Qualters and Smith Qdm750 Restoration

[Pete.Participant @pete-2]

So yeah, spent hours messing about with stuff I wasn't expecting to have to do, had to be done though that would have drove my OCD mad, ordered some paint from paragon paints last night in a fit of enthusiasm so hopefully that'll be here Tuesday or Wednesday, so for now the castings will all be prepped for paint.

[Oily RagParticipant @oilyrag]

Nice work Pete.

You'll have a fine machine when its finished. Is it 3 phase? are you going to run it off and inverter if so?

I think yours maybe an older machine than mine as the quill lock system is substantially different in the head casting with a much larger boss to accommodate the retaining outer bolt and the fine pitch adjustment inner bolt. I notice your machine plate is also quite different to mine (see attached photos) – what's your drills serial number (please)??

I earlier mis-counted the holes in the pulley lower bearing retainer plate – it has of course only 4 holes – 3 being equi spaced for the non back geared heads and an extra hole diametrically opposite one of the 3 holes for a 2 retainer system on the back geared heads. I have shown my mod of adding one more bolt to the accessible front hole.

I agree with you about the quality of these drills, everything about them oozes good design and craftsmanship. Unfortunately even the 'Fercolised' column on mine could not stop the ravages of standing outside for 5 years, but I was amazed at how good the column cleaned up where it was not fully exposed to the elements. As you also noted the quill is an excellent fit in the head and is absent from all 'slop'.

Have you noticed that many of the castings have a cast in part number that starts 'S 8 xxx' which shows its relationship to the Kerry Super 8 drilling machines. I note that the tilting table is also (at least on mine) not scribed with a '0' position. They obviously expected the operators to be able to re calibrate the table after moving it.

Apologies about the inference regarding your use of 'water pump pliers', I have not come across Knipex tools before but will certainly look out for them now.

Front view of the QDM head with the single 3/8th grub screw for the quill lock.

View showing the machine plate which is different style to Pete's machine. Note the shiny column bit just under the head then the 'dingy' section where the column was exposed to 5 years of the elements!

The extra lower bearing retainer plate bolt making use of one of the holes provided for the non back geared machines (QDM 500 and standard QDM 625)

My aluminium top cover was also lightly damaged (dinged at the back but not impacting on function in any way. I did find it 'rattly' but cured that with some thin self adhesive silicone rubber pads. I wonder if the strap fitting on your machine was to stop the skool kids raising the cover and fiddling with the belts / back gear? Seems that anything sold to edukashunal establishments have to be triple locked and plastered with warning stickers for safety of the 'Elfins!

Martin

Edited By Oily Rag on 30/10/2021 14:06:50

[Pete.Participant @pete-2]

Hi Martin,

I'll upload a photo of the serial number tomorrow, I thought I had one on my phone but it's out of focus.

The original motor was a 3 phase Hoover motor manufactured in Scotland, 1/2 horse, a lad looking for a motor with a 5/8" shaft had it off me as he needed to repair one on his surface grinder, I told him I couldn't test it as its not dual volt 3 phase but I didn't think it had been used much, he decided to use instead if fix his own motor as it worked fine, and was probably less worn.

I bought an inverter and dual volt 3 phase and all relevant switches/buttons from inverter drive supermarket, I thought might as well do it properly if going to all this trouble, I bought a 25cmx20cm electrical enclosure which will go where the original on off box was, it was smallest space recommended to put tbe inverter in, it shouldn't look too out of place, I didn't want separate items screwed to the wall..

Other than that, I fettled the lid a bit more, the bent pipe that holds it up was annoying me, I knew it can't have originally been like that, and although the sides were lining up ok with the body, the front was overhanging 5mm, you might tell in the photo below.

Whatever happened to bend it out of shape must have bent the actual hole the pipe sits in, so luckily I had 3 foot length of 1" steel bar, which I used to encourage it back to something nearer original, I'm happy with it now, it is a bench drill not the panel gap of a classic car.

[Pete.Participant @pete-2]

That's a good point about the strap holding the lid on in a school environment , being back geared, it may well have been to stop curious fingers becoming crunched fingers.

[Oily RagParticipant @oilyrag]

I reckoned that your drill had only ever run in 2nd lowest gear from the corrosion on the aluminium pulley sheaf, that's what led me to think it had been 'bolted shut'. Probably the missing knob off the detent release for the top cover is another precaution against the 'Elfins. Do you need the details of my knob? (note to moderators – this is not to be taken the wrong way ) I could probably turn one up for you in aluminium, steel or nylon if you wish as I have a ball turning attachment which would make it easy.

