Repairing a Cylinder Barrel for BIG D11 Bulldozer! | Machining, Welding & Honing

Summary

The video follows Kurtis doing a cylinder rebarrel job on a bulldozer blade tilt cylinder. He shows the worn area of the barrel that needs replacing, cuts the original barrel off to salvage the head flange, machines a new barrel section, welds the head flange onto it, hones the new barrel to spec, welds on the other barrel end, reclaims the cylinder eye, and completes the rebuild. There is friendly banter with his partner Karen and the camera operator, demonstrating the amiable shop environment.

Takeaways

• 😀 This video covers the process of rebarreling a bulldozer blade tilt cylinder barrel that had an imperfection
• 👷‍♂️ The original barrel was borderline out of spec due to being oversized, so a full rebarrel was required
• 🔨 The old barrel was cut off, and a new pre-honed tube was machined to size and welded on
• 📏 The heat affected zone caused the barrel to shrink 0.4mm which needed to be honed out
• 💎 Rough honing stones were used first, followed by finishing stones to get the final dimension
• ⚙️ The barrel end was precisely reattached using alignment marks taken before disassembly
• 🌡️ Preheating was used for the large barrel weld to prevent too rapid cooling
• 🛠️ The weld tops were sanded smooth and the eye was reclaimed after honing was complete
• ✅ The rebarreling restored the cylinder to 100% standard spec
• 😊 The completed job was wrapped up, strapped down and returned to the happy customer

Q & A

What is the name of the part being worked on?

A blade tilt barrel off a D11T bulldozer, used to tilt the blade left and right.

What was the original job for this part?

To have an eye reclaim and the barrel rehoned, as there was an imperfection in the barrel.

Why couldn't the imperfection in the barrel be honed out?

The barrel was already 8 thou oversized, which is borderline out of spec. More material would need to be removed, making it way out of spec.

What is the solution for the barrel imperfection?

To do a full barrel replacement by machining and welding a new barrel.

What material is used for the new barrel?

Pre-honed ST52 steel tube, with 10.5 inch ID and 12.75 inch OD.

What welding process is used?

GMAW or MIG welding, using a dual shield wire backed up with Argon/CO2 shielding gas.

How much did the heat from welding shrink the barrel?

0.4 thou in the heat affected zone, which is pretty standard.

What tools are used to bring the new barrel to the proper dimensions?

Rough honing stones, then finishing stones to obtain the final size and surface finish.

How will the old barrel eye be refurbished?

A standard eye reclaim procedure will be done, but not recorded, to bring it back into spec.

What is the final step once all machining and welding is complete?

The part will be wrapped, strapped down securely, and shipped back to the customer.

Outlines

00:00

😀 Introducing the bulldozer blade tilt barrel machining job

This paragraph introduces the job of machining a bulldozer blade tilt barrel. It explains that bulldozers have left and right blade tilt cylinders to tilt the blade and carry loads. The customer wanted to reclaim the eye and rehone the barrel due to an imperfection, but it was too oversized to just hone out the imperfection. So they will need to do a full rebarrel instead.

08:08

😕 Discussing clearance issues when machining the barrel

This paragraph discusses the clearance issues when machining the odd shaped barrel using button tools. There is limited ability to extend the tools before they become less rigid. New longer button tool holders will need to be made to improve reach and rigidity for future jobs.

14:02

🚧 Cutting apart and machining new barrel pieces

This paragraph covers cutting the old barrel pieces apart from the welds. It then explains machining the new barrel material to size based on the standard dimensions. The head flange is test fitted before the barrel is welded.

20:44

⛏️ Noise interruption from railway bridge pile driving

This paragraph notes the loud noise from nearby pile driving for a new railway bridge. It is expected to continue for a couple more weeks until the bridge lift is completed.

26:43

🌡️ Welding the barrel and letting it cool before honing

This paragraph explains the weld filler and gas used to weld the barrel pieces together. After allowing it to cool, it will be honed to size. Reference is made to previous honing videos for more detail.

