DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

First, determine the desired bore size. Find a hole saw thats as close as possible in OD to the cylinder skirt of your new kit.

Then, find a hole saw that has an ID thats the same as the ID of your cases. Use that hole saw to drill out a plug that will fit snugly into the cases to support the pilot bit of the hole saw. Use the hardest wood or plastic you can get to help the pilot hole last longer, this will help everything get started more smoothly.

Pop your plug into the cases. Then, take your hole saw that's the OD of your skirts and get drilling. You can do this with a hand drill, but a drill press would make things more foolproof.

Use high quality hole saws if you can, they will run much more true and will help things go smoothly.

20200510_102752.jpg
20200510_125641.jpg
20200510_125847.jpg

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /
20200510_130650.jpg

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

As you can see, it started a bit rough, and I got a little close to the stud holes. I ended up adding just a little material with alumiweld, and it will seal just fine. Went way faster than the drum sander method, and once you get it started it goes very quickly. Actual drilling time was just 2-3 minutes with stops included to clear chips and add lube. I'll still need to go in there with the dremel and carbides to clean up.

Re: DIY Case boring for large kits

Bravo Sir!

Not exactly what I expected I wonder how much a machine shop would charge for this ? Versus your pricing structure

Re: DIY Case boring for large kits

Dirty30 Dillon /

Excellent work and good innovative application.

Standard hole saws are HSS tips so they def chew through alu pretty fast.

Re: DIY Case boring for large kits

The weird thing about one of my engines is th the case was already bored. The sprocket was already bigger but it still had restrictions.

Re: DIY Case boring for large kits

Dirty30 Dillon /

> kenny s Wrote:

> -------------------------------------------------------

> The weird thing about one of my engines is th the case was already

> bored. The sprocket was already bigger but it still had restrictions.

Having a larger bore has nothing to do with sprocket size or restrictions.

Re: DIY Case boring for large kits

good one

Re: DIY Case boring for large kits

What did you use to clamp the engine to the drill press? Or did you do this with a hand drill?

I dont think my table drill press will be tall enough to do this, but I really like the idea!

Re: DIY Case boring for large kits

Use a flap wheel instead

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

> Jay Rivett Wrote:

> -------------------------------------------------------

> What did you use to clamp the engine to the drill press? Or did you do

> this with a hand drill?

>

> I dont think my table drill press will be tall enough to do this, but I

> really like the idea!

I did this with a hand drill, but Graham had the idea to turn a drill press table 90 degrees, clamp to it, and swivel it so it lines up with the chuck

Re: DIY Case boring for large kits

I’m with Alex here. This seems like a whole lot more unnecessary effort with a lot more risk of fucking up your cases than just getting an oversized flap wheel and running it and checking until your kit fits into the bore.

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

> Denis Kozlowski Wrote:

> -------------------------------------------------------

> I’m with Alex here. This seems like a whole lot more unnecessary effort

> with a lot more risk of fucking up your cases than just getting an

> oversized flap wheel and running it and checking until your kit fits

> into the bore.

If you want to spend a few hours hunched over your cases with a hand drill just boring them out, thats fine. I've done that, hated it. Too tedious and time consuming. This isn't a contest really, just an alternative method that works really well and is no more likely to ruin things if you take the time and prepare and use quality tools

Re: DIY Case boring for large kits

If it takes you hours to open up aluminum cases with a flap wheel you’re doing it wrong

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

> Denis Kozlowski Wrote:

> -------------------------------------------------------

> If it takes you hours to open up aluminum cases with a flap wheel you’re

> doing it wrong

What flap wheel are you using?

For most moped kits, you usually only need to bore cases by 2 or 3mm. This set of cases pictured needed to be bored by 8mm.

Re: DIY Case boring for large kits

> Denis Kozlowski Wrote:

> -------------------------------------------------------

> If it takes you hours to open up aluminum cases with a flap wheel you’re

> doing it wrong

Psssshh I dont even know what a flap wheel is. Ha!

Re: DIY Case boring for large kits

shut up nerds.

this + flap wheel clean up is definitely the cleanest way to bore that much without a rotary table mill. good idea.

Re: DIY Case boring for large kits

Dirty30 Dillon /

> Dave & Bummerzz Wrote:

> -------------------------------------------------------

> this + flap wheel clean up is definitely the cleanest way to bore that

> much without a rotary table mill. good idea.

100% a centered, rigid cutting tool is giving a better, more perpendicular bore than you're gettign with a flap wheel.

