Spares stock...

How much spares stock do you keep?

Being from a maintenace background, I know I'm want to essentially have a new machine on the shelf, but seing as I'm only going to be a hobby user, to start anyway, thats somewhat impractical...

What are peoples thoughts on must have spares? I'm assuming a full set of bearings, belts and some shim stock are a no brainer. What other common failpoints are there to consider? Perhaps turning a set of pulleys as a first job? 

J

Edited By Jay Nugent 1 on 20/11/2020 09:04:40

Edited By Jay Nugent 1 on 20/11/2020 09:05:16

I'm also from a maintenance background, but for a hobby use machine I would only keep spares that have a short life - less than a year and would be difficult to get in a reasonable time scale (within two weeks). Bearings on a lightly used hobby lathe can be expected to last 10 years plus, belts more than 5 years. Would you really want to keep money sitting on a shelf in spares that you will be unlikely to use, and by the time you do need them would probably have aged.

Of if you live on a ship in the middle of the ocean depending on a working machine then a full set of parts and a spare machine would be essential.

How much spares stock do you keep?

None.

My machinery is lightly used & I do nothing of desparate importance on it, so having to wait a couple of days for a spare part would not be a problem for me. I can think of better ways to invest my savings than having parts on a shelf getting older that may well not be required anyway.

The only qualification I would add is that I tend to go through any new-to-me machines when they arrive and give them a good fettling. That often includes fitting replacement drive belts, as 30-40 year old rubber belts can be past their best. I have not yet had to replace one of these replacements (in over 20 years in the S7's case), so had I bought a spare pair at the same time I fettled the machine they would have aged hardened by now in storage & would likely not be viable replacements should the need arise.

Handy to have consumables like slideway & headstock oils to hand but, again, I'm still working my way through a 5 litre can of slideway oil that must be 20 years old. Might have to buy another can in a couple of years, though.

I now apply the same rationale to tooling & measuring equipment acquisitions - buy what you need when you need it. Most of the stuff I bought speculitvely when I started out setting up a home workshop has not seen much use (non in many cases), yet I often get stopped by not having some bit of tooling I hadn't considered.

Nigel B.

As a Myford owner I keep a spare set of the Tufnol gears from the gear train as it is a showstopper if I break them, I also have a spare set of Tufnol gears for my Meddings drill as I saw a set for a price that couldn’t be refused. Belts and bearings are mostly readily available so l leave them on the suppliers shelf rather than mine. V belts I feel do not have a long shelf life so I would get one in when I notice the ones on the machine are deteriorating and as my machines have manual speed changing the belts are seen quite often so I should get a heads up that replacement time is coming. In our highly automated factory downtime was expensive so spares holding was comprehensive, complete robots and control panel were available and repaired off the machine in a maintenance department. Weld guns and grippers were all ready for a quick change and a whole department rebuilt and calibrated the guns and grippers. The guns were exchanged on a planned schedule but unplanned events could need a change. Myford and Meddings still have spares support for my lathe drill and I hope Warco could assist with my mill, I doubt that spares for my Rapidor saw are available but it’s built like a brick outhouse. Downtime is not a great concern in my home workshop so I carry very little in the way of spares. I think the items most likely to fail on my machines are the VFDs I have fitted but a replacement is probably only 24 hours away and storing them long term has its problems like reconditioning the capacitors or powering up the spare regularly to keep the caps healthy. Even bearings dislike being stored for a long time.
Mike

I dont keep spares. How do I know what I,m going to break ?

At the same time, I did have to buy a drive belt for my lathe last year, when it frayed.

I was both surprised and disappointed at this, since I only got 20 years from it. !

Must have been a cheap Chinese junk one !!!

Really, it,s not worth keeping a stack of spares because you can bet you wont have the one you need when the time comes. This is known as "Sods Law "

Almost none for the machines themselves, though it does depend on what might break!

My DC motored mini-lathe came with spare brushes, which I never got close to needing. I replaced a belt and internal 2-speed gear after a head-crash, and bought a spare belt: never needed.

No spares carried for my milling machine and lathe. Certainly not bearings. I've kept an eye on the belts but no sign of wear yet. (Maladjusted belts wear out quickly, and it might be easier to change a belt than to fiddle with alignments.)

I have a 4-way tool-post and have a stock of shims for that. Likewise odd lumps of wood and metal blocks for ad-hoc holding etc

Consumables yes. Spare band-saw blade, common twist drill sizes, carbide inserts, emery paper, super-glue, oils, acetone, meths, nuts and bolts, etc etc. Aluminium, Brass, Black & Bright Mild Steel, Silver Steel in various shapes and sizes. Some plastics.

Metal is expensive and takes up space. Rather than order one of everything I buy what's needed for a job, plus extra if there's any chance it will be useful in future. I've gradually built up a limited range of the stock sizes I use most. It all has to fit in a single-garage sized workshop, which isn't quite big enough.

Metric vs imperial is a consideration. Not possible to entirely avoid working in both, but majoring in one or the other reduces the amount of 'stuff' and tools needed. Choice depends on what the workshop is for, Imperial for building steam locos to traditional plans and mending old equipment , otherwise Metric for general-purpose and modern modelling. Another good reason for Imperial is an inherited workshop, or lack of familiarity with Metric measure.

