Dremel grinding burrs

Jay Jay

https://www.cratex.com I have solved the melting plastic dilemma by using these cone shaped abrasives. They work especially good on removing pin marks with the Dremel.

 

I find it helps to keep the tools wet.  I even do this on hand tools like those PE razor saws.  They have a lot of friction due to limited tooth offset, so keeping the blade wet with water cools the area and prevents sticking and melting.

KyleBragger

Is anyone aware of any Dremel compatible grinding burrs which are higher grits? I find burrs useful for removing ejector pin marks, both holes and raised, but the lower grit burrs tend to leave way too rough of a finish. Ideally something that will grind/sand but is also high enough grit where the resulting area isn't chopped up.

 

If you have Facebook look up “Hobby Elements”. This is a guy in Hong Kong that makes and sells some really useful and unique tools. Among them are sets of bits you put into your favorite hand-held rotary tool that makes short work of the tedious jobs you mention. I have them and really like them. I know he ships globally and I imagine shipping costs are quite reasonable. 

i've been using my external speed control on my non-varible speed dremel for over 40yrs.

Welcome back JJ. Good to see you posting again.

I use sanding sticks for sanding and the Dremel is used set at low speed for removing lots of plastic like thinning the inside of a U   Boat‘s hull to open up flood holes. The metal burs are sometime usefull to remove molded detail but the final clean up is done with sanding sticks.

If anyone has a non speed adjustable Dremel then go to Harbor Freight and get a plug in speed adapter for about $8. I use it for my old 40 year old Dremel and works just fine.

JohnnyK

The problem with a Dremel is that it runs too fast for styrene. It tends to melt the plastic. It would be a useful tool if it ran really slow.

 

Not if you get the right Dremel tool. I got this for Christmas:

https://www.lowes.com/pd/Dremel-Stylo-15-Piece-Variable-Speed-Corded-Crafting-Rotary-Tool-Kit/1000386553

It does come in variable speeds. The lowest speed is 1 - you couldn't even melt the styrene in that setting.

And another option to consider is a rotary saw blade. I love the thing. It cuts through plastic like butter, and it gives a really clean cut. Also, I don't have the issue of melting plastic building up on the blade. If you have a steady hand you can cut the burrs pretty darn close to the base of the piece. Then, I follow up with a sanding stick. This cutter has really enhanced my workflow. 

One caution though, this blade is no joke. It will cut you bad if you are not careful.

https://contenti.com/busch-rotary-saws

KyleBragger

Thanks for both replies.

I have a variable speed model that runs quite slowly at the lowest setting.

I'm open to any type of material for the grinder; I just need something that is probably equivalent to something closer to 600+ grit. Everything I'm seeing is under 300. The problem is that I don't know what to search for, etc.

 

Well, I have these in 300 and 600.

https://www.amazon.com/SE-8230DD60-30-Piece-Assorted-Diamond/dp/B003K2E7CM/ref=pd_lpo_vtph_469_bs_lp_img_1?_encoding=UTF8&psc=1&refRID=4SQEGJ3DTB5XAQA61GV7

But even the 600 leaves a rough finish. I use this Dremel; it lets me use a lighter touch.

https://www.dremel.com/en_US/products/-/show-product/tools/2050-stylo-versatile-craft-tool

I can sometimes smooth with these:

https://www.megahobby.com/products/micro-sanders-tapered-straight-supports-3ea-photo-etch-for-micro-sander-grits-45-rb-productions.html

I'm able to bend the tips.

Hope this helps.

Dave

My battery Dremel just ticks over on its slowest setting, so it works fine on styrene.  I also like the grinding stones rather than the metal burrs.  I just wish they would make some in smaller radius, like the burrs.

along the line's of what mrmike said . these spin at a very low rate . extra good on plastic too .

www.ebay.com/p/Tamiya-74041-Craft-Tools-Electric-Handy-Drill-Japan/1801604508?iid=141738945159

Not to stray too far from your original question, but I have to ask why a Dremel would be the tool of choice for fine sanding? I've used them for a lot of tasks and find they are very good for metal roughing and polishing, but too aggresive for plastic finishing even at low speed.

My personal choices for the smaller confines are the excellent small diameter sanding sticks made by Flex-i-file followed by fine grades of wet & dry sandpaper wrapped around profiles which match the contour I'm trying to achieve. Yes, it's done by hand. The good part is that it takes time and allows me to "sneak up" on the profile without having to backfill damage from mechanical tools like Dremels and coarse files.

Hope something I've said helps you and Happy New Year!

Mike

Considering how easily plastic can be scratched, that’s a high bar to meet. 

Not fully, no... just like sanding it will mar the surface... progressively finer sanding sticks afterwards can buff it out if they fit...

I use the spherical type in the center bottom row on my tool’s lowest speed setting for such work.

Thanks for both replies.

I have a variable speed model that runs quite slowly at the lowest setting.

I'm open to any type of material for the grinder; I just need something that is probably equivalent to something closer to 600+ grit. Everything I'm seeing is under 300. The problem is that I don't know what to search for, etc.

The problem with a Dremel is that it runs too fast for styrene. It tends to melt the plastic. It would be a useful tool if it ran really slow.

How about an abrasive stone (grinding, what we'd call it in a machine shop) bit? Those burrs (oddly named, IMO) are pretty aggressive for styrene, IMO.

Edit: I think my comment is bad advise. In decades of off and on modeling, I've never used a dremel for much of anything. I find them too aggressive.