Member postings for Peter Bell

Going to take the plunge and buy a UC100 controller but notice that since I first looked into it they are readily available on ebay at all sorts of prices.

Has anyone bought one of these recently?

Many thanks for all the help and info, didnt think I would so many considered replies! Yes the 30mm is a typo, they are 57mm long. EN 19 modern equivilant looks the favourite.

Perhaps I'd better explain a little. The loco is a 1916 WW1 Henschel which spent all its life after WW1 in Mozambique at the Sena Sugar plantation and was in use on a seasonal basis until around 1984. During its long active life it was extensivley repaired and welded many times but suffered from bolted components "working loose" and the bolted axle box horns are a good example of this.

The bolts were originally 18mm but we have had to ream the original holes to 3/4", 20mm and 7/8" also weld some depending on wear first, to make them suitable for a fitted bolt. As we need 32 bolts we plan getting a friendly cnc shop to machine them for us. The originals had a large size head and nut , rather like old Whitworth and we want to keep to that style. So these requirements rules out anything off the shelf. hence the question.

Difficult to gauge materials used at the time of the build but the horns and axle boxes appear to be cast steel. Another loco I have worked on which is UK built and 120 years old, also has cast steel axle boxes and connecting rods are like glass but have survived well so I can only think quite a lot was understood about using the correct materials in the right place.

We found this works photo of our loco in a book.

Condition when we bought it, complete but worn out!

Frames under repair showing the hornes and bolt locations. If you look at the frames carefully some of the welding repairs can be seen.

As part of the ongoing restoration of a 1916 loco I want to get some replacement bolts made to suit various reamed holes to attach the axle horns to the frames. The bolts are around 20mm dia and 30mm long.

Not sure what material to get these bolts machined from but readily available EN8 or EN19t springs to mind. Googling suggests these are suitable.

Can anyone with experience of bolt material/manufacturing confirm our selection or suggest any other readily available alternatives?

Thanks Peter

Thanks Martin,

Thanks for the reply, solves my mystery and good to know I haven't missed it, I was poised to buy an appropriate back issue!

I found the article interesting as I want to do something similar, perhaps if Argus visits the forum he can update us?

Peter

I think it was a general enquiry I sent to but got this auto confirmation below back on 24-11---I check spam often these days and afraid nothing there.

Peter

Ticket ID: XPL-01690

Subject: Contact form Peter <[email protected]>

With best regards,
Colin Pirie

Thanks Neil,

I mailed ME mag but heard nothing hence the post--perhaps I haven missed it after all!

Peter

I bought ME V219 nr 4571 13-26 Oct 2017 for the article "Manual to CNC".

It says to be continued but I've never managed to find it in recent copies---has it appeared and I've missed it?

Thanks Peter

Yes but its interesting and topical stuff as we're all faced with solving the problem of making 3 phase machinery work on single phase without breaking the bank.

My experience and confidence is growing and totally agree about the instructions but I find most manufacturers have a default or "run out of the box" page. Once its going you can start and find your way around the settings and alter to suit your requirements. I prefer larger units and "turn down" the current settings to suit, most go down a long way

Sorry I'm a bit late! Ive got an inverter, 240v in 410v 3phase out which operates a 2kw hydraulic power pack on a guillotine. I have a 1/2hp pilot motor running continuously and the power pack comes in when I press the machine buttons which pulls the machine contactors in. Sounds terrible in theory but works, my reasoning is its just seeing an increase in load and the electronics is current limiting etc

Peter

Hi, Thanks for the replies, its really useful having another slant on interpereting the published data. On reading it again it says about sampling dir on each leading edge of the step pulse to determine direction which is different to what I originally thought. I messaged TRINAMIC the makers of the chip and got back

"the 2100 will need a step & direction signal. This means, each step pulse makes the motor go a little bit. If this is, what you need, you can operate the motor as desired without any additional interfacing"

Which sort of agrees with keeping dir to 0v and providing a step pulse. Pretty good video, looks like the jumper between CFG1 and 0v allow selection of spreadCycle with options to tune the exact drive mode with other obscure connections!.

David J, I would be interested in further info on what connections you use with your board and what are you using to provide the step pulse?

Thanks once again

Peter

Thanks Neil, I've tried taking enable low, floating and high as per the data sheet but makes no difference. Looks like it uses a pulse into dir as well as step to make it go in the right direction from this below from the data sheet. Looking at the data in 11.1 in previous post had hoped that I only needed to keep dir low to make it go. Wrong again!

Peter

Now got my TMC 2100 but I'm not having any success in making it go using the simple pulse generator I used previously. Connected as a standalone driver for one stepper motor as per the pic feeding a nice buffered 5v 274Hz square wave.

From the data sheet info below I naively hoped that all I had to do was hold dir negative, apply a pulse and it would go but dont think it as simple as that! Looks like I've got timing issues at least?

Has anyone used a driver like this as a standalone stepper driver and not on a 3D printer with all the other driver grubbins?

Thanks Peter

Thanks John, Read the data sheet a few times previously but couldnt really find any figures that applied apart from the blandish statement below

"The STEP and DIR inputs provide a simple, standard interface compatible with many existing motion
controllers".

Peter

Ordered some parts and now at the waiting stage.

Its just occurred to me that with my present arrangement the controller I use to drive the stepper motor has opto isolators for clock, dir and enable which I feed with 5v at the appropriate time and also a 5v pulse for clock.

The 3D drivers (DRV8825, TMC2100) I intend trying have no opto isolation. Does anyone have the signal levels that a 3D printer runs these drivers on especially the clock? Has anyone put a scope on these?

I'd like to avoid frying too many before I get something working!

Thanks Peter

Think I'm a bit late posting, took these yesterday, these are bearings from an engine from around 1880 with the block split at two levels. No sign of shims, probably long gone if they existed, but it's certainly good for a few more years of service.

Peter

I want to use a TMC2100 stepper driver and it looks like these modules are a plug in part.

I want to use the module in a different project but cannot find a suitable socket or breakout board to plug it into. Never seen one in operation on a 3d printer---yet!

Can anyone guide me to a suitable socket/connector/edge connector?

Thanks

Peter

Thanks Neil, thats really good info and things to try I would never have found!

Peter

Thanks for the replies. PSU is easily coping with the current which is around 0.2-0.5a as it cycles through its sequence, pulses look good as well on the scope. Tried various current settings without much effect on the sound

Agree its a mix of technologies but a magnetic sensor clocks the shaft movement, (its a belt driven linear actuator), the picaxe counts the sensor pulses so fairly low speed and closes the loop

Its been performing quite nicely with repeatable numbers from the movement for days so dont really want to change too much, was unsure if I had faulty drivers.

Going to follow Neil's suggestion so ordered some Polou drivers to play with--is the low speed mod detailed anywhere?

Thanks

Peter

Sorry--the black one is the very odd noisy one and the open frame (2nd pic) ticks and seems to increase the step rate to 1/16.

Just glanced and see plenty of Pololu---like to give one a try--any particular reccomendations?

Peter

I'm on 1/8th step with 25v supply.

Thanks for the explanation about smoothing, never heard of that. Its on 100% smoothing, if I reduce it in stages the movement becomes progressivly more jerky.

It cycling between 73 and 2350hz under the control of a picaxe to the vco (4046) but that might have changed as I've twiddled!

When I set it for 1/16th steps the speed increases so still wonder if the driver is faulty?

As its a very cheap driver do they become smoother with price, notice some have 4 dip switches to set the step rate?