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What are your boring thoughts?

twr

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Joined
Jan 22, 2013
Messages
193
Location
texas
It seems machines are getting bigger and bigger, there running them further past the point of repair. I use a York 4-14ET that has served me well over the years, but I think lately I've been asking it to do to much, Don't get me wrong it's done them all but the bores are getting bigger and holes further apart with no way to run center bearing, could go up to 2.250 bar and fix the chatter problem but I would still have horse power problem, what ya'lls are thoughts on hydraulic set up and what kind. Thanks TWR
 

Williams Marine

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Oct 30, 2015
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Hopefully Ray F will chim in here for you.
He has a wealth of information and real experience line boring not just theory.
 

twr

Well-Known Member
Joined
Jan 22, 2013
Messages
193
Location
texas
Your right on that, seems like there are a few out there but dealers don't say much about there product.
 

Junkyard

Senior Member
Joined
Jun 5, 2016
Messages
3,621
Location
Claremore, OK
Occupation
Field Mechanic
StanRUS is also a wealth of knowledge on the subject. I'm sure some dealers have capable hands doing it. Around here....not so much. Worst part is the independents around here don't value their work as I would. Seems like $75 an hour is what they're getting. Too cheap if you ask me.
 

StanRUS

Senior Member
Joined
Mar 7, 2016
Messages
767
Location
Cal
It seems machines are getting bigger and bigger, there running them further past the point of repair. I use a York 4-14ET that has served me well over the years, but I think lately I've been asking it to do to much, Don't get me wrong it's done them all but the bores are getting bigger and holes further apart with no way to run center bearing, could go up to 2.250 bar and fix the chatter problem but I would still have horse power problem, what ya'lls are thoughts on hydraulic set up and what kind. Thanks TWR
Even with hydraulic use support bearing on each side of the bores and use tool bits with low-cutting pressure (1/2" AL for brazed on) 0deg lead angle and neutral true top rake angle of positive top rake angle (5-7degrees) ditto with throw away inserts.
Support bearings: typical pillow block type or sealed ball bearing have built in radial-axial clearance; the balls dance around causing vibrations. Use spherical rolling element bearings for supports, you'll have make you own!
York bar coupling; if that area is galled up...re machine! Galled up area act like u-joint, watch your feeder-motor carriage, is it wobbling around?
Bigger the bore diameter, greater transient vibration becomes, i.e. vibration is amplified.

Use a bore welder; uniform annealed weld build ups. Pre-bore on hardened links or machine component using thur hardened steel bosses like T1-Hardox. Thur hardened steel require increased cutting torque to shear the material; only way to machine with under powered machines is using reduced depth of cut and axial feed rates.

ET 4-14 35-45ft lbs torque; larger bore diameters require more cutting torque because the distance from bar centerline is increased (lengthened lever arm length = creates more resistance! Think torque wrench backwards)

Hydraulic end of drive; build you own with SAE2 B motor plate...mechanical rack gear feeder; 3 bar support...triangulated. Top bar notched; gear rack fits inside. Infinitely variable feed rate 0.0"-0.020" per rev. Feed cam ring activates side arms; side arms have 1-way clutch needle bearings (like C-max or wash machines). Non sliding cross shaft with pinion gear, outside mounted dog clutches; forward or reverse. Cmax BB3000 type (sliding shaft type) or Cmax facing head (non-sliding shaft type) Anti over running gear required for vertical borer use; keeps bar-feeder-motor weight from causing coasting when the feeder is neutralized. KISS design and very economical to make!

End of bar drives; NO mechanical torque multiplication like gears; need more torque requires increasing power input, i.e. pressure per square inch and flow volume = gallons per minute. 1.5hp-15hp electric motor. Higher pressures require increased oil reservoir capacity because of by-passed oil heating! Typically air-to-oil cooler is used with electric fan.

RDUs-AFUs aren't very expensive to manufacture; hydraulic power pack components for 1 unit are costly.
Want higher HP and do not have portable generator with enough capacity to 'start' (locked rotor) electric; use gasoline Honda..8Hp runs 5gal per minute @ 1200psi variable displacement pump without issues. Kohler V-twin EFI 22Hp runs 15gal per minute @ 1800psi variable displacement pump without issues.
 
