kelownafred

I've been building my first RC model, a Sig LT-40 for a few days now...things were going nicely and I was having tons of fun but now I've come to a speed bump.
I'm making the slots for the Sig Easy Hinges on the wing. Now the stabilizer went great, I was a little nervous...first time doing this and I really wanted to get them right. Well they went great! So onto the slots on the wing trailing edge with confidence and.....I've come to an almost grinding halt!![>:] The wood on the trailing edge is way harder than the stabilizer wood. I just spent 2 hours of valuable and hard to come by building time and I have two slots cut!! The Exacto blade is no match for this tough wood, I even tried a Dremel wheel but it doesn't go deep enough and if I put on a bigger wheel I'm afraid the slot will be too wide and long. Does anyone have any tips, suggestions to do this job a little faster?? Thanks for any help.

RCKen

My Feedback: (9)

The solution will cost you a little bit, but order the electric Slot Machine (or pick it up from the hobby shop). This tool is worth every penny. You can cut all the slots for your entire plane in about 5 minutes.

bruce88123

I have the electric slot cutter and it works great. I usually use Robart Hinge Points but when I do use flat hinges, this makes quick work of it. You wouldn't want soft wood in the trailing edge. They make 2 blade sets for the machine depending upon the type of hinge you are installing, get the correct set (or both). Machine is made by Great Planes and available thru Tower:
http://www2.towerhobbies.com/cgi-bin...?&I=LXK263&P=7 only $20.
Good luck.

cwrr5

My Feedback: (32)

Or you could use the Robart hinge points, then all you gotta do is drill holes instead of cutting slots.

Al Stein

If you aren't ready to invest in the Slot Machine, you could also drill a hole (about 1/16" size drill) at either end of the slot and use a piece of hacksaw blade to clean out a slit from one end hole to the other.

Hacksaw blades are very brittle, so you can hold one in a vice or even in pliers (prefer something like linemans' pliers that have a wide, straight gripping end) and break them with a hard rap of a hammer or reasonable facsimile. (DO wear eye protection... we're talking about intentionally shattering a piece of hard metal -- not good for eyes.) You jst need a piece that has the back edge tapered down to the toothed edge... taper over a length of about an inch and a half. at the "pointy" end, I keep mine about 1/8" or 3/16" wide and shapen the tip with a little grinding wheel on the dremel. That's wide enough to have some strength and sharp enough to do some piercing, given the end hgole to guide it. I made a wooden handle for mine, but wrapping the end you hold with tape should do just as well.

So, to use this thing, you draw a center line on the trailing edge staock and mark the ends of where the hinge slot goes, drill the ends, insert the home-made tool into the drill slot and use its teeth to work your way to the other end (or work from both ends in to the middle.)

The slot will be 1/32" wide -- that's perfect for pinned hinges, but wide for glue-in hinges. Personally, I use pinned hinges, so it's fine as is, but if you're using glue-ins, just take (or make) a bit of 1/32" or thinner scrap and glue that into the slot with the hinge material. It still takes a few minutes to cut a slot this way, but it works very well without any significant money invested.

One other option -- sometimes I borrow a Slot Machine. That works great and all I have to do is repay the favor of the loan. A serious builder ought to have friends who can lend things back and forth!

bruce88123

A serious builder would have a hinge machine. But that aside, use the Dremel you said you had and use it to cut (cutoff disk) the hacksaw blade if you go that way. Go slow as you do not want to heat up the blade and ruin the tempering of the metal. Just make slow and shallow cuts while allowing the metal to cool between passes. You don't want it to ever start to glow red or even get hot to the touch. Wear eye protection and watch where the residue flies(makes a mess). Wrap blade with a lot of masking (or duct) tape for handle. Try to leave about 6 inches for a handle for good control and work slowly as usual. You can do a lot of damage in a hurry

ps- if you get the machine, practice a few times on scrap until you get a feel for it, it take a couple of tries to get it right

horace315

My Feedback: (15)

if you have an old set of hair clippers that you don't like anymore remove the main blade and fasten the hacksaw blade to the vibrating end it works quite well,most blades have a hole in both ends use that hole for the screw and cut the blade as mentioned with a dermal or grinder.the one i made works very well

kelownafred

Thanks for the tips guys, I stopped at my LHS on way from work yesterday and picked up a Dubro's Slotter Tool Kit, they didn't have the electric tool. The Dubro tools worked better than an Exacto knife but on the tough balsa the tips began to bend a bit. So then I cut up a hacksaw blade with my Dremel as suggested and in combination with the "pick" tool that came in the Dubro kit I got the job done. For the tail control surfaces I will attempt that hair clipper tip of Horace315's as I suspect the electric slot machine works on the same principle with the same action. So thanks again. I'll post a few pics when I get home to show off my progress

bruce88123

Actually the slot machine use a pair of blades oscillating in opposite directions sort of working against each other in a productive way. Makes a quick, clean cut. For the $20, I would think your time and the accuracy would be worth ordering it. IMHO If you do get the machine, be sure to get the guide which automatically centers the slot for you, just a few bucks more. Get thru LHS or Tower.