What amps for a x3 dc motor

[hudmut]

This im my first post on here been read on her efor a bit but its time i need to speak out as my pcb for my motor has given up. So what i wnat to now is how many amps does the bored cut out at when under full load as i have to oppstions to me do i go to a VDf and a new motor or do i fit a Sprint 800 DC Drive 1.1Kw 8 Amps 110/240v ac Supply as it will be cheaper to do one of the to than fit a OE borad but if i was to go the VDF route what KW motor would you say to use 750w as the OE motoe is 650 what but wait there is more do i use a 2750 rpm motor and bin the gear box for a belt to the quil or keep the gear box and use the hi rpm motor still ?

Help

Stu

[Al_The_Man]

Reading between the lines, I would look for something like the KB/Baldor type SCR DC drives, they come in 120v or 240vac flavours.
If they are not readily available in UK, there may be an equivalent make, they are usually cheap on ebay.
Al.

[hudmut]

iv had a look round for what you have said on ebay and nothing has comeup at 240v can you tell me what amps they will run at ?? di you think it will get up past 10 amp with me only running of a 13amp plug i spoke about the Sprint Drive because i can get one of ebay with warranty for less tha half price is this the worng type of item im looking for

thank you

stu

[Al_The_Man]

Originally Posted by hudmut i spoke about the Sprint Drive because i can get one of ebay with warranty for less tha half price is this the worng type of item im looking for thank you stu

Looking at their site, they appear to be very sophisticated drives, if you can get the right size at the right price, it may be the way to go.
A 13amp socket at 240v should run up to a 3hp motor.
With these drives you do not have high instantanous current due to ramping etc.
Al.

[hudmut]

does high instantanous current and ramping have some thing to do with when starting and stoping the motor like setting the ramp up and down on a weilding set ? i do now im in a bit if a mine field here i just want to fit a top shelf item no more cheap import junk this is not my first bored to fail they cost to much for whay they are

[Al_The_Man]

I have not used these drives or studied the manuals in depth, but they appear to be on par with what you get in a VFD for 3 phase motors.
They also seem to exceed the KB SCR drives I mentioned.
Hopefully you may get someone who has used them chime in.
Al.

[chalky]

You can get the KBIC dc controllers on ebay from harryuk123 aka Amadeal for £70

[hudmut]

http://www.sprint-electric.com/produ...&sid=13&pid=27

Well after long hrs of reading and a few phone calls iv gone for the above drive the 680 model as work have got a acount after all this mucking around and i all so now that the motor is 3.2 amp with a max 4000 rpm.

I no the drive is down on volts but i have fitted a belt drive all ready to the mill to so it shold work out that ill end up back at the orginal rpm head speed that i started with witch im happy about ill let you all know how it works out if any one of you are intrested

thanks for you help

p.s i can all so control the drive with a pc so if i go cnc this might be a good option to have for my self

[hudmut]

for any one that might want to know

After fitting the new DC Driver i can now tell you that flat out in top running at 210 dc at the motor with 5 amps i have 2800 rpm at the chuck and 1450 in bottom and cant slow it down with my hand like i could be for with the OE driver and all this is at 1/3 settings on all the pots there is a,ot more that the drive can give but i dont think the motor will last if i tured it up any more.

The plus side to all this is a lot better speed control (moved all controls to the small panle by motor) as well as the power to stay at a set speed under full load with out over loading the motor (still only running worm with a 63mm face mill 1.5mm cut) along with a better finish becuase of this i could all so do away with the gear box (higher motor rpm now) but ill see how the motor holds out now brefore i do that oh the hole set up was less than a OE driver

The down side no reverse haveing to rewire the machine

[Al_The_Man]

Originally Posted by hudmut The down side no reverse having to rewire the machine

If you go ahead anytime to put the reverse feature on, the drive has relay outputs to aid this feature like the Zero-Speed output relay which you could use to inhibit reverse until the motor comes to a stop.
Al.