Numpty engineering ( Lathe ) Question

[Bonzo]

I have been playing with my old Harrison L5a lathe for tha last few days.

Been burried up in the workshop for about 12 months, gave it a good spring clean, topped the gear oil up, lubed all of the beds n slides & even greased my nipples ( Ooo er Mrs ) :D

When I bought the lathe it came with a 4 Jaw Chuck & I thought I would have a little look at it.

Whilst removing the jaws I noticed that the teeth on the back of one of the jaws have been dammaged

Here's a picy

http://i274.photobucket.com/albums/jj266/Bonzoronnie/100_0673.jpg

Not going to complain as I paid next to nothing for the lathe ;)

What are the chances of me finding a replacement jaw/jaw set ( No idea if they are hard or soft jaws ) ?

Is a chuck measured by its holding capacity or is it measured by outside diameter ?

It is a 4 jaw ( reversable jaws ) Burnered chuck & measures 5" in diameter ..... Is this a 5" chuck or would it be classed as a 4" one ?

It is already mounted to a Harrison backplate, how difficult is it to mount a new chuck to the Harrison backplate shoul I decide to buy a replacement chuck ?

I know, questions, questions, questions .... As you may have guessed, I can write all I know about lathes on the back of a fag paper packet :D

[AshG]

doh ronnie you fool. if you had posted this 6 months ago i could have given you almost every accessory available for a L5a. i had three of the buggers in the workshop and sold two of them off along with all the spare bits. i even had the hydraulic copy attachment and pump that were used in factories for mass production pre cnc.

shouldn't be hard to find a chuck for it some replacement parts are still available from Harrison considering the "A" version has been around since the mid 60's its incredible. does your one have power feed on the cross slide as well as the bed? only one of mine had it and it was the one i kept.

if you ever need clutch plates or consumables let me know as i still have loads of spares to keep mine going forever

[Talonmotorsport]

I had the same problem with my 8" pratt chuck which is measured by it's diameter by the way. Good second hand 4 jaws chucks can be had off ebay cheaper than new jaws in either hard or soft jaws. I paid £80 for an 8" pratt 4 jaw which looks the same as you have there, new jaws at the time where £240+.

[Bonzo]

Never mind Ash, that is the way of life :)

Yes mine has power cross feed .... Found it by accident when I first tested the lathe :cool:

When I wanted to use the cross feed, I couldn't find it again :confused:

Found it again yesterday :D

[fabbyglass]

Bonzo going into business by any chance?;)

[Bonzo]

I had the same problem with my 8" pratt chuck which is measured by it's diameter by the way. Good second hand 4 jaws chucks can be had off ebay cheaper than new jaws in either hard or soft jaws. I paid £80 for an 8" pratt 4 jaw which looks the same as you have there, new jaws at the time where £240+.

Blooming heck, I didn't think new jaws would be so pricy :eek:

Yes you can pick up a decent 6"/8" chuck for not a small fortune.

To be honest, mine has indipendent jaws, not sure how much I would use it .... Have enough problems centering things om a self centering chuck :o :o

[Bonzo]

Bonzo going into business by any chance?;)

With a manual lathe, not on your nelly Mark :D

Been spoilt by access to modern CNC stuff & folk who knew how to program them

I used to opperate one of these bad boys & took the time to learn the programing , that was my meal ticket to Laser n machine parts ;)

http://i274.photobucket.com/albums/jj266/Bonzoronnie/AmadaPega.jpg

[Twin]

I should be able to get you a new/used set of jaws bud.

Will let you know soonest if I can get them that small ;)

[Bonzo]

I should be able to get you a new/used set of jaws bud.

Will let you know soonest if I can get them that small ;)

That would be great if you could manage to find something Twin :cool:

Even a single jaw would make it useable again.

Here's a first for me .... Managed to do a good deal of work with a Carbide tipped tool yesterday & didn't break it :D

Usually I make a first cut & they just go chink

Just come in for a little rest .... How much hard work is it cutting threads by hand, blooming arms are hanging off :eek:

[RAYLEE29]

So do you have a 3 jaw chuck for it? why were you cutting threads by hand if you have a lathe? I cant believe the prices of engineering stuff that I always had access to and now dont, hope you get sorted with your jaws dont think I have any spares but will look later.
Ray:)

[AshG]

Ronnie stop being a daft batt. put the tap in the tail stock chuck deeper than the square bit on the end of the tap, but dont lock the tail stock in place. put it on the lowest rpm setting then move the tap up to the hole in the work piece. as soon as it catches it will pull its self in.

