Here is a list of all the postings Russ B has made in our forums. Click on a thread name to jump to the thread.
|Thread: Help wanted, DC motor speed controller issue|
As for mica washers..... the board and wiring had been fettled and given that the armature was accidentally connected to the field terminal adjacent I would guess finer details like mica washers slipped the attention of whoever dissasembled it in the first place. That said, when I tested it, it was on a non conductive bench, out of the machine, the heat sink was attached, however where as the SCR's and Diodes connected dry, directly to the annodised aluminium, I slipped a 0.3mm thermal pad under them believing it would be useful?
I feel like I shouldn't be touching this at all but as it didn't work, I felt I had nothing to lose and when I identified a clearly faulty SCR I thought I'd cracked it! I hope I haven't done more harm that good!
I don't think there is a field, its a brushed permenant magnet motor, all in good condition and running smoothly to my untrained eye.
This link is also referencing a KBIC, and later refers to two models, a BC2000 and a BC2200, and everything in it, seems to match almost exactly to the board in hand.
I have an issue on a motor speed controller that I've been unable to solve (I seem to have created or uncovered a different issue!?)
I'm afraid my knowledge on this repair comes from a google search and a bench test based on my limited knowledge of what is to me, a complex piece of electronics.
|Thread: Workbench top|
+1 for this comment
I have smooth metallic white sparkle worktops in the garage, when I'm rebuilding engines I have an area set aside for circling and naming unique bolts/valve shims etc.
|Thread: Myford 280 Manual and Sales Brochure|
When I got my Myford 280 I scanned the manual and sales brochure that came with it, and shared it around. Since then, multiple copies seem to have surfaced on the web for £10-20 for a download or paper copy, and I can't find the free link that I shared originally.
Edited By Russ B on 23/11/2021 15:28:06
|Thread: Chester DB7 speed control board? NVR switch doesn't lock|
After a good clean, the motor works perfectly and spins smoothly on the bench from a little 9v battery, and consumes around 200ma on 12v.
|Thread: Another chinese lathe rises through the smoke|
Anthony, I love the new thread title
My motor (now) runs perfectly smoothly and spins up in just a fraction of a second off a little 9v battery much to my surprise, and draws 190 to 210ma when connected to a 3a 12v regulated supply. If I brake the shaft with my fingers it’ll draw around an amp as it slows to just a few revolutions per second.
Testing the resistance however, I have just 4ohms all round, and in fact, 4 ohms between any two at any angle, i don’t know if this is right, but it’s all very consistent.
I’m not sure what was going on with my motor, initially I couldn’t get any sense out of the resistance it was jumping all over, I cleaned up the contacts with a soft brass suede brush and then it all seemed to measure as above.
I’ve no professional expertise here bar 6 months studying DC and AC theory as part of mechanical engineering qualifications - i’m just handy at working stuff out, I assume the lower resistance is due to my higher output (claimed) 750w motor. The DC controller quite an output of 0-180vdc
I will research this light bulb test, I assume it’s a circa 50w 240vac light across the motor controller output.
Could you do me a favour, and measure the current when the new motor is connected to a 12v supply, it should be circa 100-200ma if my googling is accurate - I'm not sure I would suggest doing the same with the old motor unless you can limit the current to protect your meter somehow.
The Chester DB7 I'm working on for a friend is a similar age to your clarke machine, and I think under the fancy clothes, they are very similar machines, although this one has had a pretty hard life by the looks of it!!
I have a Myford 280 and a Warco Super Mini (basically identical to your Clarke but green!). Now if you think a Myford Super7 is a sturdy lathe, or the Myford 254 is supreme, wait till you see a Myford 280!! It's a hell of a piece of kit. I love them both, they are both excellet machines, I'd buy another chinese lathe tomorrow if I needed one. The myford, I wouldn't replace, great machine, too expensive, unjustified. When I bought it, they were cheap.
|Thread: Chester DB7 speed control board? NVR switch doesn't lock|
Fuses aside for a moment….. motor testing didn’t check out, I think there may be an issue with the brushes or commutator which will require investigating thoroughly.
Well, I finally got round to looking at this machine. Can anyone help me confirm a few things?
I notice it has a pair of 10 amp fuses in the back, should these be 5amp fast acting, there is no information in the Chester Manual or on the parts diagram about any of the fuses rating or types - good old Chinese manuals!
