SELF-EJECTING DRAWBAR - Optimum MB4

! Morsetaper can be a pita to remove from the spindle, so i came up with this simple drawbar, which automatically ejects the tool, and you don't need to whack it with a hammer like crazy.
00:00 - The problem
00:12 - the washer
00:38 - the solution in theory
01:20 - washer machining
01:57 - the drawbar
03:19 - the hex head nut
03:56 - the oopsie...
05:48 - installment
the fusion drawing: www.dropbox.com/s/tty1sva1a0g...
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[@markjmaxwell9819]

Loved the old Bridgeport milling machines they were well built and well designed.

[@RustyInventions-wz6ir]

Very nice work. Clever idea

[@stylianos4570]

Thank you for your video! I made the same modification inspired by you! Thanks again for the idea!

[@ProfSimonHolland]

excellent work....great idea

[@arjundas708]

Excellent sir am facing the same problem, nice solution to make, thanks a lot

[@seanwolfe9321]

Very Nice! I have been considering how to do this with my Precision Matthews pm727m, this looks to be very similar. I can see where the length below in taper area is crucial, thanks for the heads up!

[@anmafab]

Nice video Christoph. I haven't seen this done before although saying that most of the KZbinrs i watch have the r8 system. Any reason why this might not be a good idea? Looking forward to the gear hobbing vid ;)

[@ChristophLehner]

Thanks for the comment andreas! Since R8 should release the tool, nobody really needs it. Some older german mills with morsetaper spindle had this kind of drawbar straight from the factory. I am afraid, the gear video will take a while, since i want to build a diesel furnace first :)

[@anmafab]

@@ChristophLehner good info. Doesn't look like a super complex mod. Is this a prerequisite to a power drawbar for an mt spindle? A diesel furnace sounds like a big project!

[@ChristophLehner]

You got me. The butterfly impact wrench is already on its way :) Yeah it's also quite expensive, but i want to get into castiron

[@HM-Projects]

@@ChristophLehner The Chinese Sieg mills have this feature as well but even with that I have to be careful to not over tighten or the MT3 taper tooling is a bit hard to dislodge.

[@billfisher7644]

I am keen to make the same modification to my Cormak ZX7045 and tried to link to the fusion drawing without success. Is there any other way I can gain access to it? Looks like a great mod though.

[@incubatork]

I have an HBM BF28 milling machine, the tool eject system it uses for the MT3 collets is almost the same but is to my mind very weak. The nut is a small 3/8 size square milled in the shaft made so it can pass through the eject collar from the top and unscrewing them both from the mill. I was looking for a way to beef things up a bit, more for peace of mind than anything else. I use an air powered butterfly wrench to tighten and loosen but at times I need to qive it a knock with a hammer or increase the air pressure to the butterfly wrench to get It to eject. I like your idea but will make a complete new drawbar, slightly longer, its a shame your video goes too fast to follow, though good and have watched it 3 times already to try to pick up finer details etc. thanks for planting the seed for the idea, now lets see how it grows. Does the Hydrocloric acid permanently blacken the steel? Here a small bottle of steel blueing liquid is expensive, 250ml over 20€. the acid is much cheaper if it works.

[@ChristophLehner]

No, the acis will slowly eat away the steel, i used it only to get rid of the zinc coating

[@vivigarr]

I am heavily considering getting one of these mills. How has working with it been like?

[@ChristophLehner]

For what it's worth it's amazing, but plan some budget for a DRO, without it's only half the fun.

[@nitropiet]

@@ChristophLehner Check out TouchDRO, it works really well. Thanks for this amazing idea, I am waiting for my 30 taper spindle to address the same issue :)

[@vivigarr]

@@ChristophLehner1 Year later I ended up going with the OEM company that makes the PM-30MV. Mill is great so far even though I haven't gotten it set up. Quality inspections seem like it's a really solid machine and all the machined surfaces are better than I expected! I was disappointed to find the ISO30 taper I thought I was getting is actually an NMTB30 taper so instead of pull studs it's threaded. However I have some threaded holes on the spindle face that are M10 and I think I can sacrifice a few millimeters to make an NMTB30 "shim" seat to BT30 tools. It'll be an interesting project some day. The main reason being I want to share tools between CNC router and manual mill. But it's not that big of a deal right now.

[@hansreker675]

I made the drawbar , but not all the collets I have are even in length (diameter) so I need to grind them even because they don’t tighten up. this system is 6:51 the only way not to load the bearings

[@AlteWurstHaut]

how did you get your stuck tool out of the spindle?

[@ChristophLehner]

With a lot of persuasion and a hammer 😶

[@juhavuorinen3945]

I will do same drawbar my mb4

[@ChristophLehner]

In the future i also want to add a pneumatic butterfly valve for semi automatic tool changes

[@vinodchopra1994]

Hello

[@josecarlosaraujogodinez9123]

The Collet r8 Made un china Is not good, this Is the problem, yo Buy Collet Made in USA