Logo 600 sx v2 o-ring damper o-ring too tight to fit

[Mr.Andersen]

Even more strange becouse my did not and the manual state two different sizes in the part list.

[amphibia]

Originally Posted by Mr.Andersen

Even more strange becouse my did not and the manual state two different sizes in the part list.

V2 or V1? In the 600sx v2 kit box, there is a big white box that holds the screws and other components. Does this white box have a stick with "v2" written on it? Mine does, so I was sure it was a 600 sx v2.

[Mr.Andersen]

These is the kit i bough last summer and theres the page from the manual that came with it.

[amphibia]

Originally Posted by Mr.Andersen

These is the kit i bough last summer and theres the page from the manual that came with it.

Yours is V1. I think V2 kit came out sometime march 2015 with a slightly updated plastic frame and a few other minor changes. One of the changes is having 6 identical 7x5 o-rings for the rotorhead.

[TomasN]

Originally Posted by amphibia

Yours is V1. I think V2 kit came out sometime march 2015 with a slightly updated plastic frame and a few other minor changes. One of the changes is having 6 identical 7x5 o-rings for the rotorhead.

I have 600SX v1 (bought autumn 2014). In my kit there was 6 identical o-rings for rotor head too.

[amphibia]

Originally Posted by TomasN

I have 600SX v1 (bought autumn 2014). In my kit there was 6 identical o-rings for rotor head too.

thanks for sharing. so in conclusion:
V2 - all 6 identical orings
V1 - some batch have 6 identical orings, some batch have different orings

[amphibia]

Just to update:

I received the new replacement rotorhead and shaft from Mikado's Hong Kong distributor KS Model two days ago (I was on a business trip and and had the delivery company hold it for me).

The new shaft fit inside the rotorhead beautifully. KS model also assembled the new rotorhead for me. I will try to finish the build soon now that I have all the parts.

[Wizza]

In advance, I apologise for the long post to follow. I wanted to write of my experience / issue with the 600sx V2 head assembly re the dampeners, and also talk about a possible solution using some shim washers and reducing preload.

While I'm no stranger to building model heli's and I've been in this hobby for long enough now, this is my first time building a Mikado kit. I've had mixed results so far assembling the Logo600 V2 head. As described above, I too had difficulty inserting the dampener (o-rings) in place. Being a V2 kit, the dampeners are 6 identical sized o-rings.

Attempt number one yesterday was a fail. Per instruction and recommendation, I lubed the o-rings with silicon grease before insertion. I inserted the spindle shaft and installed the o-rings one at a time. I was able to eventually get the first two o-rings in each side, however the third o-right would not seat in place, and kept popping back out of place. They were so far out that I didn't feel it was safe to try and force them in by screwing on the grips, for fear of damaging the bearings. So I disassembled the complete head, cleaned it all up, and left it for the night.

Attempt number two went better today. Using the socket as a drift, I inserted the o-rights "dry" into the head block without the spindle shaft in place and was able to easily seat them in place completely. They were almost completely housed within the end of the main head block. Having no lube in there, the o-rings stayed seated and in place.

I then used a q-tip (or cotton-bud on a stick) to lube the inside of the o-rings with silicon oil, and also oiled the spindle shaft. Then I drilled a hole slightly larger than the spindle shaft in a block of wood, and used the arbor press I gentle pushed the spindle shaft into place through the o-rings (o-rings already installed and seated in place). I then took a metal rule and using the arbor press once again, carefully adjusted (centred) the spindle shaft in the head block so that there was exactly the same amount of shaft sticking out each side of the head block.

Next I carefully seated the radial bearings into the grips, using a socket once again on the outside of the bearing, to make sure they were properly seated. I checked the inside of the grips for flashing before inserting the bearings. I then greased and inserted the thrust bearings, observing the correct orientation.

What I noticed at this point with the grips just sitting in place on the spindle shaft was that the spindle shaft was still slighting "inside" the outer washer of the thrust washer. The o-rings were still in place and seated properly, however it appears that installing the spindle shaft slightly expands the o-rings and they protrude out of the main block slightly. This means that when the spindle bolts are tightened, you can feel the grips moving in on the spindle shaft, and compressing (preloading) the o-rings.

