Search found 211 matches

by scmods
Mon May 29, 2017 7:40 pm
Forum: General Discussion
Topic: Rotory phase converter questions
Replies: 25
Views: 4506

Re: Rotory phase converter questions

The RPC you are attempting is the Ferraris-Arno method. Although the 3 phase motor will run (at reduced power), it will not self-start. Once the motor is running on single phase, the eddy currents in the rotor will induce an EMF in the in the unenergized windings that we can utilize to run other 3 p...
by scmods
Mon Dec 26, 2016 5:40 pm
Forum: Lathes
Topic: lathe motor 3ph vs. single phase and low rpm
Replies: 24
Views: 4775

Re: lathe motor 3ph vs. single phase and low rpm

I researched the two types mentioned here (VFD and RPC), and found commercial duty VFD units to be prohibitively expensive. There were a large number of reasonably priced VFD units, but as power means current flow, these units did not appear to have the "beans". I elected to go with the RPC system. ...
by scmods
Mon Dec 26, 2016 3:53 pm
Forum: General Discussion
Topic: Steel drawer slide lube?
Replies: 8
Views: 1500

Re: Steel drawer slide lube?

ah! Jamestown. Brick streets, climate off the end of lake Erie. Scandinavian heritage, I think. Went to AVM voting machine school there back during Jimmy Carter. Nice city, but I digress. AGAIN Anyway, when we switched from wooden to aluminum ladders in my FD (Watertown, NY). We tried a number of sl...
by scmods
Mon Dec 05, 2016 2:10 pm
Forum: Welding
Topic: MIG for Cast Iron + Small Welding Table
Replies: 75
Views: 36522

Re: MIG for Cast Iron + Small Welding Table

I didn't watch the video, but there are only so many ways to deal with carbide precipitation in cast iron welding, which is the overriding problem. As the parts involved get larger the chilling effect of the bulk metal complicate efforts to get a good weld. Nickel fillers seem to make things easier,...
by scmods
Mon Dec 05, 2016 12:37 pm
Forum: General Discussion
Topic: Tips for Cutting with Carbide Mill Drill in Steel?
Replies: 47
Views: 4293

Re: Tips for Cutting with Carbide Mill Drill in Steel?

Apparently, a basic understanding of mechanics is lacking. As Harold said, as you get closer to the center of rotation of the cutter, the sfm relationship between the cutting edge and the material drops off to almost nothing, or in the practical, zero. I would expect that, mechanically, it is simila...
by scmods
Sun Jun 05, 2016 1:24 pm
Forum: General Discussion
Topic: Polyurethane Air Hose Unreliable?
Replies: 69
Views: 4458

Re: Polyurethane Air Hose Unreliable?

Boys, boys.... Its not a matter of unreliable, unsuitable, etc. All engineered products have strengths and weaknesses, hoses included, as are extension cords. Many of these products trade one strength for another, such as lightness vs. flexibility, and within the range of what would be considered re...
by scmods
Wed Jun 01, 2016 10:05 am
Forum: General Discussion
Topic: File cleaning
Replies: 12
Views: 2029

Re: File cleaning

Daer All, I like to read old technology books, and while reading "The new Chatecism of Electricity", I noticed something you may find interesting. The subject was sharpening files, and it actually seemed to have actual scientific basis rather than the "old adage" sort of stuff you usually find. The ...
by scmods
Thu May 26, 2016 12:28 pm
Forum: General Discussion
Topic: Upper limit of heating hardened steel ?
Replies: 16
Views: 2680

Re: Upper limit of heating hardened steel ?

Just a couple of things from my experiences. First, taking things apart with heat is not the same thing as assembling a shrink fit. It is difficult to heat the outside part without heating the inside too. I assume that this is not a corrosion issue that requires near red heat to break the corrosion,...
by scmods
Sat Apr 09, 2016 1:18 pm
Forum: General Discussion
Topic: 3 phase convertor failure
Replies: 70
Views: 8506

Re: 3 phase convertor failure

Kevin Sorry about your dud. Make sure you salvage the windings for the copper, the end bells for the bearings and the mainshaft. The mainshaft on a motor that big may be keyed to the armature laminations, but should press out. Usually they are equipped with center drillings and a nice keyway. Handy ...
by scmods
Sun Apr 03, 2016 4:54 pm
Forum: General Discussion
Topic: 3 phase convertor failure
Replies: 70
Views: 8506

Re: 3 phase convertor failure

Kevin, The diagram that Webb has posted is different than the one furnished by my motor guru. I suspect that the issue has been confused by assuming that the exterior connections (delta) reflect the internal wiring configuration. I must admit that my posting expertise does not permit me to furnish a...
by scmods
Sat Apr 02, 2016 4:20 pm
Forum: General Discussion
Topic: I Created a Smooth Bore With a Tap
Replies: 49
Views: 4999

Re: I Created a Smooth Bore With a Tap

Steve, Well, there goes your hundred attaboys! Apparently the tap acted like a succession of square ended single tools rather than a helical cutter. The basic bore seems to be adequate, maybe even a little large according to the general table. Perhaps the tap did not have sufficient taper at the sta...
by scmods
Fri Apr 01, 2016 8:09 pm
Forum: General Discussion
Topic: 3 phase convertor failure
Replies: 70
Views: 8506

Re: 3 phase convertor failure

This may be a moot point by now, but here goes anyway. From the description, it sounds like a dual voltage WYE connected motor. My understanding is that with a nine lead motor, it is actually a twelve lead motor with 10,11, and 12 connected internally. This is why the jumper bars are connected betwe...