Thread: Parken Drill Press "Eye-Candy"

Good to hear someone is producing the bulk of the work in house, in Australia, and of high quality……I'm sure you will get a lot of pleasure out of using your drill.

Originally Posted by BobL

It's much less about the VFD and more about the motor.

Most 3 phase motors are made robustly with quality bearings so they can run above their rated rpm by some factor.

50Hz 2880 RPM two pole motors are typically made to also handle 60Hz or 3600 rpm (some are dual badged as 50/60 Hz) so they use the same bearings and physical structure.
In terms of cooling most can also go a little faster because their internal fans will cool them accordingly, up to a point.
100 Hz or 5600 rpm is pushing it a bit far for these motors so something like 75 Hz or 4200 rpm is often used as a top end.
At the low frequency end, 10 Hz (600 rpm) is considered by some to be to low to generate enough motor ,cooling so to be conservative some folks use 20 Hz (1200 rpm).
So a generic 3 phase 2 pole motor that has a range of 10 to 75 Hz has a hi-lo frequency ratio of ~8:1

A quality 4 pole motors (1440 rpm @50 Hz) may use the same bearings as 2 pole motors so they may be able to safely use higher frequency than two pole motors. 100 Hz operation (2880 rpm) is usually possible and 3600 rpm (120 Hz) may even be possible. Assuming a low end frequency of 10 Hz this gives a max hi-lo frequency ratio of 12:1

What I'm saying is your motor (even using its range of Pulleys) has a hi-lo ratio of 24:1 which is pretty good as that would be equivalent to 5 - 120 Hz.
However to reach 10 rpm using the 6:1 gear reduction that is equivalent to a frequency of 60 rpm or 1 Hz which I find impressive
This would mean the motor has been especially designed to handle the cooling at this low speed.
It would be interesting to know if the motor uses a fan that is independent of the VFD.

I assume the VFD still reads the frequency on its front display?
If so then would you mind placing the belt on the slowest pulley range and turn the speed down so that it takes the chuck ~6 seconds to go around once (that's 10 RPM) and read the frequency off the VFD.
Then turn it up to max and read the VFD frequency.

Thanks

Thanks BobL, you're teaching me about motors too, which I appreciate!
I've run out of time today to do the frequency testing but will do so soon, as this is interesting stuff.

I do know that the motor is 4pole, and says 1435R for 50Hz. I will do the 6 seconds revolution. Stay tuned.
When you say "independent fan" for the motor, do you mean its own fan (TEFC) or a fan with its own power source? In reply, I can say that the VFD has its own little fan which vents from the top of its metal housing, while the motor itself has a fan on the bottom of it (facing the floor)... Does that answer your question in part? (Edit: I forgot to add that the motor plate also says Class F insulation, and S1 continuous duty cycle, which I presume means its pretty good...?)

More later

Originally Posted by LuckyDuck

Hi Big Shed:

Whether it really goes up to 8600RPM remains to be seen -- BobL is on the job there. But I agree, what possible use...?

The specs on their website are a bit confusing
The motor is listed as a 1.1kW DC motor but then they also say its a 240/50 110/60 motor
Spindle run out is 10 microns which is pretty good

• • Continuously variable speed 10-10,000rpm

• Powerful 1.1kW DC motor
• Single phase power
• 12 point index table as standard
• Easy tapping with electronically controlled forward/stop/reverse fuctions
• Large hole up to 350mm can be cut with optional tool
• Minimise belts changes to improve productivity

Special Features• Precision ground hard chrome column
• Dynamically balanced J Poly Vee drive
• Electronic adjustable brake with forward and reverse modes make tapping easy without the need for expensive tapping from M1.5 to M20electronically adjustable torque and acceleration
• Very slow drilling for holesaws and trepanning tools up to 350mm in plywood, plastic and sheet metal
• Milling range 0.5mm-10mm
• Groove cutting with circular saw
• Single phase power 240V 50Hz or 110V 60Hz
• Wide range of optional accessories\

As for a use for those RPMs, probably wood milling as it is robust enough to mill metal in up to 10 mm.

A 1435RPM (@50Hz) motor with a 6:1 pulley means it will be need 2 Hz AC to generate 10 rpm.
This will definitely need special cooling to run for any length of time.

Top piece of Kit LD!!! Congratulations!!

That is the sort of machine that one would love to own just for the skite value!!

I imagine with those specs and the very fine tolerances it would be a metal workers dream machine.

Thanks Artme, I'm pretty chuffed. Incidentally, I don't have a good enough dial gauge to measure the runout on the machine. Mine measures to 0.001" and the needle moves perhaps 1/10th of one thou, but that would have quite a deviation as I'm trying to gauge how much the needle has moved off the line from 0 to 0.001". It could be worse, although my needle hardly moves. I need one of those 0.0001" gauges!

Bob, I have a couple of more details for you, and I have no idea how it stacks up.

The VFD reads 15 at its slowest. I can't get it to go any lower, it just konks out and goes straight to 0 after that. I can easily slow it down to 20, and then have to barely tweak it down to around 15-16 before it goes to 0.

