.

The soldering gun is the best foam tool you can have when building a foam wing or just shapeing. You form the wire to what you want to cut, from wheel wells to servo extention channels and spar slots. When cutting wheel wells, place the wire close but not touching for fine cuts. You can make them as long as you need but do not force the cut. Takes a little practice.
Larry K

The only thing I do not like about the saw is they make such a mess

One of the techniques I learned (here, probably) that "cleans" the wells up nicely is that if you slightly undercut your wells with the gun, even if your gun handling or template is not quite up to snuff, you can then sand the wells clean with a paint can cap and some 220 grit sandpaper wrapped around it. Not only does it sand things round and smooth but it also can sand the base of the well with some sandpaper glued to the base of the cap (use the self adhesive paper for this).

But it is certainly an acquired art. I'm still working on getting them just peachy!

David.

Find a can the size of your wheel , cut off the rim and make yourself a hole saw.

This is one good way I used as well back in the day of classic builds. I've built the saw from various things, like cans, even schedule 10 pvc pipe. I even lined the foam with foam coffee cups in lieu of balsa. Worked well

Last time I built a retract model about 10 years ago, I tried something a little different. ACP sells a nifty little tool called "Hot Hand" or something like that. It's a 5" long piece of stailess tubing about 1mm in diameter, on a handle with power leads. Connected to a 12 V 1 amp power source such as some transformers one may have lying around, this thing is excellent for carving foam.

Anyway, I cut a pair of templates from card stock with the retract holes (including the strut section) located where I wanted. Cutting perfect circles in the card stock was simple....fashioned a simple hole cutting tool using an Xacto blade, a popsickle stick and a push-pin. Both templates cut together to assure precision. One template taped on top of the foam wing the other taped to the bottom, lining up LEs TEs and root chords. The Hot Hand tool cut the holes perfectly. The same templates used on both wing panels.

FWIW2U