[Bonzo]

Hi Ray

Yes the lathe is fitted with a 6" 3 jaw chuck & ironicly I have a spare set of jaws for that one.

To be honest mate, I haven't got the confidence to try tapping in the lathe ( Read knowledge )
I just kinda assumed that a special tapping gismo was needed for the tailstock. :confused:

I have a mountain of my late fathers engineering books, propper old fashioned ones that were probalbly written when my lathe was first produced .... Really must read them some time :o

On the bright side, every time I use it, the quality of work improves .... Not really touched a lathe since I was a school :eek:

[Bonzo]

Ronnie stop being a daft batt. put the tap in the tail stock chuck deeper than the square bit on the end of the tap, but dont lock the tail stock in place. put it on the lowest rpm setting then move the tap up to the hole in the work piece. as soon as it catches it will pull its self in.

I knew that :o :o

Will give it a try tomorrow & will report back to let you know how many taps I have broke :D :D


Edit

I have not got round to sorting the coolant pump out as yet .... Typical me !! ( know it's an important thing ) Have tested the pump & it works ok, there's a leaky pipe in the suds sump & I have to make a tensioner for the drive belt pulleys.

What would be the best lubricant for tapping ? I have been using coolant from a washing up liquid bottle up till now !!

[Talonmotorsport]

CT90 cutting and tapping oil although it's a bit messy and tends to drip before you've used it , I prefer to use tapping paste which looks like black vaseoline and melts when the drill or tap gets warm. Theres nothing wrong with using washing up bottles for coolant as you don't always need alot of coolant if a small squirt will do the job.

[les g]

I knew that :o :o

Will give it a try tomorrow & will report back to let you know how many taps I have broke :D :D


Edit

I have not got round to sorting the coolant pump out as yet .... Typical me !! ( know it's an important thing ) Have tested the pump & it works ok, there's a leaky pipe in the suds sump & I have to make a tensioner for the drive belt pulleys.

What would be the best lubricant for tapping ? I have been using coolant from a washing up liquid bottle up till now !!

leave that to me old timer
i have some water soluble cutting oil
i think its Hexol
its as good as yours
cheers les g

[AshG]

ronnie you dont need to bother with the pump as long as the tap is hss, i actually took mine off so i could get the lathe closer to the wall. i have got away with using wd40 before when i run out of suds. tapping shouldnt really generate that much heat as long as you bore the hole to the correct size.

if your nervous about breaking the tap have a go on a bit of brass or ali first

[gaz05]

I remember back when I were an apprentice being told to always back a tap off a quarter turn every full turn or so to clear the flutes. Are taps used for a lathe different to normal taps? Bought myself a mini lathe but as far as i know all my taps are hand taps. Will they still do the job on the lathe?

[Twin]

I normally turn off the power, disengage the chuck gears, & while using the tail stock with a center to line up the tap ( they have a dimple in the top) use a spanner/tap wrench against the cross slide to keep the tap still. you can then rotate the chuck by hand, keeping a slight pressure on the tap with the tail stock to keep the tap straight.

I hope that's clear as mud!

[AshG]

I normally turn off the power, disengage the chuck gears, & while using the tail stock with a center to line up the tap ( they have a dimple in the top) use a spanner/tap wrench against the cross slide to keep the tap still. you can then rotate the chuck by hand, keeping a slight pressure on the tap with the tail stock to keep the tap straight.

I hope that's clear as mud!


yep that works but my lathe has a motor so im going to keep making full use of it :D

[K4KEV]

That would be great if you could manage to find something Twin

Even a single jaw would make it useable again.