32:18

🐶 Staffy interruption and comedy during barrel honing

This paragraph contains comedy and interruptions from the shop dog Staffy during the barrel honing process. The rough honing is completed and it is within tolerance before starting the finish honing.

37:33

😅 Outtakes from multiple failed recording attempts

This paragraph contains outtakes from multiple failed recording attempts, with comedy and frustration from mistakes captured during the process.

44:14

🎉 Completion of the barrel reconditioning job

This closing paragraph notes the successful completion of the barrel reconditioning job. The eye reclaim still needs to be done but will not be recorded. The barrel is now within specification and ready to be returned to the customer.

Keywords

💡rebarrel

The process of replacing the cylinder barrel on the bulldozer's hydraulic tilt mechanism. This is a key repair concept in the video - the narrator takes us through the full process of removing the damaged barrel and welding/machining a replacement.

💡cylinder

The hydraulic component that actuates the bulldozer's blade tilt function. It has a barrel and gland/seal arrangement that failed in this case due to an imperfection in the barrel bore.

💡honing

An abrasive machining process used to finish the interior diameter of the new barrel to achieve the required dimensions and surface finish. Honing is shown in detail to resize and smooth the replacement barrel.

💡heat affected zone

The region next to a weld where material properties are altered due to heat from welding. The narrator measures the heat shrinkage here to ensure proper barrel dimensions.

💡button tool

A lathe cutting tool used in the initial steps to remove the damaged barrel. Its clearance and rigidity constraints showcase some of the challenges of machining large, complex components.

💡bore gauge

An inspection tool used to accurately measure the inside diameter of the cylinder barrel at different stages during the rebarrel process.

💡gland

This refers to the stationary head of the hydraulic cylinder. A machined surface is prepared here to allow proper sealing when the gland is reinstalled with new seals after rebarreling.

💡dual shield welding

The flux-cored arc welding used to attach the replacement barrel. It provides deep weld penetration and productivity needed for heavy weld deposits.

💡roughing

Initial, aggressive machining or abrasion designed to quickly remove material. Roughing is done on both the lathe and honing machine to save time before finer finishing.

💡cross-hatching

The cross-hatched surface pattern imprinted inside the barrel by honing. Re-establishing cross-hatching ensures optimal oil retention for cylinder lubrication and break-in.

Highlights

The barrel has an imperfection that is hard to remove by honing

The imperfection will require rebarreling the cylinder

Cutting the barrel and head flange apart to remove the old barrel

Machining a new barrel section from pre-honed tubing

Shrink fitting the head flange onto the new barrel

Welding the head flange to the barrel

Machining the barrel to length and adding a weld prep

Honing the new barrel to size

Realigning the barrel end using alignment marks

Tack welding the barrel end in place

Welding the barrel end fully

Sanding welds smooth

Reclaiming the cylinder eye

Overview of process to rebarrel a cylinder

Job is now complete and cylinder is ready for customer

Transcripts

how you going guys Kurtis from Cutting Edge  engineering today's job we have a blade tilt  

barrel off a d11T bulldozer and as the name  suggests this is used for exactly that is to  

tilt the blade left to right because this is  a newer model Dozer it does have a left and  

a right blade tilt cylinder so you can actually  tilt the blade all the way back in order to carry  

a load or you can tilt it all the way forwards  or you can tilt it left or right so originally  

this job came in to have an eye reclaim and  it's Barrel rehoned the customer did make  

me aware that there was an imperfection in the  barrel and they'd like to see if we could hone  

that out so we put it up on our honing machine  I did take a bore measurement and it turns out  

the barrel is already about 8 thou oversized  which is border line being out of spec which  

means I could only really do a finish hone  in order to reset the cross-hatching after  

doing a quick cycle with the roughing stones  that imperfection became far more pronounced  

so even though I can feel that imperfection with  my finger it is hard to show on camera so I have  

used the nikko pen blued up that area and then  I've used a honing stone to really show how bad  

