Topic: Huco Couplings....Grrr (Read 32259 times)

Nige52 · « **on:** August 22, 2012, 05:24:30 pm »

I have tried and tried and am fed up with stabbing my fingers trying to get grub screws out of Huco Couplings. No...it wasn't me that rounded them off so that none of my decent quality allen keys fit, I just seem to have fatal attraction when it comes to couplings that have duff grub screws....so...
Please could anyone advise the easiest way to remove a duff grub screw from these couplings? I now have 2 motors and a shaft that seem to have welded themselves to the brass, probably why the previous owners passed them on to me.....

I have already thought of a big metal vice and a claw hammer........

Stormbringer · « **Reply #1 on:** August 22, 2012, 06:12:46 pm »

here are a couple of methods I've used for rounded grub screws on rc cars and helis
Superglue or araldite the Allen key into the rounded hex and leave till set or use a very fine drill bit and drill the grubscrew out both have worked for me

Umi_Ryuzuki · « **Reply #2 on:** August 22, 2012, 06:22:50 pm »

Apply a bit of heat to the area if you are able.
That usually works for me.

However, if the hex is stripped, there will still be
some issues backing out the grub screw

Nige52 · « **Reply #3 on:** August 22, 2012, 06:37:05 pm »

Thanks...I'm trying the Araldite method at the moment, I have nothing to lose really so we'll wait and see

Circlip · « **Reply #4 on:** August 22, 2012, 07:27:37 pm »

You need to carefully drill the grubscrews out using a drill a few thou smaller in diameter of the hole the grubsrew is screwed into, i.e. the root diameter of the thread. This is important as, if the hex is stripped, the end the key fits into will have expanded and be jamming itself into the tapped hole.

Once you have the coupling off, you can soak it in a warm super saturated solution of Alum and this will rot out the remaints of the screw.

Regards Ian.

Stavros · « **Reply #5 on:** August 22, 2012, 09:52:08 pm »

Use a dremel to grind down and through the grub screw and then bin the old coupling

Dave

catengineman · « **Reply #6 on:** August 22, 2012, 10:08:54 pm »

Quote from: Stavros on August 22, 2012, 09:52:08 pm

Use a dremel to grind down and through the grub screw and then bin the old coupling

Dave

Easiest and quickest way and as you dump the old coupling there is no chance of finding the thread damaged when you want to reuse the old one, or having to try and locate a good grub screw that fits

IMHO

grasshopper · « **Reply #7 on:** August 22, 2012, 10:24:49 pm »

Drill the whole grub screw out - then drill and tap another hole on the other side and put a new grub screw in - make sure you always use a decent allen key (or hex driver) of the correct size.

Martin (Admin) · « **Reply #8 on:** August 22, 2012, 10:58:55 pm »

What do you want to save, the coupling or motor?
Coupling? Not worth it! Wrap the motor in several layers of an old rag and hacksaw or Dremel the coupling off.
Want to save the motor? .... same procedure.

You could try a pinion pulll but that maybe the price of a new motor ..... and coupling!

http://www.ebay.co.uk/itm/Universal-Gear-Removal-Puller-Kit-for-Most-R-C-Motors-/180553938226?pt=UK_ToysGames_RadioControlled_JN&hash=item2a09da7532

http://www.ebay.co.uk/itm/Walkera-gear-puller-for-rc-helicopter-TREX-ESKY-motors-/170645179120?pt=UK_ToysGames_RadioControlled_JN&hash=item27bb3ecaf0

Good HEX keys are also worth a try... again expensive....

http://www.ebay.co.uk/itm/HSS-RC-tool-Hex-key-Hex-Screw-Driver-1-5-3mm-Regular-/200427810966?pt=UK_ToysGames_RadioControlled_JN&hash=item2eaa6db096

tobyker · « **Reply #9 on:** August 22, 2012, 11:22:00 pm »

I think that the screws in the couplings have a special hex head which is measured in Venusian micro quatlits, and no key manufactured on planet earth will fit them. Otherwice you would be able to use them more than once, and that is not the manufacturer's plan.

irishcarguy · « **Reply #10 on:** August 23, 2012, 04:05:29 am »

You may find that the grub screw is of hardened steel, a drill may not touch it & you will destroy the drill, grind it off with your dremel & be carefull you don't damage the shaft on the motor. Mick B.

catengineman · « **Reply #11 on:** August 23, 2012, 06:49:06 am »

When grinding the coupling off if you keep the cutting in line with the shaft and do it nice and steady there will be a time when the coupling is very thin (but still not through) you will possibly find the heat from the grinding has expanded the coupling and so is now looser on the shaft so can be gripped with pliers and removed without damage to the shaft of the motor or even the prop shaft etc it was connected to.

We do this with larger bearing races which are pressed on shafts though they being a steel snap when they are thin. I have done it on several model couplings though, all without any problems.

