Goblin helicopters technical support thread

[Sao]

Well my friend was wrong, just asked Bert what the gear was made of.

Hi Martin,

Main output gear is delrin, very tall and slanted.

Bert

If photobucket hadn't resized my picture you'd be able to see more clearly the marks on the main gear that one might mistake for oil blacking wearing away showing bear metal underneath, I guess it's just grease or aluminium particles from the pinion gear.

At least it's cleared up and we know for sure what it's made from

[joker]

Hi,

Is there a plant place in the drive chain where it brakes during a crash?
Which part of it brakes first?

Thanks!

Joker

[d-rudie]

Will additional pinions (different tooth count) be available to ship with the first batch of kits?

Will it be possible to specify which pinion to be shipped with each kit??

[geekindenial]

Originally Posted by d-rudie

Will additional pinions (different tooth count) be available to ship with the first batch of kits?

Will it be possible to specify which pinion to be shipped with each kit??

They have confirmed long time ago (check earlier posts in this thread) that 20-T pinion is default in kit.

[d-rudie]

Cool thanks for bringing me up to speed.

So will additional pinions (different tooth count) be available to ship with the first batch of kits?

[Tohtori R]

What is the actual part/material you are changeing to maingear system (the cause of delay)?
and why?

thanks.

[Scottyb410]

It looks to me like Goblin has "Pulleys" listed on their website ranging from 16 - 27 tooth. The Pulley attaches to the motor shaft. The pinon size seems fixed.

[McCollister911]

That's kinda what it looks like to me to. You will be changing pulley sizes not the pinion

[rdavis]

Can someone help me understand how to calculate head speed on this heli?

[Sao]

Originally Posted by rdavis

Can someone help me understand how to calculate head speed on this heli?

does this help?

[rdavis]

I should have been more clear with my question... I am wondering how to calculate what pulley size you will need with a 550kv motor to achieve head speed of 1800~2000? However, many thanks for the initial information.

[rdavis]

Are they using the term pinion as stated on the chat posted for what they are calling pulley in the parts section, and if so, I got it... Again, many thanks Sao.

[mahbouni]

Will a Scorpion 5025-440 fit in this heli? What kind of performance can I expect on 12s? I have the motor spare.

[aris2024]

As far as I know it just fits without leaving any margins. With a 24 pinion you should get around 2050 rpms. I am thinking about getting the same motor but in the 520Kv version in order to use the including pinion.

[Armadillo]

Originally Posted by aris2024

As far as I know it just fits without leaving any margins. With a 24 pinion you should get around 2050 rpms. I am thinking about getting the same motor but in the 520Kv version in order to use the including pinion.

There is no 520KV version.

Ich opened the 440KV version, devided the stator from the stator mount (a work I can not recommend) and removed the windings. A winding experienced guy in Germany rewound me the motor to KV between 510 and 530.

[aris2024]

Yes Armadilo I know, my mistake, I was talking about the 5020 not the 5025. What do you think about the 5020 520kv? Will it be good enough for 2000rpms and mild 3d?

[Scottyb410]

Actually, ReadyHeli has a Goblin setting in their head speed calculator now.

http://www.readyheli.com/headspeed-calculator.html

The ratios work out to mimic a 215T main gear. It seems pretty accurate.

Scotty

[rdavis]

Many thanks Scotty... I did not even think to look there yet.

[gww528]

Originally Posted by Sao

Well my friend was wrong, just asked Bert what the gear was made of.



If photobucket hadn't resized my picture you'd be able to see more clearly the marks on the main gear that one might mistake for oil blacking wearing away showing bear metal underneath, I guess it's just grease or aluminium particles from the pinion gear.

At least it's cleared up and we know for sure what it's made from

Saw Bert's Goblin today, it is a metal main gear but he said the production model will not be metal. It will use injection molding & then CNC.

[Sao]

Originally Posted by gww528

Saw Bert's Goblin today, it is a metal main gear but he said the production model will not be metal. It will use injection molding & then CNC.

Originally Posted by bobloblaw

If that main gear is metal I will eat my hat.
However, it is obvious that both the pinion and first stage gear is metal.

So Bob can we get some pictures or a video of you eating your hat?