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[asimmd]

Hi Guys

I have now cleared all the rubbish from the hull as recommended and I am
now ready to make the mounts for the new motors,Graupner 500E

My problem is that I have forgotten how to work out the angle at
which the mounts should be.

Can someone please advise me as to how I can do this,I don't want to
make a mess of it.

Here are 2 pictures of where I am up to.

Many thanks

Alan

http://www.4shared.com/photo/8Oq91sDO/001.html

http://www.4shared.com/photo/1qAborUo/002.html

[Tug-Kenny RIP]

I would 'opt' for the fit in situe approach, rather than calculating what it might be.

To achieve this you need to make the coupling rigid, temporarily, and connect the motors to them. This will leave them 'hanging' at the correct angle and then you can design a suitable wedge type mounting underneath so that the prop shafts rotate without wobbling.

This is the way I always do mine and it ensures a smooth running prop.   

Hope this helps

Ken

[asimmd]

Thanks Ken

Would I be right in thinking that it's a bit hit and miss?

What I really would like to know is how do I mark the piece of
wood with the right angle so when I cut it,the motors will
line up with the coupling.

Hope I've explained that properly?

Alan

[derekwarner]

Alan - it is not really hit & miss, and although you have engine couplings that will accept a certain amount of misalignment, minimising it is advantageous

a. remove both of the couplings from the shafts
b. scribe a pencil line of best fit over the exposed shaft onto a wooden block
c. this will provide a reference datum angle that is parallel to the motor armature axis ....then cut & shape the block accordingly - one block will be mirror reversed to suit the curvature of the hull
d. as Ken has suggested, "to make the coupling rigid, temporarily, and connect the motors to them" ...your hobby shop may have a DUMMY tube coupling piece for that purpose, or you could manufacture your own tube ....you just need to ensure each of the RED coupling elements outside diameters are in line

Derek

[asimmd]

Thanks Derek

I think I understand,I will use masking tape to make the couplings rigid.

I presume that the line I draw on the wood will be centre line of the coupling?

I will try this method on Sunday and report back.

Many thanks

Alan

[derekwarner]

Today is Sunday Alan.......[in OZ].....

I presume that the line I draw on the wood will be centre line of the coupling? - no not necessarily, but it is the VERY important angle you need as reference 

Depending on the motors you have..... they may be foot mounted or front flange mounted by two metal thread tappings, if the latter is the case you need to pay extra attention to your wooden blocks, as the top surface [parallel to the pencil scribed line] must have an accurate 90 degree included angle to the block front face as this will be the reference for the motor mounting

Whilst both Ken & I have spoken about wooden blocks.....there is no hard & fast rule.....you could simply use the wooden block & pencil scribed line to accurately make some simple aluminium angular brackets to mount the motors

The greater the accuracy  in the gauging & marking out of the original pencil scribed line will result in minimal need for any correction to the motor alignment.....

There are various thread articles here in Mayhem on this subject..........would be good time spent researching the archives......... Derek

 

[HS93 (RIP)]

I use this method it req a disk and a spare shaft , one set should do all your 4mm boats the shaft is just a long length of 4mm with a point on the end and the disk is just a disk of brass with a 4mm hole drilled square through it.
picture one shows the disk on the end of the shaft against the mount you can see the mount is out bend or pack mount so the disk fits flat to the mount top bottom side to side, then remove the disk and push the pointed end of the shaft against the mount this will give you the centre of the mount to drill for the motor, if it is a pre drilled mount, stick some plasticard on the back and mark a line from motor mounting screw to motor mounting screw then put a dot in the middle that should tell you where you have to align the centre of the prop shaft to then mount then check with the disk for angle.
once you have done it once it is easy.
the setup shaft has to be long enough to be in both bearings

peter

[RaaArtyGunner]

Peter (HS93)

Good illustrative solution.  

[HS93 (RIP)]

I also have some other disks exactly the same dia but drilled for motors, I use them to re align previously installed motors as you can get the height and the side to side right

peter

[asimmd]

Hi All

Many thanks for the replies.

Just to clarify, my problem is not making a motor mount,I already have those,my
problem is making the wooden mount/rails the mounts sit on.

I don't know how else to describe them.

Alan

[Martin (Admin)]

What I would suggest is, using Peter's method, mount your motor(s) in the mounts and align them to the shaft point by raising them up to the correct hight using shims (paper, card, etc.). You can also draw a line down the side casing, along the centre line of the motor anf use that to align it to the shaft.

I would also suggest using a 'double coupling' / 'Kardan' that greatly alleviate small misalignment problems.

Also see:  
http://www.modelboatmayhem.co.uk/Builds/Puffer_Jan/Part_4.htm
http://www.modelboatmayhem.co.uk/forum/index.php?topic=22795.0
http://www.modelboatmayhem.co.uk/forum/index.php?topic=16343.msg161613#msg161613

[Circlip]

If you look back at Peters solution Alan, Glue two plates of wood under where the mounts should be, now comes the trickey bit, chuck your existing mounts away and make a new pair that are tall enough to mount the motors. Looking vertically downwards you can get the wood plates in line with the shafts. Again looking vertically down you can set the motor mounting face at right angles to the shaft and screw the individual mounts to the wood. By interposing a right angled template on the top of the shaft you can then bend the face of the motor bracket so it too is at right  angles to the shaft now in both plan and side elevation.

 By sliding the shaft end to the motor plate you can mark the position of the hole required for the motor shaft.

[DickyD]

He only wants to know how to get the angle of his timber support under the mount.

Tug Kenny's way is the easiest. Did it myself today.

[asimmd]

Hi All

Thank you so much for all the replies,I didn't know there were so many different ways to do this job.

Having just returned to Model Boats after 25 years away,it takes a little time to regain the confidence
of youth that we all take so much for granted,it's only when it leaves you,that you realise how useful
it was.

I understand now how to go about thetask in hand,and although it may not be pretty,I guess it
will do the job.
As they say,practise make perfect.

Alan

[Circlip]

He only wants to know how to get the angle of his timber support under the mount.

Tug Kenny's way is the easiest. Did it myself today.

 Yes and the only way to achieve the wedgie method is to have a flat stable surface to work from. Some GRP moldings have a controlled thickness and surface finish, toy boat hulls don't.

  Both methods described have their virtues and both have their pitfalls, at least Alan has two ideas he didn't have before and as the illustrious FLJ keeps saying, Suit Yourself.

  Three actually, mine doesn't rely on a machined tube to couple the motor or a machined disk, just a right angled template.

  Regards   Ian

[hazmat]

Dunno if this will help.
When mounting my motors i use a block of plastercine for the engine plus mount to sit on and a neoprene sleeve over the UJ's to keep them straight(ish).
Once settled in place, I remove the plastercine and either take measurements from it to enable me to carve out the correct angle block for the mounts to sit on or to make a resin mold (useful if the engine sits astride a former).
Works every time.

[asimmd]

Hazmat,thats a very useful way of doing it,I will remember that.

I am pleased to say that I have now finished the first one,and
the second one is well under way.

Thanks again for the advice.

Alan