R

essex2visuvesi · « **Reply #12 on:** August 23, 2012, 07:51:30 am »

Quote from: Martin - Admin on August 22, 2012, 10:58:55 pm

Good HEX keys are also worth a try... again expensive....

http://www.ebay.co.uk/itm/HSS-RC-tool-Hex-key-Hex-Screw-Driver-1-5-3mm-Regular-/200427810966?pt=UK_ToysGames_RadioControlled_JN&hash=item2eaa6db096

I use these ones, had them for years and I have never had any issues (Except one cheap heli pinion but that was down to the grub screw being so soft)
http://buy1.snapon.com/catalog/item.asp?item_ID=644314&group_ID=682008

hopeitfloats · « **Reply #13 on:** August 23, 2012, 07:56:46 am »

i have recently had to remove a 3mm allen screw and got it by grinding the tip of a small easyout (stud extractor) and tapping it in then simply screwing it out. maybe i was lucky but it did the job.

chuffy · « **Reply #14 on:** August 23, 2012, 08:06:55 am »

Take a slightly larger key allen key than you need and grind a very gradual slope on each of the faces, by then grinding a little off the end bit by bit, at some stage you will have a size that fits perfectly. Constant downward pressure will remove the allen screw. If you haven't got a grinder use a file but only the end next to the tang, this end gets little use on most files so is still sharp, good allen keys are quite hard and can ruin a file if you use the main body of the file of it.

Nige52 · « **Reply #15 on:** August 23, 2012, 08:15:03 am »

Thanks for all the suggestions,
I let the Araldite harden properly overnight but unfortunately it didn't work. As it's the motors and shaft I want saving, I'll be cutting them off later today, thank you for all the helpful suggestions, I'll be keeping them in mind for when it happens again, as I'm sure it will....

essex2visuvesi · « **Reply #16 on:** August 23, 2012, 09:33:47 am »

Quote from: Nige52 on August 23, 2012, 08:15:03 am

Thanks for all the suggestions,
I let the Araldite harden properly overnight but unfortunately it didn't work. As it's the motors and shaft I want saving, I'll be cutting them off later today, thank you for all the helpful suggestions, I'll be keeping them in mind for when it happens again, as I'm sure it will....

Don't use a dremmel... they are for girls

You need one of these!

Martin (Admin) · « **Reply #17 on:** August 23, 2012, 09:48:27 am »

malcolmfrary · « **Reply #18 on:** August 23, 2012, 10:11:11 am »

After the event, but, while the tools are around, file a flat on the motor shaft. When the new coupling is fitted, it won't need as much brute force to fix, and the grub screw can be loctited in place for easier removal later.

essex2visuvesi · « **Reply #19 on:** August 23, 2012, 10:16:59 am »

Quote from: malcolmfrary on August 23, 2012, 10:11:11 am

After the event, but, while the tools are around, file a flat on the motor shaft. When the new coupling is fitted, it won't need as much brute force to fix, and the grub screw can be loctited in place for easier removal later.

use the blue loctite, not the red or green or you'll be figting to get it off again

AlanT · « **Reply #20 on:** August 23, 2012, 12:56:19 pm »

A tip from car restoration days re stubborn fixings....always turn to tighten first then snap back to loosen.

Regards

Alan

essex2visuvesi · « **Reply #21 on:** August 23, 2012, 01:00:32 pm »

Quote from: AlanT on August 23, 2012, 12:56:19 pm

A tip from car restoration days re stubborn fixings....always turn to tighten first then snap back to loosen.

Regards

Alan

Good tip one I also use without thinking
another thing to remember
Lefty loosey, righty tighty :) (works in most cases

Popeye · « **Reply #22 on:** August 23, 2012, 07:28:17 pm »

What couplings are reccommended if the 'grubscrew' variety are to be avoided?

Colin Bishop · « **Reply #23 on:** August 23, 2012, 08:11:36 pm »

Virtually all my boats employ belt drive. Much more foregiving to set up and has the advantage of being easily able to gear down the prop to give higher efficiency and reduce current consumption. As has been previously posted om Mayhem, the Huco types frequently suffer from out of line bores and always seem to make far too much noise however much care you take in aligning them. Theoretically belt drives might impose wear on the upper propshaft bearing but with moderate size scale models this doesn't seem to be a practical problem. You just need to get the tension right which is easy enough to do.

Colin

malcolmfrary · « **Reply #24 on:** August 23, 2012, 08:52:55 pm »

Quote from: Popeye on August 23, 2012, 07:28:17 pm

What couplings are reccommended if the 'grubscrew' variety are to be avoided?

Still stuck with grub screws for plain shafts, but I quite like the Graupner version. There's MMB's offering as well. A flat filed on the motor shaft reduces the brute force needed to make the grub screw lock, and a bit of loctite (of the blue variety)

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Author Topic: Huco Couplings....Grrr (Read 32259 times)

Stavros

catengineman

catengineman