Search found 225 matches

by Bob D.
Wed Mar 04, 2020 7:25 am
Forum: Grand Scale Railroading
Topic: Brake System Design
Replies: 10
Views: 1915

Re: Brake System Design

Thanks for the brake pad info Kimbal.
by Bob D.
Tue Mar 03, 2020 11:17 am
Forum: Grand Scale Railroading
Topic: Brake System Design
Replies: 10
Views: 1915

Re: Brake System Design

I get being able to lock up the wheels and modulating from there..... At this point I'm trying to figure out how much mechanical advantage I need to design into the linkages for the shoe operating system so a pneumatic cylinder(s) can either operate it or overcome the spring force that applies brake...
by Bob D.
Tue Mar 03, 2020 9:02 am
Forum: Grand Scale Railroading
Topic: Brake System Design
Replies: 10
Views: 1915

Re: Brake System Design

Thanks for the reply. Tractive effort comes down to a line of contact between the rail head and wheel. My cast aluminum brake pad has 3 sq inches of contact area against a cast iron wheel. The wheel diameter must come into play too as it is a lever from the pad to the axle. So I'm unsure how to figu...
by Bob D.
Tue Mar 03, 2020 8:17 am
Forum: Grand Scale Railroading
Topic: Brake System Design
Replies: 10
Views: 1915

Brake System Design

My freelanced large scale loco has progressed to the point I'm designing the mechanical brake system. My question to all of you is this. How do you determine the force required to be applied to the brake shoes against the wheels to have effective braking? My assumption is you don't need any more bra...
by Bob D.
Fri Dec 27, 2019 9:28 am
Forum: Lathes
Topic: "Put it in 'R' for Race"
Replies: 12
Views: 4072

Re: "Put it in 'R' for Race"

Have several American lathes of that vintage where I work. They all reverse the motor electrically to change spindle rotation. Since your running a VFD I assume your motor is 3 phase. Find it hard to believe there are not two mechanically interlocked motor contacters in the electrical panel for forw...
by Bob D.
Fri Nov 08, 2019 9:48 am
Forum: General Discussion
Topic: Need to broach a square hole...
Replies: 8
Views: 1981

Re: Need to broach a square hole...

Layout your square hole. Drill out the corners with say a 1/8 drill. Put in the lathe, drill/bore 3/4” center hole. Use the lathe as a shaper to broach out the remaining indexing the chuck 90 deg. with a HSS tool. Finish up with some filing.
by Bob D.
Mon Oct 28, 2019 10:48 pm
Forum: General Discussion
Topic: Mobile Base for a 3 in 1 lathe mill
Replies: 5
Views: 2050

Re: Mobile Base for a 3 in 1 lathe mill

Go for three point contact on the floor and it will never teeter. Might want to consider a lock down foot for between the swivel casters. Brings them slightly off the floor, establishes three point contact and does a better job locking the base down than most casters with brakes. Mount the fixed whe...
by Bob D.
Wed Oct 02, 2019 9:05 am
Forum: Riding Scale Railroading
Topic: 0-6-0 diesel yard switcher
Replies: 15
Views: 6245

Re: 0-6-0 diesel yard switcher

Lateral play in the axles. Blind center drivers if the overall wheelbase is large. It is the distance between the outer axle centers that determines the radius limit for the most part.
by Bob D.
Thu Jan 17, 2019 8:09 am
Forum: Riding Scale Railroading
Topic: 8hp vs 16 hp
Replies: 25
Views: 9294

Re: 8hp vs 16 hp

Those motors sure aren't happy with no air filters....
by Bob D.
Fri Jan 11, 2019 11:07 am
Forum: Riding Scale Railroading
Topic: Dimension Engineering controller question
Replies: 34
Views: 11077

Re: Dimension Engineering controller question

Mike,
You have it correct. Stripe on diode is the cathode.
You have a great railroad. Have followed yoour posts about it.

Bob