that imperfection is so in order to get it to  clean up I would have to take out another 10 thou  

of material and that would just make the barrel  way out of spec oversizing a barrel is something  

you could do but that does mean you do have to  take it 30 thou oversize in order to buy a seal kit  

from the manufacturer so you can keep using this  cylinder those seal kits aren't always available  

and you still need to identify the barrel within  the fleet of machines the customer has as being  

oversized so when they did order parts they could order  the correct seal kit but that's not something this  

customer wants to do they like everything to be  100% standard what that means is we're going to  

be doing a rebarrel we're going to get it set up so we can remove the barrel and the head flange

clearance is clearance heh

there

we'll go 70

[Karen] the corner of the tool post is getting close nah or you got enough room

so an ongoing issue I have is clearance  when I'm using the button tools because  

this is very odd shaped and there are  a few obstacles around there's not a  

great deal I can extend that tool out  before it becomes less rigid so what I  

am planning on doing is making up some  new button tool holders something that  

will reach quite a distance so we will end  up doing a shot made videos very shortly

so now we found the base of the weld joint  between the barrel and the barrel end I'm  

not going to go and machine that through  all the way while it's set up in the lathe  

because there's nothing supporting  that end of the barrel I don't want  

it to break loose so I am going to take it  over to the welding area I'm going to cut  

the rest of it with a grinder and I'll heat up the barrel and separate the two parts

so now that we've got those two pieces separated I   can take the barrel back over to the lathe

set that up and remove the head flange

so now we've found the bottom of the  weld joint for the head flange to the barrel

we're going to take this out and get them separated

now that we've got those two separated  we can get on to machining the new piece  

up for our barrel and the piece of  material we're going to be using it  

is pre honed st52 tube the ID is  10 1/2 inches and the OD is 12 and 3/4 inches

so the first thing I'm going to do is machine the OD down half an  inch

which will bring it down to 12 and  1/4 inches to suit the standard barrel

once that's done I need to machine down  one end to 300 mil to fit the head flange

now that that's done we're going to get this out  of the lathe so we can fit the head flange to the barrel

[beep]

[loud banging]

if you're wondering what that  noise is we're going to show you

[loud banging continues]

so what those guys are over there are  doing their driving in peers for the new  

Railway Bridge that's being set up out the  back for the new maintenance facility so  

we're going to have to hear that for the next  couple of weeks and then hopefully we'll get  

some footage of when they do the bridge lift  right now that that head flange is shrunk down  

onto that barrel and grabbed a hold of it  we're going to get this set up on the rotator

so we're ready to weld the filler material  we're going to be using is cig verticor in  

a 1.2 that is a dual shield wire we'll  be backing that up with Argoshield  

heavy which is 80% argon 20% CO2 be running that at about 27 volts and 6 1/2 metres of wire a minute

so that's fully welded now that took about  10 layers of weld and about half an hour  

so we're going to let that cool down  then we need to set it back up in the lathe

[squawking] come on

[squawking continues]

come on

[giggles]

so before we go back to the lathe I need to  

cut this mounting plate off the  old barrel and fit it to the new one

now that it's set up the first thing we're going  

to do is face to head flange so it's a nice machined true surface for the gland

now I'm going to chamfer the ID so when the  gland gets installed it doesn't damage the seal

so with all that done now we can  flip it over machine the barrel  

to length and put a weld prep on it for the barrel end

righto so that's all the machining done the  next thing I need to do is hone the barrel to size

so we're not going to get into too much detail about the honing process because we have done

videos about it before so if you'd like to check them out you can go back and have a look

so we got the barrel set up I've got  my stroke length set but before we  

start honing we thought we'd  show you how much this barrel  

has actually shrunk in the heat  affected zone where we've welded it

so I've set the bore gauge to zero on the far  end of the barrel that hasn't been welded

and as you can see the heat affected zone has  shrunk point 4 of a mil that's pretty standard  

for a barrel like this with that much weld on  it so because that's the tightest area of the  

barrel we will have to work the honing head  in that area in order to open it up to run  

parallel with the rest of the barrel so  we're going to start with our 45 stones  

they are roughing stone and they will get  through that heat effect design very quickly

so because this material is pre honed  I really only have about half a mil to  

come out of the ID if it was unhoned material  we would have about 1 to 1.2 mil to be honed out

