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Author Topic: Hydraulic gib key puller - hints  (Read 5787 times)

jtodd

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Hydraulic gib key puller - hints
« on: April 09, 2007, 01:29:46 PM »
I have an old Lister/Blackstone CD design single-cyl engine I'm restoring.  To get the single flywheel off, I've discovered that the gib key is being a bit obstinate.  I built a hydraulic gib key puller based on some ideas I've seen in other areas of the message board here, using 2 1/2" schedule 40 pipe and a 1/2" thick mild steel plate bolted to the end that I CNC plasma-cut to fit around the key (this has been a good excuse to learn how to use the robotic cutter.)  After giving a few days to some penetrating oils, I gave it a shot.  No luck.

My questions are:

1) for those of you that have used hydraulic pullers for gib keys, how many tons was the pump/cylinder rated for?  The cylinder I have been attempting with is a 4 ton unit.  8000 pounds seems like a pretty good amount of tugging power, but it's a Horrible Freight hand-pump unit so it might be not giving what I think it is.  I'm debating trying to rent a larger unit but I don't know if I'm barking up the wrong tree here.

2) It seems that I could just get some larger pipe, and press the flywheel more towards the engine to loosen the grip.  The problem is that the backing for such an operation would be the other side of the crank, and if I bent the crank then I'm really up a creek.  Is there some clever way to do this?  The only way I could think of was to tap the flywheel end of the crank with some BIG threads, and then use that and some creative pipe and plate assembly to mount another hydraulic cylinder to press the flywheel in away from the gib key.  Has anyone ever had success with pressing the flywheel in way from the key to "start" the process?

PS: This is a 2 1/4 shaft on this engine and a really weird gib key size.  I've got components to fit on the other side for a drive pulley (an SK-bushing v-pulley) and I'm going to have to mill a "custom" key to mate the SK keyway to the shaft.  Very disconcerting.

JT
« Last Edit: April 09, 2007, 01:41:22 PM by jtodd »

jtodd

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Re: Hydraulic gib key puller - hints
« Reply #1 on: April 09, 2007, 06:45:07 PM »

In perhaps what is optimistic forethought, I am considering how I am going to re-fasten the gib key into the way.  I'll probably end up making a new key on the mill, so I will just construct it so that there is some extra distance between the flywheel face and the key head.  In that space, I will drill and tap a smallish hole, which will have a set screw placed in it with a liberal dose of threadlock.  Hopefully I won't need much force to tap the key into the flywheel far in that case.

Has anyone ever seen a gib key with the notch in the middle like mine?  I thought that might be useful for getting penetrating oil into there, until I figured that it's also probably useful for getting water into there which is why this is such a @#(%@# to get out.  The new key will not include such a notch, or if I use the old one I'll fill it with cotton and cap it with epoxy on the outside (grind-able to remove.)

http://www.loligo.com/lister/lister-blackstone-cd/pictures/8.html

JT

dkwflight

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Re: Hydraulic gib key puller - hints
« Reply #2 on: April 09, 2007, 10:46:39 PM »
Hi
You could use a large propane torch to gently warm the entire flywheel uniformly with pressure on the gib key at the same time.
The key is to move the torch all over the flywheel and don't stay in one spot for any time. Check with your bare hand. If you feel a warm spot you need to heat other areas.
Many will say "No heat". The key is to move all over and get a uniform temp. Go slow don't rush it.

A couple of light bulbs in oposite holes and cover the wheel with a blanket over night would probably do as well.


I would have a blanket handy to cover it if there is any breeze.
Dennis
« Last Edit: April 09, 2007, 10:54:30 PM by dkwflight »
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jtodd

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Re: Hydraulic gib key puller - hints
« Reply #3 on: April 09, 2007, 11:15:47 PM »
Hi
You could use a large propane torch to gently warm the entire flywheel uniformly with pressure on the gib key at the same time.
The key is to move the torch all over the flywheel and don't stay in one spot for any time. Check with your bare hand. If you feel a warm spot you need to heat other areas.
Many will say "No heat". The key is to move all over and get a uniform temp. Go slow don't rush it.

A couple of light bulbs in oposite holes and cover the wheel with a blanket over night would probably do as well.

