Is there any reason not to replace a stud with a bolt?

[Ugly Cow]

Bollocks.....
Use only one helicoil. If you damage the inner one, you will not get it out again when a second insert is against it.
One helicoil insert is ample fixing for a standard M8 engineering stud to screw into it in your casting.
I told you earlier, the M8 inserted hole has higher strength than a basic M8 hole into alloy, so the extra thread you are trying to gain by fitting two inserts is overkill, and risky to achieve.

Bang on the money, you will have to be extremly ham fisted to strip out a helicoil from the alloy. whatever bolt/stud you fit will not sieze into an insert providing uoy apply a little copperslip to the threads. 12years on and still fine.

 

[STUBBS]

Best get someone who knows what they're doing to successfully complete the task in hand

Much less grief, I expect

No....'cos that way, I'll never learn.

I'm quite happy to look daft and ask the questions......that's what it's about, learning and then being able to do it easily the next time.

The virtual-hand holding here is fantastic......I'm not totally incapable and I do learn fast, and more importantly, I WANT to learn ......how else can anyone go forwards?

I'd rather go through the grief if I have to, and look daft asking the questions along the way, to get to the point where I'm not afraid to get stuck in.....it's the 'better pay someone who knows what they're doing' attitude that keeps overpriced dealers in business.....sorry, that's not for me

while theyre doing it you can watch and ask questions though

 

[JohnnyBoxer]

No....'cos that way, I'll never learn.

I'm quite happy to look daft and ask the questions......that's what it's about, learning and then being able to do it easily the next time.

The virtual-hand holding here is fantastic......I'm not totally incapable and I do learn fast, and more importantly, I WANT to learn ......how else can anyone go forwards?

I'd rather go through the grief if I have to, and look daft asking the questions along the way, to get to the point where I'm not afraid to get stuck in.....it's the 'better pay someone who knows what they're doing' attitude that keeps overpriced dealers in business.....sorry, that's not for me

while theyre doing it you can watch and ask questions though

+1



I wasn't necessarily meaning a dealer or an engineering shop, but someone local to you, from here who has the knowledge and can show you how to do the first time and watch/guide you on further helicoils, like a 1:1 on the day

 

[Spike]

That was a good video, never seen a heli coil fitted before so i have learned something new today.
Thought he might have covered those pots up first thought with all those metal bits flying around when drilling.

spike

 

[JayC]

I bought the most comprehensive kit I could find within my budget for this and any future jobs.......It'll work, I have faith

So , how deep are you going to be going with your new stud?

 

[thornley]

So , how deep are you going to be going with your new stud?

Same depth as the old stud. The drill will cut cleanly until it bottoms out then withdraw the drill swiftly. Don't dwell or the tapping hole will go oversize.He will do this and wonder what all the fuss was about. Not rocket science with a new drill and a new tap in soft alloy. Helicoils are far stronger than the original tapped hole. Just take your time and follow the instructions. simples

 

[JayC]

Same depth as the old stud. The drill will cut cleanly until it bottoms out then withdraw the drill swiftly. Don't dwell or the tapping hole will go oversize.He will do this and wonder what all the fuss was about. Not rocket science with a new drill and a new tap in soft alloy. Helicoils are far stronger than the original tapped hole. Just take your time and follow the instructions. simples

Fortunately I already know how to put inserts in. What I don't know is how long the original stud is, hence my question , how deep.

BTW - dwelling won't make the whole oversize , being out of square will.

 

[ELIMINATOR]

Tallow, candle making


http://www.pdm-group.co.uk/news/200...peal_against_p50_million_tallow_fuel_ban.html

 

[Fanum]

What I don't know is how long the original stud is, hence my question , how deep.

.

As deep as the original threaded hole is

Possibly a few MM less actually.....the stud that came out (whole, see pic at start of this thread) is tapered off significantly from about 8 mill from the end to the first thread.

That means to me that anything more than 8 mill or so from the end of the hole, I'm likely to be tapping into virgin cast aluminium......by that time though, I should be lined up perfectly and have plenty of bite behind the tap to get a good fresh thread cut into it.
The Motorworks replacement studs are square ended, and threaded to the end.

I won't be going any further in than the original did, although it looks like the thread will be further in, IYSWIM.

 

[Fanum]

Tallow, candle making


http://www.pdm-group.co.uk/news/200...peal_against_p50_million_tallow_fuel_ban.html

Er......yes, Tallow candles

Tallow solid fat extracted from the tissues and fatty deposits of animals, especially from suet (the fat of cattle and sheep).