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ETER

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Joined
May 31, 2015
Messages
158
Location
Upstate New York
TWR, have been grappling with same issue but on a smaller scale. Have been using a Milwaukee mag drill...
I made 1-1/2" boring bars 18", 36" and 72" long with 1/2" square broached holes on 4-6" spacing...it's very difficult / time consuming to get a proper bar to drill spindle alignment. In the process of making a "dual" u-joint shaft too compensate for misalignment with a drill motor from an older MT3 mag drill and a dc motor feed. When done, the unit will still lack the power to push a larger bar and punch out larger bores. I would really like to go hydraulic (just figured it would be cost prohibitive). I am in the process (maybe) of getting a 33K single axle with a knuckle-boom to go back into mobile repair (unit has good hydraulics). Would like too see more info on this which I am sure Ray and Stan could contribute...come to think of it, have not seen any posts from TomV lately (would also be a wealth of info on this subject) as I have been lurking due to a lack of time to be more a part of the forum.
Regards, Bob
Wow, I type slow...not Stan though!
Thanks Stan
 
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RayF

Senior Member
Joined
Jul 8, 2011
Messages
640
Location
Perth Western australia
Occupation
lineborer/welder
I have used Hofmann gear for 29 years. Its simple,hydraulically driven and reliable. It will bore 99% of gear straight out of the box. It uses ordinary self aligning support bearings that do a good job but wear out. I have changed to self aligning rollers.
I think the standard power pack is 5 hp. Mine runs 8hp. The boring bars are made out of top class hardened and chromed steel and are entirely satisfactory for heavy machining up to 800mm diameters and around 800 between bearing supports. So most equipment comes within these parameters. For 99% of my cutting I use disposable inserts. I reckon they are by far the cheapest and most reliable.My cutting tool costs are the cheapest overhead I have.
But you can make all sorts of boring gear work if you have to. Its the nut behind the wheel that ensures whether the job fits together or not. An hour ago I was called over to look at a job on a 600 tonne O&K digger. They have had a crew in line boring the carbody boom pivot. Probably about 7 feet between bores of 14 inch diameter. They had a large crane in to lift the boom into place and the pin gets half way through the last bore and jams solid. Apparently the relied on the 4 inch boring bar for alignment. They obviously have no idea of O&K tolerances and now they have a major problem. So again all the good year is useless unless the operator has a good understanding of how stuff fits together.
 

Junkyard

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Joined
Jun 5, 2016
Messages
3,621
Location
Claremore, OK
Occupation
Field Mechanic
If TomV chimmed in you'd have the line boring pro trifecta!!!

Glad to see you're still around RayF!
 

StanRUS

Senior Member
Joined
Mar 7, 2016
Messages
767
Location
Cal
twr,
Kim Randrup at York will give you a honest run down on using hydraulic with your ET 4-14 carriage, i.e. surface finish issues caused by 2 support-guide rods and acme lead screw.
Ph: 1-250-287-7716 ext 130 / kim@yorkmachine.com
Williams Marine / I'll email you York's part print for 2" bearing support. I spent over 35hrs drawing-modeling up a spherical support before concluding; waiting my time...the support is huge in comparison to Cmax, Elsa or Hofmann.

Ho$mann Mk2 price circa 2010 with both facing heads, small bar reducer kit, bore weld kit and 7.5Kw wireless remote power pack was US $138,000.00 ex works. Australians purchase Climax in greater numbers. Liebherr haul truck trays (truck beds) manufactured in Australia are line bored with Climax. WESTECH an Austin Ltd Co, Australian owned (purchased 2007), Wyoming use Climax. IMO, Hofmann Mk3 obsolete before sales to public purchasers! Correct Rayf?
Best Bang For The Buck?
If OEMs would teach boring theory; just requires a 10 page booklet...twr would not of started this thread. Cutting bit-insert with low cutting pressure geometry; applies to $6million HBM or home made mag drill borers. I am hearing, 'my inserts chip', simple shift to high gear and adjust speed controller to max revs. Cutting Tool manufactures are often doing exactly the same thing; double or triple surface speed with all other cutting parameters left the same...depth of cut and feed per rev.
Yep, the nut behind the wheel!
 