I would have a blanket handy to cover it if there is any breeze.
Dennis

That's a good idea, and actually I already did that.  I got the whole wheel up to 200F through a very long and slow propane heating cycle (spin wheel slowly while applying flame.)  I didn't want to get it any hotter, since I'm somewhat worried about the temper on the flywheel, and I have no desire to have flying lumps of metal the next time I start it up.  I figure that 200F is probably within the range of heat that would be expected of a very hot engine under load, so I think that's within the safety zone.  I then super-cooled the key (isolated from the rest of the flywheel by the puller plate) with "quick-freeze" spray liquid down to around 50F, while applying pressure with the key puller. Not a peep of movement.  However, the flywheel did stay hot for a good 8 or 10 hours afterwards.

I'm pretty sure that the answer here is "use a bigger hamm... er, hydraulic cylinder" but I'll take any advice that is offered.

PS: anyone reading this that doesn't have one of those infra-red thermometer things that cooks use, I'd strongly suggest picking one up.  They're around $35 on eBay, and well worth the investment - you can shoot a reading into angles that would be unsafe or impossible to get hands onto, and the "instant" response is really useful.  The downside is that the cook often doesn't like finding her tools in the workshop.  Additionally, if you don't have one of those $15 propane flame throwers (they call it a "torch") from Harbor Freight, I'd suggest going to get one.  Their general tools are kind of junk, but you can't go wrong with a 40,000 BTU propane flamethrower - it's the "tactical nuke" of heat application.  (The "hydrogen bomb" of heat application is an oxy-acetelyne torch, but that, like the H-Bomb, is a troublesome tool to use without collateral damage.)

JT

MeanListerGreen

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Re: Hydraulic gib key puller - hints
« Reply #4 on: April 09, 2007, 11:22:22 PM »
I wouldn't get a propane torch anywhere near my flywheel.  If you have to use heat then use a heat gun on low or a hair dryer.  Gib keys are going to vary.  I would put an acme screw on the end of your set up instead of porta power and use a couple of 4 foot levers.  Unless you have a 10 ton porta power and a good one like a Blackhawk and not some Chinese POS.  I also recommend using a pnuematic  engraving tool  ( the kind you write your name on your tools with).  Mine is adjustable and the frequencies can vary.  You get the right one and it will help alot.  Just make sure to put the tuip of the engraver on the Gib key that you are going to trash and not the flywheel hub or crankshaft. That with Kroil should be enough to free it up.  I use this combination to loosen about anything that is stuck.  Are you the fella that landed the brand spankin new 16/2?  If so how's it going with that?  Any updates?
MLG Gib Key Pullers

jtodd

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Re: Hydraulic gib key puller - hints
« Reply #5 on: April 10, 2007, 01:22:19 AM »
I wouldn't get a propane torch anywhere near my flywheel.  If you have to use heat then use a heat gun on low or a hair dryer.  Gib keys are going to vary.  I would put an acme screw on the end of your set up instead of porta power and use a couple of 4 foot levers.  Unless you have a 10 ton porta power and a good one like a Blackhawk and not some Chinese POS.  I also recommend using a pnuematic  engraving tool  ( the kind you write your name on your tools with).  Mine is adjustable and the frequencies can vary.  You get the right one and it will help alot.  Just make sure to put the tuip of the engraver on the Gib key that you are going to trash and not the flywheel hub or crankshaft. That with Kroil should be enough to free it up.  I use this combination to loosen about anything that is stuck.  Are you the fella that landed the brand spankin new 16/2?  If so how's it going with that?  Any updates?

Well, I figure pressure is pressure, and I don't have the ~$550 for the nice hydraulic set, so I'll keep busting the cheap Chinese ones or renting the nicer ones.  :-)  I'll try the vibrating engraver tool, or maybe a 1/8 steel plate pushed down against the pin and then an air chisel to vibrate some of the Kroil into the keyway further before the next attempt.

 The acme screw idea will also work, I suppose; I'd have to build a separate butt plate, but that can be done pretty quickly and I could swap out the hydraulic and acme ends pretty much as I like since the schedule 40 pipe is connected with an adapter in the middle.  How many turns per inch is the acme screw that you're using?   I worry about using an acme screw, since it involves rotational force as well as outward force, and it involves me very nearby to a system loaded with >8000 pounds of stored energy and brittle steel.  I still think I'm going to try a 10 ton cyl first, since I'm already rigged for that and it's a fairly simple swap-out.

I keep forgetting to mention things that I've tried: I had a 5 foot prybar on the rear of the plate right behind the key in addition to the portapower, so I imagine I was adding another 2000 pounds or so of "outward" force.  This sucker is in there good.

