Search found 1650 matches

by John Hasler
Fri Jan 22, 2021 6:38 pm
Forum: Riding Scale Railroading
Topic: Electric power primer
Replies: 30
Views: 4668

Re: Electric power primer

The idea is to power each motor via one of the poles of a 400 A double pole single throw contactor.
by John Hasler
Wed Jan 20, 2021 11:24 pm
Forum: Riding Scale Railroading
Topic: Controlling separate DC traction motors
Replies: 15
Views: 381

Re: Controlling separate DC traction motors

BigDumbDinosaur writes: Does a 96 volt controller even exist? Controllers to run similar sized AC motors from 96 VDC are readily available. I don't know of any offhand for series DC motors but they would be simpler than than ones for AC motors. IGBTs with the required ratings are off the shelf items...
by John Hasler
Wed Jan 20, 2021 9:15 pm
Forum: General Discussion
Topic: Why do I need a Variac?
Replies: 11
Views: 267

Re: Why do I need a Variac?

You can use two identical transformers back to back as an isolation transformer.
by John Hasler
Wed Jan 20, 2021 9:05 pm
Forum: Riding Scale Railroading
Topic: Controlling separate DC traction motors
Replies: 15
Views: 381

Re: Controlling separate DC traction motors

Putting the motors in series would be an elegant solution but it would require a single 96 V controller which you don't have so it's not really an option. For reversing you need a single 4 pole double-throw contactor rated for 400 A. You could use one double pole double throw contactor for each moto...
by John Hasler
Wed Jan 20, 2021 7:24 pm
Forum: Riding Scale Railroading
Topic: Controlling separate DC traction motors
Replies: 15
Views: 381

Re: Controlling separate DC traction motors

> If this were my project, I'd wire both motors in parallel to a single controller that has the capacity to handle the combined load.

I'd consider putting the motors in series, but then I'd be building my own controller, too. He's got the controllers he's got.
by John Hasler
Tue Jan 19, 2021 8:43 pm
Forum: Riding Scale Railroading
Topic: Controlling separate DC traction motors
Replies: 15
Views: 381

Re: Controlling separate DC traction motors

These motors are likely to match much more closely than your RC motors, especially if the RC motors were PM. It's still a concern, though. You could sometimes have one axle slip and the other not. The ideal arrangement would be to install a tach on each axle and have a microcomputer manage the motor...
by John Hasler
Tue Jan 19, 2021 4:36 pm
Forum: General Discussion
Topic: Why do I need a Variac?
Replies: 11
Views: 267

Re: Why do I need a Variac?

Triac chopper speed controls are not useful for testing inductive loads such as AC relay coils or for determining the correct AC operating voltage for a device unless it is purely resistive and you have a true RMS voltmeter.
by John Hasler
Tue Jan 12, 2021 9:22 am
Forum: Riding Scale Railroading
Topic: Electric power primer
Replies: 30
Views: 4668

Re: Electric power primer

There is a schematic in the manual (http://www.fsip.biz/Documents/1204_05.pdf). You probably cannot use a single pot for two of those controllers. Check with Curtis. Each motor requires four sets of contacts for reversing. The schematic in fig. 6 in the manual is good. Maximum total current will be ...
by John Hasler
Sun Jan 10, 2021 9:04 am
Forum: Live Steam
Topic: Could I get tips on dumpster diving for materials for your build?
Replies: 52
Views: 3237

Re: Could I get tips on dumpster diving for materials for your build?

I think that if you must interference fit aluminum onto steel you need to shrink it on, not press it.
by John Hasler
Fri Jan 08, 2021 11:10 am
Forum: Live Steam
Topic: Could I get tips on dumpster diving for materials for your build?
Replies: 52
Views: 3237

Re: Could I get tips on dumpster diving for materials for your build?

>The only problem is that cost of shipping often exceeds value of the product...

Still cheaper than Menard's, though.

> Forget brass.

When I cleaned out my father's shop I gave away several hundred pounds of brass because I didn't want to haul it down here. A mistake I regret.
by John Hasler
Thu Jan 07, 2021 9:49 pm
Forum: Live Steam
Topic: Could I get tips on dumpster diving for materials for your build?
Replies: 52
Views: 3237

Re: Could I get tips on dumpster diving for materials for your build?

There are also online metal suppliers. I've had good luck with Speedy Metals. If you are in the upper midwest place your order by phone and ask that they ship via Spee-Dee Delivery. Faster and cheaper than UPS.

https://www.speedymetals.com/

https://speedeedelivery.com/
by John Hasler
Thu Jan 07, 2021 11:09 am
Forum: Live Steam
Topic: Could I get tips on dumpster diving for materials for your build?
Replies: 52
Views: 3237

Re: Could I get tips on dumpster diving for materials for your build?

>That being said: there are some parts where you are definitely better off using material of a known specification and quantity...

Yes, of course. I don't build locomotives, but I do buy new material when necessary.