Here's a first for me .... Managed to do a good deal of work with a Carbide tipped tool yesterday & didn't break it :D

Usually I make a first cut & they just go chink

Just come in for a little rest .... How much hard work is it cutting threads by hand, blooming arms are hanging off :eek:

Correct me if I am wrong Ronnie.....but there are only 2 sets of threads that cause you to have your arms ache, and they would be the wishbone ends
M18mm x 1.5 and M20 x 2.5 .....my lathe (churchill cub) I would say be man enough for the job but I decided to cut manually especially the M20 x 2.5
it takes a lot of torque and a great deal of stress is placed on the tap and to get a really clean thread cut, as Gaz said ideally you should back it off every so often and even remove to clean the flutes.....grease is a good cutting lubricant as its viscosity decreases with heat but it also keeps the swarf between the flutes while cutting.....compressed air and blow gun is THE best way to clean out.
Yes Twin, that is exactly how I both centered and cut mine like this
http://i465.photobucket.com/albums/rr12/gfowa/Haynes%20Roadster%20build/DSC01280.jpg
http://i465.photobucket.com/albums/rr12/gfowa/Haynes%20Roadster%20build/DSC01281.jpg

[Twin]

A picture paints a thousand words :D

[Talonmotorsport]

If you use hand taps ie taper 2nd and plug then yes it does need alot of tourqe to cut the threads on m20x2.5. If you use the correct tool for the job this being a sprial point tap or high speed machine tap it makes things considerably easier.

[K4KEV]

Totally agree;) (dont need a plug on these tho)....but many peeps can only afford hand taps even mine were ebay jobbies (good ones tho)

[Bonzo]

Thank for all the valuable advice chaps it has been very helpful :)

Bang on Kev, it was the big bad boys causing the arm ache.

I used Ash's method on the M18X1.5 bosses .... Was lucky enough to find a very good quality, HSS spiral flute machine tap ebay a few years back.
That cut the thread as quick as you like.

The 20X2.5 threads wern't so easy to cut as I only have a couple of HSS sraight flute in that size ( 1st & 2nd ).
My tailstock chuck has seen better days really & I think the tailstocks 2 morse taper could do with a wee ream .... Upshot is, I couln't hold the tap tight enough.

I did manage to get them done using the method described by Twin & Kev.
Was heck of a lot easier than using a tap wrench whilst the part was being held in the vice of my drill press :cool:

Probably would have just bought the bosses if it were not for the fact that I had some 30mm round bar laying about :)

That said, saved some money and more importantly, learned a little more knowledge :cool:

[Bonzo]

Here's a picture of what I have managed to do so far, certainly a steep learning curve fo me :o

http://i274.photobucket.com/albums/jj266/Bonzoronnie/Lathework.jpg

Another of my Harrison lathe, if you can see it in amongst the clutter .... Never did get that nice new coat of paint ( Paint still sitting in the cupboard ) :rolleyes:

http://i274.photobucket.com/albums/jj266/Bonzoronnie/Harrisonlathe.jpg

Hopefuly once I have finished spending on the Roadster, I will be able to treat the lathe to some much needed new tooling.

[RAYLEE29]

Hi, yours looks newer than mine link to pic (http://picasaweb.google.com/raylee290/RoadsterPics#5434391442848966690)and abit different, also ive fitted a travdial to my saddle which is so usefull,
used to use them before dro's when i was a toolroom machinist all those years ago.
Ray:)

[AshG]

haha snap

think mine is the newest of the lot. mine is also a gap bed so i can spin up silly big things on it. it had a very easy life it before i got it. 40 years in a grammar school the last 25 of which it was under a cover stored in grease. the bedways are all like new and i have plenty of spares for it all in the plastic wrapping with dates from the late 60's, also have nearly every accessory in the book along with all the metric and imperial leadscrews every available change wheel etc etc.

http://i707.photobucket.com/albums/ww75/ashgardiner/Engine%20upgrade/IMAG0278.jpg

[rapidtornado]

Now you guys got your nice new toys (not jealous .... honest :o ) anyone fancy giving me a quote for a set of crush tubes? :D Got the bushes just need tubes

I remember day after day working on those Harrison's whilst doing my apprenticeship as a tool maker.... they are a good bit of kit, if I had the space I'd be on the look out, not seen many advertised though. My 1st choice would be a DS&G but they are like pigeon's teeth

Let me know if any of you could spin out some bushes for me...