I'm reluctant to try a 5 amp main fuse till I know what the control board and motor fuses should be.
I tested the NRV and that works and latches as it should when the control board is disconnected. Looking at the wiring, someone has been at this in a big way which is never comforting, either that or the Chinese are fond of sticking insulated crimp terminals in various lines to and from the various switches, board, motor etc etc. I tested the pot and apart from going though a dodgy almost open circuit patch just before full speed, it checks out exactly as it should.
When I tried to start the machine, I had to pot turned to minimum. I have now disconnected the drive belts and will try 9v and 12v across the motor while measuring current to quickly assess general motor health/cleanliness.
I’m picking up a faulty DB7S tonight, so this might well come in handy, thanks!
He said the motor won’t run, but he seems to think someone’s tested the motor and it checks out ok, and i’m guessing he’s checked all the internal fuses as he said there were a load, I wonder what mysteries I’ll find!
|Thread: First try with a 3D printer|
I only the buy the best filament for final parts as cheap stuff can (but doesn’t always) cause terrible quality prints. I’m typically paying £20-£25 a kg for Verbatim branded filament and £15 ish for cheap draft quality filament.
1kg goes a very long way, as most parts aren’t solid infill (especially test fits and draft parts), they’re a shell with a matrix inside, which can work out to be tougher though more flexibility (although this part probably is solid). I’d guess it’s no more than 10g, so you could make around 100 finished parts, and typical standard 3d prints are around 25% infill and you’d get double or triple the quantity.
I just printed a pair of exhaust manifolds for a classic Honda I’m restoring, bores have to be machined as it’s not super accurate, but test fit was spot on, now thinking about quotes for laser/water cutting from 5-6mm aluminium, it’s handy to have that ability! I did some carburettor adapters for fittings webber carbs years back, easy to knock out 5+ revisions inc test fits and tweaks in a day, and due to the CAD side of things I was able to properly design the flow though the part to ensure smooth transition between flanges.
|Thread: supercharged V12 2 stroke|
Great to see an email notification pop up from you relating to a thread update!! I've loved this from the start!
Thanks for putting it all online!
|Thread: Lidl Portable Bandsaw|
I think you may have just got a bad one, my blade tension can't be adjusted by any other means, but it works perfectly fine, so I see no reason why it might need to be changed.
Perhaps one defect accoutns for you both your complaints, a stray guide perhaps not holding the blade vertical, and as a result, shortening the correct route of 1140mm in length preventing you from tightening as the blade its literally cutting corners?
Edited By Russ B on 05/11/2020 13:06:58
|Thread: Parkside (Lidl) Cordless Angle Grinder|
ahhhhhhhhhhhhhhh..................I think I might have unknowingly had the brushed version? it did a few good jobs albeit at a drastically reduced speed vs my 240v/110v gear but hammered my 4ah battery, which normally lasts a week or more of daily odd jobs M16-M20/pipe/flanges etc on the 1/2" impact gun.
I sold it practially brand new for about what I paid for it (£29.99 without battery/charger)
|Thread: Lidl Portable Bandsaw|
Martin, I have the Aldi one (£149.99 delivered last year I think) - the blade tension is fine, I could play a tune on it and the weld is flat and smooth, I'd be taking it straight back before they have none left to exchange it with if I were you! (And hoping its not a crap batch!)
Milwaukee do 10, 14, 18, 24 TPI and 10/14 and 14/18 TPI variable pitch. Not all of those are available in europe in the more economical packs of 3 or more blades, so it takes a bit of looking around on the net. I can't for the life of me find where I got mine from, I'll have to check the bag/box in the garage for clues.
|Thread: I'd like a simple plastic injection machine or designs|
As I suspected, very expensive to do properly! I already have polyurethane and silicone casting equipment as I made a valve head and cast a PU sealing face onto it for a small (by my standards) injection machine (typically pulverised or pellet fuel injection)
I might contact the local supplier to see what other options might be available as the PU i have would be too soft although probably chemically compatible.
I’m still going to gave a look at this DIY machine, i’m too curious.....
Chris, it's always good to have some companies to call up, thank you, putting injection moulding terminology and quieries into google is a waste of time, I was trying to find out how NBR parts are made the other day to see if I could make my own and it was like I was asking the meaning of life, every answer was totally different and none hit the mark!
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