Yes, it was me with the 16/2 original CS.  I've not done anything with it yet; I actually have to swap out the flywheels since one of them is a double-v pulley style and I need smooth (for serpentine belt) on both sides for my particular crazy application.  In any case, it'll be another month or two before that project is complete enough for me to start up the engine; this project (the Lister/Blackstone CD) is keeping me busy while I wait for parts and the apperance of larger blocks of time for the CS effort.

JT

tiger

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Re: Hydraulic gib key puller - hints
« Reply #6 on: April 10, 2007, 05:22:34 AM »
Looking at the pic, the word is Clean the key, Clean the shaft, Clean the area around the key, all to bare metal! Use Naval Jelly, steel wool, and dental picks for all the groves and crevices!
Since you all ready started to pull, after the above, drive the key in a bit. Then apply a penetrate and let it soak for a few hours. Reapply penetrate and try it again. Kroil is rated very good for a penetrate but I have not used it. Wd 40, CRC, and ZEP Preserve have worked for me. the zep product was the best for me. If you can get the Kroil product try it first. Let us know the results, good luck!
Ps try the old marine engine .org site . They have good info on gib key removal.
Again time is on your side let the penetrate do its work!
Tiger sends
Metro 12/2 ST 10 KW

jtodd

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Re: Hydraulic gib key puller - hints
« Reply #7 on: April 17, 2007, 07:17:53 AM »

Success! 

The 20,000 pound cylinder was what was needed to do the trick.  The 4 ton cheapo Harbor Freight unit didn't budge it, but the 10-ton Enerpac rental popped it free after a disturbing amount of heavy pumping.  That key was in there for keeps!  Before pulling, I banged on it with an air chisel for a while (straight down, on a sacrificial plate) to possibly vibrate some oil into the gaps, and I gently tapped the key a few times in the three available dimensions to loosen things up.  It's been seeped in Kroil for a week or two.  I got the 10 ton cylinder in place in the rig, and it came off with a very loud "bang".  The keyway looks very clean; it didn't bind anywhere or scar the shaft - it was just age and stubbornness blocking it, apparently.  Then, I spun the rig around and used it with some chains to pull off the flywheel, which was also unwilling to just "walk" off the shaft - I needed the hydraulics to pull it off for the full depth of the flywheel/shaft mating surface before it would spin freely.

So here's the list of ingredients to make a gib key puller like mine.  The only thing that is not "off the shelf" is the plate that I made to fit over the shaft and key (I've put the PDF of the design one directory level up in the website if you're interested - note that the shaft on the CD is a 2.25" shaft, and not a 2" shaft like on the CS line so it's somewhat bigger than the plate I'll have to make for my 16/2 in order to pull the gib keys there.)

Quan  Desc
1       6" Schedule 40 iron pipe, 2.5" diameter
1       10" Schedule 40 iron pipe, 2.5" diameter
1       female-to-female schedule 40 iron pipe adapter
1       Schedule 40 2.5" pipe endcap
1       Schedule 40 2.5" threaded flange, round
1       20,000 pound hydraulic cylinder and pump
2       6' lengths of chain (reasonable weight capacity - maybe 1200#)
4       screw shackles for chain
2       eye bolts, large (1.75" or so for eye diameter)
4       3/4" nut and bolt combinations, about 3" long
4       1" long, 1" diameter steel pipe segments (spacers)
1       1/4" or better steel plate with hole pattern to match pipe flange (for flywheel pull backstop)
1       1/2" steel plate custom-cut with center hole to match shaft and "notch" to fit gib key

I won't go into the description, but you can see from my pictures how it all might go together.   This was a big pain in the rear, but in the process I learned how to use a CNC plasma cutter (for the puller plate) so there was an education in there as well.  Total cost for everything (including the expensive chain and shackles) was around $150, including the $25 rental of the hydraulic cylinder and pump.  Possibly more than might be spent with simpler methods, but I have a permanent solution now for other similar problems, and the same rig can be used for my CS engines if I cut a new puller plate (which I can do for free at the shop.)  I suppose someone with a die grinder and some free time could also make the plate themselves without the fancy robot plasma cutter, but I wanted to try something clever at the machine shop instead of doing everything the manual way.  :-)

http://www.loligo.com/lister/lister-blackstone-cd/pictures/


JT