Re spares, how many are carried is usually determined by the cost of machine down time. In a professional setting, it's often worth keeping spares and and engineer on hand: a balance between cost, profit and time. Hobby work is rarely profitable and operator time is 'free' so the calculation produces a different answer. Your choice: spend big money on a full set of machine spares so you can fix kit quickly, or spend money only when the machine demands maintenamce. Just as well lightly loaded and sympathetically operated hobby machines last for donkey's years, because hobbyists are downright mean when it comes to spending money!

Dave

For the Myford I have temporary link belts, Tufnol gears and a few spare bolts including change gear stud. Written down what the belts are, but not holding any for other machines. Spare brushes for one of the mills DC Motor and spare Electronics chip for the CNC pulse generator . The rest more consumable than spares. Spare saw blades for bandsaw. Spare cup wheel for grinder. These latter items, like the chips and cups the carriage was more than the part so double up when last needed.

I don't keep any spares for machines on the grounds that I don't know what I'll need in the event of a breakdown. There is also the possibility that I might sell a machine and buy something else, I thinking here in terms of selling a manual machine and replacing it with CNC.

Brian

I don't keep much spare stock for my machines; only fuses and spare belts since it takes some time to get them. On my oldest lathe I have had to replace the V-belt. My hobby machines aren't used that much so I don't keep spare bearings. Like Dave I do have some spare hacksaw blades and twist drills etc. but they are consumables and I never know when I'm going to break a twist drill.

Thor

Just a belt each for the mill and lathe.

Metal stock is my weakness, I tend to buy full bar lengths of the most popular sizes I need. I hate having to wait to start a job or machine down to size from a bigger section.

I'm not sure I'd count that as a weakness. Looking at the prices on eBay etc. for tiny lengths of material where you have to believe the seller's description of the spec. It's often possible to buy a full length from a stockholder for not much more money. But of course, there is the issue of the space to store it....

On the issue of spare parts, if they're not perishable and the price is right, then spares on the shelf are better than money in the bank earning 0.1 or such percent interest IMO.

Edited By Stueeee on 20/11/2020 11:21:08

I can still spend that idle money, but can’t (usually) pay with a spare drive belt or similar.🙂

Spares for the machines - none.

I do however have several spare lathes and a spare mill

David.

That's just showing off!!!

Brian

I need a spare me, this one is worn out

A well designed machine should have a long time to failure of the components, even our hobby machines, from new. Yes, there will be some "Friday afternoon" machines, but they should be a small percentage of the population, and usually come to light early on, to be repaired or replaced.

Older, ex industry machines are more likely to need spares since they will have been driven hard for many years. possibly being disposed of, shortly before when they are expected to fail / suffer severe wear.

After my RF 25 shredded the primary belt within 6 months from new, I bought a new belt and a spare, before realigning the motor..

This is still unused,, and the secondary belt is functioning satisfactorily, over 20 years later!

The lathe is 17 years old, and the belts are still OK, as is the belt on the Bandsaw.

The only other machine spare carried is oil and the cans with which to apply it.

Until the lamp was slightly modified, the worklight on the lathe used to eat the 24V 50W halogen bulbs, so there are some in stock, since there seems to be no local stockist..

There is a bearing and belt stockist within a couple of miles, so spares are easily available.

There are some duplicate Drills, Taps and Dies in stock.

material is held in stock, on "Come in handy, one day" basis Needless to say not always the size this is immediately required, so either a design change or extra swarf!

Many versions of the mini lathe use plastic gears. Currently, spares are available, either in plastic or in metal.

Bearings are changed more as an upgrade, rather than through failure, I suspect

The problem in carrying machine spares is knowing which parts are going to fail, and that knowledge comes to us in learning what failures others have had.

So, with a new machine, there is probably minimal need for machine spares, except possibly for known vulnerabilities, such as Tufnol gears. As hobbyists, rather than needing to use machines as a source of income, a stoppage is an annoyance rather than a desperate need. It can cause problems with older machines.

A friend has an elderly Chinese machine. An oil seal has failed, replacements were quoted as six months lead time. Our solution is to make a replacement housing, so that easily available standard bearings and oil seal can be used. These are the sort of actions that old machines require if they are to kept going.

Howard

A couple of items I've needed on my lathe an milling machine are the glass fuses and had to get some carbon brushes for the milling machine.

Maybe some touch-up paint if you like to keep your machines tidy and any consumables like 'way' oil and general lubrication oil and/or grease.

Lamps(bulbs) for any lighting used around the machines.

Ed.

Spares for the machines I bought new, and use occasionally for hobby work? None.

Both my work and storage space is limited, and I do have lots of tools.

That storage space is used for useful consumables: a range of fastener types/sizes for my work(M4/5/6/8&10), extra cutting tips/blanks, tap&dies, and a small quantity of metal stock in sizes that might cover unplanned jobs - turning down a common, larger size down for a single small part saves having lots of different sizes, Planned jobs I buy whatever is needed plus a bit extra if it has previously proved to be a useful size.

I have had the Myford for ten years, from new, and it is used four or five afternoons a week on generally light work. It has never unexpectedly stopped. Nothing has been replaced on it but I do have a spare wiper and a second set of tumbler gears since I think the ones fitted are now slightly damaged. The original Myford set of collets, about 20 years old, have just been retired otherwise tooling is been bought but not replaced.

The Wabeco milling machine was new 15 years ago and again has been utterly reliable. It gets a little bit more use than the lathe since it is used for general drilling,

I think both machines are getting slightly noisy but this may be my imagination.

I do not consider cutting tools, lubricants and material stock as spares. Lubricants are always bought in good time. That is one thing I do not want to run out of.

JA

My 1000th posting.

Edited By JA on 20/11/2020 13:37:53