Cheers
Rapid

[AshG]

would love to but i just dont have the time at the min, im building an mev exocet, finishing off my engine upgrade on the roadster. building a new workshop and have 2 mates weddings to go to in the next 2 months as well as working 50+ hrs a week at the day job. to say im snowed under has to be understatement of the year :D

[rapidtornado]

excuses excuses... lol :p

[baz-r]

im not keen on that photo of the tap in the lathe
i worked in a massive engineering factory as a cnc/machine tool engineer
that made parts for the plastic mould industry
i have seen quite a few people go to A&E with what thay thort was a good idea
(fingers in the swarf tray) some others where not so lucky
not sure about the model you have but i think you can get tap and die holders to fit in the tail stock (it is possible we had them made buy our tool makers)

[RAYLEE29]

Glad to see im not the only one that uses his lathe as a convenient place to store just about everything lol
Ray:)

[Bonzo]

Glad to see im not the only one that uses his lathe as a convenient place to store just about everything lol
Ray:)

Tell me about it Ray .... Took me about 1/2 a day before I could get to it :D

Looks like we nearly have enough members for a Harrison L5 owners club :)

Ash

That lathe of yours looks to be in fantastic condition, landed on your feet with that one mate :cool:

baz-r

I think that picture needs to be taken in the same context as Twin's written post.

No power to the lathe ( Not even plugged in )

Chuck to hold the work piece & tail stock to keep the tap steady .... A means to an end, that's all.
Personally, I see no huge risk in that method !!??

Take my personal safety very seriously ..... I too have spent a lifetime working with machinery & equipment that will tear you to pieces in an instant.

Yes, I could buy a tap holder for the lathe but whilst my Roadster build is ongoing, not about to lay out £200+ on something that'll be only used once in a blue moon !! ;-)

[K4KEV]

im not keen on that photo of the tap in the lathe
i worked in a massive engineering factory as a cnc/machine tool engineer
that made parts for the plastic mould industry
i have seen quite a few people go to A&E with what thay thort was a good idea
(fingers in the swarf tray) some others where not so lucky
not sure about the model you have but i think you can get tap and die holders to fit in the tail stock (it is possible we had them made buy our tool makers)

Sorry I don't understand, where is the safety issue if there is no power to the lathe ? it is being used as a safer method of hand tapping (especially getting it started and true), have you ever tried to hand tap a m20x2.5 thread ? ....I served my time in the shipyards where safety is paramount in every part of the yard and not only the shop floor.
this method was taught to me in metalwork at school using the lathe in the same way as the picture........you are suggesting that the method is unsafe.......why:confused:

[AshG]

Ash

That lathe of yours looks to be in fantastic condition, landed on your feet with that one mate :cool:



i had three of them at one point ronnie but the chap storing all three for me got fed-up of them in the end

[baz-r]

only seen it done by hand with the dam thing running once pulled off line poped the tap and bit pinged of and cut someones face about 5m away good job it didnt hit them in the eye :eek:

bits where sharp as glass not nice
funny how some people dont think in a machine shop. i pritty much made a living from repairing other peoples mistakes :rolleyes:

[jerkins]

I threaded my stuff in just the same way - but I made sure that the lathe was in neutral (I can set the gearbox on my Colchester Student so that everything is disengaged) and that the 3-phase converter is off so I can't accidentally knock the power switch lever to 'on'.

As for the 4-jaw chuck - it's worth getting it fixed as it's the only reliable way of getting a piece of metal that's already been machined to run true. 3-jaw chucks are never concentric, which is OK if you can do all your machining without removing the work from the chuck, but if you have to take it out (e.g. to turn the other end) then only a 4-jaw chuck will do. You will need a dial gauge on a stand to do it though! Once you've trued up a few pieces in a 4-jaw then the task becomes quick and easy.

[Bonzo]

Thank's Jerkins :)

Some usefull advice there.

My first purchace when I bought the lathe was a magnetic stand & dial.
Bought a few Carbide cutting tools too .... Broke a few of those though ( User error ) :D

Funny you should mention about 3 jaw chucks, spent an absolute age centering the tail stock with the chuck.
Noticed the tinyest of steps when turning a part around, now I know why :)

Cheer's, this advice is all valuable stuff to me :cool:

[jerkins]

You can get 3-jaw chucks that can be adjusted to make the workpiece concentric - you REALLY don't want to know how much they cost!

[Bonzo]

You can get 3-jaw chucks that can be adjusted to make the workpiece concentric - you REALLY don't want to know how much they cost!

I can well imagine the cost :eek:

Once I have completed my Roadster build I intend to spend some more time on the lathe.

Have some interesting locomotive plans that were my late fathers, would love to have a crack at some of those :cool:

[jerkins]

I did it the other way around - built the steam loco then built the car!

