Member postings for mgnbuk

Then you know the problem is elsewhere.

The OP did state " The forward unit will not "lock in" it runs if I push in the switch bar but doesn't hold. "

So the motor & contactor coil appear good and function, just that the contactor won't stay latched.

240V coil contactors could be used on either 240 single phase or 415V 3 phase machines - just need a neutral on the 3 phase installation for the control voltage side of things.

I would rather use a low voltage control circuit (24 or 110V), but simple machines often use mains voltage to save the cost of a transformer, fuses etc.

Nigel B.

The thermal overload will be applicable to both running directions - it is usually mounted on the output side of the contactor pair.

As the motor starts when the button is pressed but won't stay latched I suspect the "holding contact" on the contactor isn't making. This isn't unusual, as the contacts carry very little current & don't "self clean" as a result. Over time they can tarnish and, while closed, don't make electrical contact. Carefull dismantling of the contactor and contact block and cleaning the contact faces with a wipe of fine wet & dry paper often gets them working again.

There may be a mechanical interlock module between the two contactors (photo unclear due to wires passing over the area) that prevents both being actuated at the same time. If this is the case, then an identical replacement contactor would be required. Benedikt & Jaeger still exist, but the holding company and internet presence is now called Benedict - catalogues can be found online & Farnell are the UK agents.

Chances of a mechanically identical contactor still being in the range 20/30/40 years after the grinder was built are pretty slim, though, and lack of an identical replacement individual contactor would probably mean replacement of the entire 2x contactors + interlock module + overload arrangement, as all component parts are designed to work with each other for each manufacturer (no interchangeabilty between brands). Plenty of choice of manufactures in that case, but a quick look at RS suggests around £30 each for the contactors + £10 for an interlock & £30 for an overload + Vat for the lowest cost Lovato brand (which I usually choose for replacements at work & they work fine).

Nigel B.

Work bought a (large CNC) machine from Steve Mooney on a "delivered & installed" basis - happy with the machine & the service.

Nigel B.

They look like TG Collets

Nigel B.

There is another way around a locally worn screw. This method was used by a machine tool rebilding company that was part of the group I served my apprenticeship at & I was seconded there for a couple of months experience.

On a Herbert centre lathe with a worn cross slide screw, the screw was re-machined to remove the"unworn" sections of the thread to make it a constant (but now non-standard) form & a matching non-standard threadform nut made to suit, rather than replacing the screw & nut with new parts - all about keeping costs down.

In this case the screw was re-machined on a thread whirler rather than screwcut, but I don't see why it couldn't be done by screwcutting. The resultant thread has 2 new wearing faces with a now even gap along its length, but would obviously rattle in a standard nut hence the need for making a replacement nut to suit the now non-standard thread form.

I particularly remember this as it was a bit of extra money for me - I took the screw & nut to and from the sub-contract machine shop who did the work - strapped along the length of my motorcycle - & got paid the "up tp 1300cc" car mileage rate for a budget 250cc bike. Apprentice wages in 1979 were not great, so every little helped !

Nigel B.

I never got on with Scotoilers for the reasons usually stated - too variable a delivery with temperature changes, leading to over-oiling & mess when warm. The "Touring" kit that fitted behind the number plate wouldn't pull oil from the extra reservoir either, as the flexible "bung" for the fill pipe wasn't air-tight.

I prefered the Lubetronic unit sold by Motrax when used with the "optional" controller, which I see was the fore runner to the improved PD Oiler unit mentioned above.

Currently I'm using 2 of the Ebay Chinese "Gidibi" Nemo 2 units - less than £30 each delivered, easy to find a home for on the handlebars, easy to use & no mess. A fill of EP80 / 90 lasts me around 1000 miles when screwing the cap down an 1/8 of a turn every 50 miles or so.

Only issue with these has been the need to change parts before use - there was an extra body O-ring and 4mm push fit connector in the box with the oiler and fitting kit & I initially thought that these were spares. But the initial fill just ran out of the applicator overnight on the first one - swapping the O-ring & outlet fitting cured that & the first unit has been oil-tight since (3 years now). On the second one I just fitted the loose parts before installation & that has been fine for around 18 months. I find putting on an 1/8 of a turn at shorter intervals rather than 1/4 turns gives less mess.

Still prefer to have a fully enclosed chain, though - MZ items are wonderful devices.

Nigel B.

the tow vehicle is a Fiat Ducato motorhome ..........

I have a 3500 kg GVW motorhome with about 200 kg to spare when we are fully loaded. The vehicle is plated as 6500 kg gross train weight, leaving 3000 kg spare. So a 2000 kg gross trailer still leaves us well on the right side of the law. Another balancing act that gets forgotten is to keep the nose weight as high as possible (100 kg plated on my towbar) but keep the axle weights within limits (2100 kg FAW and 2400 kg RAW in this case).

A bit late WRT this posting - I was abroad in a 3.5 tonne Fiat Ducato based motorhome when it was posted & I couldn't face typing a reply on my phone.

I appreciate that the original question has been answered, but would be interested to know what model Martin's motorhome is, as the numbers quoted don't tally with any of the 4 off 3.5 Tonne Ducato based motorhomes (and one Ford) I have run over the past 15 years.

