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.

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 "

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 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

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

That's just showing off!!!

Brian

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

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.

As I see it, spares are required for commercial enterprises. If my machine breaks, I stop the job in hand and fix it.

If it’s a belt I go to ABC, the same outlet as Howard (but a few miles further away from me). If it were a feed-train gear, I would set about making a replacement on another machine. I would make a new shear pin if one failed.

I might break a drill bit, so do have a whole pile of sundry bits that I can search for a substitute (usually go to the stubby drills or precision sets which are not used as often). End mills are generally duplicated in common sizes, but one usually uses a size which can be substituted by a smaller diameter

I know when lead or feed screw nuts are nearing the end of life, so take appropriate action – usually make one.

We are supposed to be able to get over/around these hiccups as machinists/engineers/shade tree mechanics/etc.

So where is there a need, for us, to stock machine spare parts? YMMV.

It’s lucky we are our own accountants, we had a press line at work with two British Clearing presses included in a 5 press line, a critical component was the Torc PAC clutch and brake unit which was quite a lot of money, £110,000 at 1980 prices. As the lead time for a new one was 6 weeks or more a spare was purchased and of course sat in the stores for some years without being used. The stores department policy of deleting and scrapping items that sit around too long meant they wanted to throw it out, it eventually was withdrawn from the stores and lived in various maintenance areas until the line was moved to another plant. It makes no sense to me to dispose of a vital component you might need with no chance of sourcing a replacement in a short time and you have paid for it but I am not an accountant.

Mike