RayF

Senior Member
Joined
Jul 8, 2011
Messages
640
Location
Perth Western australia
Occupation
lineborer/welder
Both the Hofmann and the Climax are well regarded machines here. I would guess the Hofmann would outsell the Climax by a very large margin. I don't know what a Climax costs so value wise I don't know how they compare. The Hofmann covers a wider field of work. I prefer the welding system for onsite work. From speaking to US based contractors the facing heads are better as well.
Liebherr have used Climax since they moved the fabrication from Perth to Adelaide. Prior to the move all their line boring was done by me using Hofmann. When they bought their own gear Hofmann was their first choice but for reasons I won't go into bought Climax.
In WA Austin Eng. or Westec don't have their own Lineboring equipment. They use contractors. Almost all of them use Hofmann
Best bang for the buck is not something I think about. As a full time contractor I want the machine that does the job best. The cost for me is secondary. Thank about it. Say you pay 150K for a machine. Its entirely possible to earn that twice over in a year. The initial purchase price is not a major consideration if you are relying on the machine to make a living.
 

ETER

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Joined
May 31, 2015
Messages
158
Location
Upstate New York
the pin gets half way through the last bore and jams solid. Apparently the relied on the 4 inch boring bar for alignment. They obviously have no idea of O&K tolerances and now they have a major problem.
Wow, I am surprised that the die-grinder didn't come out and go to work when no one was looking!
 

StanRUS

Senior Member
Joined
Mar 7, 2016
Messages
767
Location
Cal
Both the Hofmann and the Climax are well regarded machines here. I would guess the Hofmann would outsell the Climax by a very large margin. I don't know what a Climax costs so value wise I don't know how they compare. The Hofmann covers a wider field of work. I prefer the welding system for onsite work. From speaking to US based contractors the facing heads are better as well.
Liebherr have used Climax since they moved the fabrication from Perth to Adelaide. Prior to the move all their line boring was done by me using Hofmann. When they bought their own gear Hofmann was their first choice but for reasons I won't go into bought Climax.
In WA Austin Eng. or Westec don't have their own Lineboring equipment. They use contractors. Almost all of them use Hofmann
Best bang for the buck is not something I think about. As a full time contractor I want the machine that does the job best. The cost for me is secondary. Thank about it. Say you pay 150K for a machine. Its entirely possible to earn that twice over in a year. The initial purchase price is not a major consideration if you are relying on the machine to make a living.
Thanks Ray,
I personally do not have issue purchase cost versus making $$$$...HEF members typically wine about 'it costs so much'. A $60K machine can earn over $1million in less than 8yrs. Hofmann facing heads are IMO best in class commercially available; facing blocks can machine faces not accessible with radial feeding facing heads and can back face bores for example...cushion hitch load cylinder inside faces. Require 2.0" clearance between workpiece and bar support arm(s).

G&L Davis twin insert boring blocks won't work with Hofmann feed boxes; not enough feed per rev that will cause insert chipping.

For OP, Cmax AFU. Make you own requires Cmax BB5000 pdf file; AFU nominal dimensions per spec's given and Cmax illustrated parts list AND drafting skills. Parts list give different component part sizes example seals, bearings...not to difficult to draws part prints. Also you can use patent drawings; AFU-RDU are not covered under any current patient! Video demo proper adjustment procedure.
HBM boring loader arms, with twin cut boring tools.
These discussions for me are redundant, try to imagine NO light weight portable boring machines available like the early 60s...design your own.
 

