U30b chassis for Tillig Gear Tower

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MacG
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Re: U30b chassis for Tillig Gear Tower

Post by MacG »

Happy Birthday, Bernd! :wave:

Did you mill it with 0.020" positioning? I would try 0.008" deep and the route wider than the milling cutter. For some space beside the cutter.

Here is my sketch for the Tillig truck holes. All measurements in mm x 10. The 130,00mm at the sketch are real 13,00mm.
Tillig truck holes
Tillig truck holes
Edit: correction of the scale
Last edited by MacG on Tue Mar 05, 2019 6:47 pm, edited 1 time in total.
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Rich1853
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Re: U30b chassis for Tillig Gear Tower

Post by Rich1853 »

I'm sorry I'm just anal with poor sketches. Been in Quality Assurance since the late 70's and this attached ASME Y14.5 is the bible of mechanical drawings.

https://en.m.wikipedia.org/wiki/Geometr ... olerancing
https://drive.google.com/file/d/1gP1nbE ... p=drivesdk
https://www.asme.org/products/codes-sta ... olerancing
Rich1853
Greetings from Melbourne, Florida USA
On the Space Coast of Florida

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RodTT
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Re: U30b chassis for Tillig Gear Tower

Post by RodTT »

Bernd wrote: What say ye model TT scalers?

Bernd
I say yes please.

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MacG
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Re: U30b chassis for Tillig Gear Tower

Post by MacG »

Bernd wrote:... Is that 130,00mm (5.118") wide or is that supposed to be 13,00mm (.5118) wide? The 13mm width is closer to what Ian has on is drawing, 15mm wide. ...
Sorry, it's my fault. I draw with SketchUp everything 10 times bigger. It's 13,00mm (.5118) wide.

Check the x-y axis at drawing a circle. Perhaps they aren't synchronously. Both of your milled holes look similar.
I mean a reducing the depth of cut. But a lower feed rate is also a try worth.
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TiTan downunder
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Re: U30b chassis for Tillig Gear Tower

Post by TiTan downunder »

Well actually, it's not a drawing but, a tracing of the finished brass plate. Sorry, I usually manage to leave something off when I do these things but, I see MacG has provided the answer.
Don't get too thick. There are mounting 'clips' in the body shell to hold the chassis in. Even with the .032" i used I had to chamfer the edges. Clipping it in is not as big a problem as getting it back out without breaking the body and gluing nylon is a pain in the rear end.

>> I'll crank out some chassis's. << Put me down for 2 - I'll just HAVE too expand the roster.

Ian

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Rob M
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Re: U30b chassis for Tillig Gear Tower

Post by Rob M »

Assuming your X axis is left-right and Y axis is top-bottom in your pics, your Y axis has a lot of backlash.

Are you using Mach3 for your controller? If so, it has a backlash compensation setting somewhere. Other controllers should as well.

But, it is best to eliminate the backlash.

TiTan downunder
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Re: U30b chassis for Tillig Gear Tower

Post by TiTan downunder »

Bernd,

>> With over sea shipping and all that will cost you your first born, a leg and an arm. << NAH, you don't wanta go there, she's been quite a handful, at times, over the years but, now has her own hands full and we just get to visit and go home again!! :crazy: :lol:

There is 2mm / 0.080" to bottom of sill and 1mm / 0.040" between walkway and chassis clips BUT it's a tight fit with NO give.
I'll try and get a couple of close shots to explain easier.

Ian

TiTan downunder
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Re: U30b chassis for Tillig Gear Tower

Post by TiTan downunder »

IMG_0775.JPG
There are 4 x clips each side - marked in red texta for clarity.
IMG_0774.JPG
IMG_0777.JPG
camera won't focus on shiny sytrene

>> I was thinking I could cut a rabbit down both sides so it would fit under the clips. I could make it less than .032". Perhaps .020" would make it easier to get under the clips. <<

Probably a good idea to go with 0.040". I have noticed the 0.032" I used does flex a bit if I fiddle too much. Going too thick could create to big a gap between the body and the trucks.
The other option would be to remove the clips but then it would rely on the couplers passing through the pilots to hold it all together. If the pilots broke you would be in deep 'doggie-do'. I've had one small disaster but was salvageable.
Ian

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MacG
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Re: U30b chassis for Tillig Gear Tower

Post by MacG »

Yes, it works. A 0.080" plate does not cause any problems. I have almost 0.157" (4mm) at my ML-4000 (with 3-point bearing).
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Rob M
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Re: U30b chassis for Tillig Gear Tower

Post by Rob M »

Bernd wrote: Sherline uses Lunix and the software running on the Sherline is EMC. I use CamBam for my CAM program. As far as I can determine from the manual there is no backlash compensation in the software. The machine has hardware backlash adjustment screws. See pic.

Bernd
You need to measure backlash with a dial indicator. Your hand is not sensitive enough to feel a few thousandths of an inch movement.

http://linuxcnc.org/docs/2.6/html/confi ... onfig.html
"BACKLASH = 0.0000 - Backlash in machine units. Backlash compensation value can be used to make up for small deficiencies in the hardware used to drive an axis. If backlash is added to an axis and you are using steppers the STEPGEN_MAXACCEL must be increased to 1.5 to 2 times the MAX_ACCELERATION for the axis.

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