One thing I did was re-black all the motor mounting pins, detent pin, depth gauge, table tilt nut, clamping items and other odds and ends which seems to have stopped the corrosion. Most of my parts were red with rust and after de-rusting they soon reverted to their previous state even though they were in a non rusting area. So during this maintenance session (to resite the inverter onto the switch plate which was where the non operating 25V LoVo light was placed. I Metalblak(ed) the parts – which touch wood, seems to have halted the habit of everything trying to revert to ferrous oxide!

As you may have seen in a previous thread asking about Hammerite paint mixing, I also repainted the drill in its original colours (Hammerite Hammered Black and Silver) I added a smidgen of Royal blue to the black to get the match correct. It appears to have worked out quite well.

I'm having a flying lead to a remote control box for my inverter which will allow speed control, set speed selects, forwards, reverse, and a jog function at arms length. The machine had previously been sharing a wall mounted inverter which was remotely controlled from another machine (the T&C grinder! ) You can see my inverter in the first photo of the machine having the wire up tested.

Martin

Edited to get rid of the bufoonish smiley

Edited By Oily Rag on 30/10/2021 21:41:04

[Oily RagParticipant @oilyrag]

One other point I forgot to mention above is that my drill is fitted with what I believe is, due to the motor being painted the same colour as the motor mount plate, the original 3 phase motor. Unusually it is of Russian origin! However I was impressed by its quietness and smooth running, the body and end plates are of cast iron so it is not a lightweight unit (tipping the scales at around 10kg ) but it is a 0.75kW (1 HP ) so, I would suggest you up your power to a similar rating. Could it have been supplied with a 1/2 HP motor to the 'edukashun' authorities to limit the damage that 'yooves' could do??

Martin

[AJAXParticipant @ajax]

Posted by Pete. on 30/10/2021 21:03:21:

That's a good point about the strap holding the lid on in a school environment , being back geared, it may well have been to stop curious fingers becoming crunched fingers.

I'm another owner of a QDM 750, but mine is the floor standing model with a workshop warning stating gear changes by authorized users only, or something to that effect.

[AJAXParticipant @ajax]

Posted by AJAX on 30/10/2021 22:10:03:

Posted by Pete. on 30/10/2021 21:03:21:

That's a good point about the strap holding the lid on in a school environment , being back geared, it may well have been to stop curious fingers becoming crunched fingers.

I'm another owner of a QDM 750, but mine is the floor standing model with a workshop warning stating gear changes by authorized users only, or something to that effect.

[AJAXParticipant @ajax]

Here's mine, fitted with a Brook Crompton 1/2 HP 3-phase motor.

I paid about £200 for the drill in full working order. All I had to do was fit a VFD + control panel. I removed the machine lamp + transformer with the intention of refitting it one day but have not found the need.

I find the slotted table and low-speed back gear very useful. The VFD makes it very easy to use and I rarely change the pulleys.

[Pete.Participant @pete-2]

Thanks for the offer of making the pull release knob, I obviously didn't pay very much attention when removing it, it does actually look like the correct part, but has had the plastic part removed, which would tie in with what you say about deterring entry into the top, I never actually thought of it like that, well noticed.

I remember you mentioning the paint previously, looks well matched, I decided to stick with a similar style to the original but with plain gloss RAL colours from paragon paints, a dark grey 'Telegrey 2' I'm using for the main body and the other colour I ordered to do the silver parts was 'papyrus white' if you look on page 3 of RAL section you'll see them, so it is in keeping with the original style, hopefully should look ok.

[Pete.Participant @pete-2]

Thanks for the preview of your Qdm750 AJAX, the T slot table definitely looks more useful, I have replaced my motor with a 1/2hp as that was what the original was, I didn't think any more was necessary as it's rated to drill 20mm holes in steel with a standard motor, time will tell but I'm sure it'll do.

[Pete.Participant @pete-2]

Hi Martin, so can you date this from the number? what does it tell you?

[Pete.Participant @pete-2]

So I finished removing all the paint from the main body, fitted the electrical enclosure to the bracket on the drill, this will house the inverter and have all the switches on the front, including a digi tacho, I'm thinking of installing the magnet by drilling into the small bolt counterweight on the top of the spindle gear, if there's room for the reader under the cover.

the electrical enclosure will be painted the same colour as the lid.