My current van is a Carado T339 - a 7 metre van on the Fiat "low profile" camper chassis frequently used on 3.5 Tonne vans. This has a front axle limit of 1850 kg , a rear axle limit of 2000 kg & a maximum train weight of 5500 kg, giving a maximum trailer weight of 2000 kg - same as the 2 previous vans I have had on this chassis. This chassis can be supplied plated to 3650 kg without any modifications & uprated to 3850 kg with the addition of air assistance to the rear axle. I have only added a towbar (type approved Memo unit with a 75kg nose weight limit) and a solar panel installation to the base vehicle (no awning, sat dish, aircon unit etc.), yet I am usually running at or within +/- 50kg of 3500 kg total (well in on both axles) as checked on the local West Yorks Trading Standards axle weighbridge at the start on most outings (it is only a few minutes from J1 of the M621 & FOC, so no inconvenience to check).

Martin's axle weights & max train weight suggest that his van is running on the Fiat "heavy duty" chassis, usually used on vans that run in the 3850 - 4500 kg range with a 2000 kg towing limit. While heavier vans can be "down-plated" to run as 3500 kg, from postings I have read on various forums these tend to struggle for usable payload as they are are larger / heavier vans to start with, so "200 kg spare when fully loaded" seems a bit strange ?

As Martin stated, it can be challenging to run a 3500 kg van legally - as I have not managed to run at anything like his figures on 5 different vans from 4 different manufacturers, I would be very interested to find out how he does it !

Nigel B.

On test, my new arrangement gave me a maximum of 480rpm in low gear and 1060 high gear, with the inverter running at 58Hz. I had read the specification for the new motor, so this was not unexpected. I will try a larger pulley on the motor

Your inverter will operate at an output frequency of up to 400 Hz - why not just increase the maximum output frequency ?

The Mitsubishi manual states that device is IP20 i.e. it should be mounted in an enclosure for protection.

Nigel B

1). I have successfully used Araldite for similar repairs. Just be wary tightening the connection afterwards.

2). Does the wire need to be extended, or could it be re-routed to fit the terminal slightly shortened ?

3). If it must be extended, crimp, don't solder. I have succesfully joined wires using an un-insulated booltlace ferrule, with the stripped wires inserted from either side, crimped with a proper bootlace ferrule crimper then insulated with heat shrink tube. Takes up less space than an insulated butt splice crimp connector. & space is always at a premium in motor connecting boxes.

4). Don't solder, just use a normal insulated crimp eylet of appropriate size for the wire & stud. One of the first lessons in "electrician school" was never to tin stranded wires that went into "pressure" type connections (screw or nut terminals). The soft solder flows (slowly ! ) under pressure & the joints always loosen then potentially overheat.

Nigel B.

I will throw into the mix again a comment I made previously in this thread, Energy consumers in France have had the next rise in costs pegged at 4%

And EDF are suing the French govenrment for billions to cover their extra costs incurred by having to sell at a price below the production cost. More here and doubtless elsewhere.

Nigel B.

Make sure that you have properly lubricated the cross slide with a suitable lubricant, I use an MDS grease.

The proper lubricant for a cross slide is slideway oil - NEVER use grease in this application.

Nigel B.

No experience of Dasqua, but have used Insight brand items from Cutwel at work since they started selling them several years ago.

Mainly digital calipers but also outside mics, a 3 point bore mic, dial and test indicators. No issues with any of them. The digital calipers have a hard life in our (exclusively graphite) machine shop, but the Insight items have survived longer than most other brands we have tried.

Worth getting on Cutwel's mailing list - they have a lot of short-term offers (some "1 day only" ) with substantial discounts. IIRC the last offer on Insight stuff was 20% off list.

Be wary of buying Mitutoyo stuff online - a lot of fakes about, apparently, so buy from a reputable outlet. If you are close to RDG & Cutwel you are also close to Mitutoyo (Elland), but I don't know if they retail small items from that site - the works CNC CMM came from there, but that cost a bit more than a micrometer !

Nigel B.

You are assuming that it is the board that is at faultt - have you considered that it might be the motor ?

Your motor has been run for several years and, being brushed, will doubtless have an accumulation of carbon dust inside. If this dust builds up to provide a path from the brushes to the motor frame, shorts can occur. On industrial sized motors this can lead to some very spectacular bangs when it happens. Modern industrial drives are pretty good at shutting themselves down when a short is detected, but armature fuses did blow occasionally if you were lucky. If unlucky, the semiconductors (usually thyristors) failed to protect the fuse.

If you don't want to strip the motor, try removing all the brushes & blowing through each brush hole with dry compressed air. Best to do this outdoors ! You can check the brush condition while they are out & it is preferable to mark the brushes to show their original location & direction they came out.

Nigel B.

I've just discovered CNCL which is an App on the Microsoft store, presumably running on a PC, that can drive a lathe using GRBL as a motion controller. I assume that it does threading by driving the spindle from a third (beefy) stepper motor,

Thanks for pointing out that a screwcutting version of GRBL (GRBL-L) is now available John - it wasn't last time I looked.