At 15, it takes 14 seconds for the spindle to complete 1 revolution. I used a "sharpie" to put a dot on the spindle and used a stop watch. By no means a perfect reading, but hopefully close enough for our purposes. I still cannot stall the machine at this speed. I have installed the Albrecht chuck, so I can get a serious grip on the knurled bit. Still can't stall it, and I'm not a little fellow.

The VFD goes to 1500.

In terms of the pulley diameters, I don't know if it helps you to have their sizes?
Spindle Pulley--Motor pulley
35mm--195mm (fastest speed)
110--125mm
135--100
200-35mm (slowest speed)

If I understood your previous post correctly, it would have been good to see what range the VFD is good for by measuring its slowest and fastest speed on a single pulley. Unfortunately, on the fastest pulley, and running the VFD at 15, I can barely see the spot going around on the spindle -- I would guess more than two revolutions per second. It would have been nice if it had been slow enough to see because then we could see what the fastest speed actually is, but perhaps you can do that with the pulley diameters?

As for the specs on the website, it is a mess. Michael does the updating himself and when I quizzed him on the discrepancies, he admitted that the website is a bit much for him and he doesn't have much time to work on it. Also, the 1.1kW you saw is an old spec. For the new variable speed model, he wanted more power and moved up to the 1.5kW. The weights, the column and spindle sizes, etc. are all different too. That's one of the reasons why I listed the specs at the beginning of this thread -- they were mostly taken off the machine I have -- except for things like the RPMs. Wish I had a counter to whack on the machine, that would tell us!

The VFD reads 15 at its slowest. I can't get it to go any lower, it just konks out and goes straight to 0 after that. I can easily slow it down to 20, and then have to barely tweak it down to around 15-16 before it goes to 0.
At 15, it takes 14 seconds for the spindle to complete 1 revolution. I used a "sharpie" to put a dot on the spindle and used a stop watch. By no means a perfect reading, but hopefully close enough for our purposes. I still cannot stall the machine at this speed. I have installed the Albrecht chuck, so I can get a serious grip on the knurled bit. Still can't stall it, and I'm not a little fellow

14s for one rev means ~4 RPM
The low speed pair of pulleys are a 6:1 so the motor must be doing 24 RPM

This translates to a VFD operation of 24/1435*50 = ~ 1Hz

Now if 1Hz = 4 RPM, then @ 10 RPM the VFD is running @ 2.5 Hz.

If the normal RPM of the motor at 1435 RPM and the top speed pair of pulleys = 1:6
This translates 6*1435 = 8610 RPM which is what the spec is

I'm impressed that if 10 RPM (or 2.5Hz VFD Operation) is the lowest recommended speed it must be an well or independently cooled motor at that speed.

I don't know what the VFD is displaying.
If you look closely at the VSD display perhaps it will say what the display is showing.
OR have a look at the manual.

in practice (apart from the cooling aspect) none of this matters - I'm just curious that's all.

On the odd occasion I visit Parken Engineering, & I must say it is an absolute pleasure. They are all very helpful, a very skilled bunch, hospitable, friendly & if its at "Cuppa" time you always get offered a drink.

If you want something made and made properly you wouldn't go any further.

I called in one day & Karl was busy studying a very small item no bigger than about a centimetre square, I said, "What the devil are you making there Karl" ... Reply "A mould for hearing aids"

As to "Australian Made" if they could get those various pieces that are made off shore made in Australia they would be on their drills.

I have two of their old Pedestal drills (25 years old) and they still purr.

Originally Posted by Mobile saw mill

On the odd occasion I visit Parken Engineering, & I must say it is an absolute pleasure. They are all very helpful, a very skilled bunch, hospitable, friendly & if its at "Cuppa" time you always get offered a drink.

If you want something made and made properly you wouldn't go any further.

I called in one day & Karl was busy studying a very small item no bigger than about a centimetre square, I said, "What the devil are you making there Karl" ... Reply "A mould for hearing aids"

As to "Australian Made" if they could get those various pieces that are made off shore made in Australia they would be on their drills.

I have two of their old Pedestal drills (25 years old) and they still purr.

Hi Mobile saw mill:

Thanks for your input.

I had wondered, considering all the custom work on their drill presses, whether Parken make one-off machines. For example, I have long wanted an oscillating spindle sander which is larger and more robust than the little ones (e.g. Delta Boss), but not a stationary machine like the big ones. I want something reasonably portable (say 40kgs or less), with a decent amount of oscillation, a good-sized motor, and high quality VFD. From what you are saying, and from what I saw when I visited the shop, it sounds like they could/would make me one!?

Cheers.

I have one of their Belt Sanders ( I was lucky enough to have picked it up on Gumtree for $150.00) I stripped it down had it sand blasted & took it into Michael, he put the stand up on the milling machine, cut a nice rectangle hole in it & fitted a VFD, Karl sprayed it "Parken" blue, a couple of nice "Parken" decals later & I wouldn't sell it for quids.

Sorry I have waffled on, but yes, they will make anything, its very interesting when you call in there, there always seems to be something different on the floor. The last time I was there they had just made a very high tech bandsaw for cutting medical foam with an inbuilt self blade sharpener. It had sensors that sensed when the blade was dull & kicked in the sharpener automatically!!

I believe Michael is also an Electrical Engineer.

Regards
Alan