[Spanners]

Your statement makes little sense.. employing high hp techniques due to having low hp...??

Why work around a lack of hp when a motor upgrade would fix the lack?

[jid2]

Based on my back to back testing of a Tormach and my machine there are substantial power gains to be had by putting a better motor in there. My 2hp Micromax is giving me power to run a 1/2" tool at 8000 RPM with typical full engagement speeds and feeds. It does flex the machine to the limit and can only be used for roughing, but the motor can do it.

[philbur]

The brand name belt manufacturers generally give chapter and verse on belt drive designs.

Have a look at the Conti V-belts download on this link (third one down).

Download Area ? Drive belts for industrial applications ? ContiTech AG

It gets quite technical but then proper engineering usually is.

I've looked at a few in the pasted, including the Tormach arrangement. Life is never as simple as it first looks. For example if you increase the diameter of the larger pulley and decrease the diameter of the smaller pulley you may have a problem with torque transmission due to the reduction in contact angle of the belt on the smaller pulley. You could try to compensate to some extent by increasing belt tension, but that gives diminishing returns, and you have to start worrying about bearing life. Also if you try to add more horsepower at the same time you get even deeper into the dodo. My investigation into the Tormach system (I was interested in adding a third pulley to give lower rpm – with lots of torque) concluded that they had a pretty good balance with respect to performance, compact size and simplicity. Fiddling with one element of the design invariably resulted in an unacceptable compromise in another element. It became clear that the Tormach system had been properly engineered and wasn't just based on what looked pretty in a 3D CAD drawing. So, before you start ripping your Tormachs apart I recommend you consider a proper engineering design exercise.

Phil

I'm thinking out loud here... I've been wanting to make pulley's to finetune the balance on the spindle and a few bells rang in my head the other day... What if we made a smaller motor pulley and a larger spindle pulley, wouldn't that increase the top end ? Any idea how to calculate the loss in Torque ?

[Spanners]

Pulleys and laps were done many moons ago in 1st yr engineering, so I think I'm good there lol

As far as Tormach 'designing or engineering' the machine....
It's a Chinese designed machine that Tormach have made some very subtle changes to and got on top of the quality a bit better and designed extras around it.
You get what you're given on the most part
The ball has well and truly been dropped in a couple of areas

[philbur]

You would need to call Greg Jackson a liar to make that one stick. Quote:

During those three years we designed five unique machines working in cooperation with five different manufacturers.

From where are you getting all your insider information. Are crystal balls still in use in your neck of the woods?

Phil

As far as Tormach 'designing or engineering' the machine....
It's a Chinese designed machine ........

[Spanners]

I've been dealing with China for around 15 yrs now.. You pick up on a few things and meet a few people in that time.
You also see 1100s without the body kit so to speak

It amazing how defensive people can get over a product with glaring faults in its design..

[philbur]

It's not defensive over a product, it's annoyance at a knob who make provocative statements with no supporting evidence apart from rhetoric.

Hoes that spindle upgrade coming along, ordered the parts yet?

Phil

[Spanners]

Just because you're happy being a groupie and lapping up the dribble like its gospel doesn't change the fact the machine can't be improved nor was it a ground up design
It's not a bad machine, never once said that, but it lacks in many areas, and those down falls certainly weren't the result of 'engineering or design' by Tormach

But being the engineering expert you are, you'll be able to justify the piss poor pulley and motor balance, lack of hp, bed quality, excuse for a chip tray, coolant system, chip basket etc by simply replying 'that's how Tormach designed it' rather than, 'that's how 99% of low end Chinese products are made'

Hop on a plane and visit Linyi City. Have a look around and you'll find a factory that just happens to make a mill and a lathe just like the ones you're so precious of, that have the same flaws.

[philbur]

You seem to believe that if a product is not as good as it could be it must have been designed in China. How strange.

So let’s have a closer look at those shocking design faults:

• Balance of the pulley motor system. Firstly it’s not a problem on mine, or most peoples, and secondly it has nothing to do with the design. If you feel you need better balance on yours then have it balanced.
• Lack of horse power. That is a matter of opinion not a design fault. You didn’t read that link I gave on belt system design did you?
• Bed quality. You will need to clarify that one.
• Chip tray, coolant system and chip basket all have nothing to do with the milling machine itself. When you buy the mill you don't have to buy the stand. If you followed the Tormach history you will know that the stand turned up quite some time later.

So to use a famous quote: "you can't be serious".

Nobody is saying the Tormach 1100 cannot be improved, least of all Tormach. However if you look beyond your bias you will see that it is designed as a CNC machine from the ground up. It never was a converted RF45 clone.

I don't need to go to China to know that the Chinese have a habit of cloning any good design that they believe they can sell.

PS: Which series PCNC1100 do you have?

[Bro5eters]

Hoes that spindle upgrade coming along, ordered the parts yet?

[Spanners]

You cant see the forest from the trees and are clearly missing the point....
Your machine does what you want adequately and that's fine, there's not a lot of point continuing on as you're clearly brainwashed into the whole 'as designed by Tormach'

Btw S3

[philbur]

I looking forward to seeing the details of that easy upgrade of motor and spindle implimented on your PCNC1100.

Phil

[Don Clement]

Phil,

You know what happens when you keep feeding them.

Don

[zephyr9900]

Don,

"a thin mint" ?

On a more productive note, when I bought my Series 1 (retroactively named--at the time it was the only Tormach mill) in 2006, I made a comment about the poor quality of the welds on the stand and chip trays. I was promptly (and probably rightly) slapped down by guys with "real CNC iron" who told me that the core of the machine is what matters, not the "tin". For that matter, at my last employer we had a Haas toolroom mill, and even without flood coolant a standard maintenance item was kitty litter to surround the machine to contain the leaks...

I have a Series 1 Tormach that will do 90 ipm rapids on all 3 axes, a full enclosure, a 20krpm auxiliary spindle controlled from the gcode, etc. etc. The basic machine is very solid and extendable. As Phil said, this was designed from the ground up as CNC (no handwheels!) and very conservatively, hence being able to "upgrade" from 65 to 90 ipm rapids on this early example (serial 128) with nothing more than a multimeter and screwdriver to balance the stepper currents...

Greg Jackson is on record having said that the 1100 spindle design should be good for 7krpm as is. I've never gotten around to trying that. But I have done milling and contouring with .009" ball-end cutters in the Proxxon on the auxiliary bracket. Good enough by far for me...

Randy

[Don Clement]

"designed from the ground up as CNC (no handwheels!)"

Randy,

I found using the 1100 with the Shuttle Jog Controller there is no need of handwheels.

"Hey, I didn't even eat the salmon mousse!"

Don

[philbur]

Phil,

You know what happens when you keep feeding them.

Don

Yes you are right, but in this case my goal was along the same lines as JC's in the "thin mint".

Phil