RFQ Response Etiquette, (The Man In A Shed) vs (The Commercial Operator)

[corkcnc]

So £97 total...

If you want it done by the end of the week for £35 including postage, let me know and I'll get my friend to cut it on this machine from 25.4mm (1") thick aluminium.

Not here to argue but I wouldn't leave a part out the door for a machine without skimming both sides so when the part is repositioned for the drilling, that the edge face is perfectly square to flat face and all the imperfections left from when the stock was rolled are eliminated. These things all take time to get right and hence the 24mm width too.
You can argue in this case that the bore and edge are in the same plane so the angle between the flat face and bore doesn't matter a fig but if there are holes going in the side and even if they are clearance holes, I'd still rather do it spot on for when it is repositioned.
I can't comment on your mates work, I'm sure he's a damn fine machinist but I've seen too many things end up on my desk after jobs by people who have ignored the small stuff and it results in spindles misaligned and tapers on edges. Hence I'll stick to my ways and even if the skimming, clamping and clocking takes extra time, I know what goes out the door is good. If something gets past me, I know it's my fault and replace a part immediately.
I must stress that this isn't a dig at you Jonathon, I have read a lot of your posts and have a lot of respect for you - you know your stuff. But this is how I operate unless a customer requests that cost is the major factor.
Rgds,
Noel.

[Jonathan]

I hear what you're saying regarding maching the faces square, however I've rarely seen people mount things that require such accuracy to the spindle mount, so didn't include it in the price. Since the bed of the machine is machined/set to be in the same plane as the machine X&Y axes, then the only inaccuracy introduced would be due to the (lack of) flatness of the material, so the top of the part would be further from square than the other side. However if the customer required greater accuracy, then I would happily add £6 to the price and skim it accurately.

When I make spindle mounts in two parts, such as those for the 80mm spindle, I use the surface plate and height gauge to measure the center height of each mount to ensure they're both within 0.01mm of each other. This is also one of the reasons why the rotating ballnut mounts I've made take a long time to machine - it's important to ensure the shaft is parallel to the mounting face(s), which necessitates careful consideration of the machining order, and accurate alignment...then someone mounts it on bits of welded box section and it's a bit demoralizing!

Anyway, the reason my friend and I can afford to machine this so cheaply is lack of overheads. I just do this to fund my hobby, which is having a workshop. I therefore only charge up to £10/hour and add the cost of materials and postage. If the part is particularly interesting (i.e. complicated, like this one) to machine I charge less per hour. So for the spindle mount, it's about 2.5 hours work plus £5 for the material (@£5.50/kg) and £4 for postage, so 2.5*10+5+4=£34 so I rounded up to £35. I don't charge for CAD as it generally only takes a few minutes and I can do it any time.
If I had to pay rent on the workshop and was doing this as a business, then yes I expect I would have to increase the hourly rate, however at least with having made the machine(s) myself I'm not having to charge lots to pay for the machine.