MAC Forum

Well today I received an Allyn B-50 model and it arrived broken. Even after asking the seller to separate the stand from the model when packing, they still packed the model with the stand connected. See images. Anyone out there have a fix for this or have any suggestions?

Thanks...

Good old-fashioned epoxy/resin should be able to fix that though I suspect an all-metal model would be a bit on the too-much side.

If you have a dremel or small drill you could drill a hole in each of the separated mounting pieces to install a strengthening pin. That's what the Vatican did to restore the Pieta after some nutsack went at it with a hammer.

Bummer, I have the same B-50 model, broken in the same way.

Another nice model succumbs to seller stupidty. I would jump both on Ebay seller and the postal source for refunds...

That said, These breaks are tough to fix and if they are "fixed" never move that ball again, too much torsion.

Ok here we go...
First try to get the two parts together and carefully mark with a fine SHARPIE marker east, west, north and south on both sides of the break. This is to facilitate the location later on in the process....

The Dremel IS the tool of choice. A set of miniature drill bits is next. You will use not only one but two pins of very small music wire and these two will be fitted to the the airplane side of the break. The wire size can be as small as .015" (Ace Hardware has all of this so far). Equal distance from the center of the break to the outside of the break in two opposite locations is where the two holes will be drilled. It is preferred that these two holes be the same diameter as the wire. Music wire is very tough wire. It is not easy to cut and the wire needs to have the burrs ground off as well. The Dremel and a cutting wheel is an absolute here. The wire needs to have an affixative (glue). The best choice is a slow curing epoxy. After at least 24 hours, you are ready for the next critical step, locating a drilling holes into the base side of the stand/arm. Do your best to allign those SHARPIE marks and mark the site ends for the music wire. Once you believe you have made the marks in the right place, drill the two holes but with a slightly larger diameter drill bit. Set the airplane into place and see how well the marks line up. If they are slightly off, try to determine which pin is off and again drill out the hole with the next size bit. Do this until the ball sits approximately in place.

If you feel confident that you have a nice fit then you can prepare for the last step, re-attachment. There is a need to support the heavy model as the epoxy cures. Build up, with books and wood, two or three (if tail heavy) support columns to steady the model during the cure. Now go for it. Clean both sides of the break with rubbing alcohol and let dry. Then, mix the epoxy and be careful to get the 50/50 mix dead-on. Apply some to the holes then a little to both faces and fit the airplane into place. Any excess can be wiped off lighter fluid. Now go take a trip someplace and do not touch this airplane for at least 3 days.

Oh yes, about those SHARPIE marks, a cotten swab and acetone if use quickly and sparingly will do the trick. Kryon makes a respectable match for the paint color... Bronze, I believe.

From here on the airplane will be ok for display but it will never fly again.

Regards,
Tom Sanders

I would follow a somewhat different approach.

First, remove the ball from the model. That is very easy. Just remove the two screws on the bottom of the model and the spring that keeps the ball tight will expel the ball out.

Then I would glue the ball to the arm of the stand using some liquid superglue. The purpose of this is to make sure that when the arm and ball are drilled the hole will be a perfect match. Then I would basically follow the same routine that Tom is suggesting by starting with a very small drill bit and slowly increasing the drill bit size until achieving the desired hole size. If using piano wire for the reinforcing plug I would make sure that the wire surfaces are ground using coarse sand paper, or better a coarse grinding stone. Epoxy glue will not adhere well to piano wire if the surface is nor rough.

Once the hole on the ball and arm are the right size I would pull the ball apart from the arm (some markings with a felt tip might help on putting the assembly back together on the right place) and glue the ball/plug/arm with the best epoxy glue you can find. Once it sets it can be sanded and polished, and the model reattached to the arm. I should be fully functional.

After giving a some time to consider further options, I think I wand to ammend the processes discussed previously and suggest that after gluing the ball in place, to would drill from the bottom up through the ball then tap the hole for a machine screw. When bolting together, put JB Weld in the hole first and then screw together. Let that set for 24 hrs. When dry, use a Dremel with a grinding wheel and grind off the head of the bolt(opposite the ball and under the arm). Various grits of emory boards can be used to smooth the area.

If this all seems a bit difficult, send the parts to me and I will see what I can do.

Regards, Tom Sanders

I was thinking the same thing! Drill from top to bottom, glue broken piece to upright and then when dry drill from bottom of upright up to the glued broken piece. Tap and bolt. The shipping paid for the insurance so I got my money back and kept the model. All in all not too bad!

Thanks

soslipstream wrote:If this all seems a bit difficult, send the parts to me and I will see what I can do.

I may take you up on that offer Tom.

Thanks,

Frank

I have repaired several of these in the past, what I did was to file the remainder of the ball post smooth with the rest of the upright part of the stand. Get a matched set of drill bit and tap to match the size of ball link to fit. Drill carefully .....tap......screw in new ball link.....done.

A ball link if you don't know is used in several different types of R/C cars and can be found in most all hobby stores. Ball links are mostly stainless steel and much stronger.