This caused smooth but quite firm (almost stiff) movement of the blade grips. No 'notchyness' at all, and all bearings still feel 100% smooth, however the preloading and compression on the dampeners makes the head assembly quite stiff.

I did note that on page 8 of the 600sx V2 manual, which shows assembly of the main rotor head, it says "After mounting, the blade holders will move a little bit tightly at first". I would say quite tight, as opposed to a little bit tight....

At this point, I'm not sure if the o-rings will compress slightly and form their seated shape in time, so to speak, and the grips will loosen up..??? I just don't know what to expect, not having built a Mikado before.

Once option I did explore was to remove the spindle bolts and the 5x15x1 washer on the ends, and install some small 5x7x0.2mm shim washers between the 5x15x1 washers and the ends of the spindle shaft. This forms a slight spacer between the end of the spindle shaft and the 5x15x1 washer, so that when the spindle bolts are tightened down hard, there is reduced preload on the o-rings, and this gives a pretty smooth head assembly. From a mechanical point of view, I cant see any issue with shimming the spindle bolts, and all the loads are still exerted exactly the same on the spindle bolts and the 5x15x1 washers, just less preload on the o-ring dampeners.

For now, I've removed the shims and assembled the head again, which is smooth but quite tight once again, and I'll leave it sit a few days and see how it feels.

Can anyone tell me if the o-rings will seat or bed in, so to speak and will the head free up..????

Can anyone see an issue with shimming the spindle bolts..???

I look forward to any experiences and/or comments out there re this issue. Doing a bit of googling of the forums, it would seem that I'm not the first to experience this situation/problem. And being new to a Mikado build, I honestly don't know what is usual or what to expect here.

Cheers for now...

Mark R

[Wizza]

Had another look at this head assembly today, and while the bearing action is free and smooth and the bearings feel fine, the preload on the dampeners makes both blade grips quite stiff to rotate. I've installed a 5x7x0.3mm shim washer on each spindle bolt, and while there is still some preloading on the dampener o-rings, both blade grips are now quite smooth and much more free and smooth to move.

The spindle bolts still lock down hard against the end of the spindle shaft, and all outward forces will still be the same against the spindle screws, except the slight spacing now does not compress the dampener o-rings quite at much.

A picture is worth a thousand words, so I've attached a photo to this post.

[Wizza]

In response to the original post, I think the key here to installing the dampener o-rings with more ease, on the 600sx V2 head, is to install them dry with no lube or grease, into the head block first, then lube the inside of the dampener o-rings (once installed) and now slide in the spindle shaft. Take some time and get the spindle shaft exactly centred (same amount sticking out each side, left and right), and then install the grips.

[Wizza]

If you've build one of the new Mikado Logo SX kits, you'll know the job it is to insert the dampeners and the spindle shaft, keeping it all in place and not damaging the dampeners in the process. In addition to silicon oil inside the dampeners and on the spindle shaft, I made an "insertion tool" the other night to aid in the process.

I took an M5 stainless hex-head bolt, and turned down the end to form a bullet shape. Once I had the shape I was looking for, I polished the end with some fine wet-and-dry paper, and then cut the bolt to length and cleaned up the thread end.

Simply screw this tool into your spindle shaft prior to lube and insertion into the head assembly, with dampeners already in place. Once the spindle shaft is in place, simply remove afterwards. I find the arbor-press and a block of wood with a hole just big enough for the spindle shaft to be the best process of insert the spindle shaft (as outlined above). This certainly made the job easier and a little quicker.

Anyhow, I always say a picture is worth a thousand words, so without further ado, hopefully this will give you an idea of what I came up with and maybe it will help some others out there.

[Johnny31297]

[IMG640] tags could save lives here..

[rcflyerheli]

I just did a new build up of a 690SX head which is similar to the 600 head as far as the dampers go. On your grip tightness, I found the silver shim can be installed facing two ways. I tried to see from looking at the manual which way Mikado said to inert it, but the drawings wern't clear enough to know for sure, so I built it up one way, and found the grips hard (as well as notchy) when the spindle bolts were tightened. So I disassembled them and turned the shims over, and the head went back together with no notchiness or hard turning, and with no play in the grips, so that was the way I left them.