First Lathe

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 08/08/2019 18:42:57:

Posted by Michael Gilligan on 08/08/2019 18:06:44:

Posted by not done it yet on 08/08/2019 10:06:34:

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Note that myford quote swing as more than twice centre height),

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Which is not unreasonable

It should be true of many lathes [depending upon the bed profile]

MichaelG.

Are all the Chinese mini lathes the same? [ … ]

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Sorry, I am not familiar with the Chinese mini lathes, so I can't say for sure.

Both viewpoints are, I think, acceptable though …

The Myford approach may be considered 'specmanship' by some; but it remains valid and is a potentially very useful piece of information.

MichaelG.

[Nathan Turner 1Participant @nathanturner1]

A very big thankyou for all of the feedback from everyone!, i didn't expect so much help. Taking Daves comments on-board i realise i've made this very difficult for everyone by not laying out my priorities for the lathe. I would like to use this post to reduce the importance of the d1-4 camlock or comprehensive screwcutting gearbox from my list and hopefully open up more options.

The camlock, which i understand limits me, was in part for safety, being new to the lathe i didnt want to spin a chuck off in reverse or similar and because i already have a 125mm 4 jaw independent and a 125mm magnetic chuck for my tool grinder. I liked the idea of being able to have quick changeover and move partially finished pieces between machines without too much fuss. I'm not very familiar with the other chuck mounting methods. If others can fulfill safety and acceptable speed of change requirements i'm open to them

The screwcutting gearbox. I have dies and use these at the moment. Firstly, is there a great difference in quality of a die-cut vs single point cut thread ? if there is then my priority will be for a better gearbox, if not then a gearbox can be almost unimportant, i will stock up on dies as i need them. As a further point i would place higher emphasis on versatility than speed for this, if there is a gearbox style that is very accomodating to making extra gears for increasing the threadcutting capabilities that would be preferred.

Spindle bore. Really i erred on the side of caution, being set for the life of the lathe. Considering i have a full set of er32 collets and they are well below 38mm i'll consider a smaller spindle bore if i can get to grips with workarounds, an er 40 set seems a waste for me and still doesent hit 38. So far i can consider a 'cat head'/spider setup supported with a fixed steady and four jaw chuck for face work on long bar stock. Part machining features and keeping the stock width as wide as possible to minimise deflection (robin renzetti showed an example of this recently) and being completely unfamiliar with 5c collets ive just discovered step collets, a quick look at arceuro seems to show the maximum capacity around 28mm). Just thse three techniques seem to obviate many instances of the need for a large through-bore but more examples to reassure me it isnt as important as i first felt would be great.

Weight-wise, a new or used machine delivered to me i could stretch to 500kg in weight but would prefer around 300. A used 500kg machine fetched/moved myself i think would be a bit daunting, mainly because i havent done it before, i have access to cheap van rental through a friend and own an import engine hoist but that is it currently.

The use of a DRO for an imperial machine (my inexperience) had completely passed me by, thankyou for mentioning it. If i can reduce the importance of the screwcutting gearbox or at least have good workarounds for my metric needs this opens up a lot of machines.

Most of the work i would like to do is also on the smaller side , mainly tooling for the machines (a lot for the tool and cutter grinder, model is brierley utg6 purchased used), Jigs for knifemaking, building a 2" by 72" beltgrinder including some of the wheels, a 24" by 24" router (i would really like to make the reduction belt pulleys for this amongst other bits) and finally model engines, which as a hobby i'm quite happy to stick to smaller projects with for a long time.

Finally, after tooling up my mill and partly tooling up the grinder i realise the costs involved, nevertheless i have a separate budget for that, this is why i put around 3k as if i find something used with lots of extras ill factor it in. Whilst the budget seems healthy i am in no way averse to going cheaper, in fact i prefer it because it increases the likelyhood of me tinkering and learning more about the machine if it needs work. I've got plenty of measuring gear currently. Thanks again for everyones input.

