rheauljj

I'm trying to drill the Robart hinge points holes accurately. I'm having a difficult time getting the two holes (control surface and wing surface) to line up correctly. The first one is easy but as I add hinge points I have holes that don't align correctly. It's driving me crazy[:@]. I realize it's because I'm not drilling these correctly but not sure if there are any strategies that will make me less frustrated.

I'm using a hand drill with a 1/8 bit and the Robart drill guide.


Any tips?

APIA

Lay the control surface on top or bottom of the wing and transfer the marks from either the aileron to the wing or vise versa. I would also recommend starting out with a smaller drill bit and work your way to the final 1/8" size. I also do not use a mechanized drill, I use a pin vise which is twisted back and forth with the fingers, a lot more control can be assured this way...

rheauljj

I'm actually using a pin vise (advice I got from Airfieldsmodels.com site). Would you drill all the holes for both surfaces at one time?...or one set (two sides) at a time?

sscherin

My Feedback: (1)

There's a 3 page thread in the tips forum on robart hinges
http://www.rcuniverse.com/forum/m_1378983/tm.htm

this is my post on that thread
http://www.rcuniverse.com/forum/fb.asp?m=6163753

I really like the Airfield models method..
http://www.airfieldmodels.com/inform...ints/index.htm



I used a variation of his method. This works best before beveling the hinge line.

Get some hardwood square stock the same thickness as the surface to be hinged to use as a drilling guide.

mark the CL and each hinge location on the hardwood mark each side of the hardwood to indicate what surfaces it faces.. that way any mistakes don't get exagarated by reversing the drill guide

drill the marked location on the hardwood block..

sandwitch the drill guide between the 2 surfaces to be hinged and make an alignment mark across all 3 pieces..

take it apart and tape the drill guide to one of the surfaces making sure to get it centered, facing the right way and aligned on the marks you just made..

drill your holes, repeat on the 2nd surface..

pieces of 1/8 dowel work great as mock up hinges to see how things line up.

APIA

I usually do one side at a time

rheauljj

Perfect. I saw your images from your post and it makes perfect sense. As long as I secure the guide to either surface I should be able to drill all holes. I just have to maintain the correct orientation of the guide for the alternate surface. Can't miss.

Thanks for the information.

scratchonly

What APIA said.

CafeenMan

rheauljj - I'm the webmaster for Airfield Models. I'd like to improve the article on my site. I agree that making sure the same side of the guide is up for both surfaces is a good idea and is what I do. I didn't mention that in my article so I'll add it.

However, I'm sorry that my article didn't get you through the process. What gave you problems? What can I do to improve the article?

Thanks,

- Paul

rheauljj

It was your site that convinced me to try hinge points in lieu of CA Hinges. I bought the Robart guide, pin vice and drill bits as per your instructions. My problem is aligning (in a 5 hinge installation) all the holes (in the two surfaces) perfectly. The best I can do is get 3 out of 5 aligned...very annoying. I know it's not the tools...it's the user. Something that will improve over time. However, making a hardwood guide seems to be a good solution.


I find your site to be the most complete RC resource out there. I'm fairly new to the hobby and enjoy building more than flying. I refer to your site for every question that comes up. It's like an encyclopedia. Very complete resource.

CafeenMan

rheauljj - Thanks for the Kudos.

The way I tackle horizontal alignment is to use low-tack double-stick tape to hold the two surfaces together - one trailing edge above the other. Then I draw the hinge locations using a machinist's square.

When I use the Robart guilde I look carefully down the hole to make sure the line is centered. Because you have to look at an angle so you don't block light getting in, the line can look centered when it's not.

I clamp the guide in place using a couple spring clamps while I'm doing this. Then I flip the surface around several times and look at it from as many angles as possible until I'm absolutely satisfied the line is centered. Then I put the bit in and give it one or two turns and remove it. Look in the hole again and make sure the dimple is on the line.

The guide should take care of vertical alignment.

I also drill for the hinges before I do any major sanding. The only sanding I do is to bring everything flush and usually I use stock that's thicker than the piece will end up being. After all the hinge holes are drilled I use dowels to put the surfaces together and I sand them as a group to bring them flush with each other. If you use thicker stock then you can sand the hinged surfaces to a perfect match.

In practice that doesn't always work so well because the next thickness from 1/4" is 3/8" and I don't want to sand 1/16" off each side. So I do the best I can with the hinges and usually end up with a surface that's a little thicker than 3/16"

If I'm building the surface from sticks then I saw my own and I can make them 5/16" thick which I can sand to 1/4".

sscherin

My Feedback: (1)

CafeenMan

I just wanted to also say thanks for your great site..

Like rheauljj I chose to give robart hinges a 2nd shot because of your articles.

gstockton

i also enjoy your site have it on my favorites list i will use robart hinges on my next build already got the guide and hinges

CafeenMan

Thanks for the kind words. I appreciate it.

If you get the knack of installing hinge points they will probably become your favorite hinge. They're a lot easier to install than flat hinges and you have a better chance of them being aligned properly.

ecmiller

Here is what I do. I drill the holes in the control surface first to finish size. Start out with a smaller pilot hole to keep the finish drill from walking. Next, insert a dowel transfer in each hole properly sized for the hole. These look like transfer punches only shorter with a lip near the top to keep you from pushing them all the way into the hole. Finally, place the control surface against whatever trailing edge you have either wing, stab or verticle fin and lightly press. Viola..the points on the transfer will make indentations to show exactly where to drill the other two holes.

You cannot miss with this method.

Good luck.

gstockton

where do you get the dowel transfer they sound like would be good way to do it

sscherin

My Feedback: (1)

they are commonly called Dowel centers.. Home depot sells them but I've never seen a set smaller than 1/4"
Rockler has them too.. same thing.. 1/4" is as small as they go
http://www.rockler.com/product.cfm?page=859