RayF

Senior Member
Joined
Jul 8, 2011
Messages
640
Location
Perth Western australia
Occupation
lineborer/welder
G&L Davis twin insert boring blocks won't work with Hofmann feed boxes; not enough feed per rev that will cause insert chipping.
Stan,can you fill me in on this one? I'm not sure what the feed box feed rate has to do with chipping? Are you talking boring? If so the feed rate is adjustable from 3 thou per rev up to around 30 thou from memory.
With those particular faces on cushion hitches I plunge them off with a 90 deg approach tool straight out of the bar. Maybe 2 or 3 minutes each.
Edit, I googled twin insert boring blocks. I know nothing about them. I don't know that I would try them for line boring?
 
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StanRUS

Senior Member
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Mar 7, 2016
Messages
767
Location
Cal
Stan,can you fill me in on this one? I'm not sure what the feed box feed rate has to do with chipping? Are you talking boring? If so the feed rate is adjustable from 3 thou per rev up to around 30 thou from memory.
RayF, google ‘sudden onset dementia’
Per Hofmann Mk1,2,3 feed rate: 0.05mm=0.00196” / 0.10mm=0.00393” / 0.20mm=0.00787” / 0.25mm=0.00984”
Audio for reading impaired:
@ 3:21 Mk1,2,3 feed rate
@ 4:34 380Nm=280lb ft @ 100rpm
@4:43 ‘speed is infinity from zero to 240rpm’
 

RayF

Senior Member
Joined
Jul 8, 2011
Messages
640
Location
Perth Western australia
Occupation
lineborer/welder
Ah,Stan, you need to say you are talking about facing head feed rate. Thats different to the feed box rate. My large Hof facing head has a variable rate and the smaller 180 is a fixed rate as you state. There is no issue at all getting it to chip break with indexable inserts. I have used nothing else in it for 25 years.
For clarification the Mark 1 always had a fixed feed. The Mk 2 as stated. At this stage there is no such animal as the Mk3. The video is years old. The gentleman in the video who I knew well passed away late 90's from memory.
 
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StanRUS

Senior Member
Joined
Mar 7, 2016
Messages
767
Location
Cal
For clarification the Mark 1 always had a fixed feed. The Mk 2 as stated. At this stage there is no such animal as the Mk3.
http://www.hofmannengineering.com/products_10_1_lineborermkiii.php
Old video yep; provided by Kevin Hatten circa late 90s while he was manager of technical sales...Kevin is now former Hofmann employee as you are aware.
People that ask about Hofmann's line borer(s); Cat dealer shop foreman's, independents...their negative reaction, i.e. big, heavy, impossible to use in space limited applications, outweigh positives of manufacturing quality and workmanship. Video becomes IMO 'anti-sales'!
35,750 views; analytics, Australians, Indonesians and South Americans (Peru-Chile) comprise the main groups of viewers. Peru, they've copied B&D-BRS and Cmax design features, 60mm bars (Patent Infringements_Can't Sell in US). Indonesians have cloned Cmax, 60-90mm bars.

Easier = Improved Efficiency, i.e. maximize productivity with minimum wasted effort and expenses.
Apply that to OP's question, 'what are your thoughts about hydraulics'. Simple answer: Purchase Climax BB5000 with Eibenstock 4 speed reversible motor! Optional hydraulic motor usage at added expense. OR BRS (clones) products; electric or hydraulic. BRS cannot fit into confined spaces, directly compared with Cmax BB5000.
Any discussion about Rayf's recent consultation, O&K 600Ton face shovel is trolling, obfuscation and off topic...ditto MY replies.
I do not post photos-videos for a specific reason; patent trolling. Obama signed '1st to file' with 1yr grace period, rest of the world is '1st to file' zero grace period. Zero grace period means, any from of publication, internet forums, blogs, trade magazines etc, i.e. share your innovative, 'novel idea(s)' NO longer patentable.
For Nerds
http://www.industryweek.com/intelle...m=email&elq2=627c9c9ff3d447ffa5241bb9878d65d0
Doing self-patent research (new novel idea, any prior art?), writing patent draft reduces cost; typically US $10-15thou after the patent attorney files for simple utility patent.
Example in this thread: End of bar driver carriage with 'feed rack gear combined with top tubular support guide' and 'anti-rack over driving mechanism'. Published and no longer patentable design features per patent's claims.
Cheers

 
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