Member postings for Hairy Pete

I would call it a pancake motor. Like this:

https://www.printedmotorworks.com/brushed-pancake-motors/

Or closer still, like this:

https://www.electronic-circuits-diagrams.com/store/LONGFORD-KOLLMORGEN-12CD-003-PANCAKE-DISC-SERVO-MOTOR-NNB-_155234707000.html

"12CD-003" seems to be thee part number.

Perhaps I should not have called it a cam. I'm talking about the eccentric disk which, if I've understood the mechanism correctly, is not keyed to the crank shaft. It is free to rotate 180 degrees with respect to the crank. May be easier to undertand by considerering that the eccentric can change either plus or minus 90 degrees with respect to TDC of the main crank. This provides the necessary valve timing changes needed to reverse the engine.

Engine direction is determing by the direction it is pushed to start with. Provided the engine is not stopped with the piston at TDC the driver can re-start it in either direction by moving the valve gear handle which is then picked-up by the gab.

My guess would be is that it stops gravity from pushing the cam forward. Consider that the cam is effectively a crank with a short throw. If force is applied in an appropriate direction, the cam can be pushed round. Normally the cam is dragged around by a pin, however, there is nothing but friction to stop the cam moving 180 degrees infront of the driving pin.When the cam goes over its top-dead-centre the weight of the eccentric could potentially flip the cam 180 degrees foward.

Have to ask: You are using the half-nut engagment lever and not the feed lever to move the carraige?

Using the 30, 80 75 60 set-up in the feed position suggests to me that the feed rate would be 0.595 (per rev).

Edited By Hairy Pete on 14/07/2023 00:19:23

Here is a pdf copy of the manual:

https://archive.org/details/manual_EL545_OM_SHARP_EN

Page 26.

HP

So, it is a software issue.

Are you using interrupts? How is the timing for the sensor-reading achieved?

It will be a thermistor - see page 14 of their catalogue.

https://tecmotors.co.uk/wp-content/uploads/2019/04/teccat.pdf

Here's one I made earlier. (8 years ago! where did that go?) It was an exercise in learning about html and javascript. It might provide some inspiration for you:

http://www.zen142641.zen.co.uk/LeadScrew.html

No guarantees - it is what it is. If it works for you, great. If not, ignore it.

David

PM me through this forum - I may have some of the files that you're looking for.

Pete

There's an example of 0.75mm pitch shown on page 18 of the manual.

The VFD monitors the resistive component of the winding. The temperature coefficient of copper is 0.39% per degree, or about 20% change for 50 degree increase - easily detectable.

In the photograph it looks like there is a capacitor between A and Z. If this is the case, you will need to break-out the capacitor and/or its winding to a separate terminal. Similarly, there appear to be two windings connected to the AZ terminal - as if the motor has been configured for only one directional running.

I'm curious to know how you square this with your opening statement:

?

H.P.

Wo = 370, basically it's 1/2 HP