BMI CAD Fin Jig Feedback Needed--have you used one?

[Viperfixr]

BMI CAD now has four different versions of fin jigs that will work (it seems) from anything 13mm up to 10" in diameter. I hate crooked fins and would like to get an easy way to get very better-than-eyeball-estimation alignment and I am considering one of these jigs. Has anyone else used a BMI CAD fin jig? Any feedback?

 

[cwbullet]

Avoid this guy at all cost. It took me 4 months to get the product and it does not work all that well. The fin slots are off. I emailed back and asked for direction on how to use it thinking I was using it wrong. He never responds to emails.

Chuck

 

[falingtrea]

Of the newer fin jig units on the market, I think the Standard Rockets Assembly Tool to be the most versatile. The production version looks really slick with the black coating.

Here are some forum threads featuring the unit:

https://www.rocketryforum.com/showthread.php?t=2651
https://www.rocketryforum.com/showthread.php?t=2102

The unit is designed to handle up to 4" body tubes, but you should be able to increase the surface area using a piece of sheet metal from the hardware store. And the magnets would still work to hold fins down.

 

[cwbullet]

This is a non-existent product. I have emailed them a half dozen times and no response.

 

[MysticalRockets]

I have one. I bought it about 3 years ago.

I use it as a weight to keep a shelving unit in place.

It's a big hunk of metal. That's what its worth.

 

[Viperfixr]

This is a non-existent product. I have emailed them a half dozen times and no response.

Chuck, do you mean the BMI Cad jig, or the Standard Rocket Assembly jig?

Seems like the later has been 'in development' since last winter...wonder when the website will be full-up.

 

[cwbullet]

I am talking about the BMI Cad Jig. I would love to have a standard rocket Jig. I am certain it will work. It is the most similar to the old estes jig and seams more flexible. The problem is they keep promising a product, but very few have seen anything. I email bout once a month and no answers.

 

[WillMarchant]

This https://www.micromark.com/MAGNETIC-GLUING-JIG-10-1and4-SQUARE,7038.html might work for smaller rockets.

I have the BMI rig and it does OK for radial alignment but not too well for longitudinal alignment. I find I have to use something else to keep the fin alignment plate pointing straight up the rocket.

 

[Chrisn]

I have the BMI rig and it does OK for radial alignment but not too well for longitudinal alignment.

Which is what it states on the website :confused2:

 

[MysticalRockets]

Part of the issue it that this is not BMI's primary business. They're a machine shop. So something like this just isn't a priority for them. Although they were at NARCON this year, I didn't have a chance to talk to them.

 

[cwbullet]

I understand the "non my primary business" line. I don't accept shotty support and 4 months to deliver products.

 

[Pat_B]

Avoid BMI at all costs. I bought their paperweight and 3 of the 4 uprights fit loosely and one was too tight. The guy said that another company made the uprights and he didn't have a chance to test the fit. He told me to put the uprights in the freezer and the base plate in the oven. That still didn't work.

After ignoring me for awhile he finally shipped out new uprights that didn't fit much better. I eventually bought an Art Rose fin jig which is much nicer.

The big problem with the BMI unit is that there is no way to make the uprights be a slide fit while still being rigid enough not to wiggle. There's also no built-in way to account for differing fin thicknesses other that the two different sets of uprights he sells. Balsa isn't that standard, and there are far too many different sizes.

Crummy design, and even worse customer service.

 

[falingtrea]

I am talking about the BMI Cad Jig. I would love to have a standard rocket Jig. I am certain it will work. It is the most similar to the old estes jig and seams more flexible. The problem is they keep promising a product, but very few have seen anything. I email bout once a month and no answers.

I saw the latest batch of Standard Rocket Jigs at my club's picnic two weekends ago. I think he almost has all the issues worked out for moving to a production mode. The latest units have a black coating and look really nice.

 

[cwbullet]

Thank you. I will be more than glad to order one quickly once they are released. The standard jig look nice.

 

[Stymye]

not to nit pick but this is (In my line of work, machining and machine construction)) considered a "fixture".And when ordering or designing something I have to go by that general definition

Broadly speaking

a "Jig" guides a tool such as a drill,file,sander,endmill..ect.

a "Fixture" secures a workpiece, like a rocket or fin.

I know everyone seems to call any contraption a "Jig".Even some machinists, So I won't argue or worry too much.. but even Estes does not call their fin alignment guide a "Jig"
Many websites get it wrong as well.

or Mabey I'm wrong but it's what I've been going by for over 25 yrs in the business.

It's much like calling a screw a "bolt" ...there is a big difference.

<soapbox mode> off

 

[Viperfixr]

So, if BMI cad is not a solid option, what high power rocket sized fixture is available to ensure really straight fin alignment?

I am going to be building a 38mm min diameter scratch build rocket, and I want to make sure it flies as straight (up) as possible. Without those fin slots to guide things, it will be a lot easier to get the fin alignment wrong. My goal is to break 10k AGL and go supersonic with it, I hope. Plus, it would be nice for everything else... straight fins and flights just make me happy.

 

[mkadams001]

Check out Vern's home made...https://www.vernk.com/Construction/ColdfireFinAttachment.htm

 

[Tim Eiszner]

BMI CAD now has four different versions of fin jigs that will work (it seems) from anything 13mm up to 10" in diameter. I hate crooked fins and would like to get an easy way to get very better-than-eyeball-estimation alignment and I am considering one of these jigs. Has anyone else used a BMI CAD fin jig? Any feedback?

The bmicad jig is superb. Fins need to be shimmed properly as it accommodates various fin thickness. If you understand the concept and implement the setup correctly, nothing is more accurate.

 

[beeblebrox]

My thoughts are, design your own and 3d print it. You can use Tinkercad for free to design it and if you don't have a 3d printer there is a service to have it printed...

 

[sandeja1]

I have NOT used either of these products but am very seriously considering purchasing for myself:

The "inventor's" website: https://www.macklinmissileworks.com/shop

Also sold at: https://www.apogeerockets.com/Building_Supplies/Tools/Guillotine_Fin_Jig

At one time there was a thread about "butterfly fin alignment" tool here as well (https://www.rocketryforum.com/threads/free-butterfly-fins-limited-offer.129885/#post-1514875)

Apogee, and several other vendors I am sure, have numerous fin alignment jigs/devices as well. I can not verify any of their functionality though as I am currently restricted to the "Mk 1 eyeball" method of alignment.

 

[cwbullet]

BMI Cad fin jig is not a great product. I have one and it is not easy to use. The uprights are often lose after a few uses.

 

[Fattbank64]

BMI Cad fin jig is not a great product. I have one and it is not easy to use. The uprights are often lose after a few uses.

+1