Here's my 'little loco' (5" gauge) driven by a friend...

http://www.dwjenkins.plus.com/lathyrus.jpg

It once hauled a line of wagons carrying 10 hefty adults - it did bark a bit though! :D

[les g]

I did it the other way around - built the steam loco then built the car!

Here's my 'little loco' (5" gauge) driven by a friend...

http://www.dwjenkins.plus.com/lathyrus.jpg

It once hauled a line of wagons carrying 10 hefty adults - it did bark a bit though! :D

your friend looks similar to our very own handyandy
cheers les g

[Bonzo]

your friend looks similar to our very own handyandy
cheers les g

I never thought of that Les :) :)

Jerkins

Yes that is the sort of thing :cool:

I have a set of full size plans for a loco & would like to build it, if I remember the details i'll post them in this thread ( Up in the loft in a tube I seem to recal )

When I say full size, I do mean full size to scale & not the original blue prints :D

[Davey]

I have in my loft a set of drawings for a full size replica of Sans Pareil, a competitor against Stephenson's Rocket in the Rainhill Trials;) . Anybody feel like building a steam loco?:D

D.

[TheArf]

Just to add my four penethworth dont bother with a three jaw, four jaw beats everything hands down. You can accomodate any shape and if you know what you are doing you can set things up just as quick. Serves my time as an apprentice started off on a Colchester Mascot finished off on an Elliott Concord 550 with a modest chuck size of 4'6" with a 42' bed length

[RAYLEE29]

As for the 4-jaw chuck - it's worth getting it fixed as it's the only reliable way of getting a piece of metal that's already been machined to run true. 3-jaw chucks are never concentric, which is OK if you can do all your machining without removing the work from the chuck, but if you have to take it out (e.g. to turn the other end) then only a 4-jaw chuck will do. You will need a dial gauge on a stand to do it though! Once you've trued up a few pieces in a 4-jaw then the task becomes quick and easy.

Im sorry but thats just total B****cks, a good thre jaw will consistantly hold to a couple of thou or better and you can always true up better.
also if you want to do batch work then a set of soft jaws will consistantly hold to a thou or less. if your having trouble getting a three jaw chuck to run true its either shagged or fitted wrongly.
I was an apprenticed toolmaker 4years and a toolroom machinist for 4 years after before going in to multi skilled maintenance by the way
Ray:)

[TheArf]

Then that makes two of us, timed served turner, qualified also as fitter, pipe fitter and welder in the chemical industry and now build corporate jets for a living

[HandyAndy]

your friend looks similar to our very own handyandy
cheers les g

Gulp :D .... I know my dad was in the navy & travelled around a bit , :p

The likeness is quite uncanny actually :o

cheers
andy

[jerkins]

Im sorry but thats just total B****cks, a good thre jaw will consistantly hold to a couple of thou or better and you can always true up better.

I'm talking about amateur kit here... or well-used second-hand...

also if you want to do batch work then a set of soft jaws will consistantly hold to a thou or less.

Soft-jaws machined to a particular job are a different kettle of fish entirely...

I still maintain that a 4-jaw will be almost as quick to set up concentrically, even if the chuck is - er - well-used. :)

[RAYLEE29]

oh well you do it your way ill do it mine.
Nice engine by the way do you have to have the boiler tested? do you make your own safety valve or do you have to buy one?
is it scratch built,kit or plans?
Ray:)

[jerkins]

It was built from a set of plans (and a book) for a design called "Sweet Pea". The original design was 0-4-0, but mine is 0-4-2. It also has a water tender, which is described in the book.

I haven't run it for a few years, but when I did I was a member of the Ipswich Model Engineering Society, who did a boiler test every 2 years (for copper boilers, every 1 year for steel). This used water pumped to 150% normal pressure to check for leaks; the pressure gauge was tested against a reference gauge at the same time. I made the safety valves, which were also tested every 2 years. Their test was to run the boiler with the blower on (so at full fire heat) and the pressure checked to ensure that it didn't go over the max pressure over a period of time (it's a tough test!).

[Twin]

That would be great if you could manage to find something Twin :cool:

Even a single jaw would make it useable again.

Here's a first for me .... Managed to do a good deal of work with a Carbide tipped tool yesterday & didn't break it :D

Usually I make a first cut & they just go chink

Just come in for a little rest .... How much hard work is it cutting threads by hand, blooming arms are hanging off :eek:

Sorry bud, I've had a good look & we don't have any that small for a 4 jaw :(

I will keep my eyes open for you.