Hand-held router on G10?

Hello,

I'm machining a mast step out of G10 for my friends boat. At work I have access to a Matsuura CNC mill with a 10k spindle, however, it is not very insulated. I know G10 likes high RPM, and 10k is alright, but I get the impression that faster would be better. I'm also worried about getting dust into the machine and the rest of the shop, as I've mentioned, it's not enclosed well. Even with a vac I expect it would get messy fast. We have been working with MDF in this manner recently and there is a light dusting everywhere.

My question is how practical would it would be to use my 20k spindle handheld router in an glovebox-like enclosure? I figure I could make a template to clamp to the 2" thick G10. My thought is if I get the right tooling (hopefully with a guide bearing) this would be a fairly strait forward project. I'm not sure if I could get a G10 endmill with that bearing though. So unless anyone knows some magical tool just for this use, I'd probably be stuck with something like in the link below, or I'd have to get a legit composite endmill and use the shank as the guide. Keep in mind this is a one-piece for my friend. I've included a picture of my design. I'd appreciate any constructive responses you might have. Thanks.

CMT 812.691.11B Pattern Bit with Bearing, 1/2-Inch Shank, 3/4-Inch Diameter, Carbide-Tipped - Straight Router Bits - Amazon.com

I've done plenty of G10 and G11. My two cents - 1/2" carbide endmill, two flute, around 3000rpm, aggressive feed, shop vac in the Matsuura using HEPA cartridge filter and a drywall dust bag.

Takes some force to cut the epoxy/glass laminate, I would not want to use a router for this large a part. Low RPM to keep from abrading the (coated) endmill, heavy feed to minimize wear. You should wear a good respirator mask while machining it, getting any of the dust into your lungs isn't great for you.

Change out the endmill when it gets truly dull, but they'll still cut with a little wear land. If you want to save money use 3/8" cutters, I don't think I'd go smaller than that for this job.

I machine a *lot* of G10 on my VMC. No enclosure on my machine, I have a vacuum system hooked up right next to the spindle. 99% of the light dust gets pulled right into the vacuum, and the heavy chips just fall like metal chips would.

Use standard 4 flute TiAIN coated carbide tooling in whatever size you like, heavy chipload as Milland suggested. Overall work to keep spindle speed down and chipload reasonably high. When profiling my handle scales I run a 3/8" 4 flute endmill at 3500RPM and 50IPM (chipload 0.0035").

Honestly it's pretty unlikely you'll have issues. G10 machines nicely and unless your tooling is really dull or your speeds/feeds way off you'll probably have an easy time of it.

I agree, that in G10 (or similar) with a hand held router would not be fun, as has been said it takes some cutting, so with say a 3/8 cutter, you'd be looking at a max of 0.1 '' DOC, - because of being able to push the cutter through the material,....unless of course you're man mountain who wrestles gators for light amusement.

Which will mean you will get through a fair few cutters, and probably have one hell of a job getting a chatter free etc etc finish on the walls of the cut.

Oh, and you might have problems getting the spindle to go slow enough, most - if not all plastics need a high feed rate, .....go too slow and you'' melt the material and ruin cutters.

Just my 2 cents - YMMV.

Very little worry of the material melting with G10 (unlike other 'plastics'). You can push your spindle speed pretty high if you want to, just have to have the feedrate to keep up with it. A lot like machining wood.

Onsrud makes some really nice router bits for that stuff. Ya gotta make a chip! Make lighter cuts with dust and cutter life goes into the toilet real fast. Feeding with a hand held router can be done, but tool life will be crap.

What boat / mast is the step for? Many spar manufacturers use a male plug style shaped to the extrusion section. This is glued and fastened to a flat plate with your bolt pattern/ slots which secure it to the boat and give adjustment in location. Basically the inverse of your modeled step.
This is very common and also pretty easy to make. I have seen many made with a bandsaw running a carbide grit blade and finished on a disk sander to fit the mast section. Then a few drilled and tapped fasteners from the underside in a flat plate and adhesive. Two piece mast step. Think funny shaped top hat.
Looking at the design currently, the internal step looks like a smaller 25-28’ boat? Check RigRite on the east coast . They have loads of OEM spar manufacturer cast aluminum mast steps.

Mattkarhan, I'll check with my friend, I have forgotten what specific boat it is. It is indeed a 30 ft mono hull. Interesting fact about the male versions, I've only seen the female type myself. Thanks for the feedback folks, really appreciated. I'll go ahead with the vac and safety gear. I was a bit surprised about the recomended spindle speed, but the aggressive cut to to improve tool life makes sense. One more question for you folks though is what tool DOC vs. cutter diameter would you do? I'd probably stick to 20% step over at 2X diameter.

You're making one part and no one is inspecting it. Keep your life simple, manageable rpm for the dust and feed appropriately. Machined plenty of boat parts out of G10 on a Bridgeport at 800rpm, it's just a boat part.

That makes me feel much better.