Axiom over propped?

[PMB]

Recently ditched mini prop gen (BV2203 MPG) and it's trolling valve with infinity variable prop speed. Now feeling axiom prop (C 2009) is not best suited. Called axiom to see what their numbers equate to  (as I found the original invoice) and was told the Axiom 18x28 is equivalent to standard 18x14". Read a couple of older posts here that seem to think the 14" is closer to 20°. Either way the BV is giving a fair amount of black smoke at about 1600 (internally governed to 1800) and I've had to drop tick over to close to 700/750 to slow the buggah down past moored boats. Any advice welcome. Oh PS 60ft Alexander hull, BV is 50hp, PRM 500 D2 (think that's a 2:1)

 

[mrsmelly]

52 minutes ago, PMB said:

Recently ditched mini prop gen (BV2203 MPG) and it's trolling valve with infinity variable prop speed. Now feeling axiom prop (C 2009) is not best suited. Called axiom to see what their numbers equate to  (as I found the original invoice) and was told the Axiom 18x28 is equivalent to standard 18x14". Read a couple of older posts here that seem to think the 14" is closer to 20°. Either way the BV is giving a fair amount of black smoke at about 1600 (internally governed to 1800) and I've had to drop tick over to close to 700/750 to slow the buggah down past moored boats. Any advice welcome. Oh PS 60ft Alexander hull, BV is 50hp, PRM 500 D2 (think that's a 2:1)

 

Fit a crowther.

[PMB]

Yup, think that's the only course of action. Maybe flog the Axiom to a WB/DB owner

[mrsmelly]

30 minutes ago, PMB said:

Yup, think that's the only course of action. Maybe flog the Axiom to a WB/DB owner

My bro in law bought an axiom and persevered with it for a couple of years, he did email me a good piece re the differences between his original prop performance and the axiom which of course was not biased as it was his money and his boat. He did not completely slag the axiom off and stated boat stopped better with it if I recall. He has now had a crowther fitted.

[OldGoat]

20 hours ago, PMB said:

Recently ditched mini prop gen (BV2203 MPG) and it's trolling valve with infinity variable prop speed. Now feeling axiom prop (C 2009) is not best suited. Called axiom to see what their numbers equate to  (as I found the original invoice) and was told the Axiom 18x28 is equivalent to standard 18x14". Read a couple of older posts here that seem to think the 14" is closer to 20°. Either way the BV is giving a fair amount of black smoke at about 1600 (internally governed to 1800) and I've had to drop tick over to close to 700/750 to slow the buggah down past moored boats. Any advice welcome. Oh PS 60ft Alexander hull, BV is 50hp, PRM 500 D2 (think that's a 2:1)

 

I'm curious - if I may - why did you ditch the whole prop gen (if that's what you did) ? It's an expensive piece of kit and you've lost the generator part as it has to run at constant speed.

At the time it looked a clever piece of kit if you wanted an all electric boat implying 3 - 5kw of 240V power. I've only seen one and the boat was almost silent.

 

[David Mack]

Shouldn't the thread title be "Axiom Oversold"?

[MtB]

I'm still puzzled. What engine is a "BV"?

An 18" diameter blade on a 50hp engine should not be overloading it whatever the pitch, within reason.

[mrsmelly]

36 minutes ago, Mike the Boilerman said:

I'm still puzzled. What engine is a "BV"?

An 18" diameter blade on a 50hp engine should not be overloading it whatever the pitch, within reason.

Its a " Beta " a PROPER Japanese jobby

[GUMPY]

If its any help my 2203 has a 19x14 on it, just right, slow enuf at tickover just but plenty of oomph for river work, 7+mph and that's not flat out

[PMB]

10 hours ago, OldGoat said:

I'm curious - if I may - why did you ditch the whole prop gen (if that's what you did) ? It's an expensive piece of kit and you've lost the generator part as it has to run at constant speed.

At the time it looked a clever piece of kit if you wanted an all electric boat implying 3 - 5kw of 240V power. I've only seen one and the boat was almost silent.

 

The all electric boat was a pain in the butt as we never had enough power storage for using after 8pm (kettle boiling mainly). We fitted gas a while back and subsequently the prop gen died for a second time, first was £1800 repair. The only thing we really wanted the 7kva gen to do was run the washing machine, but the bosch didn't like it.

More recently the electronics on the trolling valve were hit and miss resulting in losing drive on the Thames and having to pole it through some of Oxford. The suspected part was a duff PCB in the B12 connector and sadly beta haven't got any and PRM who supplied them 17 years ago had no record of it so it seemed sensible to bin the lot and go back to standard BV2203. 

 

[PMB]

On 28/07/2017 at 20:53, Loddon said:

If its any help my 2203 has a 19x14 on it, just right, slow enuf at tickover just but plenty of oomph for river work, 7+mph and that's not flat out

got a feeling the 28 degrees on the Axiom is closer to 16". Beta reckon a 18"x14" should work, which looking back on the 1999 paperwork is what the boat was built with.