Logo 500 Tail And Boom Upgrade Project

[dswitkin]

I thought I'd start a build thread about my latest project. The idea was to upgrade my Logo 500 using the 25mm boom from the Logo 600 along with its open CF tailcase, while still running 550mm blades. The result should be stiff enough not to use boom supports (the stock boom is 20mm), which means no horizontal fin either.

Here's a sneak peak at the result. I'm looking forward to your feedback.

Cheers,
Daniel

[dswitkin]

After some research comparing the two manuals, it turns out you only need four part numbers at a bare minimum. Here's my order with prices from RH:

MIK4228 Carbon Tail Rotor Case Set for LOGO 600 $70.99
MIK4139 Rudder Control Guide For 25mm Tailboom $6.99
MIK4091 Logo 600 Tail Boom Holder $6.99
MIK4098 Tail Boom LOGO 600-3D $19.99

I reused a bunch of parts from the stock Logo 500, including the control lever, tail shaft and pulley, and the entire slider and grips.

UPDATE: You may want to get MIK4074 as well, which is the longer tail shaft. See post #5.

The last picture shows all the leftover parts which are no longer needed. Goodbye, boom supports! See you in hell!

[dswitkin]

I decided I wanted a colored tail case for better visibility, so I went with yellow peel and stick covering to match my new canopy and blades. Obviously this step took a lot of time which was not necessary.

I started by tracing out both carbon pieces on each side. THIS WAS A MISTAKE! It made it much harder to apply the covering without the lines showing. It would have been far easier to stick the covering on directly out of rectangles of about the right size.

I used a hobby knife to cut everything out, which required changing blades a couple times. They get dull very quick. In fact the new blades were so sharp they took some dust off the carbon, so I had to be careful to clean that up and wash my hands thoroughly. Remember that carbon fiber dust is very dangerous.

The result wasn't too bad. It certainly doesn't compare to paint but looks good from a distance. By the way, the bearings pressed in so tightly I didn't bother to epoxy them as the instructions recommend.

[dswitkin]

Because I only intend to run 550mm blades, I chose to cut the boom down and reuse the Logo 500 stock belt. You could probably keep the boom as-is and try a 500SE or 600 belt but I can't vouch for that.

The L500 boom is 600mm, whereas the L600 boom is 760mm. I wanted to double check that chopping off 160mm was the right thing to do. Because the L500 tail case is pinned, there is a fixed distance between it and the center of the tail shaft, about 1/2". But the the L600 tail case can be slid back and forth, between 5/8" and 1 1/8" on the same measurement. So it turns out 160mm is about right, maybe a hair less.

I decided to cut off 6" exactly to start with (less than 160mm), figuring I could cut more if needed. I used a rotary tool with a cutting wheel, making small cuts and turning often. Don't tighten the vise too much, you'll crush the boom! The end required a lot of sanding and cleanup but ultimately came out OK.

UPDATE: A pipe cutter would have been easier and done a better job.

As it happens this length just barely worked, if the boom was pushed completely into the frame. I was just able to get the belt around the main pulley. I would suggest cutting 6 1/4" instead to have a little more flexibility - you can always slide the tail case away from the frame. Don't go much shorter though, you want the frame to have a solid hold on the boom to minimize vibrations.

[dswitkin]

Assembling the tail case was pretty straightforward. A few notes though:

• The tail shaft does not protrude all the way through the bearing on the fin side. This seems to be because I used MIK2476 which is 71mm. MIK4074 is the hardened shaft but is also 75mm long and should fix this issue.
• The tail pushrod is offset to one side, not in the center of the boom. I thought maybe the Logo 600 had a different control lever (MIK2447 vs. MIK2449) but they look the same, the former just comes with bearings.
• I added the top roller pulley for good measure, but I don't know whether it's needed.

Unfortunately I had used JB Weld on both ends of my tail pushrod after epoxy had failed, which left me with no adjustability. As a result my tail blades are not at zero pitch when the tail servo is at 90 degrees. Still, I have a good range in either direction, and I'll fix this in the future if it becomes a problem.