Brandon and I were chatting and I would def do this, but replace the drill bit in the hole saw with a smooth rod chucked in there, and wax the shit out of the shaft hole.

I also think this worked so well because Brandon was removing so much material.

I'd be interested to see if thin kerf hole saws are a thing?

Re: DIY Case boring for large kits

Photo of finished cases? I like this

Re: DIY Case boring for large kits

I saw Charlie Buzzard do a similar thing like 10 years ago in their Sumter shop. He had a 2x4 bolted to the cases with a hole in the middle to center the hole saw. It took maybe 2 minutes and it was done.

I really hate the flap wheel method for anything more than a little material.

This is like a faster/cheaper version of the Malossi case bore tool.

Re: DIY Case boring for large kits

🇮🇹💦 Of the Loin /

this is a really neat idea, I like that the tech is getting more advanced

I still prefer the ole "use a dremel and a tungsten carbide bit and maybe gouge your hand once" method.

If you hit your hand in that web between the thumb and first finger, you generally dont bleed much, especially if its the flat tipped bit

Re: DIY Case boring for large kits

> Dirty30 Dillon Wrote:

> -------------------------------------------------------

> wax the shit out of the shaft hole.

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

> Ben Whittle Wrote:

> -------------------------------------------------------

> Photo of finished cases? I like this

I'll get some, but they aren't going to be pretty :/ As mentioned above, I dint have the greatest start with it and I got a little close to some of the stud holes, so i added a little material with some alumiweld and some JB...it happened because my pilot hole was egg shaped from the drill bit not running true, and the hole saw not being true either...it was a cheap $8 set from harbor freight so that sums that up haha. Done with a high quality set and using Dillon's idea with a smooth shaft for the pilot instead of a drill bit, and a drill press jigged up, you'd get way better results im sure

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

I think I have some junk e50 cases laying around, i'll give it a shot with the drill press if I can jig it up.

Re: DIY Case boring for large kits

High speed and slower progression will also help keep the bore true .

Re: DIY Case boring for large kits

Just make a wooden buck with the hole saw diameter already in it that also has the cylinder bolt holes in it, bolt it to the cases and use that to start the hole.

No walking holesaw that way.

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

> Joel P Wrote:

> -------------------------------------------------------

> Just make a wooden buck with the hole saw diameter already in it that

> also has the cylinder bolt holes in it, bolt it to the cases and use

> that to start the hole.

>

> No walking holesaw that way.

That's a GREAT idea, can't believe I didn't think of it!

Another possible method I was thinking about, although maybe too risky, is using a palm router with a template bit and a template with your desired bore, and you can slowly eat away at it. You can use them on aluminum, but you need to be careful with feed rates, too fast and it can grab.

Re: DIY Case boring for large kits

> Brandon Weiss (Detective brandon to you) Wrote:

> -------------------------------------------------------

> I did this with a hand drill, but Graham had the idea to turn a drill

> press table 90 degrees, clamp to it, and swivel it so it lines up with

> the chuck

Since someone with enough brain cells to comprehend, is actually paying attention, I'll set l one up and take a picture and post it, it works great. For a straight vertical plunge cut it's every bit as stable as a mill.

The discussion on FB, I was not picturing someone removing so much material, that's wild! Definitely worth the hole saw. I've also bought myself some real nice hole saws recently and they are way way way better than shitty ones.

Re: DIY Case boring for large kits

Brandon Weiss (Detective brandon to you) /

> Graham Motzing Wrote:

> -------------------------------------------------------

> > Brandon Weiss (Detective brandon to you) Wrote:

>

> > -------------------------------------------------------

>

> > I did this with a hand drill, but Graham had the idea to turn a drill

>

> > press table 90 degrees, clamp to it, and swivel it so it lines up with

>

> > the chuck

>

> Since someone with enough brain cells to comprehend, is actually paying

> attention, I'll set l one up and take a picture and post it, it works

> great. For a straight vertical plunge cut it's every bit as stable as a

> mill.

>

> The discussion on FB, I was not picturing someone removing so much

> material, that's wild! Definitely worth the hole saw. I've also bought

> myself some real nice hole saws recently and they are way way way better

> than shitty ones.

Looking forward to seeing it! I wonder if my little 10" craftsman can hold it. I'm in the market for a 12" machine though.

Re: DIY Case boring for large kits

Kevin Bishop /

Go in reverse first and the cut will be smoother. Then switch to forward once you are an 1/8” deep.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account