MDF is indeed very nasty! Still you now have nice straight edges parallel to you X and Y axes to line workpieces up against.
Alex

 

First - check that your X axis is truly perpendicular to your spoiler board then, yes, shims.
Alex

 

Your first project better be something nice for the wife... if she ever sees this thread.........

 

Go get Fusion 360, it's free for non commercial and hobby use

 

Colin, you must Tag in the parts, otherwise they will fly
Also, have you profiled the outside correctly, they appear to be too thin, maybe you have profiled the inside of the shape?

 

I'm using "Silverline" router bits from Toolstation - they are definitely at the "value" end of the market. Screwfix don't do anything as cheap - their equivalent would probably be their "Erbauer" range. I figured while I am learning, and the jobs I am doing are really "practice pieces" a quality bit would be wasted. If I need a bit less than 3mm I use some cheap end mills from China via Ebay. I also have some "V" engraving bits from the same source.
Alex.

 

I use Trend S55/2X1/4STC Spiral Up-Cut Cutter 6.35mm Diameter which are very pricey but last and cut well.
Still not sure if you are cutting the correct size part, are you copying the original P-clamp design that you linked, or have you modified it? It seems to me that you may have no tool offset, in the profile command of vcarve you should select the "Outside..." option, the "On" option, puts the tool centre on the vector without offset.

 

Yep, I am not familiar with V-carve, but looking at your two pictures the toolpath is centred on the outline of your parts.
Alex.

 

Looks good now Colin, I was initially concerned that the hole for the captive nut was closer to the outside profle than in the model

In Oak, this would have probably split.
Agree with er indoors, cheap Chinese cutters can be a false economy, the clue is in the price, but I have found some very good quality tapered ball-ended cutters for 3d work from China, 6pc R0.25-R2.0 HRC55 2F Tapered Ball Nose Endmill CNC Router Bit Milling Cutter | eBay
Good luck with your first cuts. Geoff

 

Hmmm...
You're paying £14.75 for a bit capable of machining aluminium or brass. I'm paying £1.78 for a bit that will be fine cutting plywood. (and I won't cry if I do something really stupid and break it)
Alex.

 

Also profile of cutting edge is different for various materials - what works best in a hard material is unlikely to work well in a soft one - fibrous materials (wood) behave differently to crystalline ones. Using a tool designed for hard materials on a soft one will blunt it a lot quicker than using it on the material it was designed for.
Alex.

 

Alex, my Routing experience is mainly cutting hard Oak and other Hardwoods Images and from my experience I know that I wouldn't get that far into a job with a HSS £1.78 cutter. In the end it depends what material you are machining and the complexity and finish required, but solid carbide cutters does it for me. Not sure about the Ooznest cutters, haven't used them, but the spec looks correct. Unfortunately I have a box full of cheap HSS cutters that have dulled in minutes of use.

 

I use a local (to me in Manchester UK) company for my endmills.

Really helpful, and good quality (And they have some of the more obscure ones i needed such as a 5mm twin flute upcut end mill with a 22mm cut depth on a 6mm shank

cncpoorboy_toolstore | eBay Stores

GBR Engineering Services Ltd

 

Compared to, say, purpleheart, oak is not particularly hard on cutters. I can't comment on HSS cutters value for money - haven't seen any on sale for years - the cheap cutters I use are carbide. HSS tools do take a sharper edge than is possible with carbide (carbide keeps the edge you do get for longer) so can give a better finish especially in relatively open grain timber like oak. My main point for beginners (at cnc - I have over 50 years experience of working wood) like me and @Colin Mccourt is that cheap bits are expendable for starting with.
Alex.

 

PS; I think toolstation.com (where I get my cheap router bits from) will deliver to Northern Ireland even though they don't have a store there - will probably take a few days though.
Alex.
PS free delivery if you order £10 worth of stuff.