Seems like the early attempts at screwcutting with GRBL did use a stepper motor on the spindle, but things appear to have moved on. Now it uses an index pulse + an optional "syncronisation" pulse for more accurate tracking of spindle speed changes under load. More info here & a video of it working here

The test machine appears rather pedestrian (particularly the X axis) , though in the Wiki the author does say that it is a low cost conversion on a mini-lathe using small motors and basic drives & he doesn't appear to be controlling the spindle speed from GRBL either (so no CSS ? ). It is possible to hear the Z stepper changing the feed when the spindle slows under load to keep synchronised. I have not yet found a GRBL "front end" other than the author's CNCL to drive the turning version of GRBL.

The same author also has CNCR for controlling a stepper driven rotary table.

While it is nothing like as snappy as Sam's Emco, it does appear to be working non the less. The lack of an X axis retraction at the end of the pass rather makes me cringe, though !

While no fingers were lost in that particular video Sam, it will only be a matter of time if you keep removing ribbon swarf from the vicinity of a moving spindle ! A simple swarf hook is much safer - at least you can let go of one of those if it gets caught up & keep your fingers. I have seen some nasty cuts on others clearing swarf nests from static spindles with bare hands, let alone moving ones.

Nigel B.

Just had to place an order on Zoro for work & had a look at this vice on the main site - this particular vice is currently £274.99 + Vat there. No special offer to account holders then !

Seems like a lot of overall length for it's capacity - 270mm overall length & 100 opening. What machine are you using it on ? It would have to go "long ways" on my FB2 clone table - "normal" orientation would interfere with the column on one side of the table & hang over the handwheel on the other.

Nigel B.

Just noticed that the link I gave earlier doens't actually have the correct motor - though the "drop down" menu allows selection of the required power, mounting & speed, the details further down show that the 0.25Kw motor they sell is 71 frame, not 63.

This supplier does list a 63 frame 0.25Kw 2 pole motor, with the face mount option available.

While Googling VEB Elektromotorenwerk Gruenhain I was pleasantly suprised to see that the company survived reunification and is still trading.

Nigel B.

Pictures of the BFE65 show a flange mounted motor, so a 63 frame with a B14 flange, 2 pole 250W. Ebay has such an item for around £105 delivered here

One point to note is that the original motor had a small connecting box with a remote mounted cap - the modern motors seem to have a large connecting box that contains the cap. Space is rather at a premium at the top of the machine, so a large connecting box may not fit in the space available.

I suspect that while the original motor has "EBM" in the model number, it is very unlikely to be an EBM make motor. A quick Google brought up the rating plate of an original MD65 lathe motor - also 250W but foot mounted rather than flange. This showed it to be a product of the VEB Elektromotorenwerk Gruenhain with a model number of EBMW 63G2-SE11. I suspect that it is far more likely that the GDR manufacturer of the machines used a GDR motor supplier rather than a FRG maker.

Nigel B.

edited to add link

Edited By mgnbuk on 24/08/2022 13:05:55

Looks to me to be a Mentor mill that has been fitted with a non-standard motor via a custom made adapter - note the Parvalux speed controller in the background. There is a comment on Tony's site about the original motors running hot & expiring early.

Difficult to guess at prices these days, but £950 sounds optimistic to me for a machine with (most likely) zero spares backup. The Mentor pre-dates the FB2 (for which spares support seems sketchy at best ) & I have a recollection of having read that the gearing is a bit fragile, so lack of (or difficult to source, or expensive - or both ! ) spares could be an issue.

I would want to see demonstrated that all the gears engage & run quietly - maybe pop the access panel off the gearbox for a look inside if the seller was amenable.

The quill travel is a bit short (if I read Tony's site correctly it is 40mm, same as my FB2 clone ) & doesn't have a fine feed. From the pictures on Tony's site the Mentor also appears to lack the FB2s adjustable depth stop on the quill feed.

Nigel B.

There are assembly drawings for the Novamill on the Denford Data website / forum .

The X axis drawing shows the motor pulley is 12 teeth & P/N ST1/209, the belt is an 80XL037 P/N BI 00632. The motor mounting plate is P/N RM1/401A

The Novamill page on the Denford Data site is here and the assembly drawings are the second entry in the "Announcements" section .

Denford are still in business, though I don't know if they still have parts for older machines - maybe worth a phone call, though. Maybe also be worth joining the forum & asking if anyone has the parts left over from a conversion.

HTH

Nigel B.

" obviously I expected the English-language web-site to speak English, but not Siemens going all the way to America when there must be plenty of fluent English commentators in Germany, and Britain is very close geographically! "

Solid Edge was originally developed in the US - Siemens bought out the original developer. From Wikipedia :

Originally developed and released by Intergraph in 1996 using the ACIS geometric modeling kernel, it changed to using the Parasolid kernel when it was purchased and further developed by UGS Corp in 1998. In 2007, UGS was acquired by the Automation & Drives Division of Siemens AG. UGS company was renamed Siemens Digital Industries Software on October 1, 2007.

So not so strange that the content is American - most likely the product is still based / developed there.

Nigel B.