Shaft reversal

[Andy48]

Posted by PatMc on 11/05/2020 18:07:09:

Either prop adaptor can be used without reversing shaft.
If the shaft is reversed it needs some reworking as described by Andy Joyce because the motor isn't designed to have the shaft reversed.

Take a look at the photos of the motor. It is impossible to fit the clamp prop adaptor safely without reversing the shaft. There is only about 5mm of shaft protruding from the rotating can end.

[Dickw]

Posted by Andy48 on 11/05/2020 18:58:17:

Posted by PatMc on 11/05/2020 18:07:09:

Either prop adaptor can be used without reversing shaft.
If the shaft is reversed it needs some reworking as described by Andy Joyce because the motor isn't designed to have the shaft reversed.

Take a look at the photos of the motor. It is impossible to fit the clamp prop adaptor safely without reversing the shaft. There is only about 5mm of shaft protruding from the rotating can end.

Looking at the second photo in the first post, there seems to be plenty of shaft length to fit the clamp type prop driver as the motor is supplied - certainly a lot more than 5mm. Are you looking at the "already modified" motor?

Dick

[PatMc]

Posted by Andy48 on 11/05/2020 18:58:17:

Posted by PatMc on 11/05/2020 18:07:09:

Either prop adaptor can be used without reversing shaft.
If the shaft is reversed it needs some reworking as described by Andy Joyce because the motor isn't designed to have the shaft reversed.

Take a look at the photos of the motor. It is impossible to fit the clamp prop adaptor safely without reversing the shaft. There is only about 5mm of shaft protruding from the rotating can end.

Andy, I don't think you understand how these adaptors are intended to be used.

The motor is designed to have the shaft only in the position as supplied.
If the motor is to be mounted with the shaft facing forward the clamp type adaptor should be used.
OTOH if the motor is to be fixed to a firewall using the "X" mount the bolt on type adaptor must be used or modifications made to the shaft, as Andy Joyce has done, which is a modification to the motor's design.

That's why 2 different types of prop adaptors are supplied.

[PatMc]

Posted by John Emms 1 on 11/05/2020 11:37:42:

From memory, the first motors to have the repositionable shaft were the HET motors, but they were not particularly well made IMHO, or particularly efficient, but I believe they set the expectation for reversible shafts.

Ales Pelikán, the owner of Model Motors, glued the shafts into AXi motors (not personally!) to maintain accuracy and efficiency. We bought static display motors that looked perfect, but did not meet the spec for accuracy, and would have been down on efficiency, if they ran at all.

Mr Palická, the AXi designer, moved to HVP (that had been the Czech state ARTF producer), to develop his design ideas, and the product of that were the HVP Roton motors (an outrunner with the shaft supported at both ends in a case). I also saw Mr Palická producing prototypes for an outrunner motor in a spinner, to take a pair of folding blades.

I believe that the culmination of Mr Palická's design work came at MVVS, where the Roton ideas were developed with a move back to motors where all the parts could be replaced (in common with all of his earlier brushed motor designs).

And the point? During engine training at MVVS, I was told, yes, they supply replacement shafts, but the motor may not be so efficient after the shaft has been replaced....

Yes, Puffin Models, and perhaps that level of service coupled with low margins (not peddling low cost motors as premium quality) is the reason why I am back teaching (including the use of hand tools to an accuracy of 0.06mm), and Sandra is now a Qualified Nursing Assistant. For the future? We have outline plans for a move to Houston, TX.

Do take care Y'All

John

I see no explanation in this as to why the replacement of a shaft in a motor is so difficult that it is likely to degrade it's performance.
Speaking from experience I've never had any problems with the several motors that I've reversed shaft on.

Shame you backed the wrong horse in your Puffin business venture John.
Good luck for the future.

Take care,

Pat.

[John Emms 1]

Posted by PatMc on 11/05/2020 21:39:18:

Posted by John Emms 1 on 11/05/2020 11:37:42:

From memory, the first motors to have the repositionable shaft were the HET motors, but they were not particularly well made IMHO, or particularly efficient, but I believe they set the expectation for reversible shafts.

Ales Pelikán, the owner of Model Motors, glued the shafts into AXi motors (not personally!) to maintain accuracy and efficiency. We bought static display motors that looked perfect, but did not meet the spec for accuracy, and would have been down on efficiency, if they ran at all.

Mr Palická, the AXi designer, moved to HVP (that had been the Czech state ARTF producer), to develop his design ideas, and the product of that were the HVP Roton motors (an outrunner with the shaft supported at both ends in a case). I also saw Mr Palická producing prototypes for an outrunner motor in a spinner, to take a pair of folding blades.

