Magna

Hi all

As I'm finishing building my Excelleron 90, I ran into a dilemma. The kit come with anti vibe mount which is great but to mount it on, the instruction called for self tapping wood screw which is about 4mm size.

My question, is this self tapping screw on these built in hard wood beam is ok? I was planning to use blind nut and maching screw, but the area on the other side of the beam mount is very very tight, may not be able to fit in the blind nut.

Pls refer to picture.

Should I stay with self tapping wood screw or mod it to take blind nut?

j.duncker

My Feedback: (2)

IMHO the ST screws will not hold a big 4st. You need to go with nuts and bolts.

I have used ST screws up to 40 2st but only in plastic mounts. Anything 4st or larger then 40 needs nuts bolts and threadlock.

asmund

I use ST screws on everything (YS 110 included) along with a dab of locktite up to and including my ASP 180 fs, never a problem. I use only plastic/nylon mounts though so about the hardwood I don`t know. If it were me, I would try it and check the screws/retighten often in the beginning and see how it works

w8ye

My Feedback: (16)

While the self tapping screws hold up well in the black plastic mounts, I have found them to be very unsatisfactory when threaded into wood (Even maple).

qldviking

I would go with the bolt and blind nut for sure, ST screws will loosen in hardwood over time as the hardwood moves with the changes in humidity. I had that happen with my first pattern plane running a YS91, got quite interesting with a lose motor in the air[&:]

togatoga

My Feedback: (42)

I think you mean the supplied wood screws which is fine for the application.Wasn't an issue with mine,just check for looseness every now and then and dab rubber cement on the screw head.However,I would lose the supplied anti vib mount.The plastic blocks don't last, they break after a few flights. I had mine break after less than 15 flights.

WMB

My Feedback: (1)

I asked the same question in the Excelleron thread in the Pattern Forum. One responder said the holes stripped out after awhile. Most of the owners have had good luck with the stock mounts.

I decided to use t-nuts and machine screws, easy mod. I only have two gallons through it, so far so good.

It is a great combo, fast at full throttle. Forever verticle. I am using an APC 14x10.

togatoga

My Feedback: (42)

Unlike MK mounts, the supplied plastic block is rather stiff and of a different quality.My two rear plastic blocks sheared off and the front two show signs of breaking, the chinese haven't found the right formulation for the blocks yet!. Tried sourcing for spares but to no avail.The WM mount has a better design and better quality blocks.The system used places the unsupported blocks at great stress. Drill a hole several sizes smaller for the wood screws,tighten and use a rubber compound to dab the screw head.MK mounts uses wood screws too without issues. This is just my experience with this plane.

WMB

My Feedback: (1)

http://www.dbproducts.com/store/vd4c.htm

Iv'e heard of others having good luck with these also. Similar to the stock Excelleron. I do like the single piece design that mounts to the engine rather than the two piece of the stock set-up.

togatoga

My Feedback: (42)

The DB for beam mountiing looks like a much better design with less twisting moment.The bolt point is closer to the engine which is good.The blocks would be more durable too and spares would be readily available!

Flyer95

My Feedback: (1)

I would avoid using those soft mounts you have in pic.2. They will not hold up for such an powerfull engine and vibrate too much causing the muffler to become loose and eventually the engine too. Rock solid mounting with screw and nut is better. The beams looks too thinn for selftapping wood screws.

Magna

Hi all

I have managed to find some t nut and m4 machine screw. Managed to scrap out some balsa stock under the beam for the t nut.

As the YS110 is narrower than the beam, the 4 isolator mount has to be slanted out ward to in order to mount, maybe thats why Togatoga explain the stock setup placed more stress on the isolator block. I'm guessing!

Since i could get hold of any MK or dave brown mount now, I will just the stock mount for running in. I will keep an eye on the muffler and header to avoid loose running.

Most flyers at the Excelleron 90 thread seems ok with the stock flight for many gallons and I hope mine too.

The MK and Dave brown design needs to be modded anyway because the one piece design would not fit into the beam that wider apart that then YS110 stock mount.**Correction as I look in greater details on the MK mount. The isolator is assembled on single bolt and this allow the isolator to be angle outward even with the one piece aluminium compared to the stock version or DB.**

I just run in first this weekend on stock mount and see how it goes.

The MK mount which is stated for OS91FS will fit the YS110 dimension.

Magna

Hi WMB

Congrats on your Excelleron.

I believe you have to angle the anti vibe mount as per my description above? Still looking good with 2 gallon? You happy with the stock mount or going to replace them? I prolly need to file off the sharp angle of the aluminium block to prevent it from chaffing and cutting the crankcase.

scratchonly

I have a saito 120 bolted to a 3/8 ply plate, with the plate screwed to the hardwood beams with (6) 6 32 3/4" screws. No problem.