[Pete.Participant @pete-2]

I've ordered a digital tacho, I need to test fit all the electrical bits so it can be screwed together hassle free after painting, and fit the tacho reader, I'm thinking a simple L bracket JB welded to the back gear bracket, it doesn't weigh much so providing there is room, it'll save me having to drill into anything.

[Pete.Participant @pete-2]

Oh I forgot to ask, I think I'll replace the bearings, not sure about the spindle, as it's self contained they might be salvageable, but the exposed ones are gritty and slightly corroded, do you know a good source of high quality imperial bearings?

[Pete.Participant @pete-2]

Had an hour this evening on the project, fitted the inverter into the enclosure, start stop, forward reverse, and emergency stop, bit of a tight squeeze making sure nothing obstructed the switches from behind, should just squeeze the Tacho in there too.

[Pete.Participant @pete-2]

Had another little play in the workshop after dinner, I foolishly completely forgot about the potentiometer, luckily it had room without hitting anything behind, I fitted the tacho, drilled the two holes in bottom plate for the power in and out, and stripped it down ready to paint.

[Pete.Participant @pete-2]

Had look at the table ready to strip that down next, a bit more evidence of its school background, and luckily it escaped its time in education pretty well, only a few small drill holes in the very centre of the table, also noticed a few nice design details, the tracks either side of the slot in the table to hold square nuts captive, and machined flats on the underside of the table edges to place a clamp on if needed, I thought these were nice little touches.

Is the handle on the table clamp original? it doesn't have a captive nut which would get annoying pretty quickly, something will need to be done with that.

[Oily RagParticipant @oilyrag]

The handle is correct, and the nut is held captive along one edge of its flat against the casting. This allows for easy positioning of the handle in any of six possible orientations by changing the 'nut flat' which is captivated. I have found in use this is a brilliant system and the table clamps and unclamps in just half a turn with ease.

Clamp nut held captive by one of its flats against the table support casting. This makes the handle easy to reposition in any one of six places according to work table overhang.

The handle on mine is same as yours Pete!

Regards,

Martin

[Oily RagParticipant @oilyrag]

The table is, as you say, well designed. The slotted underside is very handy for T Nuts or T Bolts. I prefer to use the Nielsen 'mole grip' style table clamps which need a spacer to allow the foot of the ring nut to clamp on the underside, the advantage is the thread is then effectively shortened so the clamp is quickly detached and is easily accessible. These table clamps allow for a smaller drill vice to be used and clamped as the wide spaced slots, although good for heavy vices, is problematic for smaller drill hand vices.

The machined under edge is great for 'G' clamping large pieces of work, another example of how well thought out these machines are. Does your machine have the table '0' position marked?

AJAX's machine is a nice example, and I think is a later machine than mine with a serial number of 20330, against my 19521. I can't see any difference in his top cover though other than the style of badging. Thanks for sharing your machine details AJAX.

I've pretty well nailed my machine down to a 1983 DoM. It carries a BLHA asset number (British Leyland Holdings Asset) which relates to the £1.4 million facility upgrade at Longbridge for the introduction of the Metro model.

Martin

[Pete.Participant @pete-2]

Hi Martin,

I did initially have the same thought that the flat machined on the casting held the nut captive, but it didn't, I then noticed when the handle is on the left side, it does work as you say, the flat is less deep on the left hand side for some reason.

Pictures below are the cast ally lids as we have, and the square newer type, I think this is like AJAX's? possibly sheet steel? excuse the poor quality image It was a screenshot and the original was poorly focused.

[Pete.Participant @pete-2]

Bought some new tools, always nice to have an excuse to buy more tools, I had a worn out smaller set of tube wire brushes, must be one of the most useful things when doing things like this, so bought a bigger set this time, also a set of cheap bearing press discs, well worth the £40 I paid, should have bought some years ago, and a slim foot bearing puller.

[Pete.Participant @pete-2]

So removed the back gear bearing, also noticed that there was a small wear patch on the top of the head casting where the back gear sits, might put a thin oilite washer between those parts when I reassemble it.

[Pete.Participant @pete-2]

Scraped all the paint off the castings, put a bit of stripper on after and wire brushed the remaining paint off, a pointed end brush in the drill got in all the corners, very useful, got to fill a few small casting imperfections then all the parts can be etch primed.

Edited By Pete. on 04/11/2021 00:03:05

[Pete.Participant @pete-2]

Little update, after finishing cleaning all the castings down to bare metal I filled a couple of the casting imperfections.

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