MHZ Mystic 114 - my first proper build

[ManuelW]

Will also follow the build. If I ever decide to make a few of these rudders again, can I use your pictures for advertisement. I don't know which camera you have but the photos look awesome!

regards,
Manuel

[TiTu]

Will also follow the build. If I ever decide to make a few of these rudders again, can I use your pictures for advertisement. I don't know which camera you have but the photos look awesome!

regards,
Manuel

Feel free to use them if you want, I don't mind that at all! Camera which I'm using is an older Canon EOS 450D/EOS Digital Rebel XSi.

Thanks for the tip of using grease/vaseline for the screws while gluing things together, saved me from one headache.

Made some progress again. Wasn't too happy with the motor mounts that came with the set as they were made from 2mm cf-plate so made another set of mounts. Made them with smaller shaft hole so I'm able to use thrust bearings without putting more stress to screws that hold motor in place. Making those motor mounts required a little more work than I thought as I don't have any cnc milling machine but they turned up pretty nicely imo.

Got also done the transom reinforcements and templates for drilling the transoms.

[nata2run]

That looks good, but very close to the bottom!! also make sure you can fit the water pick up tube between the tunnel and the drive. you may have to move it out a little. clear about 7mm from the sharp point of the sponson.

[nata2run]

Also, I have gone away from the idea of using thrust bearings....more stuff to go wrong!!!

[drwayne]

Also, I have gone away from the idea of using thrust bearings....more stuff to go wrong!!!

burn and learn

[nata2run]

burn and learn

oh yes, I forgot you been there done that.

[TiTu]

That looks good, but very close to the bottom!! also make sure you can fit the water pick up tube between the tunnel and the drive. you may have to move it out a little. clear about 7mm from the sharp point of the sponson.

And I thought it was better to get the drives lower than higher, and also close to the tunnel. But thanks again for pointing things out to me, I raise them up from the ride pad few mm as well as move them a little away from the tunnel towards the center of the transom.

And seems like I'll ditch also the idea of using thrust bearings if the experience hasn't been that good lol.

[nata2run]

No not a millimetre only half

[nata2run]

You can go close, just make sure the drive don't overhang the sponson, the drive could be a little more outward, so it allow you to drill a hole and install the water pickup.

[TiTu]

Yeah, I was hoping to get the drives at the same level as the bottom of the hull and avoiding any overhang.

[nata2run]

you need to be able to fit your pick-up roughly like this. Aslong as you have enough room you'll be fine
Transom Template_03.jpgTransom Template_02.jpg

[cyprus31]

Hi and good luck with your building proccess.
I also own a MHZ Mystic 114 and used to run it with Leos 4082 2200kv on 6s with x445 props. The boat with this setup was very unstable in water because I am under the impression that on 6s these motors could not hold stable turns and the hull was bamping on sides all the way. I then upgraded to x447 props. Besides it was a bit more stable with the new props, I could not trust it on high speeds.
I then decited to buy 2 new Leos of 1600kv but the same x447 props. Motors now more smoothly without any stability problems and I realy enjoy it also on full speed runs with max speeds of 132klm

I think the 1600kv motors are the best for this hull size.

[Chrisg81983]

Cyprus 31 I myself and many others had run the leo 2200 kv on 6s in single and twin setups. They run/ran very very well in my opinion. Was your cg and trim setup correctly for thoes speeds. That is a pretty fast setup and takes tone work to get running 100 %. I am currently running 2950kv n 2114 kv lehners in a twin hpr for very high rpms with no problems at all. She runs very stable, but took some work to get it that way. Whike it was very easy to get it to run rite with the same motors on a lower cell count spinning less rpms. I am prettu sure if you ran your 2200kv leos on 5s and not 6s you would of have the same outcome as when you went to the 1600kv.

[TiTu]

Hi all!

Had to take a break from the project due personal reasons, but I was at last able to sort a bit time for this.

Nice to hear from your experiences Cyprus, I'll definetly plan on trying those 1600kv motors as the speed is not an issue for me (mark my words )

I'll agree Chris, building and running a boat isn't the whole job, as tuning can require a lot of work too.

I made water pickups from 2 brass tubes, soldered them together and grinded the other ends to fit the hull. The holes in the hull are far from perfect, but I'm not too worried as glue will fill most of the holes and filler spray will take care of the rest during sanding.

Got the reinforcements for transom made as well from 2mm cf and the most dreaded part for me, drilling and installing the drives. Thanks Kent to point out that I'd need to install them a bit further away from the tunnel. The 7mm you suggested was just enough to have few mm's extra so there a bit more room to work inside the boat.
They came out pretty good, got them aligned so that the differences are about 1/4mm at most. However, as the drives and hull are, it was just impossible to get the drive angle to zero, as the drivesupport lifts the propend of the drive (as seen in pic). I bet that this will give me trouble when figuring out where the CoG should be. Afaik in normal situations it's supposed to be around 32-34% forward from the sponson transoms, but with this much of angle, I'll take it that it needs to be closer the transom than that 32-34%.

I'm thinking of where to put the water outlets and come up an idea that I'd put them to transom next to drives. Is there other con in this that I can't see if the water is actually flowing through motor and esc.

Another thing I'm thinking is should I use teflon liners with flexes or not. The teflon liners and aluminum tubes that came with the boat are a bit tight for my taste and the flex (3/16) will not rotate freely at all. I got a spare teflon liner with inner diameter of 6mm so I thinking to go with that if I end up using teflon liner at all. If I leave the teflon liner out of picture, what should the inner dia of the tube be?

[Chrisg81983]

Looks nice A few things though. Definitely run Teflon with this setup. Two put the water exits wherever the shortest amount of tubing is needed. It looks nice if you just take 4-5mm brass or aluminum tubing and just drill a hole n sidewall the exact size then epoxy in. Keep the tube flush with the outside of hull. When the boat is painted or vinyl applied the water outlet becomes invisible. I might put my next exits in the tunnel underneath hull, but this will make it hard to tell if cooling correctly. Third make sure the water pickups are free of burs where you soldered them together. Usually I try to make that inlet as straight as possible at the bottom while gently curving towards the top making it easier t put cooling line on. The less of a bend you have the more efficient the cooling system will be. Third I think the drives might have too much pitch to them. Are they set a high up as possible. I never had your hardware so I can't answer that question for you. She is otherwise looking great keep up the nice work.