[dswitkin]

All in all it turned out pretty well. Of course I had to run VBar setup again to set the tail limits, which were pretty asymmetrical. I wonder if changing the pushrod would fix that. I also reset the tail in the advanced panel, turned on the optimizer, and lowered the gain 5 points because I increased the tailblades from 86mm to 92mm.

Hopefully I'll do the maiden flight this weekend. Mostly I'll keep an eye on vibrations and make sure they're reasonable. I'm a big sky sport flyer, not a 3D smacker, so I'm hoping it'll hold up well.

That's all for now!

[n6nev]

I run the same set up and I cut the 600 boom to 690mm and use the stock belt, and the carbon tail / uk blade grips and I am very pleased

[dswitkin]

Cool. I'm surprised you can leave the boom so long, mine is probably around 605mm after cutting it. Are you using the Logo 600 belt?

[Bullfrog98]

The final results look really awesome dswitkin , it gives the 500 a nice clean look.

I have wanted to do a similar mod myself for some time, but spending $70 on the 600 carbon tail setup when I already have the standard 500 one is putting me off.

A good tip I got from a flying buddy (who is a plumber) is to use a plumber's pipe cutter to cut the tail booms down. It's an easy no mess no fuss solution and it gives you a nice clean edge that does not require any cleaning up.

[BakedMopar]

By using the 500 tail shaft will you have enough travel on the tail? Isn't the 600 one longer?

Cool conversion though

[dswitkin]

Thanks Bullfrog. I was putting this project off too since the old tail was in perfect shape. I kept waiting for a crash to at least justify it but it never came! In some ways I like the L500 plastic tail case better - it has fewer parts and only needs three screws, plus it's keyed to the boom so it can't twist.

That's such a great idea about the pipe cutter. I probably even have one around. It definitely would have been faster and done a cleaner job too. Thanks for the suggestion.

[dswitkin]

Originally Posted by BakedMopar

By using the 500 tail shaft will you have enough travel on the tail? Isn't the 600 one longer?

Cool conversion though

I did a little research on Mikado tail shafts and you're right:

MIK2476: 71mm (2 per package)
MIK2475: 71mm hardened
MIK4074: 75mm hardened

That would explain why the shaft doesn't come through all the way in the fin-side bearing. I'm not sure if it's limiting my travel but it might be. I guess I'll fly it as is and see if I need to upgrade to the longer shaft.

Thanks,
Daniel

[Bullfrog98]

Originally Posted by dswitkin

I kept waiting for a crash to at least justify it but it never came!

Lol I have the same "problem".

[celm]

I.turned my 600 3d into a 550 size logo. I cut the boom, boom.support and tail rod down.I used 500se belt. All the servos, motor, esc and vbar came off my trex550. So it runs on a 6s set up

[dswitkin]

Originally Posted by celm

I.turned my 600 3d into a 550 size logo. I cut the boom, boom.support and tail rod down.I used 500se belt. All the servos, motor, esc and vbar came off my trex550. So it runs on a 6s set up

Ah, so you kept the boom supports? Did you try any flights without them?

[celm]

I did everything at once wile I was building it. So.I never did a flight without the supports, the supports to help keep the vibe down

[n6nev]

Originally Posted by dswitkin

Cool. I'm surprised you can leave the boom so long, mine is probably around 605mm after cutting it. Are you using the Logo 600 belt?

I am using the 686 xl belt, this 500 se was already mod'ed when I bought it....

[Big Fil]

Nice job and pictures. Welcome to the world of fat boom 500s. Been doing this for quite a while to my 500 as it was a great way to have parts commonality between the 600 and 600SEs.

Pipe cutter works well. Another thing that works well, if you have access to one, is a band saw. Makes quick work of the job.

I personally always kept the boom supports. Would not be comfortable without them plus I like how the helis look with the boom supports.

I would advise getting the longer tail shaft. It's only half supported on that one side through the bearing. Why take the chance?

[Santini]

It looks really nice, Daniel, looking forward to seeing it fly. Very nice build thread.

[vadimr]

Good job man, now get some real blades too