Maximat 7 Lathe

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Steamchick

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SmithDoor, I would see what rating the lathe is meant to have - e.g. Motor power, speed, and look for a Permanent Magnet DC variable speed controlled motor and controller of the same Max power and Max speed. Don't go bigger, or you'll exceed something that is a limiting factor in the design of the lathe mechanics. - It's not worth the money buying a bigger motor that damages the lathe!
Bearings (mainshaft) are a limiting factor for speed, also "balance" within chucks, faceplates, etc.
Bed, slides and guides are limiting factors for "stiffness" = how heavy and how fast you can cut metal. If you can't work as fast as you want with the current lathe, then changing the motor won't fix that. Change the lathe for something stronger - maybe bigger. - Or risk permanent damage to your precision instrument.
Usually, the safety of the machine from damaging itself is guaranteed by the manufacturer, by the size of the motor. They will never waste money putting on a motor that is big enough to damage the tool. - so you shouldn't. They are experts (not me!) so follow their principles.
 

SmithDoor

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I said buy a better motor and controller. I did not say buy bigger.
The low cost motors there put on machine tools is not up to job.
A good motor will make different.
The motor on small tools has SF 1.0 this type of motor is for fans.
Machine tools need at less SF of 1.15 I would look for SF of 1.25 . The controllers lack 100% duty cycle at low speed and will over heat.

This all using the same size motor that works all time.

Dave

SmithDoor, I would see what rating the lathe is meant to have - e.g. Motor power, speed, and look for a Permanent Magnet DC variable speed controlled motor and controller of the same Max power and Max speed. Don't go bigger, or you'll exceed something that is a limiting factor in the design of the lathe mechanics. - It's not worth the money buying a bigger motor that damages the lathe!
Bearings (mainshaft) are a limiting factor for speed, also "balance" within chucks, faceplates, etc.
Bed, slides and guides are limiting factors for "stiffness" = how heavy and how fast you can cut metal. If you can't work as fast as you want with the current lathe, then changing the motor won't fix that. Change the lathe for something stronger - maybe bigger. - Or risk permanent damage to your precision instrument.
Usually, the safety of the machine from damaging itself is guaranteed by the manufacturer, by the size of the motor. They will never waste money putting on a motor that is big enough to damage the tool. - so you shouldn't. They are experts (not me!) so follow their principles.
 

goldstar31

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Sorry to p*** on your parade but I always understood that the 7 had a two speed--- and according to people who actually owned one- bloody expensive to replace when the motor fizzled out.

Way back in the days of the Dodo, I was offered one bust one for almost nothing. Actually I sold him an Axminster 9200, the 9x20. with the myford nose.

Wasn't the Emco made in Mayrhoffen? My ( late) wife now, used to ski the Penken from there. Long before I arrived on the scene.

Am I right?
 

Bentwings

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In the days of Yore- those Good old Days, the average model maker's lathe was powered on line shafting- with a scrapped 1/4HP electric motor. Importantly, it all worked and there was nobody to ask silly questions and to get silly answers. This was the late and much lamented Don L Ashton- who wasn't an engineer but knew more engineering as his books on valve gear are still being used. So there. Don also was a world authority on tugboats, repairing musical instruments and composing music- when he wasn't re-building a full size locomotive.
He would bore me rigid at 3AM and I would be lulled into sleep.

So the other one was the much accepted Kenneth C Hart writing as Martin Cleeve on his epic 'Screwcutting in the Lathe and who hadn't enough money to take out a Patent but drove half a Myford ML7 with line shafting and TWO motors- one a full horse power and the other a 1/3rd one. That was about 1953 if my memory serves me well.
He could cut metal on the lathe faster than his home made mechanical hacksaw.

So it has ALL been done- long before there was a glint in one's father's eye.
Mine, incidentally was brazing up carbide bits- with his Decontamination Suit, tin hat and service respirator on a nail in the blacksmith's shop.

As I said- it's All been done and repeated and repeated. Being an 'engineer'? Huh, I'made more things with a fountain pen. Enough o retire comfortably at 55- far too late in life really!
One of the streetrods1 clubs I hang out with cruises the back roads.you would not believe the collections of just things that we see. We did see a full machine shop driven by line shaft just like the old days. He also had built a steam engine drive for it witthe engine built using all the machines.
 

Steamchick

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Fred Dibner - renowned Steeplejack in Bolton, Lancashire. UK, did the same to make a workshop (boiler, engine to line-shafting, belt-driven machinery) to re-build his traction engine, and lots of other stuff. His workshop may be a museum now... He did it that way to learn, and because he got it all for scrap or free.
As a steeplejack he was excellent - dropped hundreds of Tall chimney stacks and buildings without explosives or collateral damage. But although he was good at "Street mechanicing" as he called it, he admitted he needed advice from Engineers for the difficult stuff (When his work didn't work properly).
 

Steamchick

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I have a similar 7 - with 2 speeds. but invariably never need more than the "low speed" 80~1500rpm. from the variable speed controller for the motor. Only drawback s the lack of torque at lower speeds compared to my Mate's geared version which has "huge" torque at lowest gear (for the size of lathe). But for model work I don't need that much torque... rarely have a stall. Just careful size of cut, speed, feed, sharpness and tool selection, etc.
Only replacement parts needed so far = 1 "ON" push-button that blew-up!
K
 

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