[modeleng] Re: Electric Traction Problems
- From: David Everett <deverett2003@xxxxxxxxxxx>
- To: modeleng@xxxxxxxxxxxxx
- Date: Thu, 5 Apr 2007 17:08:31 +0100 (BST)
Wow. Business must be booming if they can afford to alienate customers like
that. Just as well
I'm not in the market for an Electronic Speed controller!
Regards
Dave
Saudi-Arabia-On-Sea
--- Tim Of The Above wrote:
> I can't help but I have to say my experience of 4QD matches yours.
>
> I've bought over the years maybe 10 4QD controllers. I wanted to double head
> a couple of locos and asked how it could be done. I got the answer of you
> have to buy our latest controllers. So I asked if it was impossible to use
> the old controllers and got the answer of no it is perfectly possible but we
> won't tell you how to do it as we'd rather you bought some new controllers.
>
> Sheesh.
>
>
>
>
>
> >From: "psbr20252@xxxxxxxxxxxxxxxx"
> >Subject: [modeleng] Electric Traction Problems
> >Date: Thu, 5 Apr 2007 07:10:00 -0400
> >
> >Over the Spring Lambing weekend at the LM&WR (where we gave over 1200
> >rides!) I had the opportunity to try Topsy (a petrol electric) in anger=2E=
> >
> >
> >Topsy has two 12v car batteries wired in series driving through a 4QD Uni-=
> >8 (max 135A) controller a series wound forklift traction motor=2E The
> >batteries are kept charged by a 24v alternator driven from a 5HP honda
> >engine=2E
> >
> >When solo, Topsy was very lively, in traffic (two coaches) Topsy was a wus=
> >s and couldn't pull the skin off a rice pudding!
> >
> >My initial concern was that the motor was shot (it was about 7 years old
> >and I had rescued it from a scrapyard)=2E So last weekend I tried the
> >ultimate in "bang-bang" control=2E Two jump leads from the battery direct=
> >to the Forward/Reverse contactor=2E There was no lack of power there!
> >Topsy=
> >hauled a petrol hydraulic (dead) three coaches and three adults with no
> >problem around the track=2E
> >
> >I contacted 4QD (and unlike most people) I found him rather unhelpful! I
> >was told to use the calculator (which is fine if you are designing, but
> >little use if the locomotive exists) or that Topsy was too heavy, the
> >gearing was wrong or that gradients were too steep=2E He wouldn't respond=
> >to my question of whether the Uni-8 was not able to deliver the stated
> >curent=
> >(or how it delivered it)=2E
> >
> >Now I reckon Topsy weighs approximately 300kg, the motor rating plate
> >(admittedly in German) says 24v and 90A (now as this is series wound I
> >assume this means stall current=2E)
> >
> >One item of interest is that the 4QD controller comes with 4mm sq wire
> >(smaller than a cooker cable) yet the contactor (that came with the motor)=
> >
> >has multistrand copper with the thickness of expensive car jump leads!
> >
> >Now I am loathe to pay out for a bigger controller (the biggest one from
> >4QD is =A3245!) So I have a couple of options - (1) Use the batteries as 1=
> >2v
> >then 24v=2E Possibly a bit jerky, but the cheapest option, or (2) Use a
> >carbon pile regulator=2E The latter I have seen once in practice, but can=
> >find little information out on the web=2E
> >
> >So, firstly, any thoughts as to why I am having problems with the
> >controller (is it current limiting, is being series wound affecting its
> >control=3F) and does anybody have any design information on carbon pile
> >regulators=2E
> >
> >Cheers
> >
> >Peter
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