Nathan

ps, the way this is going you'll have collectively broken all of my wishlist down into nothing! the answers to these questions should hopefully clarify the most important lathe specs

Edited By Nathan Turner 1 on 08/08/2019 20:15:58

Edited By Nathan Turner 1 on 08/08/2019 20:28:20

[JasonBModerator @jasonb]

So it sounds like you are not going to be doing a great deal of screw cutting as most model engines can be done without or on the odd occasion where something non standard or large is needed will be rare in which case something like the 290 you originally mentioned would be fine. The extra 5mins it takes to change over the gear train a few times a year is acceptable and opens up your options.

The 290 size machine can also be had with a "keyhole" type mounting which just requires the loosening of 3 nuts and off comes the chuck for another and just nip up the 3 nuts again. This is a better option than a loose nutted flange mount which can be fiddly particularly if you are mounting the faceplate or have fat fingers.

The main reason for having a large bore is that you can chuck a length of bar, machine your part and then saw or part off, if you have a smaller spindle bore then you have to cut bar into shorter lengths and end up with a growing pile of bar ends.

[not done it yetParticipant @notdoneityet]

Nathan,

Screwed chucks have been used successfully for umpteen decades. Drummond, myford, Raglan and many others, I suspect. The only provisos are that you do not cut in reverse or brake the chuck/workpiece.

Other options are generally either more expensive (better) or cheaper (slower to change).

ER32 typically only go to 20mm. Most common lathes will accept larger diameter round bar (Drummond/Myford excepted?)

Speed range is generally not a problem with rolling bearings. Sliding ones are rather limited (to 1200rpm for long life). Larger bearings are expensive to replace!

Metric is not a real problem unless you wish to do lots of thread-cutting. The advantage of single-pointing on the lathe is the hugely wide choice of threads which can be cut. In difficult materials I sometimes single-point roughly and finish with a die. Cutting on the lathe generally helps for alignment of the thread with the axis of the part/job.

A QCGB is a luxury, but one I would no longer do without. Plenty of cutting feed-rate selection available, apart from not needing to change (as many) change-wheels.

For swing, consider gap beds if the larger diameters are not long.

As you may have gathered, I like my Raglan 5”. I waited until I found a very good example and will likely never change it. However, there are several new models from numerous suppliers which would fit the bill. I am sure of that. Mine came fairly well kitted out for a LOT less than any equivalent new item.

PM me if you would like to read of the bargain I found. They are out there, but not always when you want it!

[Howard LewisParticipant @howardlewis46836]

My first lathe was a Myford ML7, replaced by a 12 " swing ( 18 inch in the gap – not used yet in 16 years! ) far eastern machine. The 38 mm bore is a huge boon after the frustratingly small 2MT mandrel on the ML 7.

The gearbox is used less for screw cutting, but more to select feed rates for facing and turning, It turns the handle far more consistently than I can.

The screw on chuck, being retained by dogs, will not unscrew when running in reverse (Occasionally useful for a quick and nasty chamfer on a hole ) DON'T ask!

The Mandrel thread is a 2 1/4 inch x 8 tpi Whit form, so some of the fittings have had to be screwcut on the lathe

The feeds are powered by a shaft , separate from the leadscrew.

Using a 5 / 3MT sleeve allows tooling to be used on either the Mill/Drill or the lathe.

I have a backplate with an ER32 collet chuck, which allows me to hold up to 20mm diameter, rarely needed.

As you may gathe;r not too displeased with my purchase!  (Including VFD fitted, cost £2K, new back end of 2003 )

Howard

Edited By Howard Lewis on 09/08/2019 11:36:12

[JasonBModerator @jasonb]

If you do go with an ER chuck then you can get oversize ER32 upto 25.4mm (1" ) and ER 40 upto 32mm

Also although you can get 5C upto 1 1/8" you can't pass that size right through teh collet, the internal thread limits you to just clear 1"

Edited By JasonB on 09/08/2019 13:49:43

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