[staffy grunts] [squeaking]

oi where's your corn

[Karen] what are you doing you crazy dog

go

[squeak]

stay

get it

[happy squeaks]

good boy [Karen] come on

[Karen] come on on your bed

so we've completed the roughing of the  barrel and it is measuring to within 0.02 of a mil

of its finished diameter so what  we're going to do now is change out from  

our roughing stones to our 87s which are  our finishing stones we're going to run  

those stones for a cycle to give us the  final dimension and the surface finish we need

so that's our finishing cycle completed we need to take a final measurement

so that's reading to within less than 0.01 of a mil

tolerance is plus or minus 0.05 of a mil so we are well within spec

so now that the honing is completed I'm  going to give the barrel a clean and then we  

can get it set back up in the lathe so  we can reattach the other end of the barrel

so this is where I made it really easy for myself  by using alignment marks and taking measurements  

before I machined apart the barrel because  now I can use those references to get everything  

back in alignment and all my measurements  correct now that we've got our barrel end in  

position I can tack that in place then take  it out of the lathe and go and weld it up

so to weld this we're going to be using  the same wire and gas combination as  

we used for the head flange and  I am going to give this a preheat  

because I don't want the well to cool too  rapidly because of the size of the part

so that joint's fully welded it took about  14 runs of weld at about 5 minutes per rotation  

now I'm going to use an 80 grit sanding disc just to take the tops off the welds and remove any weld spatter

righto guys that's our rebarrel  job completed I still need to reclaim the eye  

but we're not going to video that we have enough  videos of where we've done eye reclaims before this  

is actually not in that bad a condition the eye  is just slightly out of spec we're just going to  

bring it back into spec for our customer so the  bearings last when this is back in operation so  

that's this job 100% complete we've got the eye  claimed and the rebarrel done we're going to  

get this wrapped up and strapped down and  back to our customer thanks for watching

so we're ready to weld and what we're using  is Argo ohhh [Karen] that was great

so after doing a quick  roughing cycle with our roughing ughhh

so after doing a quick cycle with ohhh [ __ ] me  

so after doing a quick cycle [ __ ] me I nearly said psychical

and that would take the barrel fu hmmm [ __ ]

so over sewing it oh over sighging

so we're wor uhmmm [giggle]

and this plate has a hydraulics pot uhhh [ __ ] so we're  

so we're not going to ughh so we're not going to uhhhhh

woah where do we go from there [Karen] now the honing is completed  

got it right so now that the honings completed  I'm going to oh [ __ ]

ughhh [ __ ] words

[Karne] I've literally listened to 3 minutes of blabbering [Laughter]

[crazy laughter continues]

so ohhh [Karen] oh woah HEH [Laughter] [ __ ]

righto guys so the filler [Karen] just not righto guys

righto guys now that we've oh [ __ ] me

what was after that

righto guys so that's our rebail job completed  [Karen] you want to try that word again what  

[Karen] rebarrel what did I say [Karen] I don't know

[ __ ] off train

[Karen] such a nice color though it's like anodized

god they're [ __ ] hot sad and the hotter it gets the more it does  

[slow metal squealing sound]

[Karen] this thing sounds sad and the hotter it gets the more it does that

hot [Karen[ hot very hot we need a thermometer where's  it I got you a water bottle

[Karen] what is it like 100% humidity 35° plus a 87% humidity yuck pretty hot

[Laughter] it is bloody hot

[Karen] is that my tea towel

[Karen sighing] where the [ __ ] my 32 mil spanner gone

[Karen] is that it

[chirping]

[Karen] hello

[Karen] oh no he's taken his jacket off again

cause of your fat neck