Hafco AL-250G thread cutting limitations

[toglho]

Stuart, drive the lathe with the leadscrew? Please explain.

[Metalman]

Toglho, are you aware that the AL-250G will be on special for $1495 at the upcoming H&F sale? Sale date is from the 22nd of March to the 24th.
Regards, Mm.

[slhouetteV8]

Not to sure what you were trying to convey in your reply regards Pitch/TPI in relation to thread OD.

As long as the depth of thread is less than the OD of the material diameter doesnt matter when cutting threads.

What I was trying to convey is that you cant catch a shark with a spool of cotton and a toothpick. If you could turn #### into gold we'd all be rich.

[slhouetteV8]

What do you want from a $1500 dollar lathe? Maybe that's more direct.

Im not trying to be harsh but in the scheme of things in this day and age a couple of grand isn't much. When you get people that pump $500 into the pokies in half an hour, a boat and fishing gear, or any other hobby, #### I could do $1500 having a good night out. Maybe that's why my wife cracked it.

[tongleh]

Yep, same here. There's a lot of criticisms out there, on not just Chinese lathes, but Chinese products in general: People change their minds ever so slowly, I remember back in the 60s when Japanese products first started appearing on our shelves, now look, the same happened with Korean products and now with Chinese products. Both of my Chinese lathes were excellent, I wouldn't buy anything else - not that I could afford to.

[tongleh]

No, I didn't know that Metalman, I think my mind is almost made up.

[Stustoys]

Stuart, drive the lathe with the leadscrew? Please explain.

Its something I've only heard of but never tried or put much thought into, just stored in the "I'll remember that if I ever need it" file(I hope).
You put a hand wheel or motor on the right hand end of the leadscrew and use that to turn the lead screw, the leacscrew then drives the spindle.(sure sounds easy)

Stuart

[MarkEF]

Have just purchased a Hafco AL_250g lathe, seems like a nice little lathe, have not done much with it yet, am only a beginner not having done much with a lathe besides drilling holes in drill chokes at work with the big one. Purchased this lathe to get experiance on a lathe. But if anyone works out how to convert it into cutting imperial threads, would love to know (would be a great little project to do)

[Retromilling]

I see your replacing you 3rd lathe, I would say in a few years time you will find the limitations of this lathe and be replacing your 4th lathe with a 300 x 900 one.

A few guys have asked about this size lathe and while some guys have them and seem to do fine, I would recommend if you can afford it to jump strait to a 300 x 900mm lathe and be done with buying any more lathes. It will be something you will have for many many years to come and may never get rid of it ever. I have one and I do some pretty big stuff sometimes and it takes all I can throw at it, and then on the other hand it will do intricate parts.

It's up to you, but like I said if you can spare the bit extra it will save you down the track. You can usually find them around second hand as well, so you might get one for the same price as this lathe.

Dave

I agree with Dave . However your AL250G does not have a thread cutting gearbox and does feed and metric thread cutting off the Metric lead screw. Any Imperial threads it can cut will be the ones that happen by luck to corrospond to the metric pitch's it can cut .
That is why in the H&F specs it only states a Metric thread range.
I think you would have been much better served by spending an extra grand and getting the AL 336 . Metric and Imperial thread range througha gearbox and an Imperial lead screw. Which means you still have to do some manual slip on gear changing between Metric and Imperial and sets of threads but at least the whole thread range is visable on the gearbox lever positions so no calculations are required just slip on the gear teeth required as per the labeled instructions on the lathe housing and set the gearbox for the thread required . For every slip on gear selection you usually have a few threads to choose from in the gearbox . As the lathes get more expensive they require less manual gear changing to get the whole thread range in the gearbox.

[Retromilling]

Have just purchased a Hafco AL_250g lathe, seems like a nice little lathe, have not done much with it yet, am only a beginner not having done much with a lathe besides drilling holes in drill chokes at work with the big one. Purchased this lathe to get experiance on a lathe. But if anyone works out how to convert it into cutting imperial threads, would love to know (would be a great little project to do)

Without making mechanical changes to the lathe .
If you take a 1.25 mm pitch and multiply it by .03937 you will get .0492125.
Which is close enough to .049 .
Then divide 49 thousandths into 1000 (in an inch ) and you get 20.408 TPI .
1.25 mm pitch is close enough to 20 TPI .
So to cut a 20 TPI thread select the 1.25 Metric pitch and so on. However it does have severe limitations in how many threads match close enough.

[tongleh]

I ordered my AL-250G last Thursday from General ToolsT so it should turn up later this week or early next week, I also ordered a 4 jaw chuck, a live centre and a drill chuck. I'll also be getting a vertical mill slide to make it a little more usefull. Hafco said it comes with two change gears, so when it turns up I'll have a look and see if a 127 or 63 tooth gear can be adapted somewhere in the chain, if it can't I'm not too worried, metric is fine. I've adapted a fountain pump for the coolant and got in a heap of RHS for the stand, me thinks I'll.be busy for a while.

[Retromilling]

You can make anything new you want with Metric and it is way easy to work out tapping drill diameters with metric. Take the metric diameter and subtract the pitch and that is the correct drill diameter. EG. M12 - 1.75 pitch. 12 -- 1.75= 10.25 mm drill.10 mm for a 100% thread fit and a harder tapping job or 10.5 mm for approx 75% fit and an easier tapping job , handy for harder metals that might break taps .

[MarkEF]

Be careful of the al250g lathe, after working on it for an hour this morning I noticed the motor starting to smoke (was only cutting threads nothing major.) So I shut the unit off and went round behind to unplug it from the wall, then the motor exploded and have now got burns all over my neck and face, Luckily I was wearing safety goggles n got nothing in my eye. I Have only had this machine for a little over a week and was only the third time I used it. Have not contacted Hare n Forbes yet as they are closed for the long weekend. I hope this is not a common problem and does not happen to you

[Stustoys]

Hi Mark,
Sorry to hear that.
Pictures?
I assume it was one of the caps that let go?
Were you threading by leaving the halfnuts closed and reversing the motor?

Stuart

[RayG]

Hi Mark,

Outch, that's not good.. I hope you are ok..

Stuart is probably right it most likely is a capacitor that let go. Assuming that's what it was...

A friend bought a bandsaw from Hafco, and within a few days the motor cap let go, and filled his workshop with smoke.. very spectacular.. Installed a replacement cap and it was up and going the same day. I've heard of other similar events.

So, it's not a completely unique or unusual happening, and in this case the injuries you've suffered might hopefully serve as a wakeup call to Hafco to lift their game.

Lucky you had your safety glasses on.

Regards
Ray