Jump to content

Ecofan fan fixing screw

MtB

By MtB
in Boat Equipment

 Share

Featured Posts

MtB Veteran II

MtBDonate to Canal World

Posted
Posted (edited)

This has been discussed here long ago but I can't find the thread now.

 

One of my Ecofans, this one a genuine Ecofan not a clone or copy, has a fan blade that falls off the motor shaft with annoying regulatity. The reason is I cannot find an Allen key the right size to fit the hexagon socket on the grub screw that tightens it onto the electric motor shaft. I have purchased Allen keys every possible size both metric and imperial that are close and none fits. They either won't go in the hole or the slightest size smaller spins in the hole.

 

So the best fix I reckon is to replace the stupid grub screw with a proper screw with a head! So now now I find it's a weird thread too. The diameter across the tips of the threads is 3.41mm and the pitch of the thread is 0.81mm (or rather, the pitch measured across four turns of thread is 3.26mm), a very coarse looking thread. Can anyone identify this thread please?

 

Thanks,

MtB

 

(edit to correct the pitch value.)

Edited by Mike the Boilerman
Link to comment
Share on other sites
craftycarper Rising Star

craftycarper

Posted
Posted

This has been discussed here long ago but I can't find the thread now.

 

One of my Ecofans, this one a genuine Ecofan not a clone or copy, has a fan blade that falls off the motor shaft with annoying regulatity. The reason is I cannot find an Allen key the right size to fit the hexagon socket on the grub screw that tightens it onto the electric motor shaft. I have purchased Allen keys every possible size both metric and imperial that are close and none fits. They either won't go in the hole or the slightest size smaller spins in the hole.

 

So the best fix I reckon is to replace the stupid grub screw with a proper screw with a head! So now now I find it's a weird thread too. The diameter across the tips of the threads is 3.41mm and the pitch of the thread is 0.81mm (or rather, the pitch measured across four turns of thread is 3.26mm), a very coarse looking thread. Can anyone identify this thread please? Can't help you with regard to thread size but have a set of star keys similar to Allan keys but with a star shaped head, these will often sit inside an Allen screw head and bite into the sides enough to tighten or loosen it off, also I think the grub screw you refer to is only going through a few mil of ali so a slightly larger stainless steel screw will probably cut its own thread through the Ali fan and lock it in place

 

Thanks,

MtB

 

(edit to correct the pitch value.)

 

This has been discussed here long ago but I can't find the thread now.

 

One of my Ecofans, this one a genuine Ecofan not a clone or copy, has a fan blade that falls off the motor shaft with annoying regulatity. The reason is I cannot find an Allen key the right size to fit the hexagon socket on the grub screw that tightens it onto the electric motor shaft. I have purchased Allen keys every possible size both metric and imperial that are close and none fits. They either won't go in the hole or the slightest size smaller spins in the hole.

 

So the best fix I reckon is to replace the stupid grub screw with a proper screw with a head! So now now I find it's a weird thread too. The diameter across the tips of the threads is 3.41mm and the pitch of the thread is 0.81mm (or rather, the pitch measured across four turns of thread is 3.26mm), a very coarse looking thread. Can anyone identify this thread please? Can't help you with regard to thread size but have a set of star keys similar to Allan keys but with a star shaped head, these will often sit inside an Allen screw head and bite into the sides enough to tighten or loosen it off, also I think the grub screw you refer to is only going through a few mil of ali so a slightly larger stainless steel screw will probably cut its own thread through the Ali fan and lock it in place

 

Thanks,

MtB

 

(edit to correct the pitch value.)

sorry about that done it wrong but hope it helps
Link to comment
Share on other sites
frangar Veteran II

frangar

Posted
Posted

Hmm. That's interesting. I replaced the motor on mine last year and an Allen key was included in the motor kit which I used without thinking about it...I then put it in my Allen key pot...that might be amusing if I ever need it again or try to use it for something else....

 

Cheers

 

Gareth

Link to comment
Share on other sites
MtB Veteran II

MtBDonate to Canal World

Posted
  • Author
Posted

Could be 5/32" Whitworth - cant see any in my "bits" box but used on old Brit bikes

Ray

 

Yes it 'looks like' a Whitworth thread even though they fell from use before I left skool!

 

Really odd if it is, on a fan manufactured in about 2008.

 

And Biz's idea of filing down the Allen key that won't fit seems a non-starter, I'd have thought. Allen keys are made from wonderfully hard and strong steel so I didn't even try a file on one, but I will. If it won't touch it as I suspect, I'll dig out an oilstone and use the coarse side. As 1.5mm spins in the hole yet 1/16" won't go in, it isn't going to need much material removing!

 

MtB

Link to comment
Share on other sites
cereal tiller Veteran

cereal tillerDonate to Canal World

Posted
Posted

This has been discussed here long ago but I can't find the thread now.

