Propshaft to flex shaft / MHZ drive

[Gerwin Brommer]

Please show us a pic of the propshaft.
If the shaft is 6mm indeed, it must be possible to fit a 4,75 flex.

btw : DRILLING that hole exact isn't possible, you HAVE to do it on a lathe.

[uncledirty]

The flexshaft show the step from 6m to 4,75 and on 4,75 section there are the ballbearings. Other ballbearings are in the other end and still inside in the "black tube".

I will show this on weekend to cnc miller, but probably the lathe he has is made to handle bigger parts. Clocksmith would be better. MHZ advised to make a 30mm long hole. (after 10mm long 4,75 section is taken out. So in a scale it would go about half way of the shaft. Hard to make. would the ballbearing lay on flexshaft?

I would say that possible to do, but its no everyday job for cnc miller used cope with bigger parts... so why they sell these together if they know that it is basicly just theory to connect these.... "buy 1674/A and 1674/F (flexshaft 4,7mm) for it... "

BTW: I also got email that MHZ will sent the missing hydraulic dummies that should have came with rudder... gradually all fit in to its place.


this is why I am concidering other options than flexshaft...

[Gerwin Brommer]

I don't get it.

There is plenty of room for a 30mm deep hole.
You should NOT shorten the shaft !!!!!!!!!!!!

Edit : hm, do I get it right ? : the first part of the shaft is thinner, and the bearings on the pic are on that part ?
The innerdia of the bearings in NOT 6mm ?

What are these 3/16th ballbearings for ???????????????????????
They seem useless to me.

[uncledirty]

Yes the first part is thinner 4,75mm and bearings are on that part. The inner part of bearings is 4,75 and the outer about 8-9mm.

There is similar set of bearings in the other end stamped to that black cover. The propshaft is also thinner in in the other end for the bearings but of course for the prop. The propshaft is suported only by these two set of bearings in both ends.

So if I enlarge the hole to 4.7mm I lose the first thinner part and bearings. So same as cutting the thinner part away. Then the propshaft wont be supported anymore from this end unless I put bearings to flexshaft. Dont know if it would work because flexshaft will shape a bit under stress.

[Gerwin Brommer]

If the 4,75 mm bearings are pulled out/off , all 4 :
what do you see inside the drives ?
Bushings 6mm ? brass-coloured ?

Edit : just noticed what you said : only supported by these 4 bearings.

Well , the only possibillity : mill the shaft to 4,75 mm for the flex and replace the bearings ( on the flex-side of the shaft ) by 6mm bearings.

[Gerwin Brommer]

Uncledirty.

I've send an email to Ernest ( in German :-) ) to ask him what
the right "procedure" is if you wanna change to 4,75 flex.

[uncledirty]

I am really grateful.

[Gerwin Brommer]

Shirley replied !

According to HER , slidebushings ( right word ??) are the STANDARD by MHZ.
Ballbearings are impossible , to small and to weak for those high revs.

I'm gonna send her your photo from the drives, shafts/ballbearings.

[Gerwin Brommer]

Another reply van Shirley :

these trimms are for 2mm wire ONLY.
You should have asked for specific 4,75 flex shaft in your order.

[uncledirty]

F**k MHZ, I trusted their opinioins 1674/A (drive) possible to fit 4,7mm flex shaft... hopefully they correct things to webshop imidiately.

I will ask for refunds and I will GET my refunds.. and missing parts along side.

Thank Youa thousend times for taking Your time to help me!

[Gerwin Brommer]

I strongly suggest you write them an email and explain the whole situation.
Tell them their site is misleading ( correct english ?? )
Maybe you can swap the trimms if you send your trimms back ?

[Gerwin Brommer]

The 2mm wiredrives are for setups to max. 700 watt, that's what Shirley wrote to me.

[Jeff Wohlt]

700 watts from a 2mm wire? I have some out there with 078 basically-- 2mm and they are way over that like (DOUBLE)without any issues running NEU motors.

[Gerwin Brommer]

I know, I think MHZ want's to stay on the safe side.

[uncledirty]

I send an email today and looked from their webshop that the other possible drive for mystic (different code) is actually just the same drive with same 2mm hole...

I asked for refund or suggestion how to solve problem. Lets see... I dont have my hopes very high because every part ordered has had problems: missing parts, not turning drives. Hull is quite ok atleast.