 

[JayC]

As deep as the original threaded hole is

Possibly a few MM less actually.....the stud that came out (whole, see pic at start of this thread) is tapered off significantly from about 8 mill from the end to the first thread.

...and how deep is the original hole?

The pic you see at the start of this thread is invisible to me.

 

[bowser]

do yourself a favor and put studs in and throw the Nuts AWAY, get some brass nuts, if you can find them in the right size, some anti vibe ones, they have two slots cut across the top of the nut and it stops them vibrating loose.

Its virtually certain you will have no more issues with snaping studs, or nuts seizing on the stud, and if you strip anything its a cheap brass nut not the stud.

 

[Fanum]

...and how deep is the original hole?

The pic you see at the start of this thread is invisible to me.

To be established before I start reaming out.....I'll stick a suitable widget in there and take that depth as a measure, transferred to drill bit and marked up with tape

Bowser....the original steel hex nut is still in pretty good shape......I'd intended on re-using that, as it hasn't caused me any concern before and came off very easily....the damage was towards the end of the stud INSIDE the head.

I take your point on brass though.

 

[JayC]

To be established before I start reaming out.....I'll stick a suitable widget in there and take that depth as a measure, transferred to drill bit and marked up with tape

Of course , THAT pic , I remember now!

 

[(RIP) Kaister]

I used to build mag F1 gearboxes

The trickiest helicoil I ever had to do was between practice and qually back int he day when it was on the same day.

we had to do a ratio change , which was hard enough anyway as you pulled the box off, undid a 400Nm nut on the main shaft that locked the gears on, then pull the ratios out, throw them in a box and swap all the worn ones and replace and rebuild.

if you had notice it was happening you could get everything ready and do the whole job in 20 mins or so - then bolt the car back together

I think we had about an hour start to finish ...

anyway - I'd pulled the ratios out and thrown them in a tray and was having a quick look inside the box. there is a separate oil pump and filter mesh system in there.
to my horror the single 1/4 unc bolt that holds the oil pump in was hanging out by its lockwire as the magnesium had let the helicoil loosen.

the only way to do this particular helicoil was to redrill deeper and re helicoil. problem was it was at 90 deg to the opening as it was normally accessed from another cover that was left on for ratio changes and obscured by wishbones.

I had to use a drill in a ratcheting tap wrench and re helicoil using a modified bolt especially made for such emergencies.

Alll this while the box and oil were red hot and the whole team watching.

anyway it got done and rebuilt ready for qually much to my immense relief.


Btw....you'll be fine with yours.

 

[thornley]

Fortunately I already know how to put inserts in. What I don't know is how long the original stud is, hence my question , how deep.

BTW - dwelling won't make the whole oversize , being out of square will.

Fortunately so do I. I remember sparking out sheared studs back in the 70's when we used to make our own oversized inserts. Happy days! Dwelling with a hand drill tends to cock the drill and the alloy on these heads is very soft, so in and out cleanly. The original stud was definitely not longer than the hole it came out of

 

[(RIP) DitchWater]

...a ratcheting tap wrench...

I wish I had one of those.

Btw....you'll be fine with yours.

Quite right. I did one myself after my gearbox stripdown (might as well give it a good going over when it's in two halves) and didn't think twice about the job.

 

[thornley]

Er......yes, Tallow candles

I had a tin of tallow given to me by the toolroom instructor as an apprentice. It was totally rank but it was superb for tapping in ali. If you could get the smell off your hands. Yes it's made from animal fat. That was almost 40 years ago, still got it somewhere unless the missus has used it to baste the sunday lunch

 

[(RIP) Kaister]

I wish I had one of those.

http://www.ebay.co.uk/sch/sis.html?_nkw=DRAPER+RATCHET+T+TYPE+TAP+WRENCH+45680+schroder+germany

 

[Smug]

Screw the new bolt/stud into the helicoil insert and measure how deep you need to tap to position the top of the insert just below the surface. Transfer this measurement to the tap allowing extra for the tap taper and wrap insulating tape round the tap to show how deep you want to go.

If possible use a drill that will run at a slower speed than the air drill use in the video. The video was ok but you will get a better thread if you unscrew the tap a quarter of a turn after every few turns to break off the swarf.

Best of luck, not that you need it.