 

One of my Ecofans, this one a genuine Ecofan not a clone or copy, has a fan blade that falls off the motor shaft with annoying regulatity. The reason is I cannot find an Allen key the right size to fit the hexagon socket on the grub screw that tightens it onto the electric motor shaft. I have purchased Allen keys every possible size both metric and imperial that are close and none fits. They either won't go in the hole or the slightest size smaller spins in the hole.

 

So the best fix I reckon is to replace the stupid grub screw with a proper screw with a head! So now now I find it's a weird thread too. The diameter across the tips of the threads is 3.41mm and the pitch of the thread is 0.81mm (or rather, the pitch measured across four turns of thread is 3.26mm), a very coarse looking thread. Can anyone identify this thread please?

 

Thanks,

MtB

 

(edit to correct the pitch value.)

Remove Grubscrew,cut a slot across the top,tighten it back in with a Slothead Screwdriver.

Is there a flat in the Eek!ofan motor shaft?if not,file grind one on it,will be better at coping with the Massive turning moment manifested when the Fan starts up!

CT

Link to comment
Share on other sites
MtB Veteran II

MtBDonate to Canal World

Posted
  • Author
Posted

Angle grinder with a stone in it under your foot or in a vice

On an Allen key the size of a toothpick?? We're only trying to remove two or three thou from each of the six faces!

 

 

ohmy.png

 

 

MtB

Remove Grubscrew,cut a slot across the top,tighten it back in with a Slothead Screwdriver.

 

I suspect the grub screw material is harder than a hacksaw blade but I'll have a bash laters!

 

MtB

Link to comment
Share on other sites
Alan Saunders Rising Star

Alan Saunders

Posted
Posted

Is this fan American?

Thread is probably no 6 UNC (6-32 NC).

See this link for details http://www.modelfixings.co.uk/steel_grub_screws.htm#UNC%20grubs

Also, it may not be a hex key. I may still have, somewhere, sets of four-flute and six-flute keys that I used on machines designed over fifty years ago in the USA. These are a bit like torx but round with semi-circular flutes. My American standard hexagonal keys are exactly the same as Imperial. I probably also have 6-32, ¼-20 etc. taps.

 

May be best to tap to the next largest metric size?

 

Alan

 

Alan

Link to comment
Share on other sites
MtB Veteran II

MtBDonate to Canal World

Posted
  • Author
Posted

Well mine is a one sixteenth Allen key cause I tried it hours ago.

 

 

Ok thanks, just got my imperial Allen key set out.

 

Interestingly the key labelled 1/16" actually measures 0.0665" across the flats. 1/16" is a bit less than that at 0.0625" but even so, it spins freely around freely in the grubscrew.

 

The next size up in the set is labelled 5/64" and measures 0.083". Too big to fit.

 

No intermediate imperial sizes so I looked back to metric. My 1.5mm metric Allen key actually measures 1.68mm (0.062") and is too small. It spins freely in the slot. The next size up in my set is nominally 2.0mm and measures 2.04mm (0.082") Same size near as dammit as the 5/64" key. Too big.

 

A brief search of the net shows there are no intermediate sizes of Allen key so I tried Cereal Tiller's suggestion of cutting a slot for a flat blade screwdriver in the head of the grubscrew. The metal is too hard for a hacksaw blade to cut. I now have a blunt hacksaw blade.

 

Finally, looking at a UNC thread spec chart I think adrianh is correct. My measurements coincide almost exactly with UNC #6, 32TPI and major diameter of 3.5mm. I'll order one from his link, WITH Allen key to fit. Thanks Adrian!

 

 

MtB

Link to comment
Share on other sites
ditchcrawler Veteran II

ditchcrawlerDonate to Canal World

Posted
Posted

 

 

Ok thanks, just got my imperial Allen key set out.

 

Interestingly the key labelled 1/16" actually measures 0.0665" across the flats. 1/16" is a bit less than that at 0.0625" but even so, it spins freely around freely in the grubscrew.

 

The next size up in the set is labelled 5/64" and measures 0.083". Too big to fit.

 

No intermediate imperial sizes so I looked back to metric. My 1.5mm metric Allen key actually measures 1.68mm (0.062") and is too small. It spins freely in the slot. The next size up in my set is nominally 2.0mm and measures 2.04mm (0.082") Same size near as dammit as the 5/64" key. Too big.

 

A brief search of the net shows there are no intermediate sizes of Allen key so I tried Cereal Tiller's suggestion of cutting a slot for a flat blade screwdriver in the head of the grubscrew. The metal is too hard for a hacksaw blade to cut. I now have a blunt hacksaw blade.

 

Finally, looking at a UNC thread spec chart I think adrianh is correct. My measurements coincide almost exactly with UNC #6, 32TPI and major diameter of 3.5mm. I'll order one from his link, WITH Allen key to fit. Thanks Adrian!

 

 

MtB

Strange my 1/16 fits snug as a bug and the screw is quite tight so needed a bit of effort to move it. I can't measure it as I don't have a micrometer onboard only a 5 mt rule.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.