I believe that the culmination of Mr Palická's design work came at MVVS, where the Roton ideas were developed with a move back to motors where all the parts could be replaced (in common with all of his earlier brushed motor designs).

And the point? During engine training at MVVS, I was told, yes, they supply replacement shafts, but the motor may not be so efficient after the shaft has been replaced....

Yes, Puffin Models, and perhaps that level of service coupled with low margins (not peddling low cost motors as premium quality) is the reason why I am back teaching (including the use of hand tools to an accuracy of 0.06mm), and Sandra is now a Qualified Nursing Assistant. For the future? We have outline plans for a move to Houston, TX.

Do take care Y'All

John

I see no explanation in this as to why the replacement of a shaft in a motor is so difficult that it is likely to degrade it's performance.
Speaking from experience I've never had any problems with the several motors that I've reversed shaft on.

Shame you backed the wrong horse in your Puffin business venture John.
Good luck for the future.

Take care,

Pat.

We bought static display motors that looked perfect, but did not meet the spec for accuracy, and would have been down on efficiency, if they ran at all.

During engine training at MVVS, I was told, yes, they supply replacement shafts, but the motor may not be so efficient after the shaft has been replaced....

Hope that helps,

John

[Keith Berriman]

So lots been said on here about motor etc has Andy got his reversal done ?? Has he got his prop adaptor fitted and got the motor mounted into his model and got all his results ??

[Mike T]

Posted by RC Plane Flyer on 12/05/2020 14:13:19:

So lots been said on here about motor etc has Andy got his reversal done ?? Has he got his prop adaptor fitted and got the motor mounted into his model and got all his results ??

He described how he did it (with pictures) immediately above your previous post on this thread...

[PatMc]

Posted by John Emms 1 on 12/05/2020 13:43:22:

Posted by PatMc on 11/05/2020 21:39:18:

Posted by John Emms 1 on 11/05/2020 11:37:42:

From memory, the first motors to have the repositionable shaft were the HET motors, but they were not particularly well made IMHO, or particularly efficient, but I believe they set the expectation for reversible shafts.

Ales Pelikán, the owner of Model Motors, glued the shafts into AXi motors (not personally!) to maintain accuracy and efficiency. We bought static display motors that looked perfect, but did not meet the spec for accuracy, and would have been down on efficiency, if they ran at all.

Mr Palická, the AXi designer, moved to HVP (that had been the Czech state ARTF producer), to develop his design ideas, and the product of that were the HVP Roton motors (an outrunner with the shaft supported at both ends in a case). I also saw Mr Palická producing prototypes for an outrunner motor in a spinner, to take a pair of folding blades.

I believe that the culmination of Mr Palická's design work came at MVVS, where the Roton ideas were developed with a move back to motors where all the parts could be replaced (in common with all of his earlier brushed motor designs).

And the point? During engine training at MVVS, I was told, yes, they supply replacement shafts, but the motor may not be so efficient after the shaft has been replaced....

Yes, Puffin Models, and perhaps that level of service coupled with low margins (not peddling low cost motors as premium quality) is the reason why I am back teaching (including the use of hand tools to an accuracy of 0.06mm), and Sandra is now a Qualified Nursing Assistant. For the future? We have outline plans for a move to Houston, TX.

Do take care Y'All

John

I see no explanation in this as to why the replacement of a shaft in a motor is so difficult that it is likely to degrade it's performance.
Speaking from experience I've never had any problems with the several motors that I've reversed shaft on.

Shame you backed the wrong horse in your Puffin business venture John.
Good luck for the future.

Take care,

Pat.

We bought static display motors that looked perfect, but did not meet the spec for accuracy, and would have been down on efficiency, if they ran at all.

During engine training at MVVS, I was told, yes, they supply replacement shafts, but the motor may not be so efficient after the shaft has been replaced....

Hope that helps,

John

It doesn't.

Still no explanation.

But, back on topic, I've no doubt that Andy's motor will now perform as he intended.

[Andy48]

Posted by PatMc on 11/05/2020 20:26:50:

Andy, I don't think you understand how these adaptors are intended to be used.

The motor is designed to have the shaft only in the position as supplied.
If the motor is to be mounted with the shaft facing forward the clamp type adaptor should be used.
OTOH if the motor is to be fixed to a firewall using the "X" mount the bolt on type adaptor must be used or modifications made to the shaft, as Andy Joyce has done, which is a modification to the motor's design.

That's why 2 different types of prop adaptors are supplied.

My apologies, of course you are right.

[Andy J]

Posted by PatMc on 11/05/2020 20:26:50:

Posted by Andy48 on 11/05/2020 18:58:17:

Posted by PatMc on 11/05/2020 18:07:09:

Either prop adaptor can be used without reversing shaft.
If the shaft is reversed it needs some reworking as described by Andy Joyce because the motor isn't designed to have the shaft reversed.

Take a look at the photos of the motor. It is impossible to fit the clamp prop adaptor safely without reversing the shaft. There is only about 5mm of shaft protruding from the rotating can end.

Andy, I don't think you understand how these adaptors are intended to be used.

The motor is designed to have the shaft only in the position as supplied.
If the motor is to be mounted with the shaft facing forward the clamp type adaptor should be used.
OTOH if the motor is to be fixed to a firewall using the "X" mount the bolt on type adaptor must be used or modifications made to the shaft, as Andy Joyce has done, which is a modification to the motor's design.

That's why 2 different types of prop adaptors are supplied.

Pat, the reason I could't use the threaded prop extension was that I have a folding spinner which is designed to fit a 5mm shaft and there was no way it could be converted to fit the 6mm threaded prop extension. Given the tight fuselage installation having the motor connections at the front was simply not possible, hence the need for the shaft reversal.

Anyway thanks all for the comments but still await a proper explanation from John why you should not reverse a shaft as simple home mods allow this. Suspect the reason Turnigy don't provide this option is simply cost to add an extra circlip grove and secondly the chance of idiots removing the shaft with a hammer. Yes I have done that in the past and yes it does bend.

[Denis Watkins]

And to add, the soft casting at the front of the motor, with the large ventilation holes

Distorts readily, putting the soft motor shaft out of true.

[PatMc]

Posted by Andy Joyce on 13/05/2020 16:58:58:

Posted by PatMc on 11/05/2020 20:26:50:

Posted by Andy48 on 11/05/2020 18:58:17:

Posted by PatMc on 11/05/2020 18:07:09:

Either prop adaptor can be used without reversing shaft.
If the shaft is reversed it needs some reworking as described by Andy Joyce because the motor isn't designed to have the shaft reversed.

Take a look at the photos of the motor. It is impossible to fit the clamp prop adaptor safely without reversing the shaft. There is only about 5mm of shaft protruding from the rotating can end.

Andy, I don't think you understand how these adaptors are intended to be used.

The motor is designed to have the shaft only in the position as supplied.
If the motor is to be mounted with the shaft facing forward the clamp type adaptor should be used.
OTOH if the motor is to be fixed to a firewall using the "X" mount the bolt on type adaptor must be used or modifications made to the shaft, as Andy Joyce has done, which is a modification to the motor's design.

That's why 2 different types of prop adaptors are supplied.

Pat, the reason I could't use the threaded prop extension was that I have a folding spinner which is designed to fit a 5mm shaft and there was no way it could be converted to fit the 6mm threaded prop extension. Given the tight fuselage installation having the motor connections at the front was simply not possible, hence the need for the shaft reversal.

Andy, I had a fair idea why you couldn't use the threaded extension, my replies were to Andy48.

What model is it ? It looks sleek, I'm now curious to know how you will be able to remove the motor if you need to. Are you using an "X" mount ? Is there any access to the fixing screws ?

I've only ever used an "X" mount on one glider but that was converted from originally being powered by a geared brushed motor. I made a ply & balsa cowl that fitted quite well.
I usually manage to mount at the front, even in quite tight spaces.

Original brushed motor nose.

Bare firewall mounted motor.

Cowled brushless (longer) nose.

[Geoff S]

I fitted a HK Gliderdrive motor to my Phoenix 2K when the supplied motor failed. They fit snugly as front mount and the fact that the connections are at the back is a big bonus as is the case, which means the rotating part is contained.

The usual problem with front mounting brushless outrunners is the need to keep the connections clear of the outer lest the motor commits suicide by severing its own supply

Geoff

[Andy J]

Afraid in my installation it will be a dismantle job if the motor ever fails. Yes did use the the X mount mounted on a 5mm ply former.

Model is a standard Bird of Time with a scratch built fuselage and modified wing joint. Built the model as a test for my laser cutter but suspect it would have been cheaper to buy a kit as the laser eats balsa just to get the right shape and size. Wanted to build a laser cutter as had a desire to build a large Philippe Kent Sparrowhawk but as luck would have it I purchased a 84" version of ebay last week at a great price so the cutter is now taking up room on my workbench.

Did want to fit a gliderdrive on the Bird of Time but got the impression Turnigy have stopped making that motor as its no longer featured on their web-site as was out of stock on the HK site.